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Dialogue: 0,0:00:00.00,0:00:09.50,Default,,0000,0000,0000,,{\i1}preroll music{\i0}
Dialogue: 0,0:00:09.50,0:00:14.01,Default,,0000,0000,0000,,Herald: Our next speaker has studied in Bielefeld,
Dialogue: 0,0:00:14.01,0:00:18.65,Default,,0000,0000,0000,,and he studied... {\i1}laughter{\i0}{\i1}clapping{\i0}
Dialogue: 0,0:00:18.65,0:00:21.23,Default,,0000,0000,0000,,what he did is: He studied laser physics.
Dialogue: 0,0:00:21.23,0:00:26.31,Default,,0000,0000,0000,,And now he is working at the Max Planck Institute\Nfor extraterrestrial physics.
Dialogue: 0,0:00:26.31,0:00:28.25,Default,,0000,0000,0000,,And today he will explain you
Dialogue: 0,0:00:28.25,0:00:31.20,Default,,0000,0000,0000,,how it is possible to use laser light
Dialogue: 0,0:00:31.20,0:00:33.16,Default,,0000,0000,0000,,to enhance distorted images
Dialogue: 0,0:00:33.16,0:00:34.65,Default,,0000,0000,0000,,that were take from the earth
Dialogue: 0,0:00:34.65,0:00:36.90,Default,,0000,0000,0000,,of stars and galaxies and nebulars.
Dialogue: 0,0:00:36.90,0:00:39.27,Default,,0000,0000,0000,,So I want to hear a
Dialogue: 0,0:00:39.27,0:00:40.74,Default,,0000,0000,0000,,really loud and warm applaus
Dialogue: 0,0:00:40.74,0:00:42.49,Default,,0000,0000,0000,,for Peter Buschkamp with
Dialogue: 0,0:00:42.49,0:00:43.76,Default,,0000,0000,0000,,"Shooting lasers into space -
Dialogue: 0,0:00:43.76,0:00:45.96,Default,,0000,0000,0000,,For science"! {\i1}applause{\i0}
Dialogue: 0,0:00:45.96,0:00:58.11,Default,,0000,0000,0000,,All right! Thank you for the nice introduction
Dialogue: 0,0:00:58.11,0:01:00.12,Default,,0000,0000,0000,,Thank you, for coming here
Dialogue: 0,0:01:00.12,0:01:00.71,Default,,0000,0000,0000,,this evening.
Dialogue: 0,0:01:00.71,0:01:01.97,Default,,0000,0000,0000,,I'm very excited
Dialogue: 0,0:01:01.97,0:01:04.84,Default,,0000,0000,0000,,to speak at the conference.
Dialogue: 0,0:01:04.84,0:01:05.56,Default,,0000,0000,0000,,Finally I find a talk
Dialogue: 0,0:01:05.56,0:01:08.40,Default,,0000,0000,0000,,where I can contribute
Dialogue: 0,0:01:08.40,0:01:09.63,Default,,0000,0000,0000,,after all those years.
Dialogue: 0,0:01:09.63,0:01:11.59,Default,,0000,0000,0000,,I'm not going to talk about Bielefeld.
Dialogue: 0,0:01:11.59,0:01:13.19,Default,,0000,0000,0000,,You might want to hear something about that.
Dialogue: 0,0:01:13.19,0:01:17.21,Default,,0000,0000,0000,,I'm not allowed to tell you... right?
Dialogue: 0,0:01:17.21,0:01:20.75,Default,,0000,0000,0000,,Okay, so today I'm going to talk about
Dialogue: 0,0:01:20.75,0:01:23.40,Default,,0000,0000,0000,,a bit what is in my field
Dialogue: 0,0:01:23.40,0:01:27.78,Default,,0000,0000,0000,,of experties.
Dialogue: 0,0:01:27.78,0:01:29.21,Default,,0000,0000,0000,,If there is one thing
Dialogue: 0,0:01:29.21,0:01:31.03,Default,,0000,0000,0000,,I want to bring across to you
Dialogue: 0,0:01:31.03,0:01:31.90,Default,,0000,0000,0000,,then it is
Dialogue: 0,0:01:31.90,0:01:33.61,Default,,0000,0000,0000,,It's not about a single person
Dialogue: 0,0:01:33.61,0:01:37.32,Default,,0000,0000,0000,,showing this to you this evening.
Dialogue: 0,0:01:37.32,0:01:41.77,Default,,0000,0000,0000,,This is a team effort and a real team effort.
Dialogue: 0,0:01:41.77,0:01:43.21,Default,,0000,0000,0000,,So most of the images are done by
Dialogue: 0,0:01:43.21,0:01:45.98,Default,,0000,0000,0000,,a college of mine Julian Ziegeleder.
Dialogue: 0,0:01:45.98,0:01:47.88,Default,,0000,0000,0000,,And the PI of the project,
Dialogue: 0,0:01:47.88,0:01:48.74,Default,,0000,0000,0000,,so the leader of the project
Dialogue: 0,0:01:48.74,0:01:50.55,Default,,0000,0000,0000,,Sebastian Rabien
Dialogue: 0,0:01:50.55,0:01:53.00,Default,,0000,0000,0000,,has contributed some slides.
Dialogue: 0,0:01:53.00,0:01:54.54,Default,,0000,0000,0000,,And I wouldn't be standing here today
Dialogue: 0,0:01:54.54,0:01:59.92,Default,,0000,0000,0000,,and showing you these images
Dialogue: 0,0:01:59.92,0:02:01.60,Default,,0000,0000,0000,,if it wasn't for a huge team
Dialogue: 0,0:02:01.60,0:02:03.09,Default,,0000,0000,0000,,and many people.
Dialogue: 0,0:02:03.09,0:02:06.06,Default,,0000,0000,0000,,I hope this is reasonably complete,
Dialogue: 0,0:02:06.06,0:02:08.12,Default,,0000,0000,0000,,but I think there were even more.
Dialogue: 0,0:02:08.12,0:02:12.61,Default,,0000,0000,0000,,Many people have tributed most and
Dialogue: 0,0:02:12.61,0:02:16.13,Default,,0000,0000,0000,,long years of there career into such a project.
Dialogue: 0,0:02:16.13,0:02:18.18,Default,,0000,0000,0000,,So this is never about something
Dialogue: 0,0:02:18.18,0:02:19.45,Default,,0000,0000,0000,,which a single person does
Dialogue: 0,0:02:19.45,0:02:21.63,Default,,0000,0000,0000,,and he or she finds something very cool
Dialogue: 0,0:02:21.63,0:02:22.80,Default,,0000,0000,0000,,and then saves the world.
Dialogue: 0,0:02:22.80,0:02:27.67,Default,,0000,0000,0000,,No, it's always a big, big team!
Dialogue: 0,0:02:27.67,0:02:29.49,Default,,0000,0000,0000,,But before we actually see the lasers
Dialogue: 0,0:02:29.49,0:02:34.88,Default,,0000,0000,0000,,then in working, we have of course to clarify
Dialogue: 0,0:02:34.88,0:02:36.17,Default,,0000,0000,0000,,why we do this.
Dialogue: 0,0:02:36.17,0:02:38.29,Default,,0000,0000,0000,,This is not just because we can.
Dialogue: 0,0:02:38.29,0:02:41.64,Default,,0000,0000,0000,,We can! But there is a reason for that,
Dialogue: 0,0:02:41.64,0:02:43.20,Default,,0000,0000,0000,,because if you want to get funding,
Dialogue: 0,0:02:43.20,0:02:47.19,Default,,0000,0000,0000,,you have to write a reason and a reasonable\Nreason.
Dialogue: 0,0:02:47.19,0:02:50.26,Default,,0000,0000,0000,,Not just because "We want to!"
Dialogue: 0,0:02:50.26,0:02:51.16,Default,,0000,0000,0000,,So in the first part
Dialogue: 0,0:02:51.16,0:02:53.81,Default,,0000,0000,0000,,I will introduce you
Dialogue: 0,0:02:53.81,0:02:54.52,Default,,0000,0000,0000,,to the whole thing
Dialogue: 0,0:02:54.52,0:02:57.47,Default,,0000,0000,0000,,and we talk about bit... about the problem
Dialogue: 0,0:02:57.47,0:02:59.45,Default,,0000,0000,0000,,which we want to tackle
Dialogue: 0,0:02:59.45,0:03:03.11,Default,,0000,0000,0000,,with this kind of technique.
Dialogue: 0,0:03:03.11,0:03:06.67,Default,,0000,0000,0000,,I will mostly present only diagrams
Dialogue: 0,0:03:06.67,0:03:09.37,Default,,0000,0000,0000,,not actual hardware blocks or relays.
Dialogue: 0,0:03:09.37,0:03:12.29,Default,,0000,0000,0000,,So you get the basic concept.
Dialogue: 0,0:03:12.29,0:03:14.58,Default,,0000,0000,0000,,So when we do astronomy
Dialogue: 0,0:03:14.58,0:03:15.98,Default,,0000,0000,0000,,we do two types of things.
Dialogue: 0,0:03:15.98,0:03:18.14,Default,,0000,0000,0000,,We either do imaging,
Dialogue: 0,0:03:18.14,0:03:20.35,Default,,0000,0000,0000,,which is: We maybe produce a nice image
Dialogue: 0,0:03:20.35,0:03:23.92,Default,,0000,0000,0000,,of a star - so that's the blop over there -
Dialogue: 0,0:03:23.92,0:03:25.65,Default,,0000,0000,0000,,or we take this image,
Dialogue: 0,0:03:25.65,0:03:28.35,Default,,0000,0000,0000,,maybe this little blop over there,
Dialogue: 0,0:03:28.35,0:03:30.51,Default,,0000,0000,0000,,and make it into a spectrum,
Dialogue: 0,0:03:30.51,0:03:32.06,Default,,0000,0000,0000,,so disperse the light,
Dialogue: 0,0:03:32.06,0:03:36.69,Default,,0000,0000,0000,,and then we look at the differential intensity
Dialogue: 0,0:03:36.69,0:03:38.60,Default,,0000,0000,0000,,between the diverse colors
Dialogue: 0,0:03:38.60,0:03:39.96,Default,,0000,0000,0000,,or are there maybe
Dialogue: 0,0:03:39.96,0:03:42.80,Default,,0000,0000,0000,,- for example you see black lines in there -
Dialogue: 0,0:03:42.80,0:03:46.26,Default,,0000,0000,0000,,absorption bands and so on.
Dialogue: 0,0:03:46.26,0:03:49.80,Default,,0000,0000,0000,,To do such a thing you need a spectrograph
Dialogue: 0,0:03:49.80,0:03:50.82,Default,,0000,0000,0000,,and in a spectrograph
Dialogue: 0,0:03:50.82,0:03:53.97,Default,,0000,0000,0000,,there is a thing called an entrance slit.
Dialogue: 0,0:03:53.97,0:03:55.43,Default,,0000,0000,0000,,So this slit you have to
Dialogue: 0,0:03:55.43,0:03:56.78,Default,,0000,0000,0000,,put over your objects,
Dialogue: 0,0:03:56.78,0:04:00.46,Default,,0000,0000,0000,,so you don't get light from left or right next to the object
Dialogue: 0,0:04:00.46,0:04:03.15,Default,,0000,0000,0000,,to what you want to observe or analyse
Dialogue: 0,0:04:03.15,0:04:06.78,Default,,0000,0000,0000,,so that you only get light from where you\Nwanted.
Dialogue: 0,0:04:06.78,0:04:08.29,Default,,0000,0000,0000,,The thing is now
Dialogue: 0,0:04:08.29,0:04:11.03,Default,,0000,0000,0000,,this slit can not be made
Dialogue: 0,0:04:11.03,0:04:14.08,Default,,0000,0000,0000,,arbitrarily wide or small,
Dialogue: 0,0:04:14.08,0:04:18.14,Default,,0000,0000,0000,,because the width of the slit directly
Dialogue: 0,0:04:18.14,0:04:20.38,Default,,0000,0000,0000,,determines what kind of resolution
Dialogue: 0,0:04:20.38,0:04:22.22,Default,,0000,0000,0000,,you have in such a spectrometer.
Dialogue: 0,0:04:22.22,0:04:24.50,Default,,0000,0000,0000,,as it's called. This is a quantity
Dialogue: 0,0:04:24.50,0:04:26.41,Default,,0000,0000,0000,,Which needs to be above a certain value
Dialogue: 0,0:04:26.41,0:04:28.88,Default,,0000,0000,0000,,when you want to do certain kinds of analyses.
Dialogue: 0,0:04:28.88,0:04:31.53,Default,,0000,0000,0000,,So it has fixed width.
Dialogue: 0,0:04:31.53,0:04:34.37,Default,,0000,0000,0000,,So now if we look at an image produced
Dialogue: 0,0:04:34.37,0:04:36.62,Default,,0000,0000,0000,,of one of the most capable telescopes
Dialogue: 0,0:04:36.62,0:04:38.33,Default,,0000,0000,0000,,on this planet
Dialogue: 0,0:04:38.33,0:04:41.78,Default,,0000,0000,0000,,and we put a representation for this slit
Dialogue: 0,0:04:41.78,0:04:42.36,Default,,0000,0000,0000,,over the star
Dialogue: 0,0:04:42.36,0:04:45.54,Default,,0000,0000,0000,,- okay now its white, let's make this black -
Dialogue: 0,0:04:45.54,0:04:47.31,Default,,0000,0000,0000,,then you see if you want to go
Dialogue: 0,0:04:47.31,0:04:48.61,Default,,0000,0000,0000,,for that star over there,
Dialogue: 0,0:04:48.61,0:04:50.65,Default,,0000,0000,0000,,you do have a problem already.
Dialogue: 0,0:04:50.65,0:04:52.82,Default,,0000,0000,0000,,As said, you can't make this slit wider,
Dialogue: 0,0:04:52.82,0:04:56.37,Default,,0000,0000,0000,,but the star is actually larger than the slit,
Dialogue: 0,0:04:56.37,0:04:57.79,Default,,0000,0000,0000,,meaning that you lose light.
Dialogue: 0,0:04:57.79,0:04:59.97,Default,,0000,0000,0000,,"Well you lose some light...." No!
Dialogue: 0,0:04:59.97,0:05:02.11,Default,,0000,0000,0000,,If you want to quantitative measurements
Dialogue: 0,0:05:02.11,0:05:03.70,Default,,0000,0000,0000,,you want to have all the lights
Dialogue: 0,0:05:03.70,0:05:05.69,Default,,0000,0000,0000,,and all the pixels.
Dialogue: 0,0:05:05.69,0:05:07.10,Default,,0000,0000,0000,,So you can't get rid of them
Dialogue: 0,0:05:07.10,0:05:09.84,Default,,0000,0000,0000,,and just throwing something away.
Dialogue: 0,0:05:09.84,0:05:13.42,Default,,0000,0000,0000,,So, but our image is looking like that.
Dialogue: 0,0:05:13.42,0:05:17.73,Default,,0000,0000,0000,,It's maybe nice, so but can we do better?
Dialogue: 0,0:05:17.73,0:05:19.54,Default,,0000,0000,0000,,Yes, we can!
Dialogue: 0,0:05:19.54,0:05:21.01,Default,,0000,0000,0000,,And this is what we can achieve with
Dialogue: 0,0:05:21.01,0:05:22.32,Default,,0000,0000,0000,,adaptive optics.
Dialogue: 0,0:05:22.32,0:05:23.98,Default,,0000,0000,0000,,This is an image that has been produce
Dialogue: 0,0:05:23.98,0:05:25.82,Default,,0000,0000,0000,,with adaptive optics with a
Dialogue: 0,0:05:25.82,0:05:29.17,Default,,0000,0000,0000,,LASER AO assisted system.
Dialogue: 0,0:05:29.17,0:05:31.53,Default,,0000,0000,0000,,And if I flip back and forth you see
Dialogue: 0,0:05:31.53,0:05:34.85,Default,,0000,0000,0000,,there is a difference!
Dialogue: 0,0:05:34.85,0:05:40.72,Default,,0000,0000,0000,,All right! So why is that?
Dialogue: 0,0:05:40.72,0:05:45.09,Default,,0000,0000,0000,,Why don't we get this ideal images?
Dialogue: 0,0:05:45.09,0:05:47.56,Default,,0000,0000,0000,,The reason is because there is the atmosphere.
Dialogue: 0,0:05:47.56,0:05:50.83,Default,,0000,0000,0000,,The atmosphere is great for breathing.
Dialogue: 0,0:05:50.83,0:05:53.05,Default,,0000,0000,0000,,It's not that great for astronomy.
Dialogue: 0,0:05:53.05,0:05:55.12,Default,,0000,0000,0000,,So if you have a star up there somewhere
Dialogue: 0,0:05:55.12,0:05:55.89,Default,,0000,0000,0000,,in outer space
Dialogue: 0,0:05:55.89,0:05:58.53,Default,,0000,0000,0000,,- can be very far away - so the photon
Dialogue: 0,0:05:58.53,0:06:01.30,Default,,0000,0000,0000,,have travelled for 11 Billion years
Dialogue: 0,0:06:01.30,0:06:03.08,Default,,0000,0000,0000,,and now they finally hit the atmosphere
Dialogue: 0,0:06:03.08,0:06:04.33,Default,,0000,0000,0000,,and then something happens
Dialogue: 0,0:06:04.33,0:06:05.72,Default,,0000,0000,0000,,which you do not want.
Dialogue: 0,0:06:05.72,0:06:07.42,Default,,0000,0000,0000,,Okay, first they travel freely.
Dialogue: 0,0:06:07.42,0:06:09.94,Default,,0000,0000,0000,,There is a nice planar wavefront.
Dialogue: 0,0:06:09.94,0:06:12.00,Default,,0000,0000,0000,,So it's not disturbed by anything,
Dialogue: 0,0:06:12.00,0:06:14.40,Default,,0000,0000,0000,,maybe something but that's not the
Dialogue: 0,0:06:14.40,0:06:18.22,Default,,0000,0000,0000,,scope of this evening. It's planar, it's nice!
Dialogue: 0,0:06:18.22,0:06:20.18,Default,,0000,0000,0000,,And if you actually have a satellite,
Dialogue: 0,0:06:20.18,0:06:21.17,Default,,0000,0000,0000,,it's very cool.
Dialogue: 0,0:06:21.17,0:06:23.44,Default,,0000,0000,0000,,Because then you can directly record this
Dialogue: 0,0:06:23.44,0:06:25.00,Default,,0000,0000,0000,,undisturbed light.
Dialogue: 0,0:06:25.00,0:06:27.40,Default,,0000,0000,0000,,If you have something on the ground,
Dialogue: 0,0:06:27.40,0:06:30.82,Default,,0000,0000,0000,,well, you do get a problem,
Dialogue: 0,0:06:30.82,0:06:33.08,Default,,0000,0000,0000,,because the atmosphere introduces turbulence,
Dialogue: 0,0:06:33.08,0:06:36.57,Default,,0000,0000,0000,,because, well, the air wobbles a bit.
Dialogue: 0,0:06:36.57,0:06:38.47,Default,,0000,0000,0000,,There are stream coming from all directions.
Dialogue: 0,0:06:38.47,0:06:40.27,Default,,0000,0000,0000,,There are temperature gradients in there.
Dialogue: 0,0:06:40.27,0:06:42.52,Default,,0000,0000,0000,,And these all work together
Dialogue: 0,0:06:42.52,0:06:44.42,Default,,0000,0000,0000,,and make from this nice planar wave front
Dialogue: 0,0:06:44.42,0:06:46.53,Default,,0000,0000,0000,,a crumbled one.
Dialogue: 0,0:06:46.53,0:06:49.45,Default,,0000,0000,0000,,If you have a perfect image
Dialogue: 0,0:06:49.45,0:06:50.15,Default,,0000,0000,0000,,which you create
Dialogue: 0,0:06:50.15,0:06:51.51,Default,,0000,0000,0000,,- This is called "diffraction limit".
Dialogue: 0,0:06:51.51,0:06:53.31,Default,,0000,0000,0000,,This is just limited by the size
Dialogue: 0,0:06:53.31,0:06:54.78,Default,,0000,0000,0000,,of your optics.
Dialogue: 0,0:06:54.78,0:06:56.70,Default,,0000,0000,0000,,So the wider your optics is,
Dialogue: 0,0:06:56.70,0:06:59.40,Default,,0000,0000,0000,,the nicer your resolution is of your image.
Dialogue: 0,0:06:59.40,0:07:01.09,Default,,0000,0000,0000,,If you then build a large facility with
Dialogue: 0,0:07:01.09,0:07:04.15,Default,,0000,0000,0000,,maybe two 8 meter mirrors on the ground,
Dialogue: 0,0:07:04.15,0:07:08.55,Default,,0000,0000,0000,,well, you only get your seeing limited image.
Dialogue: 0,0:07:08.55,0:07:10.25,Default,,0000,0000,0000,,Seeing limited. The Seeing is this wobbling
Dialogue: 0,0:07:10.25,0:07:12.83,Default,,0000,0000,0000,,of the atmosphere as it's called.
Dialogue: 0,0:07:12.83,0:07:13.53,Default,,0000,0000,0000,,And that's about it.
Dialogue: 0,0:07:13.53,0:07:15.43,Default,,0000,0000,0000,,You can make it arbitrarily large.
Dialogue: 0,0:07:15.43,0:07:17.75,Default,,0000,0000,0000,,You won't get a better resolution
Dialogue: 0,0:07:17.75,0:07:18.99,Default,,0000,0000,0000,,then a backyard telescope
Dialogue: 0,0:07:18.99,0:07:22.17,Default,,0000,0000,0000,,of having 20cm in diameter.
Dialogue: 0,0:07:22.17,0:07:24.68,Default,,0000,0000,0000,,So yeah...
Dialogue: 0,0:07:24.68,0:07:28.07,Default,,0000,0000,0000,,What to do?
Dialogue: 0,0:07:28.07,0:07:30.89,Default,,0000,0000,0000,,There have been people, of course,
Dialogue: 0,0:07:30.89,0:07:33.58,Default,,0000,0000,0000,,thinking about this problem longer.
Dialogue: 0,0:07:33.58,0:07:38.13,Default,,0000,0000,0000,,And the first idea came up in 1953.
Dialogue: 0,0:07:38.13,0:07:40.87,Default,,0000,0000,0000,,And some guy Palomar Observatory
Dialogue: 0,0:07:40.87,0:07:44.38,Default,,0000,0000,0000,,in California said: "Well, if we have
Dialogue: 0,0:07:44.38,0:07:46.39,Default,,0000,0000,0000,,the means of continuously measuring
Dialogue: 0,0:07:46.39,0:07:48.56,Default,,0000,0000,0000,,the deviation of rays from all parts
Dialogue: 0,0:07:48.56,0:07:52.14,Default,,0000,0000,0000,,of the mirror and amplifying and feedback
Dialogue: 0,0:07:52.14,0:07:55.31,Default,,0000,0000,0000,,this information so as to correct locally
Dialogue: 0,0:07:55.31,0:07:56.45,Default,,0000,0000,0000,,the figure of the mirror
Dialogue: 0,0:07:56.45,0:07:58.37,Default,,0000,0000,0000,,in response to schlieren pattern,
Dialogue: 0,0:07:58.37,0:08:00.87,Default,,0000,0000,0000,,we could expect to compensate both
Dialogue: 0,0:08:00.87,0:08:03.76,Default,,0000,0000,0000,,for the seeing and for the inherent imperfections
Dialogue: 0,0:08:03.76,0:08:04.85,Default,,0000,0000,0000,,in the optical figure."
Dialogue: 0,0:08:04.85,0:08:07.45,Default,,0000,0000,0000,,Ehhh... what?
Dialogue: 0,0:08:07.45,0:08:11.75,Default,,0000,0000,0000,,So if we could somehow get rid of this wobbling
Dialogue: 0,0:08:11.75,0:08:13.24,Default,,0000,0000,0000,,or conteract that,
Dialogue: 0,0:08:13.24,0:08:15.49,Default,,0000,0000,0000,,then we could get this perfect
Dialogue: 0,0:08:15.49,0:08:17.98,Default,,0000,0000,0000,,diffraction limited imaging we get in space
Dialogue: 0,0:08:17.98,0:08:20.48,Default,,0000,0000,0000,,also on the ground.
Dialogue: 0,0:08:20.48,0:08:22.21,Default,,0000,0000,0000,,In the 1970s the US military started
Dialogue: 0,0:08:22.21,0:08:23.42,Default,,0000,0000,0000,,to experiment on that.
Dialogue: 0,0:08:23.42,0:08:25.28,Default,,0000,0000,0000,,Well, I guess the Russians too,
Dialogue: 0,0:08:25.28,0:08:29.24,Default,,0000,0000,0000,,but it's not... it's known that the US started
Dialogue: 0,0:08:29.24,0:08:31.89,Default,,0000,0000,0000,,at Starfire Optical Range.
Dialogue: 0,0:08:31.89,0:08:35.32,Default,,0000,0000,0000,,In 1982 they build the first AO system,
Dialogue: 0,0:08:35.32,0:08:37.95,Default,,0000,0000,0000,,adaptive optics system.
Dialogue: 0,0:08:37.95,0:08:39.94,Default,,0000,0000,0000,,The "Compensated Imaging System" on Hawaii.
Dialogue: 0,0:08:39.94,0:08:44.03,Default,,0000,0000,0000,,And in the late 80s the first astronomical\Nuse,
Dialogue: 0,0:08:44.03,0:08:45.87,Default,,0000,0000,0000,,adaptive optics system "COME-ON"
Dialogue: 0,0:08:45.87,0:08:48.27,Default,,0000,0000,0000,,as it was called was installed at the
Dialogue: 0,0:08:48.27,0:08:50.64,Default,,0000,0000,0000,,Observatoire Haute-Provence
Dialogue: 0,0:08:50.64,0:08:53.56,Default,,0000,0000,0000,,and at ESO at La Silla.
Dialogue: 0,0:08:53.56,0:09:01.00,Default,,0000,0000,0000,,That's the European Space Observatory.
Dialogue: 0,0:09:01.00,0:09:03.24,Default,,0000,0000,0000,,All right so that was:
Dialogue: 0,0:09:03.24,0:09:06.51,Default,,0000,0000,0000,,Yeah, we get for we found that this
Dialogue: 0,0:09:06.51,0:09:08.09,Default,,0000,0000,0000,,fussy blob is actually not a fussy blob,
Dialogue: 0,0:09:08.09,0:09:10.07,Default,,0000,0000,0000,,but two fussy blobs.
Dialogue: 0,0:09:10.07,0:09:11.89,Default,,0000,0000,0000,,{\i1}laughter{\i0}
Dialogue: 0,0:09:11.89,0:09:15.71,Default,,0000,0000,0000,,Well it's a binary system as I would say
Dialogue: 0,0:09:15.71,0:09:19.23,Default,,0000,0000,0000,,if this was at an astronomical conference.
Dialogue: 0,0:09:19.23,0:09:23.83,Default,,0000,0000,0000,,But yeah, you disentangle things
Dialogue: 0,0:09:23.83,0:09:26.54,Default,,0000,0000,0000,,you could not see before.
Dialogue: 0,0:09:26.54,0:09:30.95,Default,,0000,0000,0000,,Okay! How does this AO system look like in\Nprinciple?
Dialogue: 0,0:09:30.95,0:09:33.33,Default,,0000,0000,0000,,So again we have this star somewhere,
Dialogue: 0,0:09:33.33,0:09:34.43,Default,,0000,0000,0000,,we've learned already that
Dialogue: 0,0:09:34.43,0:09:37.23,Default,,0000,0000,0000,,we do have... - actually you see this slight
Dialogue: 0,0:09:37.23,0:09:38.65,Default,,0000,0000,0000,,schlieren pattern in the air
Dialogue: 0,0:09:38.65,0:09:41.65,Default,,0000,0000,0000,,for the warm and the exhaust from the...
Dialogue: 0,0:09:41.65,0:09:45.44,Default,,0000,0000,0000,,Yes, there is a bit flimmering in the background.
Dialogue: 0,0:09:45.44,0:09:47.83,Default,,0000,0000,0000,,That's seeing. Okay?
Dialogue: 0,0:09:47.83,0:09:49.39,Default,,0000,0000,0000,,So the image is not as sharp here as
Dialogue: 0,0:09:49.39,0:09:52.29,Default,,0000,0000,0000,,it comes from the projector.
Dialogue: 0,0:09:52.29,0:09:55.41,Default,,0000,0000,0000,,Okay, that comes from somewhere
Dialogue: 0,0:09:55.41,0:09:57.05,Default,,0000,0000,0000,,and then we need a system
Dialogue: 0,0:09:57.05,0:09:59.69,Default,,0000,0000,0000,,which has three components.
Dialogue: 0,0:09:59.69,0:10:02.36,Default,,0000,0000,0000,,One is a deformable mirror,
Dialogue: 0,0:10:02.36,0:10:04.50,Default,,0000,0000,0000,,the other is a wave front sensor
Dialogue: 0,0:10:04.50,0:10:07.44,Default,,0000,0000,0000,,and the third one is a real time computer.
Dialogue: 0,0:10:07.44,0:10:09.32,Default,,0000,0000,0000,,We need something to actually measure
Dialogue: 0,0:10:09.32,0:10:11.11,Default,,0000,0000,0000,,what is going on.
Dialogue: 0,0:10:11.11,0:10:14.27,Default,,0000,0000,0000,,Then we need to take this measurement
Dialogue: 0,0:10:14.27,0:10:16.32,Default,,0000,0000,0000,,and extract some information from
Dialogue: 0,0:10:16.32,0:10:20.17,Default,,0000,0000,0000,,this measurement
Dialogue: 0,0:10:20.17,0:10:21.09,Default,,0000,0000,0000,,and then we need something
Dialogue: 0,0:10:21.09,0:10:23.92,Default,,0000,0000,0000,,which can correct this wave front,
Dialogue: 0,0:10:23.92,0:10:24.77,Default,,0000,0000,0000,,straighten it out so to speak,
Dialogue: 0,0:10:24.77,0:10:27.56,Default,,0000,0000,0000,,'cause we want to have it straight again.
Dialogue: 0,0:10:27.56,0:10:31.53,Default,,0000,0000,0000,,So the wave front sensor sends some information
Dialogue: 0,0:10:31.53,0:10:32.93,Default,,0000,0000,0000,,to the real time computer.
Dialogue: 0,0:10:32.93,0:10:35.13,Default,,0000,0000,0000,,This some information namely is:
Dialogue: 0,0:10:35.13,0:10:36.63,Default,,0000,0000,0000,,What is the curvature?
Dialogue: 0,0:10:36.63,0:10:39.07,Default,,0000,0000,0000,,How does this wiggled thingy look like?
Dialogue: 0,0:10:39.07,0:10:40.57,Default,,0000,0000,0000,,- The wavefront -
Dialogue: 0,0:10:40.57,0:10:42.86,Default,,0000,0000,0000,,And that real time computer computes
Dialogue: 0,0:10:42.86,0:10:44.55,Default,,0000,0000,0000,,then information that goes
Dialogue: 0,0:10:44.55,0:10:46.00,Default,,0000,0000,0000,,to the deformable mirror
Dialogue: 0,0:10:46.00,0:10:47.70,Default,,0000,0000,0000,,and that in real time shaped
Dialogue: 0,0:10:47.70,0:10:49.50,Default,,0000,0000,0000,,in an arbitrary shape
Dialogue: 0,0:10:49.50,0:10:54.44,Default,,0000,0000,0000,,conteracting that incoming wave front
Dialogue: 0,0:10:54.44,0:10:55.87,Default,,0000,0000,0000,,and then straightening it out.
Dialogue: 0,0:10:55.87,0:10:58.15,Default,,0000,0000,0000,,So we do have a light path like this.
Dialogue: 0,0:10:58.15,0:11:00.15,Default,,0000,0000,0000,,First it goes on the deformable mirror,
Dialogue: 0,0:11:00.15,0:11:01.36,Default,,0000,0000,0000,,goes on something else,
Dialogue: 0,0:11:01.36,0:11:02.93,Default,,0000,0000,0000,,which I will come to in a minute,
Dialogue: 0,0:11:02.93,0:11:04.86,Default,,0000,0000,0000,,and then this wave front sensor.
Dialogue: 0,0:11:04.86,0:11:08.83,Default,,0000,0000,0000,,And of course this means if you run it
Dialogue: 0,0:11:08.83,0:11:12.71,Default,,0000,0000,0000,,you do have a control loop,
Dialogue: 0,0:11:12.71,0:11:14.17,Default,,0000,0000,0000,,meaning measure something here,
Dialogue: 0,0:11:14.17,0:11:14.79,Default,,0000,0000,0000,,the wavefront,
Dialogue: 0,0:11:14.79,0:11:16.71,Default,,0000,0000,0000,,you put the information into there feeding
Dialogue: 0,0:11:16.71,0:11:18.57,Default,,0000,0000,0000,,that into the deformable mirror,
Dialogue: 0,0:11:18.57,0:11:20.88,Default,,0000,0000,0000,,that deforms somehow,
Dialogue: 0,0:11:20.88,0:11:24.44,Default,,0000,0000,0000,,modifies this wave front that comes
Dialogue: 0,0:11:24.44,0:11:26.17,Default,,0000,0000,0000,,from above and then of course
Dialogue: 0,0:11:26.17,0:11:28.49,Default,,0000,0000,0000,,you want to have a feedback loop:
Dialogue: 0,0:11:28.49,0:11:30.03,Default,,0000,0000,0000,,Is that what I did enough?
Dialogue: 0,0:11:30.03,0:11:31.25,Default,,0000,0000,0000,,Do I have to do more?
Dialogue: 0,0:11:31.25,0:11:35.24,Default,,0000,0000,0000,,And also: Of course in the next second
Dialogue: 0,0:11:35.24,0:11:36.92,Default,,0000,0000,0000,,or split second this pattern
Dialogue: 0,0:11:36.92,0:11:38.02,Default,,0000,0000,0000,,will have changed,
Dialogue: 0,0:11:38.02,0:11:39.42,Default,,0000,0000,0000,,because the atmosphere is dynamic.
Dialogue: 0,0:11:39.42,0:11:41.24,Default,,0000,0000,0000,,If it wasn't dynamic we don't need
Dialogue: 0,0:11:41.24,0:11:42.48,Default,,0000,0000,0000,,to do this in real time,
Dialogue: 0,0:11:42.48,0:11:44.05,Default,,0000,0000,0000,,but we have to do it in real time.
Dialogue: 0,0:11:44.05,0:11:46.42,Default,,0000,0000,0000,,Real time meaning we have to do this correction
Dialogue: 0,0:11:46.42,0:11:50.08,Default,,0000,0000,0000,,and calculation and sensing at a rate of
Dialogue: 0,0:11:50.08,0:11:54.39,Default,,0000,0000,0000,,about 1 kHz, so a 1000 times a second.
Dialogue: 0,0:11:54.39,0:11:55.60,Default,,0000,0000,0000,,Then we have a scientific instrument
Dialogue: 0,0:11:55.60,0:11:58.65,Default,,0000,0000,0000,,because actually we do want to see
Dialogue: 0,0:11:58.65,0:11:59.44,Default,,0000,0000,0000,,what is in there.
Dialogue: 0,0:11:59.44,0:12:00.68,Default,,0000,0000,0000,,And so this thing in the middle
Dialogue: 0,0:12:00.68,0:12:02.44,Default,,0000,0000,0000,,is a beam splitter.
Dialogue: 0,0:12:02.44,0:12:03.83,Default,,0000,0000,0000,,It takes some of the light,
Dialogue: 0,0:12:03.83,0:12:04.90,Default,,0000,0000,0000,,puts it to the wave front sensor
Dialogue: 0,0:12:04.90,0:12:07.42,Default,,0000,0000,0000,,not all, because most of it should go into
Dialogue: 0,0:12:07.42,0:12:08.80,Default,,0000,0000,0000,,the scientific instrument
Dialogue: 0,0:12:08.80,0:12:10.54,Default,,0000,0000,0000,,and there, as you see here,
Dialogue: 0,0:12:10.54,0:12:12.08,Default,,0000,0000,0000,,then the wave front is straightened out
Dialogue: 0,0:12:12.08,0:12:13.95,Default,,0000,0000,0000,,again and then I can focus it
Dialogue: 0,0:12:13.95,0:12:17.43,Default,,0000,0000,0000,,into my instrument.
Dialogue: 0,0:12:17.43,0:12:18.84,Default,,0000,0000,0000,,To do actually that
Dialogue: 0,0:12:18.84,0:12:19.55,Default,,0000,0000,0000,,I have to do...
Dialogue: 0,0:12:19.55,0:12:21.63,Default,,0000,0000,0000,,- This is the one slide in this talk
Dialogue: 0,0:12:21.63,0:12:26.54,Default,,0000,0000,0000,,with a Greek symbol -
Dialogue: 0,0:12:26.54,0:12:30.51,Default,,0000,0000,0000,,You have to this incoming wave front
Dialogue: 0,0:12:30.51,0:12:31.95,Default,,0000,0000,0000,,which is shown in orange
Dialogue: 0,0:12:31.95,0:12:33.96,Default,,0000,0000,0000,,and then you do a piecewise linear fit
Dialogue: 0,0:12:33.96,0:12:35.65,Default,,0000,0000,0000,,which is an approximation
Dialogue: 0,0:12:35.65,0:12:36.69,Default,,0000,0000,0000,,of the slope.
Dialogue: 0,0:12:36.69,0:12:38.39,Default,,0000,0000,0000,,Of it actually how it looks like.
Dialogue: 0,0:12:38.39,0:12:43.38,Default,,0000,0000,0000,,It's put into linear pieces.
Dialogue: 0,0:12:43.38,0:12:46.01,Default,,0000,0000,0000,,And the size of what is normally
Dialogue: 0,0:12:46.01,0:12:49.32,Default,,0000,0000,0000,,can be taken als a linear fit
Dialogue: 0,0:12:49.32,0:12:51.86,Default,,0000,0000,0000,,Piece is roughly 10 - 15 cm
Dialogue: 0,0:12:51.86,0:12:53.60,Default,,0000,0000,0000,,for good observation sites
Dialogue: 0,0:12:53.60,0:12:55.29,Default,,0000,0000,0000,,while this thingy here
Dialogue: 0,0:12:55.29,0:12:57.65,Default,,0000,0000,0000,,so this is the primary mirror of the telescope
Dialogue: 0,0:12:57.65,0:12:58.86,Default,,0000,0000,0000,,which collects all the light
Dialogue: 0,0:12:58.86,0:13:01.31,Default,,0000,0000,0000,,that comes from outer space
Dialogue: 0,0:13:01.31,0:13:04.34,Default,,0000,0000,0000,,is usually for the big telescopes
Dialogue: 0,0:13:04.34,0:13:06.99,Default,,0000,0000,0000,,at this point 8 to 10 meters
Dialogue: 0,0:13:06.99,0:13:13.73,Default,,0000,0000,0000,,Okay, but how do we get this slope?
Dialogue: 0,0:13:13.73,0:13:15.98,Default,,0000,0000,0000,,Now we know that we can approximate it
Dialogue: 0,0:13:15.98,0:13:18.00,Default,,0000,0000,0000,,in pieces, but how do we get
Dialogue: 0,0:13:18.00,0:13:19.96,Default,,0000,0000,0000,,the slope?
Dialogue: 0,0:13:19.96,0:13:22.14,Default,,0000,0000,0000,,Because we need theses slopes of course
Dialogue: 0,0:13:22.14,0:13:25.22,Default,,0000,0000,0000,,fed into this deformable mirror
Dialogue: 0,0:13:25.22,0:13:25.71,Default,,0000,0000,0000,,to maybe okay:
Dialogue: 0,0:13:25.71,0:13:27.56,Default,,0000,0000,0000,,If it comes like this, I go like this
Dialogue: 0,0:13:27.56,0:13:29.62,Default,,0000,0000,0000,,and it comes in nicely
Dialogue: 0,0:13:29.62,0:13:30.96,Default,,0000,0000,0000,,or comes out nicely.
Dialogue: 0,0:13:30.96,0:13:33.65,Default,,0000,0000,0000,,So is where the sensor comes in.
Dialogue: 0,0:13:33.65,0:13:36.29,Default,,0000,0000,0000,,There are different types of these sensors,
Dialogue: 0,0:13:36.29,0:13:37.47,Default,,0000,0000,0000,,but the one we are using
Dialogue: 0,0:13:37.47,0:13:40.91,Default,,0000,0000,0000,,is a so called Shack-Hartmann-Sensor.
Dialogue: 0,0:13:40.91,0:13:43.64,Default,,0000,0000,0000,,And it looks like this.
Dialogue: 0,0:13:43.64,0:13:45.85,Default,,0000,0000,0000,,We have... this is the ideal case of course.
Dialogue: 0,0:13:45.85,0:13:48.06,Default,,0000,0000,0000,,So we have an incoming planar wave front
Dialogue: 0,0:13:48.06,0:13:49.56,Default,,0000,0000,0000,,- straight on.
Dialogue: 0,0:13:49.56,0:13:51.69,Default,,0000,0000,0000,,And we do have an array of lenses,
Dialogue: 0,0:13:51.69,0:13:57.02,Default,,0000,0000,0000,,so it's just 1.. 2.. 3.. 4.. lenses
Dialogue: 0,0:13:57.02,0:14:00.05,Default,,0000,0000,0000,,and then in an array like 4 by 4.
Dialogue: 0,0:14:00.05,0:14:02.30,Default,,0000,0000,0000,,And they all focus what is coming in
Dialogue: 0,0:14:02.30,0:14:05.50,Default,,0000,0000,0000,,into onto a detector and this wave front
Dialogue: 0,0:14:05.50,0:14:07.35,Default,,0000,0000,0000,,that is coming in is planar
Dialogue: 0,0:14:07.35,0:14:09.22,Default,,0000,0000,0000,,like this on the left.
Dialogue: 0,0:14:09.22,0:14:11.71,Default,,0000,0000,0000,,Then you do get a regular spaced grid
Dialogue: 0,0:14:11.71,0:14:15.42,Default,,0000,0000,0000,,of focus points, in this case 4 times 4
Dialogue: 0,0:14:15.42,0:14:17.63,Default,,0000,0000,0000,,so 16.
Dialogue: 0,0:14:17.63,0:14:19.43,Default,,0000,0000,0000,,If now this incoming wave front
Dialogue: 0,0:14:19.43,0:14:24.40,Default,,0000,0000,0000,,is no planar it looks like this.
Dialogue: 0,0:14:24.40,0:14:26.97,Default,,0000,0000,0000,,So the focus points do move a bit,
Dialogue: 0,0:14:26.97,0:14:28.67,Default,,0000,0000,0000,,because, well, it came in like this,
Dialogue: 0,0:14:28.67,0:14:29.96,Default,,0000,0000,0000,,so the focus is offset.
Dialogue: 0,0:14:29.96,0:14:33.73,Default,,0000,0000,0000,,I will flip it back and forth again.
Dialogue: 0,0:14:33.73,0:14:36.54,Default,,0000,0000,0000,,So it's looking like this and you see
Dialogue: 0,0:14:36.54,0:14:39.24,Default,,0000,0000,0000,,of course you do know what is perfect
Dialogue: 0,0:14:39.24,0:14:43.10,Default,,0000,0000,0000,,meaning they are\Nat their designated grid points.
Dialogue: 0,0:14:43.10,0:14:47.48,Default,,0000,0000,0000,,If its imperfect, well, then just measure
Dialogue: 0,0:14:47.48,0:14:50.45,Default,,0000,0000,0000,,the deviation from their zero position
Dialogue: 0,0:14:50.45,0:14:51.27,Default,,0000,0000,0000,,so to speak
Dialogue: 0,0:14:51.27,0:14:55.72,Default,,0000,0000,0000,,and then you do have a proxy for the slope.
Dialogue: 0,0:14:55.72,0:14:57.57,Default,,0000,0000,0000,,Of course it's a bit more complicated\Nthan that.
Dialogue: 0,0:14:57.57,0:15:00.30,Default,,0000,0000,0000,,There are matrices involved which are not
Dialogue: 0,0:15:00.30,0:15:04.79,Default,,0000,0000,0000,,necessarily in a square form
Dialogue: 0,0:15:04.79,0:15:05.89,Default,,0000,0000,0000,,and you have to invert them
Dialogue: 0,0:15:05.89,0:15:10.97,Default,,0000,0000,0000,,and if you don't... yeah... ...
Dialogue: 0,0:15:10.97,0:15:12.66,Default,,0000,0000,0000,,There are pretty clever people
Dialogue: 0,0:15:12.66,0:15:15.61,Default,,0000,0000,0000,,and programmers working on this type of
Dialogue: 0,0:15:15.61,0:15:16.87,Default,,0000,0000,0000,,problems.
Dialogue: 0,0:15:16.87,0:15:19.03,Default,,0000,0000,0000,,And this is actual current research.
Dialogue: 0,0:15:19.03,0:15:23.65,Default,,0000,0000,0000,,This is far from done, this field.
Dialogue: 0,0:15:23.65,0:15:27.52,Default,,0000,0000,0000,,Okay, so suppose we do have the slopes.
Dialogue: 0,0:15:27.52,0:15:29.43,Default,,0000,0000,0000,,Then we take a deformable mirror
Dialogue: 0,0:15:29.43,0:15:32.58,Default,,0000,0000,0000,,and this is the zeros order approximation
Dialogue: 0,0:15:32.58,0:15:33.95,Default,,0000,0000,0000,,of a deformable mirror.
Dialogue: 0,0:15:33.95,0:15:35.64,Default,,0000,0000,0000,,Let's say the wave front looks like that,
Dialogue: 0,0:15:35.64,0:15:37.63,Default,,0000,0000,0000,,well, then take just a mirror which is
Dialogue: 0,0:15:37.63,0:15:39.65,Default,,0000,0000,0000,,maybe reset a bit in the middle
Dialogue: 0,0:15:39.65,0:15:41.47,Default,,0000,0000,0000,,the other tipped forward.
Dialogue: 0,0:15:41.47,0:15:43.45,Default,,0000,0000,0000,,It bounces on this mirror
Dialogue: 0,0:15:43.45,0:15:45.82,Default,,0000,0000,0000,,and because there is something sticking out there
Dialogue: 0,0:15:45.82,0:15:46.68,Default,,0000,0000,0000,,and in there
Dialogue: 0,0:15:46.68,0:15:49.43,Default,,0000,0000,0000,,well if this approaches there goes back
Dialogue: 0,0:15:49.43,0:15:50.79,Default,,0000,0000,0000,,and in the end the whole thing
Dialogue: 0,0:15:50.79,0:15:54.51,Default,,0000,0000,0000,,when it has been reflected is planar again.
Dialogue: 0,0:15:54.51,0:15:57.17,Default,,0000,0000,0000,,Okay, that as said,
Dialogue: 0,0:15:57.17,0:15:58.91,Default,,0000,0000,0000,,that is the easiest order approximation
Dialogue: 0,0:15:58.91,0:16:01.03,Default,,0000,0000,0000,,for that. It's a bit more complicated.
Dialogue: 0,0:16:01.03,0:16:03.93,Default,,0000,0000,0000,,Your incoming wave front doesn't look like that
Dialogue: 0,0:16:03.93,0:16:08.68,Default,,0000,0000,0000,,It's normally a bit more complex.
Dialogue: 0,0:16:08.68,0:16:10.85,Default,,0000,0000,0000,,And that means you do have to have
Dialogue: 0,0:16:10.85,0:16:17.17,Default,,0000,0000,0000,,more wobbling in your deformable mirror.
Dialogue: 0,0:16:17.17,0:16:18.28,Default,,0000,0000,0000,,You could do this.
Dialogue: 0,0:16:18.28,0:16:21.40,Default,,0000,0000,0000,,That's in the upper diagram.
Dialogue: 0,0:16:21.40,0:16:22.90,Default,,0000,0000,0000,,You could do this with a membran
Dialogue: 0,0:16:22.90,0:16:24.20,Default,,0000,0000,0000,,which is continues
Dialogue: 0,0:16:24.20,0:16:27.73,Default,,0000,0000,0000,,or maybe it's also in pieces
Dialogue: 0,0:16:27.73,0:16:29.58,Default,,0000,0000,0000,,and this segments are driven up and down
Dialogue: 0,0:16:29.58,0:16:32.45,Default,,0000,0000,0000,,or maybe tilted by piezo stages
Dialogue: 0,0:16:32.45,0:16:35.14,Default,,0000,0000,0000,,that are put underneath.
Dialogue: 0,0:16:35.14,0:16:36.54,Default,,0000,0000,0000,,Remember they have to do like
Dialogue: 0,0:16:36.54,0:16:38.76,Default,,0000,0000,0000,,a thousand times a second
Dialogue: 0,0:16:38.76,0:16:40.22,Default,,0000,0000,0000,,or you could do something like
Dialogue: 0,0:16:40.22,0:16:43.72,Default,,0000,0000,0000,,you take a two piezo electric wafers
Dialogue: 0,0:16:43.72,0:16:45.40,Default,,0000,0000,0000,,they have opposite polarizations
Dialogue: 0,0:16:45.40,0:16:47.11,Default,,0000,0000,0000,,put electrodes inbetween
Dialogue: 0,0:16:47.11,0:16:49.06,Default,,0000,0000,0000,,and then when you apply a voltage to this blue
Dialogue: 0,0:16:49.06,0:16:51.35,Default,,0000,0000,0000,,electrodes then you have local bending.
Dialogue: 0,0:16:51.35,0:16:52.95,Default,,0000,0000,0000,,So the one thing will bend up,
Dialogue: 0,0:16:52.95,0:16:55.99,Default,,0000,0000,0000,,the other ones will bend in the opposite direction.
Dialogue: 0,0:16:55.99,0:16:58.08,Default,,0000,0000,0000,,And then you do have changing curvature
Dialogue: 0,0:16:58.08,0:17:00.56,Default,,0000,0000,0000,,on this whole thing.
Dialogue: 0,0:17:00.56,0:17:04.26,Default,,0000,0000,0000,,It's not that easy of course in reality,
Dialogue: 0,0:17:04.26,0:17:07.51,Default,,0000,0000,0000,,because they are not completely independent
Dialogue: 0,0:17:07.51,0:17:09.43,Default,,0000,0000,0000,,one cell will influence the other
Dialogue: 0,0:17:09.43,0:17:11.52,Default,,0000,0000,0000,,and yes...
Dialogue: 0,0:17:11.52,0:17:14.32,Default,,0000,0000,0000,,But this is the basic principle.
Dialogue: 0,0:17:14.32,0:17:18.37,Default,,0000,0000,0000,,Okay, now you have seen
Dialogue: 0,0:17:18.37,0:17:19.97,Default,,0000,0000,0000,,there was this beam splitter.
Dialogue: 0,0:17:19.97,0:17:22.15,Default,,0000,0000,0000,,So most of the thing goes into the
Dialogue: 0,0:17:22.15,0:17:23.10,Default,,0000,0000,0000,,science instrument
Dialogue: 0,0:17:23.10,0:17:26.27,Default,,0000,0000,0000,,and some goes to our wave front sensor
Dialogue: 0,0:17:26.27,0:17:27.76,Default,,0000,0000,0000,,of the light.
Dialogue: 0,0:17:27.76,0:17:30.55,Default,,0000,0000,0000,,If the object we want to record like
Dialogue: 0,0:17:30.55,0:17:34.67,Default,,0000,0000,0000,,a galaxy that is 11 Billion lightyears away
Dialogue: 0,0:17:34.67,0:17:36.19,Default,,0000,0000,0000,,then this galaxy is to faint.
Dialogue: 0,0:17:36.19,0:17:38.86,Default,,0000,0000,0000,,We can't analyse it's light.
Dialogue: 0,0:17:38.86,0:17:41.14,Default,,0000,0000,0000,,So what do we do?
Dialogue: 0,0:17:41.14,0:17:43.23,Default,,0000,0000,0000,,We need maybe a star that is nearby.
Dialogue: 0,0:17:43.23,0:17:45.03,Default,,0000,0000,0000,,So our galaxy, which we actually do want
Dialogue: 0,0:17:45.03,0:17:47.16,Default,,0000,0000,0000,,to observe, is the red thingy
Dialogue: 0,0:17:47.16,0:17:49.03,Default,,0000,0000,0000,,the bright star is the yellow one
Dialogue: 0,0:17:49.03,0:17:50.79,Default,,0000,0000,0000,,and if there are reasonably close together
Dialogue: 0,0:17:50.79,0:17:52.50,Default,,0000,0000,0000,,- reasonably close meaning
Dialogue: 0,0:17:52.50,0:17:56.28,Default,,0000,0000,0000,,about 10-20 arcseconds.
Dialogue: 0,0:17:56.28,0:17:58.35,Default,,0000,0000,0000,,If you stretch your arm and look at
Dialogue: 0,0:17:58.35,0:18:01.75,Default,,0000,0000,0000,,your little finger at the finger nail,
Dialogue: 0,0:18:01.75,0:18:06.12,Default,,0000,0000,0000,,this is about 30 arcminutes.
Dialogue: 0,0:18:06.12,0:18:08.95,Default,,0000,0000,0000,,1 arcminute has 60 arcseconds so it's
Dialogue: 0,0:18:08.95,0:18:09.90,Default,,0000,0000,0000,,very close!
Dialogue: 0,0:18:09.90,0:18:11.08,Default,,0000,0000,0000,,It's not like the galaxy is there
Dialogue: 0,0:18:11.08,0:18:13.50,Default,,0000,0000,0000,,and the star is there. No!
Dialogue: 0,0:18:13.50,0:18:15.55,Default,,0000,0000,0000,,It's there!
Dialogue: 0,0:18:15.55,0:18:18.46,Default,,0000,0000,0000,,Because if you have a large separation
Dialogue: 0,0:18:18.46,0:18:22.14,Default,,0000,0000,0000,,then they do sense different turbulence.
Dialogue: 0,0:18:22.14,0:18:27.33,Default,,0000,0000,0000,,Simple as that.
Dialogue: 0,0:18:27.33,0:18:28.53,Default,,0000,0000,0000,,Now the thing is
Dialogue: 0,0:18:28.53,0:18:31.08,Default,,0000,0000,0000,,that less than 10% of the objects
Dialogue: 0,0:18:31.08,0:18:31.66,Default,,0000,0000,0000,,you have on sky
Dialogue: 0,0:18:31.66,0:18:33.11,Default,,0000,0000,0000,,which you are normally interested
Dialogue: 0,0:18:33.11,0:18:36.39,Default,,0000,0000,0000,,do have a sufficiently close and bright star
Dialogue: 0,0:18:36.39,0:18:37.16,Default,,0000,0000,0000,,nearby.
Dialogue: 0,0:18:37.16,0:18:38.23,Default,,0000,0000,0000,,So what to do?
Dialogue: 0,0:18:38.23,0:18:45.29,Default,,0000,0000,0000,,And now we come to the lasers.\N{\i1}laughter{\i0}
Dialogue: 0,0:18:45.29,0:18:48.27,Default,,0000,0000,0000,,Because if don't have your....
Dialogue: 0,0:18:48.27,0:18:49.75,Default,,0000,0000,0000,,If the don't wanna play nicely
Dialogue: 0,0:18:49.75,0:18:54.75,Default,,0000,0000,0000,,build your own themepark with yes ... you know.
Dialogue: 0,0:18:54.75,0:18:57.93,Default,,0000,0000,0000,,So make your own star!
Dialogue: 0,0:18:57.93,0:18:59.61,Default,,0000,0000,0000,,This is what we do.
Dialogue: 0,0:18:59.61,0:19:02.68,Default,,0000,0000,0000,,Because if the star is not nearby,
Dialogue: 0,0:19:02.68,0:19:04.80,Default,,0000,0000,0000,,a sufficiently bright one,
Dialogue: 0,0:19:04.80,0:19:07.83,Default,,0000,0000,0000,,well, why has it to be sufficiently bright?
Dialogue: 0,0:19:07.83,0:19:09.62,Default,,0000,0000,0000,,Because if you want to do this computation
Dialogue: 0,0:19:09.62,0:19:12.12,Default,,0000,0000,0000,,a thousand times a second, well,
Dialogue: 0,0:19:12.12,0:19:19.47,Default,,0000,0000,0000,,then the time for your CCD\Nwhen you record this image
Dialogue: 0,0:19:19.47,0:19:23.82,Default,,0000,0000,0000,,for your wavefront is a thousands of a second.
Dialogue: 0,0:19:23.82,0:19:25.28,Default,,0000,0000,0000,,And if you don't have enough photons
Dialogue: 0,0:19:25.28,0:19:26.80,Default,,0000,0000,0000,,in a thousands of a second, well,
Dialogue: 0,0:19:26.80,0:19:29.30,Default,,0000,0000,0000,,then there is no computation of this offset
Dialogue: 0,0:19:29.30,0:19:31.64,Default,,0000,0000,0000,,of this little green dots on that grid.
Dialogue: 0,0:19:31.64,0:19:33.49,Default,,0000,0000,0000,,So you need a lot of photons.
Dialogue: 0,0:19:33.49,0:19:36.55,Default,,0000,0000,0000,,So let's get enough photons!
Dialogue: 0,0:19:36.55,0:19:37.58,Default,,0000,0000,0000,,And there are actually two things
Dialogue: 0,0:19:37.58,0:19:38.80,Default,,0000,0000,0000,,what you can do.
Dialogue: 0,0:19:38.80,0:19:42.48,Default,,0000,0000,0000,,There is a conveniently placed sodium layer
Dialogue: 0,0:19:42.48,0:19:44.28,Default,,0000,0000,0000,,in the upper atmosphere.
Dialogue: 0,0:19:44.28,0:19:45.62,Default,,0000,0000,0000,,{\i1}laughing{\i0}
Dialogue: 0,0:19:45.62,0:19:47.53,Default,,0000,0000,0000,,It's 19 km above ground
Dialogue: 0,0:19:47.53,0:19:49.99,Default,,0000,0000,0000,,and there is a sodium layer.
Dialogue: 0,0:19:49.99,0:19:52.07,Default,,0000,0000,0000,,And what you actually can do is
Dialogue: 0,0:19:52.07,0:19:54.87,Default,,0000,0000,0000,,you can take a laser on ground here,
Dialogue: 0,0:19:54.87,0:19:58.18,Default,,0000,0000,0000,,and then shot laser which corresponds
Dialogue: 0,0:19:58.18,0:20:02.63,Default,,0000,0000,0000,,to the energy transition of this sodium atoms
Dialogue: 0,0:20:02.63,0:20:07.61,Default,,0000,0000,0000,,which is 589.2 nm. It's orange.
Dialogue: 0,0:20:07.61,0:20:09.18,Default,,0000,0000,0000,,And excited those atoms up there
Dialogue: 0,0:20:09.18,0:20:09.96,Default,,0000,0000,0000,,in the atmosphere and they will
Dialogue: 0,0:20:09.96,0:20:10.62,Default,,0000,0000,0000,,start to glow.
Dialogue: 0,0:20:10.62,0:20:12.01,Default,,0000,0000,0000,,And if you have a focus,
Dialogue: 0,0:20:12.01,0:20:13.25,Default,,0000,0000,0000,,if you focus it in there,
Dialogue: 0,0:20:13.25,0:20:17.40,Default,,0000,0000,0000,,and than you have a blob of sodium atoms
Dialogue: 0,0:20:17.40,0:20:19.27,Default,,0000,0000,0000,,lighting up in the upper atmosphere,
Dialogue: 0,0:20:19.27,0:20:21.67,Default,,0000,0000,0000,,maybe... what ever some hundred meters long
Dialogue: 0,0:20:21.67,0:20:26.64,Default,,0000,0000,0000,,and some meters wide\Nas big as your focus is there.
Dialogue: 0,0:20:26.64,0:20:30.44,Default,,0000,0000,0000,,This can be done with a continuous laser.
Dialogue: 0,0:20:30.44,0:20:31.56,Default,,0000,0000,0000,,This has been done in the past.
Dialogue: 0,0:20:31.56,0:20:33.75,Default,,0000,0000,0000,,Yes, of course.
Dialogue: 0,0:20:33.75,0:20:37.10,Default,,0000,0000,0000,,And actually the first instruments
Dialogue: 0,0:20:37.10,0:20:39.36,Default,,0000,0000,0000,,were build like that.
Dialogue: 0,0:20:39.36,0:20:40.24,Default,,0000,0000,0000,,The thing is
Dialogue: 0,0:20:40.24,0:20:42.72,Default,,0000,0000,0000,,in those days they were very, very expensive.
Dialogue: 0,0:20:42.72,0:20:44.80,Default,,0000,0000,0000,,There is no sodium laser.
Dialogue: 0,0:20:44.80,0:20:50.26,Default,,0000,0000,0000,,There are only Di LASERs and they are messy
Dialogue: 0,0:20:50.26,0:20:52.03,Default,,0000,0000,0000,,and expensive.
Dialogue: 0,0:20:52.03,0:20:55.10,Default,,0000,0000,0000,,Nowadays we can build this as fibre laser
Dialogue: 0,0:20:55.10,0:20:57.73,Default,,0000,0000,0000,,but not ten 10 years ago or 15 years ago.
Dialogue: 0,0:20:57.73,0:21:00.07,Default,,0000,0000,0000,,An other solution is to actually
Dialogue: 0,0:21:00.07,0:21:03.47,Default,,0000,0000,0000,,use Rayleigh scattering in the atmosphere.
Dialogue: 0,0:21:03.47,0:21:06.22,Default,,0000,0000,0000,,You use a Nd-YAG LASER
Dialogue: 0,0:21:06.22,0:21:08.90,Default,,0000,0000,0000,,which is 532nm. It's green.
Dialogue: 0,0:21:08.90,0:21:10.65,Default,,0000,0000,0000,,It's easily available, it's cheap
Dialogue: 0,0:21:10.65,0:21:12.54,Default,,0000,0000,0000,,compared to the other one.
Dialogue: 0,0:21:12.54,0:21:15.86,Default,,0000,0000,0000,,And then you focus it in the atmosphere.
Dialogue: 0,0:21:15.86,0:21:17.82,Default,,0000,0000,0000,,The only thing is:
Dialogue: 0,0:21:17.82,0:21:19.77,Default,,0000,0000,0000,,You will do have backscatter of photons
Dialogue: 0,0:21:19.77,0:21:21.18,Default,,0000,0000,0000,,all along the way.
Dialogue: 0,0:21:21.18,0:21:22.41,Default,,0000,0000,0000,,So you have to think about
Dialogue: 0,0:21:22.41,0:21:24.62,Default,,0000,0000,0000,,how can I only record light from
Dialogue: 0,0:21:24.62,0:21:26.72,Default,,0000,0000,0000,,a certain height above ground?
Dialogue: 0,0:21:26.72,0:21:28.89,Default,,0000,0000,0000,,Because otherwise I don't have a spot,
Dialogue: 0,0:21:28.89,0:21:31.21,Default,,0000,0000,0000,,I have a ...ehhh... a laser beam column
Dialogue: 0,0:21:31.21,0:21:33.12,Default,,0000,0000,0000,,somewhere there.
Dialogue: 0,0:21:33.12,0:21:34.40,Default,,0000,0000,0000,,Okay!
Dialogue: 0,0:21:34.40,0:21:35.99,Default,,0000,0000,0000,,How do this things look like?
Dialogue: 0,0:21:35.99,0:21:37.96,Default,,0000,0000,0000,,Can we dim these lights actually a bit?
Dialogue: 0,0:21:37.96,0:21:40.00,Default,,0000,0000,0000,,Or is it only an off switch?
Dialogue: 0,0:21:40.00,0:21:45.17,Default,,0000,0000,0000,,Can you check on this? Let's check on there...
Dialogue: 0,0:21:45.17,0:21:49.04,Default,,0000,0000,0000,,Just push the button... come on...
Dialogue: 0,0:21:49.04,0:21:54.78,Default,,0000,0000,0000,,No? No. No!
Dialogue: 0,0:21:54.78,0:21:57.80,Default,,0000,0000,0000,,laughing
Dialogue: 0,0:21:57.80,0:22:06.38,Default,,0000,0000,0000,,Nooo!
Dialogue: 0,0:22:06.38,0:22:07.70,Default,,0000,0000,0000,,It's still on here...
Dialogue: 0,0:22:07.70,0:22:12.53,Default,,0000,0000,0000,,{\i1}gasp{\i0}
Dialogue: 0,0:22:12.53,0:22:16.54,Default,,0000,0000,0000,,All right, it's looking like this.
Dialogue: 0,0:22:16.54,0:22:19.38,Default,,0000,0000,0000,,Who has been at the camp?
Dialogue: 0,0:22:19.38,0:22:21.15,Default,,0000,0000,0000,,There was an astronomy talk at the camp
Dialogue: 0,0:22:21.15,0:22:24.91,Default,,0000,0000,0000,,from Liz.
Dialogue: 0,0:22:24.91,0:22:27.89,Default,,0000,0000,0000,,Actually if this talk had been tomorrow
Dialogue: 0,0:22:27.89,0:22:29.43,Default,,0000,0000,0000,,we would had have a live conference
Dialogue: 0,0:22:29.43,0:22:31.72,Default,,0000,0000,0000,,to that side because Liz is right now here
Dialogue: 0,0:22:31.72,0:22:35.05,Default,,0000,0000,0000,,and she send me that picture
Dialogue: 0,0:22:35.05,0:22:36.07,Default,,0000,0000,0000,,just some hours ago.
Dialogue: 0,0:22:36.07,0:22:38.52,Default,,0000,0000,0000,,That is how the just do things on
Dialogue: 0,0:22:38.52,0:22:41.06,Default,,0000,0000,0000,,Paranal in Chile.
Dialogue: 0,0:22:41.06,0:22:42.31,Default,,0000,0000,0000,,The thing I will talk about
Dialogue: 0,0:22:42.31,0:22:44.90,Default,,0000,0000,0000,,is the green one to the right.
Dialogue: 0,0:22:44.90,0:22:49.64,Default,,0000,0000,0000,,That's the thing I have been involved with.
Dialogue: 0,0:22:49.64,0:22:52.60,Default,,0000,0000,0000,,Yea, let's look into that.
Dialogue: 0,0:22:52.60,0:22:55.98,Default,,0000,0000,0000,,So if you shoot the laser into the atmosphere
Dialogue: 0,0:22:55.98,0:22:57.49,Default,,0000,0000,0000,,of course you do have problem.
Dialogue: 0,0:22:57.49,0:22:58.86,Default,,0000,0000,0000,,The star is very far away,
Dialogue: 0,0:22:58.86,0:23:00.79,Default,,0000,0000,0000,,it's infinitely far away.
Dialogue: 0,0:23:00.79,0:23:01.96,Default,,0000,0000,0000,,And the light that comes down
Dialogue: 0,0:23:01.96,0:23:05.10,Default,,0000,0000,0000,,is in a cylinder.
Dialogue: 0,0:23:05.10,0:23:08.66,Default,,0000,0000,0000,,And if you shoot a laser up, it's a cone.
Dialogue: 0,0:23:08.66,0:23:10.94,Default,,0000,0000,0000,,So you only probe the green region.
Dialogue: 0,0:23:10.94,0:23:15.58,Default,,0000,0000,0000,,The unsampled volume of turbulence\Nis to the side.
Dialogue: 0,0:23:15.58,0:23:18.65,Default,,0000,0000,0000,,That is a problem with our laser AO.
Dialogue: 0,0:23:18.65,0:23:26.20,Default,,0000,0000,0000,,An other problem we face is this one.
Dialogue: 0,0:23:26.20,0:23:30.14,Default,,0000,0000,0000,,When we take a star to measure the wave front
Dialogue: 0,0:23:30.14,0:23:33.38,Default,,0000,0000,0000,,then it passes only once through the atmosphere.
Dialogue: 0,0:23:33.38,0:23:35.53,Default,,0000,0000,0000,,The laser beam goes up and down.
Dialogue: 0,0:23:35.53,0:23:36.63,Default,,0000,0000,0000,,And so there is a component
Dialogue: 0,0:23:36.63,0:23:37.76,Default,,0000,0000,0000,,called tip tilt component
Dialogue: 0,0:23:37.76,0:23:40.87,Default,,0000,0000,0000,,which is actually just the thing moving around
Dialogue: 0,0:23:40.87,0:23:43.80,Default,,0000,0000,0000,,It's not just the phase
Dialogue: 0,0:23:43.80,0:23:45.93,Default,,0000,0000,0000,,that gets disturbance introduced
Dialogue: 0,0:23:45.93,0:23:48.60,Default,,0000,0000,0000,,in the wave front but this moving around.
Dialogue: 0,0:23:48.60,0:23:54.63,Default,,0000,0000,0000,,So not the bright and more\Nor less bright twinkling
Dialogue: 0,0:23:54.63,0:23:56.54,Default,,0000,0000,0000,,little star thingy,
Dialogue: 0,0:23:56.54,0:23:58.29,Default,,0000,0000,0000,,but the moving around.
Dialogue: 0,0:23:58.29,0:24:00.40,Default,,0000,0000,0000,,And that can not be sensed\Nwith a laser guild star.
Dialogue: 0,0:24:00.40,0:24:02.55,Default,,0000,0000,0000,,So when ever we do laser AO
Dialogue: 0,0:24:02.55,0:24:04.57,Default,,0000,0000,0000,,We do need an other star
Dialogue: 0,0:24:04.57,0:24:05.60,Default,,0000,0000,0000,,to get this component.
Dialogue: 0,0:24:05.60,0:24:08.08,Default,,0000,0000,0000,,But this star can be a bit further away,
Dialogue: 0,0:24:08.08,0:24:11.67,Default,,0000,0000,0000,,like an arcminute or 2 arcminutes or so.
Dialogue: 0,0:24:11.67,0:24:17.15,Default,,0000,0000,0000,,So it's that... is wide. There are enough.
Dialogue: 0,0:24:17.15,0:24:18.49,Default,,0000,0000,0000,,And then we should think about
Dialogue: 0,0:24:18.49,0:24:20.22,Default,,0000,0000,0000,,actually what we have to correct and so
Dialogue: 0,0:24:20.22,0:24:23.79,Default,,0000,0000,0000,,we should make a profile of the turbulence
Dialogue: 0,0:24:23.79,0:24:25.10,Default,,0000,0000,0000,,above ground.
Dialogue: 0,0:24:25.10,0:24:27.06,Default,,0000,0000,0000,,And this is how it looks like.
Dialogue: 0,0:24:27.06,0:24:29.39,Default,,0000,0000,0000,,And for example for the side
Dialogue: 0,0:24:29.39,0:24:32.37,Default,,0000,0000,0000,,where we are there in Arizona
Dialogue: 0,0:24:32.37,0:24:34.45,Default,,0000,0000,0000,,we see that most of the turbulence
Dialogue: 0,0:24:34.45,0:24:37.40,Default,,0000,0000,0000,,is actually just above the ground.
Dialogue: 0,0:24:37.40,0:24:39.36,Default,,0000,0000,0000,,So we maybe should care mostly
Dialogue: 0,0:24:39.36,0:24:41.22,Default,,0000,0000,0000,,about the ground layer.
Dialogue: 0,0:24:41.22,0:24:44.56,Default,,0000,0000,0000,,It's not so much about the high altitude things.
Dialogue: 0,0:24:44.56,0:24:47.23,Default,,0000,0000,0000,,So and then what we do is:
Dialogue: 0,0:24:47.23,0:24:48.58,Default,,0000,0000,0000,,Well we want to sample
Dialogue: 0,0:24:48.58,0:24:50.66,Default,,0000,0000,0000,,the ground stuff nicely
Dialogue: 0,0:24:50.66,0:24:54.68,Default,,0000,0000,0000,,so we don't take one but 3 lasers.
Dialogue: 0,0:24:54.68,0:24:58.04,Default,,0000,0000,0000,,So to fill this area nicely.
Dialogue: 0,0:24:58.04,0:25:00.21,Default,,0000,0000,0000,,And yes, of course, we can also combine this
Dialogue: 0,0:25:00.21,0:25:03.41,Default,,0000,0000,0000,,and this looks like that.
Dialogue: 0,0:25:03.41,0:25:05.63,Default,,0000,0000,0000,,This combination we will not talk about today.
Dialogue: 0,0:25:05.63,0:25:09.81,Default,,0000,0000,0000,,We will only talk about that.
Dialogue: 0,0:25:09.81,0:25:11.08,Default,,0000,0000,0000,,This is how it looks like.
Dialogue: 0,0:25:11.08,0:25:13.11,Default,,0000,0000,0000,,So this is our telescope, the primary mirror
Dialogue: 0,0:25:13.11,0:25:16.59,Default,,0000,0000,0000,,which receives the light from outer space
Dialogue: 0,0:25:16.59,0:25:19.46,Default,,0000,0000,0000,,it then deflects on the secondary, tertiary
Dialogue: 0,0:25:19.46,0:25:20.60,Default,,0000,0000,0000,,and than somewhere here.
Dialogue: 0,0:25:20.60,0:25:22.61,Default,,0000,0000,0000,,But first we need to have to shoot the laser up.
Dialogue: 0,0:25:22.61,0:25:25.54,Default,,0000,0000,0000,,And it's launched from a laser box
Dialogue: 0,0:25:25.54,0:25:28.94,Default,,0000,0000,0000,,onto a mirror behind that secondary mirror
Dialogue: 0,0:25:28.94,0:25:30.53,Default,,0000,0000,0000,,over there into the atmosphere
Dialogue: 0,0:25:30.53,0:25:33.40,Default,,0000,0000,0000,,and after 40 microseconds it reaches
Dialogue: 0,0:25:33.40,0:25:36.20,Default,,0000,0000,0000,,an altitude of 12 km.
Dialogue: 0,0:25:36.20,0:25:37.62,Default,,0000,0000,0000,,And then of course it comes back.
Dialogue: 0,0:25:37.62,0:25:40.22,Default,,0000,0000,0000,,After 80 microseconds it's here
Dialogue: 0,0:25:40.22,0:25:41.42,Default,,0000,0000,0000,,in our detector again.
Dialogue: 0,0:25:41.42,0:25:43.73,Default,,0000,0000,0000,,So the star then lights up,
Dialogue: 0,0:25:43.73,0:25:46.05,Default,,0000,0000,0000,,has this cone, get's focused there, focus,
Dialogue: 0,0:25:46.05,0:25:48.46,Default,,0000,0000,0000,,reflected to here
Dialogue: 0,0:25:48.46,0:25:53.82,Default,,0000,0000,0000,,and we do have our signal\Nin our detector after 80 ms
Dialogue: 0,0:25:53.82,0:25:55.43,Default,,0000,0000,0000,,and as said, because of course
Dialogue: 0,0:25:55.43,0:25:59.07,Default,,0000,0000,0000,,the laser has scattering all along its path,
Dialogue: 0,0:25:59.07,0:26:03.35,Default,,0000,0000,0000,,you want to gate this information to 12 km
Dialogue: 0,0:26:03.35,0:26:05.54,Default,,0000,0000,0000,,and well then you just -just- look at
Dialogue: 0,0:26:05.54,0:26:06.88,Default,,0000,0000,0000,,when your laser pulse started
Dialogue: 0,0:26:06.88,0:26:09.42,Default,,0000,0000,0000,,wait. wait. wait. wait. wait.
Dialogue: 0,0:26:09.42,0:26:11.50,Default,,0000,0000,0000,,open the shutter for the detector
Dialogue: 0,0:26:11.50,0:26:14.98,Default,,0000,0000,0000,,for short time after 80ms,
Dialogue: 0,0:26:14.98,0:26:16.35,Default,,0000,0000,0000,,close it again and then analyse
Dialogue: 0,0:26:16.35,0:26:18.70,Default,,0000,0000,0000,,and read out what you just did.
Dialogue: 0,0:26:18.70,0:26:19.96,Default,,0000,0000,0000,,Easy, huh?
Dialogue: 0,0:26:19.96,0:26:21.52,Default,,0000,0000,0000,,So we are done.
Dialogue: 0,0:26:21.52,0:26:23.39,Default,,0000,0000,0000,,Thank you for coming to my talk
Dialogue: 0,0:26:23.39,0:26:26.40,Default,,0000,0000,0000,,and now go out and build your own lasers
Dialogue: 0,0:26:26.40,0:26:28.80,Default,,0000,0000,0000,,with... to...
Dialogue: 0,0:26:28.80,0:26:30.98,Default,,0000,0000,0000,,{\i1}laughing{\i0}
Dialogue: 0,0:26:30.98,0:26:34.31,Default,,0000,0000,0000,,Now we are going to look at this thing
Dialogue: 0,0:26:34.31,0:26:37.37,Default,,0000,0000,0000,,which is actually build and which works.
Dialogue: 0,0:26:37.37,0:26:39.65,Default,,0000,0000,0000,,So this is called ARGOS.
Dialogue: 0,0:26:39.65,0:26:41.25,Default,,0000,0000,0000,,It's a ground layer AO system.
Dialogue: 0,0:26:41.25,0:26:42.57,Default,,0000,0000,0000,,That's what we want to build.
Dialogue: 0,0:26:42.57,0:26:44.21,Default,,0000,0000,0000,,It has wide field corrections.
Dialogue: 0,0:26:44.21,0:26:46.11,Default,,0000,0000,0000,,That means you can not correct
Dialogue: 0,0:26:46.11,0:26:49.56,Default,,0000,0000,0000,,just a tiny patch on sky but for for astronomical use
Dialogue: 0,0:26:49.56,0:26:52.19,Default,,0000,0000,0000,,a huge area, meaning it's not just
Dialogue: 0,0:26:52.19,0:26:54.07,Default,,0000,0000,0000,,a circle of 10 arcseconds but
Dialogue: 0,0:26:54.07,0:26:56.85,Default,,0000,0000,0000,,this thing can correct 4 by 4 arcminutes
Dialogue: 0,0:26:56.85,0:26:58.23,Default,,0000,0000,0000,,which is huge,
Dialogue: 0,0:26:58.23,0:27:01.56,Default,,0000,0000,0000,,so all the objects that are in there.
Dialogue: 0,0:27:01.56,0:27:03.67,Default,,0000,0000,0000,,We have a multi-laser constellation.
Dialogue: 0,0:27:03.67,0:27:05.14,Default,,0000,0000,0000,,We have seen that why we need this,
Dialogue: 0,0:27:05.14,0:27:05.85,Default,,0000,0000,0000,,because we want to fill
Dialogue: 0,0:27:05.85,0:27:06.94,Default,,0000,0000,0000,,the complete ground layer.
Dialogue: 0,0:27:06.94,0:27:10.29,Default,,0000,0000,0000,,So we have 3 laser guild stars per eye.
Dialogue: 0,0:27:10.29,0:27:11.48,Default,,0000,0000,0000,,Why per eye?
Dialogue: 0,0:27:11.48,0:27:14.07,Default,,0000,0000,0000,,This will be clear in minute.
Dialogue: 0,0:27:14.07,0:27:17.42,Default,,0000,0000,0000,,And we use high power pulse green lasers.
Dialogue: 0,0:27:17.42,0:27:20.71,Default,,0000,0000,0000,,And this deformable mirror is actually
Dialogue: 0,0:27:20.71,0:27:22.97,Default,,0000,0000,0000,,build in the telescope system already.
Dialogue: 0,0:27:22.97,0:27:25.30,Default,,0000,0000,0000,,The secondary mirror is the deformable mirror
Dialogue: 0,0:27:25.30,0:27:26.96,Default,,0000,0000,0000,,which is very convenient,
Dialogue: 0,0:27:26.96,0:27:29.32,Default,,0000,0000,0000,,because then all the instruments,
Dialogue: 0,0:27:29.32,0:27:31.02,Default,,0000,0000,0000,,that sit on the telescope can benefit from
Dialogue: 0,0:27:31.02,0:27:33.98,Default,,0000,0000,0000,,this system.
Dialogue: 0,0:27:33.98,0:27:36.27,Default,,0000,0000,0000,,It's installed at this telescope.
Dialogue: 0,0:27:36.27,0:27:38.24,Default,,0000,0000,0000,,Look's pretty odd. Yes, I admit that.
Dialogue: 0,0:27:38.24,0:27:39.78,Default,,0000,0000,0000,,That's the Large Binocular Telescope.
Dialogue: 0,0:27:39.78,0:27:41.85,Default,,0000,0000,0000,,It's two telescopes on one mount.
Dialogue: 0,0:27:41.85,0:27:44.30,Default,,0000,0000,0000,,One primary, two primaries.
Dialogue: 0,0:27:44.30,0:27:47.57,Default,,0000,0000,0000,,It's roughly 23 by 25 by 12 meters.
Dialogue: 0,0:27:47.57,0:27:50.79,Default,,0000,0000,0000,,It sits on Mont Graham in Arizona.
Dialogue: 0,0:27:50.79,0:27:52.47,Default,,0000,0000,0000,,And it has an adaptive secondary mirror
Dialogue: 0,0:27:52.47,0:27:58.16,Default,,0000,0000,0000,,which is this violette coloured thingy
Dialogue: 0,0:27:58.16,0:28:00.63,Default,,0000,0000,0000,,up there in the middle on top.
Dialogue: 0,0:28:00.63,0:28:04.76,Default,,0000,0000,0000,,This is how it looks like.
Dialogue: 0,0:28:04.76,0:28:05.72,Default,,0000,0000,0000,,This is the control room
Dialogue: 0,0:28:05.72,0:28:06.80,Default,,0000,0000,0000,,where you sit.
Dialogue: 0,0:28:06.80,0:28:09.47,Default,,0000,0000,0000,,This stays fixed.
Dialogue: 0,0:28:09.47,0:28:11.89,Default,,0000,0000,0000,,All this shiny part rotates.
Dialogue: 0,0:28:11.89,0:28:12.86,Default,,0000,0000,0000,,That's the actual telescope,
Dialogue: 0,0:28:12.86,0:28:14.50,Default,,0000,0000,0000,,the red thing that moves up and down.
Dialogue: 0,0:28:14.50,0:28:17.17,Default,,0000,0000,0000,,So the whole building rotates and it moves
Dialogue: 0,0:28:17.17,0:28:19.21,Default,,0000,0000,0000,,up and down.
Dialogue: 0,0:28:19.21,0:28:27.42,Default,,0000,0000,0000,,It's from ceiling... the ceiling is at level\N11.
Dialogue: 0,0:28:27.42,0:28:30.99,Default,,0000,0000,0000,,So when you actually sit there,
Dialogue: 0,0:28:30.99,0:28:34.78,Default,,0000,0000,0000,,you can watch around a bit
Dialogue: 0,0:28:34.78,0:28:39.96,Default,,0000,0000,0000,,... this is outside... it's winter... yuh!...\Nlet's see...
Dialogue: 0,0:28:39.96,0:28:41.94,Default,,0000,0000,0000,,There is a ladder...
Dialogue: 0,0:28:41.94,0:28:46.07,Default,,0000,0000,0000,,Yes, this thing is huge...eh.. nice.. cool
Dialogue: 0,0:28:46.07,0:28:47.96,Default,,0000,0000,0000,,Okay, that's what it's looks like
Dialogue: 0,0:28:47.96,0:28:53.74,Default,,0000,0000,0000,,when you are actually there.
Dialogue: 0,0:28:53.74,0:28:56.87,Default,,0000,0000,0000,,Okay, our system layout is like this.
Dialogue: 0,0:28:56.87,0:28:59.79,Default,,0000,0000,0000,,We have this adaptive secondary mirror
Dialogue: 0,0:28:59.79,0:29:02.82,Default,,0000,0000,0000,,which is the deformable mirror.
Dialogue: 0,0:29:02.82,0:29:05.58,Default,,0000,0000,0000,,We have the primary, tertiary.
Dialogue: 0,0:29:05.58,0:29:06.90,Default,,0000,0000,0000,,That is clear already.
Dialogue: 0,0:29:06.90,0:29:11.52,Default,,0000,0000,0000,,So we have a laser box.
Dialogue: 0,0:29:11.52,0:29:15.24,Default,,0000,0000,0000,,The green things is the lasers themselfs.
Dialogue: 0,0:29:15.24,0:29:16.30,Default,,0000,0000,0000,,So that's how it looks like.
Dialogue: 0,0:29:16.30,0:29:18.18,Default,,0000,0000,0000,,We produce some laser beams.
Dialogue: 0,0:29:18.18,0:29:19.97,Default,,0000,0000,0000,,We have steering mirrors in there
Dialogue: 0,0:29:19.97,0:29:22.19,Default,,0000,0000,0000,,to get them into the right pattern on sky
Dialogue: 0,0:29:22.19,0:29:22.98,Default,,0000,0000,0000,,of course.
Dialogue: 0,0:29:22.98,0:29:24.33,Default,,0000,0000,0000,,We do have control cameras,
Dialogue: 0,0:29:24.33,0:29:25.87,Default,,0000,0000,0000,,if : Is the focus right?
Dialogue: 0,0:29:25.87,0:29:27.06,Default,,0000,0000,0000,,Is the position right?
Dialogue: 0,0:29:27.06,0:29:28.28,Default,,0000,0000,0000,,This is one control loop
Dialogue: 0,0:29:28.28,0:29:30.04,Default,,0000,0000,0000,,another control loop, another control loop
Dialogue: 0,0:29:30.04,0:29:31.59,Default,,0000,0000,0000,,an other control loop.
Dialogue: 0,0:29:31.59,0:29:33.14,Default,,0000,0000,0000,,The black thing is the shutter.
Dialogue: 0,0:29:33.14,0:29:35.03,Default,,0000,0000,0000,,Because we have to close this whole thing,
Dialogue: 0,0:29:35.03,0:29:36.87,Default,,0000,0000,0000,,when aircrafts are overhead,
Dialogue: 0,0:29:36.87,0:29:38.50,Default,,0000,0000,0000,,when satellites are overhead.
Dialogue: 0,0:29:38.50,0:29:40.12,Default,,0000,0000,0000,,So if you want to use this system,
Dialogue: 0,0:29:40.12,0:29:43.10,Default,,0000,0000,0000,,you have to, 6 weeks in advance, you have to
Dialogue: 0,0:29:43.10,0:29:45.81,Default,,0000,0000,0000,,put out your list of observable targets
Dialogue: 0,0:29:45.81,0:29:47.23,Default,,0000,0000,0000,,to some military agency.
Dialogue: 0,0:29:47.23,0:29:49.31,Default,,0000,0000,0000,,And they will tell you: Okay! Not Okay!
Dialogue: 0,0:29:49.31,0:29:51.84,Default,,0000,0000,0000,,Okay! Not Okay! Not Okay! Not Okay! Okay!
Dialogue: 0,0:29:51.84,0:29:54.60,Default,,0000,0000,0000,,Not Okay, meaning something is passing overhead.
Dialogue: 0,0:29:54.60,0:29:56.71,Default,,0000,0000,0000,,Hmm... what could this be?
Dialogue: 0,0:29:56.71,0:30:03.46,Default,,0000,0000,0000,,{\i1}laughing{\i0}
Dialogue: 0,0:30:03.46,0:30:04.95,Default,,0000,0000,0000,,Of course, at some point the lasers
Dialogue: 0,0:30:04.95,0:30:07.36,Default,,0000,0000,0000,,come down again in this cone shape.
Dialogue: 0,0:30:07.36,0:30:11.04,Default,,0000,0000,0000,,They will reach the primary mirror
Dialogue: 0,0:30:11.04,0:30:14.11,Default,,0000,0000,0000,,and ultimately it will end up
Dialogue: 0,0:30:14.11,0:30:15.21,Default,,0000,0000,0000,,in the wave front sensor
Dialogue: 0,0:30:15.21,0:30:18.27,Default,,0000,0000,0000,,which is much more complex than just this box.
Dialogue: 0,0:30:18.27,0:30:21.93,Default,,0000,0000,0000,,I showed you before.
Dialogue: 0,0:30:21.93,0:30:23.22,Default,,0000,0000,0000,,So there are aquisition cameras
Dialogue: 0,0:30:23.22,0:30:25.41,Default,,0000,0000,0000,,which detect are we at the right spot.
Dialogue: 0,0:30:25.41,0:30:27.99,Default,,0000,0000,0000,,Do the spots get onto the detector
Dialogue: 0,0:30:27.99,0:30:29.79,Default,,0000,0000,0000,,in a nice fashion.
Dialogue: 0,0:30:29.79,0:30:31.66,Default,,0000,0000,0000,,We do have to do this gating, remember?
Dialogue: 0,0:30:31.66,0:30:33.02,Default,,0000,0000,0000,,We have to open this shutter
Dialogue: 0,0:30:33.02,0:30:36.57,Default,,0000,0000,0000,,for the CCD when we want to record the light.
Dialogue: 0,0:30:36.57,0:30:39.66,Default,,0000,0000,0000,,This tiny fraction after 80ms.
Dialogue: 0,0:30:39.66,0:30:43.51,Default,,0000,0000,0000,,After the laser pulse has been launched.
Dialogue: 0,0:30:43.51,0:30:44.25,Default,,0000,0000,0000,,It's done in here.
Dialogue: 0,0:30:44.25,0:30:45.18,Default,,0000,0000,0000,,These are Pockel Cells.
Dialogue: 0,0:30:45.18,0:30:49.32,Default,,0000,0000,0000,,So its an electro optical effect.
Dialogue: 0,0:30:49.32,0:30:53.98,Default,,0000,0000,0000,,And then there is also something
Dialogue: 0,0:30:53.98,0:30:55.94,Default,,0000,0000,0000,,in addition because I said
Dialogue: 0,0:30:55.94,0:30:58.55,Default,,0000,0000,0000,,we can't do without the tip tilt
Dialogue: 0,0:30:58.55,0:31:00.05,Default,,0000,0000,0000,,and there is another unit in here
Dialogue: 0,0:31:00.05,0:31:03.06,Default,,0000,0000,0000,,that sits right in front of the science instrument
Dialogue: 0,0:31:03.06,0:31:04.80,Default,,0000,0000,0000,,that detects this tip tilt star,
Dialogue: 0,0:31:04.80,0:31:08.14,Default,,0000,0000,0000,,this additional star.
Dialogue: 0,0:31:08.14,0:31:11.02,Default,,0000,0000,0000,,So you have the laser wave front light,
Dialogue: 0,0:31:11.02,0:31:13.97,Default,,0000,0000,0000,,the green one, you do have this tip tilt light,
Dialogue: 0,0:31:13.97,0:31:15.05,Default,,0000,0000,0000,,the blue one,
Dialogue: 0,0:31:15.05,0:31:17.08,Default,,0000,0000,0000,,and you do have the actual science light
Dialogue: 0,0:31:17.08,0:31:20.25,Default,,0000,0000,0000,,from the object you want to observe on sky.
Dialogue: 0,0:31:20.25,0:31:22.80,Default,,0000,0000,0000,,That goes directly into this scientific instrument
Dialogue: 0,0:31:22.80,0:31:25.25,Default,,0000,0000,0000,,in the end.
Dialogue: 0,0:31:25.25,0:31:28.02,Default,,0000,0000,0000,,And then you have a lot of control things.
Dialogue: 0,0:31:28.02,0:31:29.93,Default,,0000,0000,0000,,Of course, you do need a common clock
Dialogue: 0,0:31:29.93,0:31:33.47,Default,,0000,0000,0000,,for this synchronization of all this pulses
Dialogue: 0,0:31:33.47,0:31:35.76,Default,,0000,0000,0000,,and the gating and what not.
Dialogue: 0,0:31:35.76,0:31:37.26,Default,,0000,0000,0000,,And of course you need the information
Dialogue: 0,0:31:37.26,0:31:40.26,Default,,0000,0000,0000,,for the tip tilt component and for the wave\Nfront
Dialogue: 0,0:31:40.26,0:31:41.44,Default,,0000,0000,0000,,into this computer
Dialogue: 0,0:31:41.44,0:31:44.11,Default,,0000,0000,0000,,which sends then all the slops
Dialogue: 0,0:31:44.11,0:31:45.76,Default,,0000,0000,0000,,- you remember we have to do this
Dialogue: 0,0:31:45.76,0:31:48.76,Default,,0000,0000,0000,,linear approximation pieces wise, yes -
Dialogue: 0,0:31:48.76,0:31:49.93,Default,,0000,0000,0000,,into the secondary mirror
Dialogue: 0,0:31:49.93,0:31:52.88,Default,,0000,0000,0000,,which than deforms in real time.
Dialogue: 0,0:31:52.88,0:31:57.12,Default,,0000,0000,0000,,And does this a thousand times a second.
Dialogue: 0,0:31:57.12,0:31:59.47,Default,,0000,0000,0000,,This is how it looks like.
Dialogue: 0,0:31:59.47,0:32:05.21,Default,,0000,0000,0000,,So when I am there I am roughly that tall.
Dialogue: 0,0:32:05.21,0:32:08.00,Default,,0000,0000,0000,,The two black tubes right in the middle,
Dialogue: 0,0:32:08.00,0:32:11.96,Default,,0000,0000,0000,,those are the two tubes which go up.
Dialogue: 0,0:32:11.96,0:32:14.71,Default,,0000,0000,0000,,Looks like this.
Dialogue: 0,0:32:14.71,0:32:17.53,Default,,0000,0000,0000,,So, this is how the components are distributed
Dialogue: 0,0:32:17.53,0:32:21.46,Default,,0000,0000,0000,,over the telescope... once back.. okay
Dialogue: 0,0:32:21.46,0:32:24.22,Default,,0000,0000,0000,,primary mirror, primary mirror,
Dialogue: 0,0:32:24.22,0:32:26.39,Default,,0000,0000,0000,,some instruments in the middle,
Dialogue: 0,0:32:26.39,0:32:28.41,Default,,0000,0000,0000,,some tertiary mirror,
Dialogue: 0,0:32:28.41,0:32:31.84,Default,,0000,0000,0000,,the secondaries, the adaptive ones up there.
Dialogue: 0,0:32:31.84,0:32:37.90,Default,,0000,0000,0000,,Yes, I hate to use this laser pointers.
Dialogue: 0,0:32:37.90,0:32:39.44,Default,,0000,0000,0000,,{\i1}laughing{\i0}
Dialogue: 0,0:32:39.44,0:32:40.69,Default,,0000,0000,0000,,Because I am always going like this... eee
Dialogue: 0,0:32:40.69,0:32:44.52,Default,,0000,0000,0000,,(green laser pointer on the slides)
Dialogue: 0,0:32:44.52,0:32:48.61,Default,,0000,0000,0000,,{\i1}laughing{\i0}
Dialogue: 0,0:32:48.61,0:32:52.94,Default,,0000,0000,0000,,That's my man! {\i1}laughing{\i0}
Dialogue: 0,0:32:52.94,0:32:54.65,Default,,0000,0000,0000,,So okay!
Dialogue: 0,0:32:54.65,0:32:58.44,Default,,0000,0000,0000,,So we do have the adaptive secondary
Dialogue: 0,0:32:58.44,0:33:00.94,Default,,0000,0000,0000,,up there and then it goes back on the
Dialogue: 0,0:33:00.94,0:33:02.86,Default,,0000,0000,0000,,tertiary down there and then it goes over
Dialogue: 0,0:33:02.86,0:33:04.58,Default,,0000,0000,0000,,into the science instrument,
Dialogue: 0,0:33:04.58,0:33:11.100,Default,,0000,0000,0000,,all the wave front sensors and what not.
Dialogue: 0,0:33:11.100,0:33:14.88,Default,,0000,0000,0000,,Again, we do have a laser system.
Dialogue: 0,0:33:14.88,0:33:16.76,Default,,0000,0000,0000,,We have to place somewhere a launch system
Dialogue: 0,0:33:16.76,0:33:19.70,Default,,0000,0000,0000,,for the laser, a dichroic to separate
Dialogue: 0,0:33:19.70,0:33:23.48,Default,,0000,0000,0000,,between the laser light, the tip tilt light\Nand the science light.
Dialogue: 0,0:33:23.48,0:33:25.46,Default,,0000,0000,0000,,We do have to have a wave front sensor
Dialogue: 0,0:33:25.46,0:33:27.53,Default,,0000,0000,0000,,to check how the wave front looks like.
Dialogue: 0,0:33:27.53,0:33:29.04,Default,,0000,0000,0000,,We do have to have this tip tilt control.
Dialogue: 0,0:33:29.04,0:33:29.89,Default,,0000,0000,0000,,We have calibration source.
Dialogue: 0,0:33:29.89,0:33:31.24,Default,,0000,0000,0000,,A calibration source would be nice
Dialogue: 0,0:33:31.24,0:33:33.51,Default,,0000,0000,0000,,to calibrate the system during daytime,
Dialogue: 0,0:33:33.51,0:33:38.26,Default,,0000,0000,0000,,aircraft detection, yes, satellite avoidance,
Dialogue: 0,0:33:38.26,0:33:41.28,Default,,0000,0000,0000,,-also an issue here- and a control software.
Dialogue: 0,0:33:41.28,0:33:43.84,Default,,0000,0000,0000,,There are many people just writing...
Dialogue: 0,0:33:43.84,0:33:45.83,Default,,0000,0000,0000,,...just haha... writing software for this.
Dialogue: 0,0:33:45.83,0:33:51.35,Default,,0000,0000,0000,,And this is really hard.
Dialogue: 0,0:33:51.35,0:33:53.18,Default,,0000,0000,0000,,Some are also on the conference.
Dialogue: 0,0:33:53.18,0:33:54.37,Default,,0000,0000,0000,,They don't want to be pointed out
Dialogue: 0,0:33:54.37,0:33:56.20,Default,,0000,0000,0000,,as I learned, but you will find them
Dialogue: 0,0:33:56.20,0:34:01.06,Default,,0000,0000,0000,,at the conference, if you look at the right places.
Dialogue: 0,0:34:01.06,0:34:05.70,Default,,0000,0000,0000,,That's where the laser box is located.
Dialogue: 0,0:34:05.70,0:34:09.45,Default,,0000,0000,0000,,Just next to it is the electronics rack.
Dialogue: 0,0:34:09.45,0:34:10.84,Default,,0000,0000,0000,,How does this thing look like?
Dialogue: 0,0:34:10.84,0:34:12.73,Default,,0000,0000,0000,,So that is one of our lasers.
Dialogue: 0,0:34:12.73,0:34:17.84,Default,,0000,0000,0000,,It's about 20 W. Don't get your finger in there.
Dialogue: 0,0:34:17.84,0:34:19.10,Default,,0000,0000,0000,,{\i1}laughing{\i0}
Dialogue: 0,0:34:19.10,0:34:20.94,Default,,0000,0000,0000,,It really hurts.
Dialogue: 0,0:34:20.94,0:34:25.33,Default,,0000,0000,0000,,(Did you try?) No!
Dialogue: 0,0:34:25.33,0:34:30.26,Default,,0000,0000,0000,,There is a mandatory annual laser training of course.
Dialogue: 0,0:34:30.26,0:34:34.68,Default,,0000,0000,0000,,Yes, if you want to have something\Nlike this at home,
Dialogue: 0,0:34:34.68,0:34:37.28,Default,,0000,0000,0000,,you do need a huge refrigerator next to it
Dialogue: 0,0:34:37.28,0:34:38.94,Default,,0000,0000,0000,,just for the cooling of that thing.
Dialogue: 0,0:34:38.94,0:34:41.58,Default,,0000,0000,0000,,This is nothing you want to have at home.
Dialogue: 0,0:34:41.58,0:34:46.42,Default,,0000,0000,0000,,Just because it's... that bulky... no..it's\Nnot..
Dialogue: 0,0:34:46.42,0:34:47.82,Default,,0000,0000,0000,,but actually when you do
Dialogue: 0,0:34:47.82,0:34:49.38,Default,,0000,0000,0000,,this green laser pointer thingy
Dialogue: 0,0:34:49.38,0:34:50.79,Default,,0000,0000,0000,,then there is always this always this:
Dialogue: 0,0:34:50.79,0:34:52.77,Default,,0000,0000,0000,,"Don't use this for more than 10 seconds."
Dialogue: 0,0:34:52.77,0:34:54.43,Default,,0000,0000,0000,,Because why? Because the crystal inside
Dialogue: 0,0:34:54.43,0:34:55.43,Default,,0000,0000,0000,,heats up.
Dialogue: 0,0:34:55.43,0:34:56.98,Default,,0000,0000,0000,,And if you can't dissipate that heat
Dialogue: 0,0:34:56.98,0:34:58.77,Default,,0000,0000,0000,,the crystal at some point breaks
Dialogue: 0,0:34:58.77,0:35:00.71,Default,,0000,0000,0000,,and then your laser pointer is broken.
Dialogue: 0,0:35:00.71,0:35:02.99,Default,,0000,0000,0000,,This thing gets continuously cooled.
Dialogue: 0,0:35:02.99,0:35:06.51,Default,,0000,0000,0000,,So, therefore it's a bit more expensive.
Dialogue: 0,0:35:06.51,0:35:08.96,Default,,0000,0000,0000,,{\i1}laughing{\i0}
Dialogue: 0,0:35:08.96,0:35:10.25,Default,,0000,0000,0000,,If you than put it up,
Dialogue: 0,0:35:10.25,0:35:12.19,Default,,0000,0000,0000,,so this is still on the lab table
Dialogue: 0,0:35:12.19,0:35:13.59,Default,,0000,0000,0000,,when it was integrated and tested
Dialogue: 0,0:35:13.59,0:35:15.53,Default,,0000,0000,0000,,and than at some point it gets put all
Dialogue: 0,0:35:15.53,0:35:17.82,Default,,0000,0000,0000,,in a box with all this control mirrors
Dialogue: 0,0:35:17.82,0:35:20.02,Default,,0000,0000,0000,,and cameras and what not.
Dialogue: 0,0:35:20.02,0:35:22.03,Default,,0000,0000,0000,,But finally you see in the middle
Dialogue: 0,0:35:22.03,0:35:23.52,Default,,0000,0000,0000,,on this picture there is
Dialogue: 0,0:35:23.52,0:35:26.01,Default,,0000,0000,0000,,a focusing lens and then you see
Dialogue: 0,0:35:26.01,0:35:29.30,Default,,0000,0000,0000,,these 3 tiny little beam coming out of there
Dialogue: 0,0:35:29.30,0:35:32.36,Default,,0000,0000,0000,,which than expand on sky in size
Dialogue: 0,0:35:32.36,0:35:36.09,Default,,0000,0000,0000,,of course when they are in 12 km height
Dialogue: 0,0:35:36.09,0:35:38.73,Default,,0000,0000,0000,,but that's how they come out of it.
Dialogue: 0,0:35:38.73,0:35:41.34,Default,,0000,0000,0000,,And if you install this in the telescope,
Dialogue: 0,0:35:41.34,0:35:42.87,Default,,0000,0000,0000,,you actually have to tilt the telescope,
Dialogue: 0,0:35:42.87,0:35:44.28,Default,,0000,0000,0000,,because otherwise you can't reach it.
Dialogue: 0,0:35:44.28,0:35:48.88,Default,,0000,0000,0000,,And then you need your climbing gear.
Dialogue: 0,0:35:48.88,0:35:50.52,Default,,0000,0000,0000,,So once you have produced the lasers,
Dialogue: 0,0:35:50.52,0:35:52.31,Default,,0000,0000,0000,,you need to propagate them to a through
Dialogue: 0,0:35:52.31,0:35:57.85,Default,,0000,0000,0000,,a dust tube onto a launch mirror,
Dialogue: 0,0:35:57.85,0:36:00.37,Default,,0000,0000,0000,,a folding mirror and from there to
Dialogue: 0,0:36:00.37,0:36:02.96,Default,,0000,0000,0000,,a launch mirror.
Dialogue: 0,0:36:02.96,0:36:06.46,Default,,0000,0000,0000,,Yes and then it looks like this!
Dialogue: 0,0:36:06.46,0:36:09.73,Default,,0000,0000,0000,,Okay, so the lasers come from here into that
Dialogue: 0,0:36:09.73,0:36:11.69,Default,,0000,0000,0000,,and then over to the other side
Dialogue: 0,0:36:11.69,0:36:14.86,Default,,0000,0000,0000,,over the secondary mirror and then
Dialogue: 0,0:36:14.86,0:36:17.92,Default,,0000,0000,0000,,being shot right up into space
Dialogue: 0,0:36:17.92,0:36:20.45,Default,,0000,0000,0000,,like this.
Dialogue: 0,0:36:20.45,0:36:23.95,Default,,0000,0000,0000,,Okay, so if you want to have that at home,
Dialogue: 0,0:36:23.95,0:36:27.02,Default,,0000,0000,0000,,.... eh... but I can tell you the whole facility
Dialogue: 0,0:36:27.02,0:36:31.98,Default,,0000,0000,0000,,does cost less than one fully equipped Eurofighter
Dialogue: 0,0:36:31.98,0:36:44.75,Default,,0000,0000,0000,,{\i1}laughing{\i0}\N{\i1}applause{\i0}
Dialogue: 0,0:36:44.75,0:36:48.47,Default,,0000,0000,0000,,Thank you for taking the hint.
Dialogue: 0,0:36:48.47,0:36:50.34,Default,,0000,0000,0000,,Yeah, that's how it looks like.
Dialogue: 0,0:36:50.34,0:36:53.26,Default,,0000,0000,0000,,It's.... yes it's... {\i1}laughing{\i0} ... yeah...
Dialogue: 0,0:36:53.26,0:36:56.62,Default,,0000,0000,0000,,{\i1}laughing{\i0}{\i1}applause{\i0} Okay?
Dialogue: 0,0:36:56.62,0:36:59.96,Default,,0000,0000,0000,,okay... I have to admit this are a bit longer exposers.
Dialogue: 0,0:36:59.96,0:37:01.42,Default,,0000,0000,0000,,It's not that bright and green
Dialogue: 0,0:37:01.42,0:37:04.45,Default,,0000,0000,0000,,when you are actually at the telescope up\Nthere.
Dialogue: 0,0:37:04.45,0:37:07.51,Default,,0000,0000,0000,,But if you have been in the dark long enough
Dialogue: 0,0:37:07.51,0:37:11.46,Default,,0000,0000,0000,,around ten minutes, then I really becomes bright.
Dialogue: 0,0:37:11.46,0:37:13.64,Default,,0000,0000,0000,,There is a little telescope that observes,
Dialogue: 0,0:37:13.64,0:37:15.86,Default,,0000,0000,0000,,where actually the spots are on sky.
Dialogue: 0,0:37:15.86,0:37:17.09,Default,,0000,0000,0000,,And if we have clear sky,
Dialogue: 0,0:37:17.09,0:37:19.26,Default,,0000,0000,0000,,then we have this constellation on the right.
Dialogue: 0,0:37:19.26,0:37:21.83,Default,,0000,0000,0000,,So that is how the lasers come up.
Dialogue: 0,0:37:21.83,0:37:25.33,Default,,0000,0000,0000,,As I said you do see them all the way up,
Dialogue: 0,0:37:25.33,0:37:26.99,Default,,0000,0000,0000,,but we are interested in the little dots
Dialogue: 0,0:37:26.99,0:37:27.49,Default,,0000,0000,0000,,at the end.
Dialogue: 0,0:37:27.49,0:37:28.91,Default,,0000,0000,0000,,You can barely see them.
Dialogue: 0,0:37:28.91,0:37:30.19,Default,,0000,0000,0000,,If there are high clouds,
Dialogue: 0,0:37:30.19,0:37:36.08,Default,,0000,0000,0000,,well than we produce something like this.
Dialogue: 0,0:37:36.08,0:37:39.00,Default,,0000,0000,0000,,We have the dichroic when the light comes\Nback down
Dialogue: 0,0:37:39.00,0:37:39.93,Default,,0000,0000,0000,,as said.
Dialogue: 0,0:37:39.93,0:37:42.35,Default,,0000,0000,0000,,Which separates the science light in red
Dialogue: 0,0:37:42.35,0:37:44.32,Default,,0000,0000,0000,,and the laser light in green.
Dialogue: 0,0:37:44.32,0:37:46.03,Default,,0000,0000,0000,,This is how it looks like.
Dialogue: 0,0:37:46.03,0:37:49.89,Default,,0000,0000,0000,,Actually the dichroic is right in front of\NSebatian there
Dialogue: 0,0:37:49.89,0:37:51.93,Default,,0000,0000,0000,,and from there it gets then reflected
Dialogue: 0,0:37:51.93,0:37:55.22,Default,,0000,0000,0000,,on a reflector and then up into the
Dialogue: 0,0:37:55.22,0:37:59.31,Default,,0000,0000,0000,,wave front sensing unit.
Dialogue: 0,0:37:59.31,0:38:03.99,Default,,0000,0000,0000,,So there is the dichroic, there is the reflector,
Dialogue: 0,0:38:03.99,0:38:06.42,Default,,0000,0000,0000,,and it goes over in this unit
Dialogue: 0,0:38:06.42,0:38:11.30,Default,,0000,0000,0000,,which is the wave front sensing unit
Dialogue: 0,0:38:11.30,0:38:13.35,Default,,0000,0000,0000,,which sits there, at the side.
Dialogue: 0,0:38:13.35,0:38:20.15,Default,,0000,0000,0000,,That's how it looks, when it gets installed.
Dialogue: 0,0:38:20.15,0:38:22.36,Default,,0000,0000,0000,,And that is how it looks inside.
Dialogue: 0,0:38:22.36,0:38:24.16,Default,,0000,0000,0000,,So you have the 3 laser beams coming
Dialogue: 0,0:38:24.16,0:38:26.62,Default,,0000,0000,0000,,from the side, from the sky, of course.
Dialogue: 0,0:38:26.62,0:38:27.72,Default,,0000,0000,0000,,You have patrol cameras
Dialogue: 0,0:38:27.72,0:38:30.03,Default,,0000,0000,0000,,which monitor where are these?
Dialogue: 0,0:38:30.03,0:38:32.57,Default,,0000,0000,0000,,Are they at the right spot?
Dialogue: 0,0:38:32.57,0:38:36.33,Default,,0000,0000,0000,,Do we have to steer the lasers a bit?
Dialogue: 0,0:38:36.33,0:38:42.16,Default,,0000,0000,0000,,Than we have some control for the position
Dialogue: 0,0:38:42.16,0:38:45.76,Default,,0000,0000,0000,,of the laser spots and the field.
Dialogue: 0,0:38:45.76,0:38:47.31,Default,,0000,0000,0000,,The Pockel cells are the ones
Dialogue: 0,0:38:47.31,0:38:49.52,Default,,0000,0000,0000,,that do this opening and closing in front
Dialogue: 0,0:38:49.52,0:38:50.23,Default,,0000,0000,0000,,of the shutter.
Dialogue: 0,0:38:50.23,0:38:52.09,Default,,0000,0000,0000,,You can't use a mechanic shutter in front
Dialogue: 0,0:38:52.09,0:38:52.89,Default,,0000,0000,0000,,of the CCD.
Dialogue: 0,0:38:52.89,0:38:55.28,Default,,0000,0000,0000,,We have to do this electro optically
Dialogue: 0,0:38:55.28,0:38:59.97,Default,,0000,0000,0000,,So you have a polarization of the laserbeams.
Dialogue: 0,0:38:59.97,0:39:03.44,Default,,0000,0000,0000,,And you have a polarizer... a cross polarizer
Dialogue: 0,0:39:03.44,0:39:05.42,Default,,0000,0000,0000,,and then you just turn the polarisation
Dialogue: 0,0:39:05.42,0:39:06.74,Default,,0000,0000,0000,,of the crystals.
Dialogue: 0,0:39:06.74,0:39:08.41,Default,,0000,0000,0000,,It's an electro optical effect
Dialogue: 0,0:39:08.41,0:39:10.70,Default,,0000,0000,0000,,and then it gets passed through
Dialogue: 0,0:39:10.70,0:39:12.70,Default,,0000,0000,0000,,or it gets blocked.
Dialogue: 0,0:39:12.70,0:39:15.54,Default,,0000,0000,0000,,Then you also of course have this lens slit arrays
Dialogue: 0,0:39:15.54,0:39:19.08,Default,,0000,0000,0000,,in there and then the CCD
Dialogue: 0,0:39:19.08,0:39:21.60,Default,,0000,0000,0000,,which actually records this dot pattern.
Dialogue: 0,0:39:21.60,0:39:23.47,Default,,0000,0000,0000,,You remember, this 4 by 4...
Dialogue: 0,0:39:23.47,0:39:25.54,Default,,0000,0000,0000,,well it's not 4 by 4 in our case we do
Dialogue: 0,0:39:25.54,0:39:28.66,Default,,0000,0000,0000,,have a bit more resolution.
Dialogue: 0,0:39:28.66,0:39:32.34,Default,,0000,0000,0000,,The sensory looks like this.
Dialogue: 0,0:39:32.34,0:39:35.59,Default,,0000,0000,0000,,This is actually a custom build CCD.
Dialogue: 0,0:39:35.59,0:39:37.17,Default,,0000,0000,0000,,Very special.
Dialogue: 0,0:39:37.17,0:39:38.60,Default,,0000,0000,0000,,The imaging area is in the middle
Dialogue: 0,0:39:38.60,0:39:40.99,Default,,0000,0000,0000,,and when you read out the thing,
Dialogue: 0,0:39:40.99,0:39:43.25,Default,,0000,0000,0000,,you split the image in half,
Dialogue: 0,0:39:43.25,0:39:44.72,Default,,0000,0000,0000,,you transfer it to the sides
Dialogue: 0,0:39:44.72,0:39:46.96,Default,,0000,0000,0000,,to the frame store area and than read it out.
Dialogue: 0,0:39:46.96,0:39:49.21,Default,,0000,0000,0000,,'Cause read out is slow, transfer is fast.
Dialogue: 0,0:39:49.21,0:39:51.38,Default,,0000,0000,0000,,And you have to do this a thousand times
Dialogue: 0,0:39:51.38,0:39:54.19,Default,,0000,0000,0000,,a second at very low read out noise,
Dialogue: 0,0:39:54.19,0:39:58.56,Default,,0000,0000,0000,,which is only 4 electron read out noise.
Dialogue: 0,0:39:58.56,0:40:01.11,Default,,0000,0000,0000,,For the experts here in the audience,
Dialogue: 0,0:40:01.11,0:40:05.03,Default,,0000,0000,0000,,this is very good.
Dialogue: 0,0:40:05.03,0:40:08.28,Default,,0000,0000,0000,,It's not many pixels but it's more than enough for us.
Dialogue: 0,0:40:08.28,0:40:09.73,Default,,0000,0000,0000,,So how does this look like?
Dialogue: 0,0:40:09.73,0:40:11.03,Default,,0000,0000,0000,,It looks like that!
Dialogue: 0,0:40:11.03,0:40:13.38,Default,,0000,0000,0000,,So there you have your pattern again,
Dialogue: 0,0:40:13.38,0:40:15.13,Default,,0000,0000,0000,,regularly spaces pattern of course
Dialogue: 0,0:40:15.13,0:40:19.31,Default,,0000,0000,0000,,from 3 laser guild stars you get 3 patterns
Dialogue: 0,0:40:19.31,0:40:21.90,Default,,0000,0000,0000,,and then you analyse, well, the position,
Dialogue: 0,0:40:21.90,0:40:24.23,Default,,0000,0000,0000,,the relative position, the absolute position
Dialogue: 0,0:40:24.23,0:40:26.49,Default,,0000,0000,0000,,of those stars on their grid,
Dialogue: 0,0:40:26.49,0:40:29.53,Default,,0000,0000,0000,,and somehow compute this slopes
Dialogue: 0,0:40:29.53,0:40:33.07,Default,,0000,0000,0000,,from there feed them back, compute then
Dialogue: 0,0:40:33.07,0:40:35.53,Default,,0000,0000,0000,,actually electrical information from them
Dialogue: 0,0:40:35.53,0:40:37.45,Default,,0000,0000,0000,,which you can than feed into your
Dialogue: 0,0:40:37.45,0:40:39.24,Default,,0000,0000,0000,,deformable mirror again
Dialogue: 0,0:40:39.24,0:40:42.95,Default,,0000,0000,0000,,which sits on top of the telescope
Dialogue: 0,0:40:42.95,0:40:47.18,Default,,0000,0000,0000,,and then hopefully everything works.
Dialogue: 0,0:40:47.18,0:40:49.78,Default,,0000,0000,0000,,This you can digest at home.\N{\i1}laughing{\i0}
Dialogue: 0,0:40:49.78,0:40:52.22,Default,,0000,0000,0000,,It's in the stream now so it will be
Dialogue: 0,0:40:52.22,0:40:54.33,Default,,0000,0000,0000,,saved for all eternity
Dialogue: 0,0:40:54.33,0:40:55.24,Default,,0000,0000,0000,,and all the aliens
Dialogue: 0,0:40:55.24,0:40:57.94,Default,,0000,0000,0000,,which record all the electromagnetic field
Dialogue: 0,0:40:57.94,0:41:00.79,Default,,0000,0000,0000,,from Bielefeld... (mumbling)
Dialogue: 0,0:41:00.79,0:41:02.05,Default,,0000,0000,0000,,{\i1}laughing{\i0}
Dialogue: 0,0:41:02.05,0:41:05.58,Default,,0000,0000,0000,,Anyway, so, just in short.
Dialogue: 0,0:41:05.58,0:41:08.55,Default,,0000,0000,0000,,There is down in green there is this thing
Dialogue: 0,0:41:08.55,0:41:12.14,Default,,0000,0000,0000,,that goes up from the lasers through
Dialogue: 0,0:41:12.14,0:41:14.66,Default,,0000,0000,0000,,some steering mirrors.
Dialogue: 0,0:41:14.66,0:41:19.71,Default,,0000,0000,0000,,We have diagnostics, then we got to focus
Dialogue: 0,0:41:19.71,0:41:21.53,Default,,0000,0000,0000,,check launch mirror one and launch mirror two
Dialogue: 0,0:41:21.53,0:41:24.58,Default,,0000,0000,0000,,onto sky and then we go back
Dialogue: 0,0:41:24.58,0:41:27.00,Default,,0000,0000,0000,,up there N1 is the primary mirror.
Dialogue: 0,0:41:27.00,0:41:29.10,Default,,0000,0000,0000,,And then we go through this whole chain
Dialogue: 0,0:41:29.10,0:41:31.74,Default,,0000,0000,0000,,and there are various control loops
Dialogue: 0,0:41:31.74,0:41:35.11,Default,,0000,0000,0000,,sitting in there.
Dialogue: 0,0:41:35.11,0:41:37.07,Default,,0000,0000,0000,,And all this things have to talk together
Dialogue: 0,0:41:37.07,0:41:40.72,Default,,0000,0000,0000,,on very high rates.
Dialogue: 0,0:41:40.72,0:41:44.58,Default,,0000,0000,0000,,Sometimes you see 1 kHz other things are a bit slower.
Dialogue: 0,0:41:44.58,0:41:50.03,Default,,0000,0000,0000,,This all needs highly sophisticated control software.
Dialogue: 0,0:41:50.03,0:41:51.95,Default,,0000,0000,0000,,And the programmers can be real proud
Dialogue: 0,0:41:51.95,0:41:54.05,Default,,0000,0000,0000,,of what they did in the past
Dialogue: 0,0:41:54.05,0:41:56.99,Default,,0000,0000,0000,,with all this control loops.
Dialogue: 0,0:41:56.99,0:42:00.20,Default,,0000,0000,0000,,The tip tilt is very... much much much easier,
Dialogue: 0,0:42:00.20,0:42:00.83,Default,,0000,0000,0000,,because all the...
Dialogue: 0,0:42:00.83,0:42:01.96,Default,,0000,0000,0000,,you remember this tip tilt
Dialogue: 0,0:42:01.96,0:42:03.40,Default,,0000,0000,0000,,so this all is moving around.
Dialogue: 0,0:42:03.40,0:42:06.03,Default,,0000,0000,0000,,So you have 4 quadrants at a little cell
Dialogue: 0,0:42:06.03,0:42:08.39,Default,,0000,0000,0000,,and it moves to somewhere up, down,
Dialogue: 0,0:42:08.39,0:42:09.06,Default,,0000,0000,0000,,left, right.
Dialogue: 0,0:42:09.06,0:42:10.76,Default,,0000,0000,0000,,You can easily detect that.
Dialogue: 0,0:42:10.76,0:42:14.28,Default,,0000,0000,0000,,That is feed into an array
Dialogue: 0,0:42:14.28,0:42:17.47,Default,,0000,0000,0000,,of 4 Avalanche Photon Diodes
Dialogue: 0,0:42:17.47,0:42:20.02,Default,,0000,0000,0000,,to actually record this and for that
Dialogue: 0,0:42:20.02,0:42:22.12,Default,,0000,0000,0000,,we don't need many photons.
Dialogue: 0,0:42:22.12,0:42:24.18,Default,,0000,0000,0000,,So this tip tilt star can comparably...
Dialogue: 0,0:42:24.18,0:42:28.13,Default,,0000,0000,0000,,be comparably dim.
Dialogue: 0,0:42:28.13,0:42:30.68,Default,,0000,0000,0000,,The calibration unit for the daytime calibration
Dialogue: 0,0:42:30.68,0:42:32.13,Default,,0000,0000,0000,,can be put into the beam,
Dialogue: 0,0:42:32.13,0:42:34.15,Default,,0000,0000,0000,,so this arms can swing over,
Dialogue: 0,0:42:34.15,0:42:35.75,Default,,0000,0000,0000,,over the primary mirror and then we can
Dialogue: 0,0:42:35.75,0:42:40.91,Default,,0000,0000,0000,,inject artificial stars via a hologram
Dialogue: 0,0:42:40.91,0:42:42.89,Default,,0000,0000,0000,,into the whole unit during daytime
Dialogue: 0,0:42:42.89,0:42:44.51,Default,,0000,0000,0000,,and calibrate this whole thing.
Dialogue: 0,0:42:44.51,0:42:48.56,Default,,0000,0000,0000,,And than yes, we are back here.
Dialogue: 0,0:42:48.56,0:42:52.21,Default,,0000,0000,0000,,This is how we look like.
Dialogue: 0,0:42:52.21,0:42:57.46,Default,,0000,0000,0000,,Maybe concentrate on this two areas first.
Dialogue: 0,0:42:57.46,0:43:00.75,Default,,0000,0000,0000,,I will flip back an forth many times.
Dialogue: 0,0:43:00.75,0:43:02.26,Default,,0000,0000,0000,,But, yeah, what is this?
Dialogue: 0,0:43:02.26,0:43:04.40,Default,,0000,0000,0000,,Are this two stars which are just fuzzy
Dialogue: 0,0:43:04.40,0:43:05.70,Default,,0000,0000,0000,,and dim?
Dialogue: 0,0:43:05.70,0:43:07.51,Default,,0000,0000,0000,,Or is this an extended object?
Dialogue: 0,0:43:07.51,0:43:09.48,Default,,0000,0000,0000,,The upper one may be a galaxy because it's
Dialogue: 0,0:43:09.48,0:43:11.03,Default,,0000,0000,0000,,elongated.
Dialogue: 0,0:43:11.03,0:43:13.97,Default,,0000,0000,0000,,Okay, concentrate on that.
Dialogue: 0,0:43:13.97,0:43:24.45,Default,,0000,0000,0000,,Well, it actually just a bunch of stars.
Dialogue: 0,0:43:24.45,0:43:26.10,Default,,0000,0000,0000,,And this is over a huge field.
Dialogue: 0,0:43:26.10,0:43:28.17,Default,,0000,0000,0000,,So the correction is not just in the middle
Dialogue: 0,0:43:28.17,0:43:30.57,Default,,0000,0000,0000,,but you can see also at the very edges
Dialogue: 0,0:43:30.57,0:43:33.04,Default,,0000,0000,0000,,of this image, we do see this improvement
Dialogue: 0,0:43:33.04,0:43:34.54,Default,,0000,0000,0000,,in image quality.
Dialogue: 0,0:43:34.54,0:43:39.48,Default,,0000,0000,0000,,Of course you can have the diagram, if you want.
Dialogue: 0,0:43:39.48,0:43:43.19,Default,,0000,0000,0000,,So the blue line is without the thing beam activated,
Dialogue: 0,0:43:43.19,0:43:44.30,Default,,0000,0000,0000,,open loop,
Dialogue: 0,0:43:44.30,0:43:46.35,Default,,0000,0000,0000,,and if we close the control loop, to do
Dialogue: 0,0:43:46.35,0:43:49.04,Default,,0000,0000,0000,,this measurement and correction in real time
Dialogue: 0,0:43:49.04,0:43:53.59,Default,,0000,0000,0000,,we do squeeze all the energy into a few pixels
Dialogue: 0,0:43:53.59,0:43:54.80,Default,,0000,0000,0000,,which of course also means
Dialogue: 0,0:43:54.80,0:43:57.73,Default,,0000,0000,0000,,our signal to noise level in a single pixel
Dialogue: 0,0:43:57.73,0:43:59.14,Default,,0000,0000,0000,,goes up tremendously.
Dialogue: 0,0:43:59.14,0:44:00.46,Default,,0000,0000,0000,,Meaning you can decrease
Dialogue: 0,0:44:00.46,0:44:03.32,Default,,0000,0000,0000,,your exposer time.
Dialogue: 0,0:44:03.32,0:44:06.20,Default,,0000,0000,0000,,Which is important if you want to observe\Ngalaxies
Dialogue: 0,0:44:06.20,0:44:09.35,Default,,0000,0000,0000,,at this telescopes
Dialogue: 0,0:44:09.35,0:44:12.48,Default,,0000,0000,0000,,it's 200 Dollars a minute.
Dialogue: 0,0:44:12.48,0:44:16.46,Default,,0000,0000,0000,,{\i1}laughing{\i0}
Dialogue: 0,0:44:16.46,0:44:18.37,Default,,0000,0000,0000,,It's not cheap.
Dialogue: 0,0:44:18.37,0:44:23.92,Default,,0000,0000,0000,,Okay, good so... the thing...
Dialogue: 0,0:44:23.92,0:44:27.52,Default,,0000,0000,0000,,just last week there was\Nanother commissioning run
Dialogue: 0,0:44:27.52,0:44:30.34,Default,,0000,0000,0000,,testing commissioning run for this system.
Dialogue: 0,0:44:30.34,0:44:34.42,Default,,0000,0000,0000,,And my colleges José Borelli and Lorenzo Busoni
Dialogue: 0,0:44:34.42,0:44:36.45,Default,,0000,0000,0000,,have done a nice video.
Dialogue: 0,0:44:36.45,0:44:38.81,Default,,0000,0000,0000,,The music btw. "hallo gamer"
Dialogue: 0,0:44:38.81,0:44:42.60,Default,,0000,0000,0000,,it's royalty for ears...
Dialogue: 0,0:44:42.60,0:44:46.04,Default,,0000,0000,0000,,If it was now darker therefore I asked,
Dialogue: 0,0:44:46.04,0:44:47.88,Default,,0000,0000,0000,,this would come up nicer,
Dialogue: 0,0:44:47.88,0:44:49.06,Default,,0000,0000,0000,,but let's see!
Dialogue: 0,0:44:49.06,0:44:50.88,Default,,0000,0000,0000,,There is sound hopefully,
Dialogue: 0,0:44:50.88,0:44:53.26,Default,,0000,0000,0000,,so the sound guys, let's see!
Dialogue: 0,0:46:40.72,0:47:00.02,Default,,0000,0000,0000,,{\i1}applause{\i0}
Dialogue: 0,0:47:00.02,0:47:02.54,Default,,0000,0000,0000,,Of course this a longer exposure.
Dialogue: 0,0:47:02.54,0:47:07.09,Default,,0000,0000,0000,,It's not that starwars like
Dialogue: 0,0:47:07.09,0:47:09.81,Default,,0000,0000,0000,,I would have loved to use some starwars
Dialogue: 0,0:47:09.81,0:47:13.35,Default,,0000,0000,0000,,tones along those. But you know, all those rights
Dialogue: 0,0:47:13.35,0:47:16.64,Default,,0000,0000,0000,,and... what not... yes... anyway!
Dialogue: 0,0:47:16.64,0:47:17.77,Default,,0000,0000,0000,,That's how it looks like.
Dialogue: 0,0:47:17.77,0:47:22.56,Default,,0000,0000,0000,,So you have 3 laser beams per eye.
Dialogue: 0,0:47:22.56,0:47:24.91,Default,,0000,0000,0000,,Remember, we have 2 telescopes on one mount.
Dialogue: 0,0:47:24.91,0:47:26.49,Default,,0000,0000,0000,,They look roughly in the same direction
Dialogue: 0,0:47:26.49,0:47:28.63,Default,,0000,0000,0000,,but still...
Dialogue: 0,0:47:28.63,0:47:31.46,Default,,0000,0000,0000,,So if you observe two telescopes
Dialogue: 0,0:47:31.46,0:47:39.64,Default,,0000,0000,0000,,at the same time it's only 100 dollars a minute.
Dialogue: 0,0:47:39.64,0:47:44.27,Default,,0000,0000,0000,,Yea, This is not so much the shiny part
Dialogue: 0,0:47:44.27,0:47:47.13,Default,,0000,0000,0000,,on the dome itself, but if you actually
Dialogue: 0,0:47:47.13,0:47:49.24,Default,,0000,0000,0000,,do stand on the mountain during night
Dialogue: 0,0:47:49.24,0:47:50.86,Default,,0000,0000,0000,,and are a bit dark adapted,
Dialogue: 0,0:47:50.86,0:47:54.80,Default,,0000,0000,0000,,you see the laser beams like that.
Dialogue: 0,0:47:54.80,0:47:57.23,Default,,0000,0000,0000,,And don't be fooled!
Dialogue: 0,0:47:57.23,0:47:59.77,Default,,0000,0000,0000,,If you are at the valley,
Dialogue: 0,0:47:59.77,0:48:02.56,Default,,0000,0000,0000,,or very far away you hardly see them.
Dialogue: 0,0:48:02.56,0:48:03.83,Default,,0000,0000,0000,,You don't see them at all.
Dialogue: 0,0:48:03.83,0:48:04.99,Default,,0000,0000,0000,,You see them there.
Dialogue: 0,0:48:04.99,0:48:08.08,Default,,0000,0000,0000,,If you are two kilometers off side already,
Dialogue: 0,0:48:08.08,0:48:10.65,Default,,0000,0000,0000,,it's merely a dim greenish something.
Dialogue: 0,0:48:10.65,0:48:13.39,Default,,0000,0000,0000,,If you are down in the valley 10 km off,
Dialogue: 0,0:48:13.39,0:48:14.64,Default,,0000,0000,0000,,you don't see them any more.
Dialogue: 0,0:48:14.64,0:48:17.46,Default,,0000,0000,0000,,If you take a camera, 5 minutes exposer, yes!
Dialogue: 0,0:48:17.46,0:48:18.92,Default,,0000,0000,0000,,But otherwise, No!
Dialogue: 0,0:48:18.92,0:48:20.18,Default,,0000,0000,0000,,There is no such thing as
Dialogue: 0,0:48:20.18,0:48:22.69,Default,,0000,0000,0000,,"The people in the valley down can see like
Dialogue: 0,0:48:22.69,0:48:29.35,Default,,0000,0000,0000,,these lasers pew pew every night.".. and no.
Dialogue: 0,0:48:29.35,0:48:37.33,Default,,0000,0000,0000,,Ok, which gets me to the last part.
Dialogue: 0,0:48:37.33,0:48:40.09,Default,,0000,0000,0000,,How, do you become
Dialogue: 0,0:48:40.09,0:48:45.95,Default,,0000,0000,0000,,and how do you work as a laser rocket scientist?
Dialogue: 0,0:48:45.95,0:48:48.10,Default,,0000,0000,0000,,Yes, I put this in the talk directly,
Dialogue: 0,0:48:48.10,0:48:50.66,Default,,0000,0000,0000,,because I do get this question in the Q&A, normally,
Dialogue: 0,0:48:50.66,0:48:52.69,Default,,0000,0000,0000,,when I talk about these things,
Dialogue: 0,0:48:52.69,0:48:53.67,Default,,0000,0000,0000,,and it's always like:
Dialogue: 0,0:48:53.67,0:48:58.66,Default,,0000,0000,0000,,"What do I need to do if I want to do this?"
Dialogue: 0,0:48:58.66,0:49:01.52,Default,,0000,0000,0000,,Maybe you have already an idea about this
Dialogue: 0,0:49:01.52,0:49:05.12,Default,,0000,0000,0000,,because you have seen\Nhow complex this thing is.
Dialogue: 0,0:49:05.12,0:49:12.86,Default,,0000,0000,0000,,And, there are so many things to do in these\Nkind of projects
Dialogue: 0,0:49:12.86,0:49:16.15,Default,,0000,0000,0000,,and on various levels, also in the administration,
Dialogue: 0,0:49:16.15,0:49:22.45,Default,,0000,0000,0000,,also for senior people, new people, maybe\Nmaster thesis works on that
Dialogue: 0,0:49:22.45,0:49:28.82,Default,,0000,0000,0000,,or bachelor, or PHD or then as a post-doc.
Dialogue: 0,0:49:28.82,0:49:30.16,Default,,0000,0000,0000,,It's very complex.
Dialogue: 0,0:49:30.16,0:49:34.15,Default,,0000,0000,0000,,Yes, and it's not only about just shooting\Nlasers in the end.
Dialogue: 0,0:49:34.15,0:49:39.25,Default,,0000,0000,0000,,Sometimes it's just about checking the cables
Dialogue: 0,0:49:39.25,0:49:41.02,Default,,0000,0000,0000,,It needs to be done.
Dialogue: 0,0:49:41.02,0:49:45.69,Default,,0000,0000,0000,,There is a tremendous amount of electronics\Nand electrics involved.
Dialogue: 0,0:49:45.69,0:49:52.24,Default,,0000,0000,0000,,There are all the mechanical components in\Nsuch a system are custom built.
Dialogue: 0,0:49:52.24,0:49:55.58,Default,,0000,0000,0000,,Either the institutes built it themselves
Dialogue: 0,0:49:55.58,0:49:59.21,Default,,0000,0000,0000,,or they give it out of house.
Dialogue: 0,0:49:59.21,0:50:01.32,Default,,0000,0000,0000,,There are these real time computers, for example.
Dialogue: 0,0:50:01.32,0:50:02.83,Default,,0000,0000,0000,,this is by the way our real time computer
Dialogue: 0,0:50:02.83,0:50:05.88,Default,,0000,0000,0000,,from micrograde, if you want to look that up.
Dialogue: 0,0:50:05.88,0:50:08.46,Default,,0000,0000,0000,,it's company. It builds these things.
Dialogue: 0,0:50:08.46,0:50:10.65,Default,,0000,0000,0000,,They need to be programmed.
Dialogue: 0,0:50:10.65,0:50:13.58,Default,,0000,0000,0000,,Oh, if actually somebody is here in the audience
Dialogue: 0,0:50:13.58,0:50:15.60,Default,,0000,0000,0000,,with real hard core experience on
Dialogue: 0,0:50:15.60,0:50:18.75,Default,,0000,0000,0000,,real time computing, coding and such things,
Dialogue: 0,0:50:18.75,0:50:20.59,Default,,0000,0000,0000,,do talk to me!
Dialogue: 0,0:50:20.59,0:50:23.54,Default,,0000,0000,0000,,{\i1}laughing{\i0}
Dialogue: 0,0:50:23.54,0:50:26.54,Default,,0000,0000,0000,,Yeah, this is how our software system looks like.
Dialogue: 0,0:50:26.54,0:50:31.84,Default,,0000,0000,0000,,A very small part of the GUIs. It's a lot of code
Dialogue: 0,0:50:31.84,0:50:35.01,Default,,0000,0000,0000,,and a lot of work and a lot of sleepless nights
Dialogue: 0,0:50:35.01,0:50:38.76,Default,,0000,0000,0000,,in front of these computers\Nand just testing it and testing it
Dialogue: 0,0:50:38.76,0:50:41.83,Default,,0000,0000,0000,,and then testing some more,\Nand testing even more.
Dialogue: 0,0:50:41.83,0:50:44.86,Default,,0000,0000,0000,,And, to be involved in these kind of projects,
Dialogue: 0,0:50:44.86,0:50:48.56,Default,,0000,0000,0000,,you don't need to be a laser physicist,
Dialogue: 0,0:50:48.56,0:50:51.48,Default,,0000,0000,0000,,because there is no one thing.
Dialogue: 0,0:50:51.48,0:50:54.89,Default,,0000,0000,0000,,If you want to take 3 messages\Nout of this, it's:
Dialogue: 0,0:50:54.89,0:50:57.06,Default,,0000,0000,0000,,it's a team effort, there are many tasks,
Dialogue: 0,0:50:57.06,0:51:01.50,Default,,0000,0000,0000,,and there are many jobs,\Nand you have to pick one.
Dialogue: 0,0:51:01.50,0:51:04.17,Default,,0000,0000,0000,,Because in this one job you do in these projects
Dialogue: 0,0:51:04.17,0:51:06.50,Default,,0000,0000,0000,,you have to be very, very, very good.
Dialogue: 0,0:51:06.50,0:51:09.75,Default,,0000,0000,0000,,Because there are other people that are very,\Nvery, very good.
Dialogue: 0,0:51:09.75,0:51:13.65,Default,,0000,0000,0000,,If you work in these kind of projects, if\Nyou meet a new person for the first time
Dialogue: 0,0:51:13.65,0:51:17.36,Default,,0000,0000,0000,,just assume that he or she knows\Neverything about this
Dialogue: 0,0:51:17.36,0:51:18.94,Default,,0000,0000,0000,,and you know nothing.
Dialogue: 0,0:51:18.94,0:51:24.13,Default,,0000,0000,0000,,You will quickly realize if that is true.
Dialogue: 0,0:51:24.13,0:51:26.32,Default,,0000,0000,0000,,But otherwise, if you assume it\Nthe other way round,
Dialogue: 0,0:51:26.32,0:51:28.73,Default,,0000,0000,0000,,you just make a fool of yourself, okay?
Dialogue: 0,0:51:28.73,0:51:29.85,Default,,0000,0000,0000,,Don't do that.
Dialogue: 0,0:51:29.85,0:51:34.17,Default,,0000,0000,0000,,People in science, second most important thing\Nif you really want go into this,
Dialogue: 0,0:51:34.17,0:51:38.74,Default,,0000,0000,0000,,people in science are just like\Npeople outside science
Dialogue: 0,0:51:38.74,0:51:42.43,Default,,0000,0000,0000,,meaning you will meet nice people\Nand you will meet.....
Dialogue: 0,0:51:42.43,0:51:44.80,Default,,0000,0000,0000,,{\i1}laughing{\i0}
Dialogue: 0,0:51:44.80,0:51:47.48,Default,,0000,0000,0000,,just like in life.
Dialogue: 0,0:51:47.48,0:51:52.47,Default,,0000,0000,0000,,It's not that these things are spheres\Nwhere people are, you know
Dialogue: 0,0:51:52.47,0:51:57.18,Default,,0000,0000,0000,,floating above the lab surface and nice coloured.
Dialogue: 0,0:51:57.18,0:52:00.82,Default,,0000,0000,0000,,No, it's hard work.
Dialogue: 0,0:52:00.82,0:52:04.83,Default,,0000,0000,0000,,And if you actually go into this\Nlike study physics
Dialogue: 0,0:52:04.83,0:52:08.64,Default,,0000,0000,0000,,or maybe if you want to construct this,
Dialogue: 0,0:52:08.64,0:52:10.48,Default,,0000,0000,0000,,of course all the drawings are done by
Dialogue: 0,0:52:10.48,0:52:13.34,Default,,0000,0000,0000,,people how have learned this in there studies,
Dialogue: 0,0:52:13.34,0:52:16.81,Default,,0000,0000,0000,,so "Maschinenbau" what ever...
Dialogue: 0,0:52:16.81,0:52:18.21,Default,,0000,0000,0000,,Go for that one.
Dialogue: 0,0:52:18.21,0:52:21.08,Default,,0000,0000,0000,,Building optics needs optics experience.
Dialogue: 0,0:52:21.08,0:52:23.52,Default,,0000,0000,0000,,If you want to actually build stuff,
Dialogue: 0,0:52:23.52,0:52:26.08,Default,,0000,0000,0000,,well, there are many people in this institutes
Dialogue: 0,0:52:26.08,0:52:28.10,Default,,0000,0000,0000,,or universities who work
Dialogue: 0,0:52:28.10,0:52:30.50,Default,,0000,0000,0000,,in the mechanical fabrication departments
Dialogue: 0,0:52:30.50,0:52:31.61,Default,,0000,0000,0000,,or electronics departments.
Dialogue: 0,0:52:31.61,0:52:35.46,Default,,0000,0000,0000,,They just do PCB layouting all the time.
Dialogue: 0,0:52:35.46,0:52:38.37,Default,,0000,0000,0000,,But this things do need sophisticated electronics
Dialogue: 0,0:52:38.37,0:52:40.14,Default,,0000,0000,0000,,and this all custom built.
Dialogue: 0,0:52:40.14,0:52:42.16,Default,,0000,0000,0000,,This is nothing you can buy of the shelf.
Dialogue: 0,0:52:42.16,0:52:45.30,Default,,0000,0000,0000,,Nothing of it! Almost nothing.
Dialogue: 0,0:52:45.30,0:52:46.50,Default,,0000,0000,0000,,And this means you might end up
Dialogue: 0,0:52:46.50,0:52:48.82,Default,,0000,0000,0000,,with something equally cool.
Dialogue: 0,0:52:48.82,0:52:51.10,Default,,0000,0000,0000,,It's not that you can have this one thing
Dialogue: 0,0:52:51.10,0:52:53.83,Default,,0000,0000,0000,,and then BAM ten years later you will be
Dialogue: 0,0:52:53.83,0:52:56.83,Default,,0000,0000,0000,,the laser-rocket scientist. You won't!
Dialogue: 0,0:52:56.83,0:52:58.74,Default,,0000,0000,0000,,You might become one
Dialogue: 0,0:52:58.74,0:53:01.82,Default,,0000,0000,0000,,and then even after 10 years,
Dialogue: 0,0:53:01.82,0:53:04.01,Default,,0000,0000,0000,,you might realize this is not the thing
Dialogue: 0,0:53:04.01,0:53:07.66,Default,,0000,0000,0000,,you want to do forever.
Dialogue: 0,0:53:07.66,0:53:09.38,Default,,0000,0000,0000,,So I have to correct
Dialogue: 0,0:53:09.38,0:53:10.90,Default,,0000,0000,0000,,the introduction in one point:
Dialogue: 0,0:53:10.90,0:53:12.75,Default,,0000,0000,0000,,I'm no longer working there.
Dialogue: 0,0:53:12.75,0:53:14.82,Default,,0000,0000,0000,,I recently left.
Dialogue: 0,0:53:14.82,0:53:17.85,Default,,0000,0000,0000,,I'm now have my own company.
Dialogue: 0,0:53:17.85,0:53:19.27,Default,,0000,0000,0000,,I'm still involved in these things.
Dialogue: 0,0:53:19.27,0:53:21.71,Default,,0000,0000,0000,,I do calculations for this kinds of things,
Dialogue: 0,0:53:21.71,0:53:23.52,Default,,0000,0000,0000,,but I'm not at an institute any more,
Dialogue: 0,0:53:23.52,0:53:25.90,Default,,0000,0000,0000,,because I decided for example for me
Dialogue: 0,0:53:25.90,0:53:29.19,Default,,0000,0000,0000,,that the contract conditions in this type
Dialogue: 0,0:53:29.19,0:53:33.44,Default,,0000,0000,0000,,of scientific work are not of the type,
Dialogue: 0,0:53:33.44,0:53:38.40,Default,,0000,0000,0000,,which I want to live with any more.
Dialogue: 0,0:53:38.40,0:53:40.50,Default,,0000,0000,0000,,Like one year contracts.
Dialogue: 0,0:53:40.50,0:53:49.22,Default,,0000,0000,0000,,{\i1}applause{\i0}
Dialogue: 0,0:53:49.22,0:53:51.76,Default,,0000,0000,0000,,And so there are many ways\Nof being involved in this
Dialogue: 0,0:53:51.76,0:53:53.97,Default,,0000,0000,0000,,and don't just... don't just\Nfocus on the this!
Dialogue: 0,0:53:53.97,0:53:56.71,Default,,0000,0000,0000,,Focus on what you really want to do and
Dialogue: 0,0:53:56.71,0:53:59.44,Default,,0000,0000,0000,,you might end up in this
Dialogue: 0,0:53:59.44,0:54:00.65,Default,,0000,0000,0000,,and if you don't,
Dialogue: 0,0:54:00.65,0:54:03.56,Default,,0000,0000,0000,,well you do something equally cool.
Dialogue: 0,0:55:52.88,0:55:56.73,Default,,0000,0000,0000,,All right! Questions?
Dialogue: 0,0:55:56.73,0:56:04.80,Default,,0000,0000,0000,,{\i1}applause{\i0}
Dialogue: 0,0:56:04.80,0:56:06.84,Default,,0000,0000,0000,,Herald: Okay, first of all
Dialogue: 0,0:56:06.84,0:56:10.45,Default,,0000,0000,0000,,thank you for our daily dosis of lasers.
Dialogue: 0,0:56:10.45,0:56:13.73,Default,,0000,0000,0000,,I have said... Ich hab keine Zeit...
Dialogue: 0,0:56:13.73,0:56:16.59,Default,,0000,0000,0000,,cause we have really not much time left for Q&A,
Dialogue: 0,0:56:16.59,0:56:19.53,Default,,0000,0000,0000,,so I'm first asking the signal angel,
Dialogue: 0,0:56:19.53,0:56:21.41,Default,,0000,0000,0000,,if there are any questions from the internet,
Dialogue: 0,0:56:21.41,0:56:25.88,Default,,0000,0000,0000,,because... was that a 2? 2! ok.
Dialogue: 0,0:56:25.88,0:56:28.67,Default,,0000,0000,0000,,because this people can't ask questions afterwards,\Nsoo...
Dialogue: 0,0:56:28.67,0:56:31.33,Default,,0000,0000,0000,,Peter: I'll be all congress and\Nif you want to reach me
Dialogue: 0,0:56:31.33,0:56:35.70,Default,,0000,0000,0000,,directly 7319 is this telephone.
Dialogue: 0,0:56:35.70,0:56:39.03,Default,,0000,0000,0000,,Herald: Ok, the signal angel questions.
Dialogue: 0,0:56:39.03,0:56:41.13,Default,,0000,0000,0000,,Signal A.: Yeah, the first question from the\Ninternet was:
Dialogue: 0,0:56:41.13,0:56:43.56,Default,,0000,0000,0000,,How strong the laser actually is
Dialogue: 0,0:56:43.56,0:56:45.51,Default,,0000,0000,0000,,or if it could be any danger for something
Dialogue: 0,0:56:45.51,0:56:47.38,Default,,0000,0000,0000,,in the vicinity?
Dialogue: 0,0:56:47.38,0:56:48.44,Default,,0000,0000,0000,,Peter: Actually, no!
Dialogue: 0,0:56:48.44,0:56:51.21,Default,,0000,0000,0000,,So we shoot up around 15 to 20 W
Dialogue: 0,0:56:51.21,0:56:53.29,Default,,0000,0000,0000,,per laser beam.
Dialogue: 0,0:56:53.29,0:56:55.58,Default,,0000,0000,0000,,If there was actually a plane flying through
Dialogue: 0,0:56:55.58,0:56:58.41,Default,,0000,0000,0000,,our laser beam,
Dialogue: 0,0:56:58.41,0:57:01.38,Default,,0000,0000,0000,,then nothing happens to the pilots.
Dialogue: 0,0:57:01.38,0:57:03.04,Default,,0000,0000,0000,,They don't get blinded or what not,
Dialogue: 0,0:57:03.04,0:57:06.29,Default,,0000,0000,0000,,because it's di... the beamsize at that altitude
Dialogue: 0,0:57:06.29,0:57:09.07,Default,,0000,0000,0000,,is so big already.. they will of course look like:
Dialogue: 0,0:57:09.07,0:57:10.71,Default,,0000,0000,0000,,"Errr what is this?"
Dialogue: 0,0:57:10.71,0:57:12.72,Default,,0000,0000,0000,,And that's what we do not want,
Dialogue: 0,0:57:12.72,0:57:14.47,Default,,0000,0000,0000,,because then they might push some other buttons
Dialogue: 0,0:57:14.47,0:57:16.66,Default,,0000,0000,0000,,which they are not suppose to push.
Dialogue: 0,0:57:16.66,0:57:17.75,Default,,0000,0000,0000,,{\i1}laughing{\i0}
Dialogue: 0,0:57:17.75,0:57:20.27,Default,,0000,0000,0000,,If you of course work directly at the system,
Dialogue: 0,0:57:20.27,0:57:21.20,Default,,0000,0000,0000,,you have to maintain it,
Dialogue: 0,0:57:21.20,0:57:24.14,Default,,0000,0000,0000,,you open it, you have to align the lasers
Dialogue: 0,0:57:24.14,0:57:27.56,Default,,0000,0000,0000,,and what not beyond there self aligning capabilities,
Dialogue: 0,0:57:27.56,0:57:29.62,Default,,0000,0000,0000,,you do have to wear\Nall this protective laser goggles
Dialogue: 0,0:57:29.62,0:57:32.14,Default,,0000,0000,0000,,and what not, because if you do...
Dialogue: 0,0:57:32.14,0:57:35.36,Default,,0000,0000,0000,,if you don't you do have instant eye damage.
Dialogue: 0,0:57:35.36,0:57:39.19,Default,,0000,0000,0000,,It is not... no its instant.
Dialogue: 0,0:57:39.19,0:57:41.40,Default,,0000,0000,0000,,You might not see it instantly.
Dialogue: 0,0:57:41.40,0:57:45.16,Default,,0000,0000,0000,,But the instant... it's there instantly, period.
Dialogue: 0,0:57:45.16,0:57:48.29,Default,,0000,0000,0000,,So really, folks, don't experiment on this
Dialogue: 0,0:57:48.29,0:57:49.59,Default,,0000,0000,0000,,laser stuff at home,
Dialogue: 0,0:57:49.59,0:57:53.32,Default,,0000,0000,0000,,if you are not following basic\Nlaser safety rules.
Dialogue: 0,0:57:53.32,0:57:56.29,Default,,0000,0000,0000,,Not prying this things from the DVD burners
Dialogue: 0,0:57:56.29,0:58:00.54,Default,,0000,0000,0000,,or no blue ray thingys "uuh does it really work?"
Dialogue: 0,0:58:00.54,0:58:02.03,Default,,0000,0000,0000,,Just, just don't!
Dialogue: 0,0:58:02.03,0:58:05.33,Default,,0000,0000,0000,,Your eyesight is not worth it. period.
Dialogue: 0,0:58:05.33,0:58:08.08,Default,,0000,0000,0000,,It's not!
Dialogue: 0,0:58:08.08,0:58:10.85,Default,,0000,0000,0000,,Herald: Please remember to cover\Nyour still working eye!
Dialogue: 0,0:58:10.85,0:58:13.50,Default,,0000,0000,0000,,Peter: Yeah... only look into the laser\Nbeam
Dialogue: 0,0:58:13.50,0:58:16.13,Default,,0000,0000,0000,,with your remaining eye.
Dialogue: 0,0:58:16.13,0:58:17.49,Default,,0000,0000,0000,,Herald: The other question?
Dialogue: 0,0:58:17.49,0:58:20.04,Default,,0000,0000,0000,,Signal A. :And the second question from the internet
Dialogue: 0,0:58:20.04,0:58:21.94,Default,,0000,0000,0000,,was... It's actually commenting that,
Dialogue: 0,0:58:21.94,0:58:24.23,Default,,0000,0000,0000,,this was a very cool concept already been used
Dialogue: 0,0:58:24.23,0:58:26.52,Default,,0000,0000,0000,,and where do you see this going
Dialogue: 0,0:58:26.52,0:58:28.85,Default,,0000,0000,0000,,in the next 10 years, so what's the outlook
Dialogue: 0,0:58:28.85,0:58:31.82,Default,,0000,0000,0000,,for observation from the Earth's surface
Dialogue: 0,0:58:31.82,0:58:33.25,Default,,0000,0000,0000,,in the next 10 years?
Dialogue: 0,0:58:33.25,0:58:34.57,Default,,0000,0000,0000,,Peter: Oh, of course
Dialogue: 0,0:58:34.57,0:58:36.09,Default,,0000,0000,0000,,the telescopes will get bigger and bigger.
Dialogue: 0,0:58:36.09,0:58:38.17,Default,,0000,0000,0000,,The next generation of the telescope is coming up
Dialogue: 0,0:58:38.17,0:58:39.66,Default,,0000,0000,0000,,in the 2020s.
Dialogue: 0,0:58:39.66,0:58:41.37,Default,,0000,0000,0000,,The European Extremely Large Telescope
Dialogue: 0,0:58:41.37,0:58:45.20,Default,,0000,0000,0000,,will be about roughly around\N40 meters in diameter.
Dialogue: 0,0:58:45.20,0:58:47.22,Default,,0000,0000,0000,,These are so huge they can't work in
Dialogue: 0,0:58:47.22,0:58:49.25,Default,,0000,0000,0000,,seeing limited operation any more.
Dialogue: 0,0:58:49.25,0:58:54.03,Default,,0000,0000,0000,,They do have to have laser AO all the time.
Dialogue: 0,0:58:54.03,0:58:55.61,Default,,0000,0000,0000,,It will look similar to this.
Dialogue: 0,0:58:55.61,0:58:57.35,Default,,0000,0000,0000,,So this is in that sense also
Dialogue: 0,0:58:57.35,0:58:58.65,Default,,0000,0000,0000,,a technology demonstrator.
Dialogue: 0,0:58:58.65,0:59:01.91,Default,,0000,0000,0000,,There will be a combined thing.
Dialogue: 0,0:59:01.91,0:59:03.85,Default,,0000,0000,0000,,You may remember this diagram
Dialogue: 0,0:59:03.85,0:59:06.26,Default,,0000,0000,0000,,with the one sodium laser in the middle
Dialogue: 0,0:59:06.26,0:59:07.74,Default,,0000,0000,0000,,and the others outside.
Dialogue: 0,0:59:07.74,0:59:09.32,Default,,0000,0000,0000,,So these combined things.
Dialogue: 0,0:59:09.32,0:59:12.24,Default,,0000,0000,0000,,And then you can also imagine something,
Dialogue: 0,0:59:12.24,0:59:13.87,Default,,0000,0000,0000,,that you probe different heights
Dialogue: 0,0:59:13.87,0:59:14.91,Default,,0000,0000,0000,,in the atmosphere,
Dialogue: 0,0:59:14.91,0:59:18.13,Default,,0000,0000,0000,,because you do have different turbulence layers
Dialogue: 0,0:59:18.13,0:59:22.48,Default,,0000,0000,0000,,and all of these then have their own
Dialogue: 0,0:59:22.48,0:59:23.75,Default,,0000,0000,0000,,deformable mirror.
Dialogue: 0,0:59:23.75,0:59:25.66,Default,,0000,0000,0000,,So it's a very comp... gets a very complex\Nset,
Dialogue: 0,0:59:25.66,0:59:29.46,Default,,0000,0000,0000,,a multi conjugate AO as it's called.
Dialogue: 0,0:59:29.46,0:59:30.70,Default,,0000,0000,0000,,And then there are of course
Dialogue: 0,0:59:30.70,0:59:33.94,Default,,0000,0000,0000,,new... there is research being done on
Dialogue: 0,0:59:33.94,0:59:36.95,Default,,0000,0000,0000,,how to detect this wave front
Dialogue: 0,0:59:36.95,0:59:38.09,Default,,0000,0000,0000,,most efficently.
Dialogue: 0,0:59:38.09,0:59:40.38,Default,,0000,0000,0000,,And there is a so called thing called
Dialogue: 0,0:59:40.38,0:59:42.41,Default,,0000,0000,0000,,the pyramid sensor.
Dialogue: 0,0:59:42.41,0:59:44.23,Default,,0000,0000,0000,,You can look for that, also
Dialogue: 0,0:59:44.23,0:59:46.22,Default,,0000,0000,0000,,we do have one in our system.
Dialogue: 0,0:59:46.22,0:59:47.73,Default,,0000,0000,0000,,And this is very efficient.
Dialogue: 0,0:59:47.73,0:59:49.68,Default,,0000,0000,0000,,So it takes much less photons
Dialogue: 0,0:59:49.68,0:59:52.75,Default,,0000,0000,0000,,to get to the same signal to noise level.
Dialogue: 0,0:59:52.75,0:59:55.74,Default,,0000,0000,0000,,This is active research and... well...
Dialogue: 0,0:59:55.74,0:59:58.14,Default,,0000,0000,0000,,Every major telescope of course now has this.
Dialogue: 0,0:59:58.14,1:00:00.40,Default,,0000,0000,0000,,And every big telescopes in the future
Dialogue: 0,1:00:00.40,1:00:04.87,Default,,0000,0000,0000,,will have this all over the place.
Dialogue: 0,1:00:04.87,1:00:09.27,Default,,0000,0000,0000,,Herald: Okay, we're completely out of time.\NAgain.
Dialogue: 0,1:00:09.27,1:00:10.58,Default,,0000,0000,0000,,Again, so thank you very much.
Dialogue: 0,1:00:10.58,1:00:12.07,Default,,0000,0000,0000,,Peter: Thank you!
Dialogue: 0,1:00:12.07,1:00:17.49,Default,,0000,0000,0000,,{\i1}applause{\i0}
Dialogue: 0,1:00:17.49,1:00:22.85,Default,,0000,0000,0000,,{\i1}postroll music{\i0}
Dialogue: 0,1:00:22.85,1:00:29.00,Default,,0000,0000,0000,,subtitles created by c3subtitles.de\Nin the year 2016. Join, and help us!