[Script Info]
Title: 
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:00.76,0:00:05.10,Default,,0000,0000,0000,,Space, the final frontier.
Dialogue: 0,0:00:05.10,0:00:09.62,Default,,0000,0000,0000,,I first heard these words\Nwhen I was just six years old,
Dialogue: 0,0:00:09.62,0:00:12.07,Default,,0000,0000,0000,,and I was completely inspired.
Dialogue: 0,0:00:12.07,0:00:14.45,Default,,0000,0000,0000,,I wanted to explore strange new worlds.
Dialogue: 0,0:00:14.45,0:00:16.25,Default,,0000,0000,0000,,I wanted to seek out new life.
Dialogue: 0,0:00:16.25,0:00:20.19,Default,,0000,0000,0000,,I wanted to see everything\Nthat the universe had to offer.
Dialogue: 0,0:00:20.19,0:00:23.93,Default,,0000,0000,0000,,And those dreams, those words,\Nthey took me on a journey,
Dialogue: 0,0:00:23.93,0:00:25.42,Default,,0000,0000,0000,,a journey of discovery,
Dialogue: 0,0:00:25.42,0:00:27.49,Default,,0000,0000,0000,,through school, through university,
Dialogue: 0,0:00:27.49,0:00:31.95,Default,,0000,0000,0000,,to do a PhD and finally to become\Na professional astronomer.
Dialogue: 0,0:00:31.95,0:00:35.37,Default,,0000,0000,0000,,Now I learned two amazing things,\None slightly unfortunate,
Dialogue: 0,0:00:35.37,0:00:38.43,Default,,0000,0000,0000,,when I was doing my PhD.
Dialogue: 0,0:00:38.43,0:00:40.84,Default,,0000,0000,0000,,I learned that the reality was
Dialogue: 0,0:00:40.84,0:00:45.62,Default,,0000,0000,0000,,I wouldn't be piloting a starship\Nany time soon.
Dialogue: 0,0:00:45.62,0:00:50.30,Default,,0000,0000,0000,,But I also learned that the universe\Nis strange, wonderful, and vast,
Dialogue: 0,0:00:50.30,0:00:53.50,Default,,0000,0000,0000,,actually too vast to be\Nexplored by spaceship.
Dialogue: 0,0:00:53.50,0:00:58.14,Default,,0000,0000,0000,,And so I turned my attention\Nto astronomy, to using telescopes.
Dialogue: 0,0:00:58.14,0:01:01.35,Default,,0000,0000,0000,,Now, I show you before you\Nan image of the night sky.
Dialogue: 0,0:01:01.35,0:01:03.26,Default,,0000,0000,0000,,You might see it anywhere in the world.
Dialogue: 0,0:01:03.26,0:01:07.71,Default,,0000,0000,0000,,And all of these stars are part\Nof our local galaxy, the Milky Way.
Dialogue: 0,0:01:07.71,0:01:10.67,Default,,0000,0000,0000,,Now if you were to go\Nto a darker part of the sky,
Dialogue: 0,0:01:10.67,0:01:12.92,Default,,0000,0000,0000,,a nice dark site, perhaps in the desert,
Dialogue: 0,0:01:12.92,0:01:15.56,Default,,0000,0000,0000,,you might see the center\Nof our Milky Way galaxy
Dialogue: 0,0:01:15.56,0:01:18.66,Default,,0000,0000,0000,,spread out before you,\Nhundreds of billions of stars.
Dialogue: 0,0:01:18.66,0:01:20.61,Default,,0000,0000,0000,,And it's a very beautiful image.
Dialogue: 0,0:01:20.61,0:01:22.02,Default,,0000,0000,0000,,It's colorful.
Dialogue: 0,0:01:22.02,0:01:25.70,Default,,0000,0000,0000,,And again, this is just a local corner\Nof our universe.
Dialogue: 0,0:01:25.70,0:01:30.16,Default,,0000,0000,0000,,You can see there's a sort of strange\Ndark dust across it.
Dialogue: 0,0:01:30.16,0:01:31.16,Default,,0000,0000,0000,,Now, that is local dust
Dialogue: 0,0:01:31.16,0:01:33.68,Default,,0000,0000,0000,,that's obscuring the light of the stars.
Dialogue: 0,0:01:33.68,0:01:35.11,Default,,0000,0000,0000,,But we can do a pretty good job.
Dialogue: 0,0:01:35.11,0:01:38.61,Default,,0000,0000,0000,,Just with our own eyes, we can explore\Nour little corner of the universe.
Dialogue: 0,0:01:38.61,0:01:40.10,Default,,0000,0000,0000,,It's possible to do better.
Dialogue: 0,0:01:40.10,0:01:44.30,Default,,0000,0000,0000,,You can use wonderful telescopes\Nlike the Hubble space Telescope.
Dialogue: 0,0:01:44.30,0:01:46.55,Default,,0000,0000,0000,,Now astronomers have\Nput together this image.
Dialogue: 0,0:01:46.55,0:01:48.32,Default,,0000,0000,0000,,It's called the Hubble Deep Field,
Dialogue: 0,0:01:48.32,0:01:52.98,Default,,0000,0000,0000,,and they've spent hundreds of hours\Nobserving just a tiny patch of the sky
Dialogue: 0,0:01:52.98,0:01:55.77,Default,,0000,0000,0000,,no larger than your thumbnail\Nheld at arm's length.
Dialogue: 0,0:01:55.77,0:01:56.91,Default,,0000,0000,0000,,And in this image
Dialogue: 0,0:01:56.91,0:01:58.62,Default,,0000,0000,0000,,you can see thousands of galaxies,
Dialogue: 0,0:01:58.62,0:02:02.19,Default,,0000,0000,0000,,and we know that there must be\Nhundreds of millions, billions of galaxies
Dialogue: 0,0:02:02.19,0:02:03.51,Default,,0000,0000,0000,,in the entire universe,
Dialogue: 0,0:02:03.51,0:02:06.21,Default,,0000,0000,0000,,some like our own and some very different.
Dialogue: 0,0:02:06.21,0:02:08.83,Default,,0000,0000,0000,,So you think, okay, well,\NI can continue this journey.
Dialogue: 0,0:02:08.83,0:02:11.48,Default,,0000,0000,0000,,This is easy. I can just use\Na very powerful telescope
Dialogue: 0,0:02:11.48,0:02:14.11,Default,,0000,0000,0000,,and just look at the sky, no problem.
Dialogue: 0,0:02:14.11,0:02:18.12,Default,,0000,0000,0000,,It's actually really missing out\Nif we just do that.
Dialogue: 0,0:02:18.12,0:02:20.87,Default,,0000,0000,0000,,Now, that's because everything\NI've talked about so far
Dialogue: 0,0:02:20.87,0:02:24.88,Default,,0000,0000,0000,,is just using the physical spectrum,\Njust the thing that your eyes can see,
Dialogue: 0,0:02:24.88,0:02:26.38,Default,,0000,0000,0000,,and that's a tiny slice,
Dialogue: 0,0:02:26.38,0:02:27.82,Default,,0000,0000,0000,,a tiny, tiny slice
Dialogue: 0,0:02:27.82,0:02:30.07,Default,,0000,0000,0000,,of what the universe has to offer us.
Dialogue: 0,0:02:30.07,0:02:35.18,Default,,0000,0000,0000,,Now, there's also two very important\Nproblems with using visible light.
Dialogue: 0,0:02:35.18,0:02:38.02,Default,,0000,0000,0000,,Not only are we missing out\Non all the other processes
Dialogue: 0,0:02:38.02,0:02:40.81,Default,,0000,0000,0000,,that are emitting other kinds of light,
Dialogue: 0,0:02:40.81,0:02:43.01,Default,,0000,0000,0000,,but there's two issues.
Dialogue: 0,0:02:43.01,0:02:45.79,Default,,0000,0000,0000,,Now, the first is that dust,\Nwhich I mentioned earlier.
Dialogue: 0,0:02:45.79,0:02:50.28,Default,,0000,0000,0000,,The dust stops the visible light\Nfrom getting to us.
Dialogue: 0,0:02:50.28,0:02:53.68,Default,,0000,0000,0000,,So as we look deeper\Ninto the universe, we see less light.
Dialogue: 0,0:02:53.68,0:02:55.87,Default,,0000,0000,0000,,The dust stops it getting to us.
Dialogue: 0,0:02:55.87,0:02:59.16,Default,,0000,0000,0000,,There's a really strange problem\Nwith using visible light
Dialogue: 0,0:02:59.16,0:03:01.93,Default,,0000,0000,0000,,in order to try and explore the universe.
Dialogue: 0,0:03:01.93,0:03:04.02,Default,,0000,0000,0000,,Now take a break for a minute.
Dialogue: 0,0:03:04.02,0:03:07.17,Default,,0000,0000,0000,,Say your standing on a corner,\Na busy street corner.
Dialogue: 0,0:03:07.17,0:03:08.72,Default,,0000,0000,0000,,There's cars going by.
Dialogue: 0,0:03:08.72,0:03:10.47,Default,,0000,0000,0000,,An ambulance approaches.
Dialogue: 0,0:03:10.47,0:03:12.53,Default,,0000,0000,0000,,It has high-pitched siren.
Dialogue: 0,0:03:12.53,0:03:18.73,Default,,0000,0000,0000,,The siren appeared to change in pitch
Dialogue: 0,0:03:18.73,0:03:21.09,Default,,0000,0000,0000,,as it moved towards and away from you.
Dialogue: 0,0:03:21.09,0:03:25.30,Default,,0000,0000,0000,,The ambulance driver did not change\Nthe siren just to mess with you.
Dialogue: 0,0:03:25.30,0:03:28.84,Default,,0000,0000,0000,,That was a product of your perception.
Dialogue: 0,0:03:28.84,0:03:31.93,Default,,0000,0000,0000,,The sound waves,\Nas the ambulance approached,
Dialogue: 0,0:03:31.93,0:03:32.71,Default,,0000,0000,0000,,were compressed,
Dialogue: 0,0:03:32.71,0:03:34.86,Default,,0000,0000,0000,,and they changed higher in pitch.
Dialogue: 0,0:03:34.86,0:03:37.37,Default,,0000,0000,0000,,As the ambulance receded,\Nthe sound waves were stretched,
Dialogue: 0,0:03:37.37,0:03:39.59,Default,,0000,0000,0000,,and they sounded lower in pitch.
Dialogue: 0,0:03:39.59,0:03:42.18,Default,,0000,0000,0000,,The same thing happens with light.
Dialogue: 0,0:03:42.18,0:03:44.49,Default,,0000,0000,0000,,Objects moving towards us,
Dialogue: 0,0:03:44.49,0:03:47.81,Default,,0000,0000,0000,,their light waves are compressed\Nand they appear bluer.
Dialogue: 0,0:03:47.81,0:03:51.25,Default,,0000,0000,0000,,Objects moving away from us,\Ntheir light waves are stretched,
Dialogue: 0,0:03:51.25,0:03:52.50,Default,,0000,0000,0000,,and they appear redder.
Dialogue: 0,0:03:52.50,0:03:56.53,Default,,0000,0000,0000,,So we call these effects\Nblueshift and redshift.
Dialogue: 0,0:03:56.53,0:03:59.60,Default,,0000,0000,0000,,Now, our universe is expanding,
Dialogue: 0,0:03:59.60,0:04:03.90,Default,,0000,0000,0000,,so everything is moving away\Nfrom everything else,
Dialogue: 0,0:04:03.90,0:04:06.72,Default,,0000,0000,0000,,and that means everything\Nappears to be red,
Dialogue: 0,0:04:06.72,0:04:11.01,Default,,0000,0000,0000,,and oddly enough, as you look\Nmore deeply into the universe,
Dialogue: 0,0:04:11.01,0:04:14.65,Default,,0000,0000,0000,,more distant objects\Nare moving away further and faster,
Dialogue: 0,0:04:14.65,0:04:17.70,Default,,0000,0000,0000,,so they appear more red.
Dialogue: 0,0:04:17.70,0:04:20.53,Default,,0000,0000,0000,,So if I come back\Nto the Hubble Deep Field
Dialogue: 0,0:04:20.53,0:04:23.28,Default,,0000,0000,0000,,and we were to continue\Nto peer deeply into the universe
Dialogue: 0,0:04:23.28,0:04:24.76,Default,,0000,0000,0000,,just using the Hubble,
Dialogue: 0,0:04:24.76,0:04:27.53,Default,,0000,0000,0000,,as we get to a certain distance away,
Dialogue: 0,0:04:27.53,0:04:29.16,Default,,0000,0000,0000,,everything becomes red,
Dialogue: 0,0:04:29.16,0:04:32.06,Default,,0000,0000,0000,,and that presents something of a problem.
Dialogue: 0,0:04:32.06,0:04:34.22,Default,,0000,0000,0000,,Eventually, we get so far away
Dialogue: 0,0:04:34.22,0:04:36.86,Default,,0000,0000,0000,,everything is shifted into the infrared
Dialogue: 0,0:04:36.86,0:04:38.95,Default,,0000,0000,0000,,and we can't see anything at all.
Dialogue: 0,0:04:39.90,0:04:41.36,Default,,0000,0000,0000,,So there must be a way around this.
Dialogue: 0,0:04:41.36,0:04:43.54,Default,,0000,0000,0000,,Otherwise, I'm limited in my journey.
Dialogue: 0,0:04:43.54,0:04:45.17,Default,,0000,0000,0000,,I wanted to explore the whole universe,
Dialogue: 0,0:04:45.17,0:04:47.17,Default,,0000,0000,0000,,not just whatever I can see
Dialogue: 0,0:04:47.17,0:04:49.91,Default,,0000,0000,0000,,before the redshift kicks in.
Dialogue: 0,0:04:49.91,0:04:51.61,Default,,0000,0000,0000,,There is a technique.
Dialogue: 0,0:04:51.61,0:04:53.09,Default,,0000,0000,0000,,It's called radio astronomy.
Dialogue: 0,0:04:53.09,0:04:55.49,Default,,0000,0000,0000,,Astronomists have been\Nusing this for decades.
Dialogue: 0,0:04:55.49,0:04:58.45,Default,,0000,0000,0000,,It's a fantastic technique. I show you\Nthe Parkes Radio Telescope,
Dialogue: 0,0:04:58.45,0:05:00.06,Default,,0000,0000,0000,,affectionately known as the Dish.
Dialogue: 0,0:05:00.06,0:05:01.66,Default,,0000,0000,0000,,You may have seen the movie.
Dialogue: 0,0:05:01.66,0:05:03.62,Default,,0000,0000,0000,,And radio is really brilliant.
Dialogue: 0,0:05:03.62,0:05:06.36,Default,,0000,0000,0000,,It allows us to peer much more deeply.
Dialogue: 0,0:05:06.36,0:05:08.93,Default,,0000,0000,0000,,It doesn't get stopped by dust,
Dialogue: 0,0:05:08.93,0:05:11.24,Default,,0000,0000,0000,,so you can see everything in the universe,
Dialogue: 0,0:05:11.24,0:05:13.23,Default,,0000,0000,0000,,and redshift is less of a problem
Dialogue: 0,0:05:13.23,0:05:16.75,Default,,0000,0000,0000,,because we can build receivers\Nthat receive across a large band.
Dialogue: 0,0:05:16.75,0:05:19.18,Default,,0000,0000,0000,,So what does Parkes see when we turn it
Dialogue: 0,0:05:19.18,0:05:20.83,Default,,0000,0000,0000,,to the center of the Milky Way?
Dialogue: 0,0:05:20.83,0:05:23.04,Default,,0000,0000,0000,,We should see something fantastic, right?
Dialogue: 0,0:05:23.04,0:05:26.26,Default,,0000,0000,0000,,Well, we do see something interesting.
Dialogue: 0,0:05:26.26,0:05:28.05,Default,,0000,0000,0000,,All that dust has gone.
Dialogue: 0,0:05:28.05,0:05:31.86,Default,,0000,0000,0000,,As I mentioned, radio goes\Nstraight through dust, so not a problem.
Dialogue: 0,0:05:31.86,0:05:33.85,Default,,0000,0000,0000,,But the view is very different.
Dialogue: 0,0:05:33.85,0:05:37.76,Default,,0000,0000,0000,,We can see that the center\Nof the Milky Way is aglow,
Dialogue: 0,0:05:37.76,0:05:39.67,Default,,0000,0000,0000,,and this isn't starlight.
Dialogue: 0,0:05:39.67,0:05:43.48,Default,,0000,0000,0000,,This is a light called\Nsynchrotron radiation,
Dialogue: 0,0:05:43.48,0:05:48.42,Default,,0000,0000,0000,,and it's form from electrons\Nspiraling around cosmic magnetic fields.
Dialogue: 0,0:05:48.42,0:05:51.41,Default,,0000,0000,0000,,So the plane is aglow with this light,
Dialogue: 0,0:05:51.41,0:05:55.03,Default,,0000,0000,0000,,and we can also see strange tufts\Ncoming off of it,
Dialogue: 0,0:05:55.03,0:05:58.66,Default,,0000,0000,0000,,and objects which don't appear to light up\Nwith anything that we can see
Dialogue: 0,0:05:58.66,0:06:00.49,Default,,0000,0000,0000,,with our own eyes.
Dialogue: 0,0:06:00.49,0:06:02.79,Default,,0000,0000,0000,,But it's hard to really\Ninterpret this image,
Dialogue: 0,0:06:02.79,0:06:05.74,Default,,0000,0000,0000,,because as you can see,\Nit's very low resolution.
Dialogue: 0,0:06:05.74,0:06:07.92,Default,,0000,0000,0000,,Radio waves have a wavelength that's long,
Dialogue: 0,0:06:07.92,0:06:09.90,Default,,0000,0000,0000,,and that makes their resolution poorer.
Dialogue: 0,0:06:09.90,0:06:12.26,Default,,0000,0000,0000,,This image is also black and white,
Dialogue: 0,0:06:12.26,0:06:16.98,Default,,0000,0000,0000,,so we don't really know,\Nwhat is the color of everything in here?
Dialogue: 0,0:06:16.98,0:06:18.42,Default,,0000,0000,0000,,Well fast forward to today.
Dialogue: 0,0:06:18.42,0:06:21.10,Default,,0000,0000,0000,,We can build telescopes
Dialogue: 0,0:06:21.10,0:06:22.45,Default,,0000,0000,0000,,which can get over these problems.
Dialogue: 0,0:06:22.45,0:06:25.44,Default,,0000,0000,0000,,Now I'm showing you here an image\Nof the Murchison Radio Observatory,
Dialogue: 0,0:06:25.44,0:06:28.34,Default,,0000,0000,0000,,a fantastic place\Nto build radio telescopes.
Dialogue: 0,0:06:28.34,0:06:30.67,Default,,0000,0000,0000,,It's flat, it's dry,
Dialogue: 0,0:06:30.67,0:06:33.99,Default,,0000,0000,0000,,and most importantly, it's radio quiet:
Dialogue: 0,0:06:33.99,0:06:34.47,Default,,0000,0000,0000,,no mobile phones, no wifi, nothing,
Dialogue: 0,0:06:34.47,0:06:38.15,Default,,0000,0000,0000,,just very, very radio quiet,
Dialogue: 0,0:06:38.15,0:06:42.92,Default,,0000,0000,0000,,so a perfect place\Nto build a radio telescope.
Dialogue: 0,0:06:42.92,0:06:45.76,Default,,0000,0000,0000,,Now, the telescope that I've been\Nworking on for a few years
Dialogue: 0,0:06:45.76,0:06:47.85,Default,,0000,0000,0000,,is called the Murchison Wide Field Array,
Dialogue: 0,0:06:47.85,0:06:49.69,Default,,0000,0000,0000,,and I'm going to show you a little\Ntime lapse of it being built.
Dialogue: 0,0:06:49.69,0:06:54.08,Default,,0000,0000,0000,,This is a group of undergraduate\Nand postgraduate students
Dialogue: 0,0:06:54.08,0:06:55.42,Default,,0000,0000,0000,,located in Perth.
Dialogue: 0,0:06:55.42,0:06:57.19,Default,,0000,0000,0000,,We call them the Student Army,
Dialogue: 0,0:06:57.19,0:07:00.25,Default,,0000,0000,0000,,and they volunteered their time\Nto build a radio telescope.
Dialogue: 0,0:07:00.25,0:07:02.56,Default,,0000,0000,0000,,There's no course credit for this.
Dialogue: 0,0:07:02.56,0:07:05.56,Default,,0000,0000,0000,,And they're putting together\Nthese radio dipoles.
Dialogue: 0,0:07:05.56,0:07:07.58,Default,,0000,0000,0000,,They just receive at low frequencies,
Dialogue: 0,0:07:07.58,0:07:11.27,Default,,0000,0000,0000,,a bit like your FM radio or your TV.
Dialogue: 0,0:07:11.27,0:07:14.24,Default,,0000,0000,0000,,And here we are deploying them\Nacross the desert.
Dialogue: 0,0:07:14.24,0:07:16.82,Default,,0000,0000,0000,,The final telescope covers\N10 square kilometers
Dialogue: 0,0:07:16.82,0:07:18.89,Default,,0000,0000,0000,,of the Western Australian Desert.
Dialogue: 0,0:07:18.89,0:07:21.57,Default,,0000,0000,0000,,And the interesting thing is,\Nthere's no moving parts.
Dialogue: 0,0:07:21.57,0:07:24.00,Default,,0000,0000,0000,,We just deploy these little antennas
Dialogue: 0,0:07:24.00,0:07:26.30,Default,,0000,0000,0000,,essentially on chicken mesh.
Dialogue: 0,0:07:26.30,0:07:27.62,Default,,0000,0000,0000,,It's fairly cheap.
Dialogue: 0,0:07:27.62,0:07:29.56,Default,,0000,0000,0000,,Cables take the signals
Dialogue: 0,0:07:29.56,0:07:31.65,Default,,0000,0000,0000,,from the antennas
Dialogue: 0,0:07:31.65,0:07:34.25,Default,,0000,0000,0000,,and bring them to central\Nprocessing events.
Dialogue: 0,0:07:34.25,0:07:36.88,Default,,0000,0000,0000,,And it's the size of this telescope,\Nthe fact that we've built it
Dialogue: 0,0:07:36.88,0:07:38.65,Default,,0000,0000,0000,,over the entire desert
Dialogue: 0,0:07:38.65,0:07:41.98,Default,,0000,0000,0000,,that gives us a better\Nresolution than Parkes.
Dialogue: 0,0:07:41.98,0:07:43.93,Default,,0000,0000,0000,,Now eventually all those cables
Dialogue: 0,0:07:43.93,0:07:45.30,Default,,0000,0000,0000,,bring them to a unit
Dialogue: 0,0:07:45.30,0:07:48.04,Default,,0000,0000,0000,,which sends it off to a supercomputer
Dialogue: 0,0:07:48.04,0:07:49.23,Default,,0000,0000,0000,,here in Perth,
Dialogue: 0,0:07:49.23,0:07:50.94,Default,,0000,0000,0000,,and that's where I come in.
Dialogue: 0,0:07:50.94,0:07:54.97,Default,,0000,0000,0000,,Radio data.
Dialogue: 0,0:07:54.97,0:07:57.71,Default,,0000,0000,0000,,I have spent the last five years
Dialogue: 0,0:07:57.71,0:07:58.80,Default,,0000,0000,0000,,working with very difficult,\Nvery interesting data
Dialogue: 0,0:07:58.80,0:08:00.59,Default,,0000,0000,0000,,that no one had really looked at before.
Dialogue: 0,0:08:00.59,0:08:02.81,Default,,0000,0000,0000,,I've spent a long time calibrating it,
Dialogue: 0,0:08:02.81,0:08:06.78,Default,,0000,0000,0000,,running millions of CPU hours\Non supercomputers,
Dialogue: 0,0:08:06.78,0:08:09.52,Default,,0000,0000,0000,,and really trying to understand that data.
Dialogue: 0,0:08:09.52,0:08:11.65,Default,,0000,0000,0000,,And with this telescope,
Dialogue: 0,0:08:11.65,0:08:12.74,Default,,0000,0000,0000,,with this data,
Dialogue: 0,0:08:12.74,0:08:14.02,Default,,0000,0000,0000,,we've performed a survey
Dialogue: 0,0:08:14.02,0:08:16.80,Default,,0000,0000,0000,,of the entire southern sky,
Dialogue: 0,0:08:16.80,0:08:21.68,Default,,0000,0000,0000,,the Galactic and Extragalactic\NAll-sky MWA Survey,
Dialogue: 0,0:08:21.68,0:08:24.26,Default,,0000,0000,0000,,or GLEAM, as I call it.
Dialogue: 0,0:08:24.26,0:08:26.45,Default,,0000,0000,0000,,And I'm very excited.
Dialogue: 0,0:08:26.45,0:08:29.38,Default,,0000,0000,0000,,This survey is just about to be published,\Nbut it hasn't been shown yet,
Dialogue: 0,0:08:29.38,0:08:32.99,Default,,0000,0000,0000,,so you are literally the first people\Nto see this southern survey
Dialogue: 0,0:08:32.99,0:08:34.92,Default,,0000,0000,0000,,of the entire sky.
Dialogue: 0,0:08:34.92,0:08:39.06,Default,,0000,0000,0000,,So I'm delighted to share with you\Nsome images from this survey.
Dialogue: 0,0:08:39.06,0:08:41.12,Default,,0000,0000,0000,,Now, imagine you went to the Murchison,
Dialogue: 0,0:08:41.12,0:08:43.13,Default,,0000,0000,0000,,you camped out underneath the stars,
Dialogue: 0,0:08:43.13,0:08:44.91,Default,,0000,0000,0000,,and you looked towards the south.
Dialogue: 0,0:08:44.91,0:08:46.56,Default,,0000,0000,0000,,You saw the south's celestial pole,
Dialogue: 0,0:08:46.56,0:08:47.69,Default,,0000,0000,0000,,the galaxy rising.
Dialogue: 0,0:08:47.69,0:08:50.29,Default,,0000,0000,0000,,If I fade in the radio light,
Dialogue: 0,0:08:50.29,0:08:51.44,Default,,0000,0000,0000,,this is what we observe with our survey.
Dialogue: 0,0:08:51.44,0:08:56.06,Default,,0000,0000,0000,,You can see that the galactic plane\Nis no longer dark with dust.
Dialogue: 0,0:08:56.06,0:08:58.40,Default,,0000,0000,0000,,It's alight with synchrotron radiation,
Dialogue: 0,0:08:58.40,0:09:00.88,Default,,0000,0000,0000,,and thousands of dots are in the sky.
Dialogue: 0,0:09:00.88,0:09:04.27,Default,,0000,0000,0000,,Our large Magellanic Cloud,\Nour nearest galactic neighbor,
Dialogue: 0,0:09:04.27,0:09:06.08,Default,,0000,0000,0000,,is orange instead of\Nits more familiar blue-white.
Dialogue: 0,0:09:06.08,0:09:10.71,Default,,0000,0000,0000,,So there's a lot going on in this.\NLet's take a closer look.
Dialogue: 0,0:09:10.71,0:09:13.33,Default,,0000,0000,0000,,If we look back towards\Nthe galactic center,
Dialogue: 0,0:09:13.33,0:09:16.66,Default,,0000,0000,0000,,where we originally saw the Parkes image\Nthat I showed you earlier,
Dialogue: 0,0:09:16.66,0:09:18.77,Default,,0000,0000,0000,,low resolution, black and white,
Dialogue: 0,0:09:18.77,0:09:22.26,Default,,0000,0000,0000,,and we fade toe the GLEAM view,
Dialogue: 0,0:09:22.26,0:09:26.37,Default,,0000,0000,0000,,you can see the resolution has gone up\Nby a factor of a hundred.
Dialogue: 0,0:09:26.37,0:09:29.19,Default,,0000,0000,0000,,We now have a color view of the sky,
Dialogue: 0,0:09:29.19,0:09:30.49,Default,,0000,0000,0000,,a technicolor view.
Dialogue: 0,0:09:30.49,0:09:33.56,Default,,0000,0000,0000,,Now, it's not a false color view.
Dialogue: 0,0:09:33.56,0:09:36.35,Default,,0000,0000,0000,,These are real radio colors.
Dialogue: 0,0:09:36.35,0:09:39.77,Default,,0000,0000,0000,,What I've done is I've colored\Nthe lowest frequencies red
Dialogue: 0,0:09:39.77,0:09:41.39,Default,,0000,0000,0000,,and the highest frequencies blue,
Dialogue: 0,0:09:41.39,0:09:42.36,Default,,0000,0000,0000,,and the middle ones green.
Dialogue: 0,0:09:42.36,0:09:45.14,Default,,0000,0000,0000,,And that gives us this rainbow view.
Dialogue: 0,0:09:45.14,0:09:47.26,Default,,0000,0000,0000,,And this isn't just false color.
Dialogue: 0,0:09:47.26,0:09:50.26,Default,,0000,0000,0000,,The colors in this image tell us\Nabout the physical processes
Dialogue: 0,0:09:50.26,0:09:51.62,Default,,0000,0000,0000,,going on in the universe.
Dialogue: 0,0:09:51.62,0:09:55.03,Default,,0000,0000,0000,,So for instance, if you look\Nalong the plane of the galaxy,
Dialogue: 0,0:09:55.03,0:09:56.47,Default,,0000,0000,0000,,it's alight with synchrotron,
Dialogue: 0,0:09:56.47,0:09:57.59,Default,,0000,0000,0000,,which is mostly reddish orange,
Dialogue: 0,0:09:57.59,0:10:02.51,Default,,0000,0000,0000,,but if we look very closely\Nwe see little blue dots.
Dialogue: 0,0:10:02.51,0:10:04.10,Default,,0000,0000,0000,,Now if we zoom in,
Dialogue: 0,0:10:04.10,0:10:06.54,Default,,0000,0000,0000,,these blue dots are ionized plasma
Dialogue: 0,0:10:06.54,0:10:08.69,Default,,0000,0000,0000,,around very bright stars,
Dialogue: 0,0:10:08.69,0:10:11.42,Default,,0000,0000,0000,,and what happens is that\Nthey block the red light,
Dialogue: 0,0:10:11.42,0:10:13.84,Default,,0000,0000,0000,,so they appear blue.
Dialogue: 0,0:10:13.84,0:10:15.79,Default,,0000,0000,0000,,And these can tell us\Nabout these star-forming regions
Dialogue: 0,0:10:15.79,0:10:18.28,Default,,0000,0000,0000,,in our galaxy.
Dialogue: 0,0:10:18.28,0:10:19.69,Default,,0000,0000,0000,,And we just see them immediately.
Dialogue: 0,0:10:19.69,0:10:22.99,Default,,0000,0000,0000,,We look at the galaxy, and the color\Ntells us that they're there.
Dialogue: 0,0:10:22.99,0:10:24.93,Default,,0000,0000,0000,,You can see little soap bubbles,
Dialogue: 0,0:10:24.93,0:10:27.99,Default,,0000,0000,0000,,little circular images\Naround the galactic plane,
Dialogue: 0,0:10:27.99,0:10:30.85,Default,,0000,0000,0000,,and these are supernova remnants.
Dialogue: 0,0:10:30.85,0:10:32.51,Default,,0000,0000,0000,,When a star explodes,
Dialogue: 0,0:10:32.51,0:10:34.100,Default,,0000,0000,0000,,its outer shell is cast off
Dialogue: 0,0:10:34.100,0:10:38.32,Default,,0000,0000,0000,,and it travels outward into space\Ngathering up material,
Dialogue: 0,0:10:38.32,0:10:40.82,Default,,0000,0000,0000,,and it produces a little shell.
Dialogue: 0,0:10:40.82,0:10:43.86,Default,,0000,0000,0000,,It's been a longstanding\Nmystery to astronomers
Dialogue: 0,0:10:43.86,0:10:47.06,Default,,0000,0000,0000,,where all the supernova remnants are.
Dialogue: 0,0:10:47.06,0:10:51.65,Default,,0000,0000,0000,,We know that there must be a lot\Nof high-energy electrons in the plane
Dialogue: 0,0:10:51.65,0:10:54.25,Default,,0000,0000,0000,,to produce the synchrotron\Nradiation that we see,
Dialogue: 0,0:10:54.25,0:10:56.91,Default,,0000,0000,0000,,and we think they're produced\Nby supernova remnants,
Dialogue: 0,0:10:56.91,0:10:58.39,Default,,0000,0000,0000,,but there don't seem to be enough.
Dialogue: 0,0:10:58.39,0:11:02.65,Default,,0000,0000,0000,,Fortunately, GLEAM is really, really\Ngood at detecting supernova remnants,
Dialogue: 0,0:11:02.65,0:11:05.67,Default,,0000,0000,0000,,so we're hoping to have a new paper\Nout on that soon.
Dialogue: 0,0:11:05.67,0:11:07.30,Default,,0000,0000,0000,,Now that's fine.
Dialogue: 0,0:11:07.30,0:11:09.62,Default,,0000,0000,0000,,We've explored our little local universe,
Dialogue: 0,0:11:09.62,0:11:11.95,Default,,0000,0000,0000,,but I wanted to go deeper.\NI wanted to go further.
Dialogue: 0,0:11:11.95,0:11:14.58,Default,,0000,0000,0000,,I wanted to go beyond the Milky Way.
Dialogue: 0,0:11:14.58,0:11:18.65,Default,,0000,0000,0000,,Well as it happens we can see a very\Ninteresting objecting the top right,
Dialogue: 0,0:11:18.65,0:11:20.83,Default,,0000,0000,0000,,and this is a local radio galaxy,
Dialogue: 0,0:11:20.83,0:11:22.51,Default,,0000,0000,0000,,Centaurus A.
Dialogue: 0,0:11:22.51,0:11:25.83,Default,,0000,0000,0000,,If we zoom in on this, we can see\Nthat there are two huge plumes
Dialogue: 0,0:11:25.83,0:11:27.81,Default,,0000,0000,0000,,going out into space,
Dialogue: 0,0:11:27.81,0:11:30.80,Default,,0000,0000,0000,,and if you look right in the center\Nbetween those two plumes,
Dialogue: 0,0:11:30.80,0:11:33.25,Default,,0000,0000,0000,,you'll see a galaxy just like our own.
Dialogue: 0,0:11:33.25,0:11:35.62,Default,,0000,0000,0000,,It has a spiral. It has a dust plane.
Dialogue: 0,0:11:35.62,0:11:37.69,Default,,0000,0000,0000,,It's a normal galaxy.
Dialogue: 0,0:11:37.69,0:11:40.68,Default,,0000,0000,0000,,But these jets are only\Nvisible in the radio.
Dialogue: 0,0:11:40.68,0:11:41.82,Default,,0000,0000,0000,,If we looked in the visible,\Nwe wouldn't even know they were there,
Dialogue: 0,0:11:41.82,0:11:47.73,Default,,0000,0000,0000,,and they're thousands of times larger\Nthan the host galaxy.
Dialogue: 0,0:11:47.73,0:11:50.50,Default,,0000,0000,0000,,Well, what's going on?\NWhat's producing these jets?
Dialogue: 0,0:11:50.50,0:11:54.67,Default,,0000,0000,0000,,At the center of every galaxy\Nthat we know about
Dialogue: 0,0:11:54.67,0:11:58.34,Default,,0000,0000,0000,,is a supermassive black hole.
Dialogue: 0,0:11:58.34,0:12:00.78,Default,,0000,0000,0000,,Now, black holes are invisible.\NThat's why they're called that.
Dialogue: 0,0:12:00.78,0:12:03.39,Default,,0000,0000,0000,,All you can see is the deflection\Nof the light around them,
Dialogue: 0,0:12:03.39,0:12:07.98,Default,,0000,0000,0000,,and occasionally, when a star\Nor a cloud of gas comes into their orbit,
Dialogue: 0,0:12:07.98,0:12:10.76,Default,,0000,0000,0000,,it is ripped apart by tidal forces,
Dialogue: 0,0:12:10.76,0:12:13.90,Default,,0000,0000,0000,,forming what we call an accretion disk.
Dialogue: 0,0:12:13.90,0:12:17.10,Default,,0000,0000,0000,,The accretion disk glows\Nbrightly in the x-rays,
Dialogue: 0,0:12:17.10,0:12:18.76,Default,,0000,0000,0000,,and huge magnetic fields
Dialogue: 0,0:12:18.76,0:12:21.31,Default,,0000,0000,0000,,can launch the material into space
Dialogue: 0,0:12:21.31,0:12:23.56,Default,,0000,0000,0000,,at nearly the speed of light.
Dialogue: 0,0:12:23.56,0:12:27.42,Default,,0000,0000,0000,,So these jets are visible in the radio
Dialogue: 0,0:12:27.42,0:12:30.27,Default,,0000,0000,0000,,and this is what we pick up in our survey.
Dialogue: 0,0:12:30.27,0:12:34.24,Default,,0000,0000,0000,,Well very well, so we've seen\None radio galaxy. That's nice.
Dialogue: 0,0:12:34.24,0:12:36.42,Default,,0000,0000,0000,,But if you just look at\Nthe top of that image,
Dialogue: 0,0:12:36.42,0:12:38.27,Default,,0000,0000,0000,,you'll see another radio galaxy.
Dialogue: 0,0:12:38.27,0:12:41.85,Default,,0000,0000,0000,,It's a little bit smaller, and that's\Njust because it's further away.
Dialogue: 0,0:12:41.85,0:12:44.30,Default,,0000,0000,0000,,Okay. Two radio galaxies.
Dialogue: 0,0:12:44.30,0:12:46.68,Default,,0000,0000,0000,,We can see this. This is fine.
Dialogue: 0,0:12:46.68,0:12:47.85,Default,,0000,0000,0000,,Well, what about all the other dots?
Dialogue: 0,0:12:47.85,0:12:49.63,Default,,0000,0000,0000,,Presumably those are just stars.
Dialogue: 0,0:12:49.63,0:12:51.24,Default,,0000,0000,0000,,They're not.
Dialogue: 0,0:12:51.24,0:12:53.10,Default,,0000,0000,0000,,They're all radio galaxies.
Dialogue: 0,0:12:53.10,0:12:56.09,Default,,0000,0000,0000,,Every single one of the dots in this image
Dialogue: 0,0:12:56.09,0:12:58.80,Default,,0000,0000,0000,,is a distant galaxy,
Dialogue: 0,0:12:58.80,0:13:01.04,Default,,0000,0000,0000,,millions to billions of light years away
Dialogue: 0,0:13:01.04,0:13:03.49,Default,,0000,0000,0000,,with a supermassive\Nblack hole at its center
Dialogue: 0,0:13:03.49,0:13:07.50,Default,,0000,0000,0000,,pushing material into space\Nat nearly the speed of light.
Dialogue: 0,0:13:07.50,0:13:09.41,Default,,0000,0000,0000,,It is mindblowing.
Dialogue: 0,0:13:09.41,0:13:13.62,Default,,0000,0000,0000,,And this survey is even larger\Nthan what I've shown here.
Dialogue: 0,0:13:13.62,0:13:16.13,Default,,0000,0000,0000,,If we zoom out to\Nthe full extent of the survey,
Dialogue: 0,0:13:16.13,0:13:20.05,Default,,0000,0000,0000,,you can see I found 300,000\Nof these radio galaxies.
Dialogue: 0,0:13:20.05,0:13:23.58,Default,,0000,0000,0000,,So it's truly an epic journey.
Dialogue: 0,0:13:23.58,0:13:25.95,Default,,0000,0000,0000,,We've discovered all of these galaxies
Dialogue: 0,0:13:25.95,0:13:30.19,Default,,0000,0000,0000,,right back to the very first\Nsupermassive black holes.
Dialogue: 0,0:13:30.19,0:13:33.64,Default,,0000,0000,0000,,I'm very proud of this\Nand it will be published next week.
Dialogue: 0,0:13:33.64,0:13:36.34,Default,,0000,0000,0000,,Now, that's not all.
Dialogue: 0,0:13:36.34,0:13:40.45,Default,,0000,0000,0000,,I've explored the furthest reaches\Nof the galaxy with this survey,
Dialogue: 0,0:13:40.45,0:13:43.95,Default,,0000,0000,0000,,but there's something\Neven more in this image.
Dialogue: 0,0:13:43.95,0:13:47.87,Default,,0000,0000,0000,,Now, I'll take you right back\Nto the dawn of time.
Dialogue: 0,0:13:47.87,0:13:51.13,Default,,0000,0000,0000,,Now, when the universe formed,\Nit was a big bang,
Dialogue: 0,0:13:51.13,0:13:55.69,Default,,0000,0000,0000,,which left the universe\Nas a sea of hydrogen,
Dialogue: 0,0:13:55.69,0:13:57.06,Default,,0000,0000,0000,,neutral hydrogen,
Dialogue: 0,0:13:57.06,0:13:59.77,Default,,0000,0000,0000,,and when the very first stars\Nand galaxies switched on,
Dialogue: 0,0:13:59.77,0:14:02.09,Default,,0000,0000,0000,,they ionized that hydrogen.
Dialogue: 0,0:14:02.09,0:14:06.40,Default,,0000,0000,0000,,So the universe went\Nfrom neutral to ionized.
Dialogue: 0,0:14:06.40,0:14:09.65,Default,,0000,0000,0000,,That imprinted a signal all around us.
Dialogue: 0,0:14:09.65,0:14:11.44,Default,,0000,0000,0000,,Everywhere, it pervades us,
Dialogue: 0,0:14:11.44,0:14:12.81,Default,,0000,0000,0000,,like the Force.
Dialogue: 0,0:14:12.81,0:14:16.80,Default,,0000,0000,0000,,Now, because that happened so long ago,
Dialogue: 0,0:14:16.80,0:14:19.73,Default,,0000,0000,0000,,the signal was redshifted,
Dialogue: 0,0:14:19.73,0:14:23.24,Default,,0000,0000,0000,,so now that signal\Nis at very low frequencies.
Dialogue: 0,0:14:23.24,0:14:25.51,Default,,0000,0000,0000,,It's at the same frequency as my survey,
Dialogue: 0,0:14:25.51,0:14:27.08,Default,,0000,0000,0000,,but it's so faint,
Dialogue: 0,0:14:27.08,0:14:31.55,Default,,0000,0000,0000,,it's a billionth the size of any\Nof the objects in my survey.
Dialogue: 0,0:14:31.55,0:14:36.24,Default,,0000,0000,0000,,So our telescope may not be quite\Nsensitive enough to pick up this signal.
Dialogue: 0,0:14:36.24,0:14:38.86,Default,,0000,0000,0000,,However, there's a new radio telescope.
Dialogue: 0,0:14:38.86,0:14:40.48,Default,,0000,0000,0000,,So I can't have a starship,
Dialogue: 0,0:14:40.48,0:14:42.31,Default,,0000,0000,0000,,but I can hopefully have
Dialogue: 0,0:14:42.31,0:14:43.84,Default,,0000,0000,0000,,one of the biggest radio telescopes
Dialogue: 0,0:14:43.84,0:14:44.89,Default,,0000,0000,0000,,in the world.
Dialogue: 0,0:14:44.89,0:14:46.88,Default,,0000,0000,0000,,We're build the Square Kilometer Array,\Na new radio telescope,
Dialogue: 0,0:14:46.88,0:14:51.09,Default,,0000,0000,0000,,and it's going to be a thousand\Ntimes bigger than the MWA,
Dialogue: 0,0:14:51.09,0:14:54.02,Default,,0000,0000,0000,,a thousand times more sensitive,\Nand have an even better resolution.
Dialogue: 0,0:14:54.02,0:14:56.34,Default,,0000,0000,0000,,So we should find tens\Nof millions of galaxies.
Dialogue: 0,0:14:56.34,0:14:59.02,Default,,0000,0000,0000,,And perhaps, deep in that signal,
Dialogue: 0,0:14:59.02,0:15:00.51,Default,,0000,0000,0000,,I will get to look upon
Dialogue: 0,0:15:00.51,0:15:03.01,Default,,0000,0000,0000,,the very first stars and galaxies\Nswitching on,
Dialogue: 0,0:15:03.01,0:15:05.89,Default,,0000,0000,0000,,the beginning of time itself.
Dialogue: 0,0:15:05.89,0:15:07.42,Default,,0000,0000,0000,,Thank you.
Dialogue: 0,0:15:07.42,0:15:12.10,Default,,0000,0000,0000,,(Applause)