[Script Info]
Title: 
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:19.39,0:00:21.25,Default,,0000,0000,0000,,In the movie "Interstellar,"
Dialogue: 0,0:00:21.27,0:00:24.60,Default,,0000,0000,0000,,we get an up-close look\Nat a supermassive black hole.
Dialogue: 0,0:00:24.62,0:00:26.76,Default,,0000,0000,0000,,Set against a backdrop of bright gas,
Dialogue: 0,0:00:26.79,0:00:28.91,Default,,0000,0000,0000,,the black hole's massive\Ngravitational pull
Dialogue: 0,0:00:28.93,0:00:30.36,Default,,0000,0000,0000,,bends light into a ring.
Dialogue: 0,0:00:30.39,0:00:32.50,Default,,0000,0000,0000,,However, this isn't a real photograph,
Dialogue: 0,0:00:32.52,0:00:34.31,Default,,0000,0000,0000,,but a computer graphic rendering --
Dialogue: 0,0:00:34.33,0:00:37.72,Default,,0000,0000,0000,,an artistic interpretation\Nof what a black hole might look like.
Dialogue: 0,0:00:38.35,0:00:39.52,Default,,0000,0000,0000,,A hundred years ago,
Dialogue: 0,0:00:39.54,0:00:43.14,Default,,0000,0000,0000,,Albert Einstein first published\Nhis theory of general relativity.
Dialogue: 0,0:00:43.17,0:00:44.60,Default,,0000,0000,0000,,In the years since then,
Dialogue: 0,0:00:44.63,0:00:47.60,Default,,0000,0000,0000,,scientists have provided\Na lot of evidence in support of it.
Dialogue: 0,0:00:47.63,0:00:50.71,Default,,0000,0000,0000,,But one thing predicted\Nfrom this theory, black holes,
Dialogue: 0,0:00:50.73,0:00:53.08,Default,,0000,0000,0000,,still have not been directly observed.
Dialogue: 0,0:00:53.11,0:00:56.31,Default,,0000,0000,0000,,Although we have some idea\Nas to what a black hole might look like,
Dialogue: 0,0:00:56.34,0:00:59.12,Default,,0000,0000,0000,,we've never actually taken\Na picture of one before.
Dialogue: 0,0:00:59.14,0:01:01.32,Default,,0000,0000,0000,,However, you might be surprised to know
Dialogue: 0,0:01:01.34,0:01:05.51,Default,,0000,0000,0000,,that we may be seeing our first picture\Nof a black hole in the next couple years.
Dialogue: 0,0:01:05.53,0:01:09.49,Default,,0000,0000,0000,,Getting this first picture will come down\Nto an international team of scientists,
Dialogue: 0,0:01:09.51,0:01:11.08,Default,,0000,0000,0000,,an Earth-sized telescope
Dialogue: 0,0:01:11.10,0:01:13.94,Default,,0000,0000,0000,,and an algorithm that puts together\Nthe final picture.
Dialogue: 0,0:01:13.96,0:01:17.49,Default,,0000,0000,0000,,Although I won't be able to show you\Na real picture of a black hole today,
Dialogue: 0,0:01:17.51,0:01:20.42,Default,,0000,0000,0000,,I'd like to give you a brief glimpse\Ninto the effort involved
Dialogue: 0,0:01:20.45,0:01:22.06,Default,,0000,0000,0000,,in getting that first picture.
Dialogue: 0,0:01:23.97,0:01:25.41,Default,,0000,0000,0000,,My name is Katie Bouman,
Dialogue: 0,0:01:25.44,0:01:28.00,Default,,0000,0000,0000,,and I'm a PhD student at MIT.
Dialogue: 0,0:01:28.03,0:01:30.06,Default,,0000,0000,0000,,I do research in a computer science lab
Dialogue: 0,0:01:30.08,0:01:33.38,Default,,0000,0000,0000,,that works on making computers\Nsee through images and video.
Dialogue: 0,0:01:33.80,0:01:35.96,Default,,0000,0000,0000,,But although I'm not an astronomer,
Dialogue: 0,0:01:35.99,0:01:37.27,Default,,0000,0000,0000,,today I'd like to show you
Dialogue: 0,0:01:37.30,0:01:40.20,Default,,0000,0000,0000,,how I've been able to contribute\Nto this exciting project.
Dialogue: 0,0:01:42.22,0:01:45.15,Default,,0000,0000,0000,,If you go out past\Nthe bright city lights tonight,
Dialogue: 0,0:01:45.18,0:01:47.61,Default,,0000,0000,0000,,you may just be lucky enough\Nto see a stunning view
Dialogue: 0,0:01:47.64,0:01:49.13,Default,,0000,0000,0000,,of the Milky Way Galaxy.
Dialogue: 0,0:01:49.66,0:01:52.12,Default,,0000,0000,0000,,And if you could zoom past\Nmillions of stars,
Dialogue: 0,0:01:52.14,0:01:55.90,Default,,0000,0000,0000,,26,000 light-years toward the heart\Nof the spiraling Milky Way,
Dialogue: 0,0:01:55.92,0:01:59.44,Default,,0000,0000,0000,,we'd eventually reach\Na cluster of stars right at the center.
Dialogue: 0,0:01:59.46,0:02:02.67,Default,,0000,0000,0000,,Peering past all the galactic dust\Nwith infrared telescopes,
Dialogue: 0,0:02:02.70,0:02:06.56,Default,,0000,0000,0000,,astronomers have watched these stars\Nfor over 16 years.
Dialogue: 0,0:02:06.59,0:02:09.69,Default,,0000,0000,0000,,But it's what they don't see\Nthat is the most spectacular.
Dialogue: 0,0:02:10.20,0:02:13.26,Default,,0000,0000,0000,,These stars seem to orbit\Nan invisible object.
Dialogue: 0,0:02:15.56,0:02:17.88,Default,,0000,0000,0000,,By tracking the paths of these stars,
Dialogue: 0,0:02:17.91,0:02:19.20,Default,,0000,0000,0000,,astronomers have concluded
Dialogue: 0,0:02:19.22,0:02:22.20,Default,,0000,0000,0000,,that the only thing small and heavy\Nenough to cause this motion
Dialogue: 0,0:02:22.22,0:02:24.34,Default,,0000,0000,0000,,is a supermassive black hole --
Dialogue: 0,0:02:24.37,0:02:28.55,Default,,0000,0000,0000,,an object so dense that it sucks up\Nanything that ventures too close --
Dialogue: 0,0:02:28.57,0:02:30.06,Default,,0000,0000,0000,,even light.
Dialogue: 0,0:02:30.09,0:02:33.15,Default,,0000,0000,0000,,But what happens if we were\Nto zoom in even further?
Dialogue: 0,0:02:33.17,0:02:37.91,Default,,0000,0000,0000,,Is it possible to see something\Nthat, by definition, is impossible to see?
Dialogue: 0,0:02:39.51,0:02:42.75,Default,,0000,0000,0000,,Well, it turns out that if we were\Nto zoom in at radio wavelengths,
Dialogue: 0,0:02:42.78,0:02:44.46,Default,,0000,0000,0000,,we'd expect to see a ring of light
Dialogue: 0,0:02:44.48,0:02:46.89,Default,,0000,0000,0000,,caused by the gravitational\Nlensing of hot plasma
Dialogue: 0,0:02:46.92,0:02:48.75,Default,,0000,0000,0000,,zipping around the black hole.
Dialogue: 0,0:02:48.77,0:02:49.93,Default,,0000,0000,0000,,In other words,
Dialogue: 0,0:02:49.96,0:02:53.13,Default,,0000,0000,0000,,the black hole casts a shadow\Non this backdrop of bright material,
Dialogue: 0,0:02:53.15,0:02:54.99,Default,,0000,0000,0000,,carving out a sphere of darkness.
Dialogue: 0,0:02:55.45,0:02:58.78,Default,,0000,0000,0000,,This bright ring reveals\Nthe black hole's event horizon,
Dialogue: 0,0:02:58.81,0:03:01.21,Default,,0000,0000,0000,,where the gravitational pull\Nbecomes so great
Dialogue: 0,0:03:01.23,0:03:02.86,Default,,0000,0000,0000,,that not even light can escape.
Dialogue: 0,0:03:04.79,0:03:07.65,Default,,0000,0000,0000,,Einstein's equations predict\Nthe size and shape of this ring,
Dialogue: 0,0:03:07.68,0:03:10.88,Default,,0000,0000,0000,,so taking a picture of it\Nwouldn't only be really cool,
Dialogue: 0,0:03:10.91,0:03:13.53,Default,,0000,0000,0000,,it would also help to verify\Nthat these equations hold
Dialogue: 0,0:03:13.55,0:03:16.02,Default,,0000,0000,0000,,in the extreme conditions\Naround the black hole.
Dialogue: 0,0:03:16.48,0:03:19.04,Default,,0000,0000,0000,,However, this black hole\Nis so far away from us,
Dialogue: 0,0:03:19.06,0:03:22.16,Default,,0000,0000,0000,,that from Earth, this ring appears\Nincredibly small --
Dialogue: 0,0:03:22.18,0:03:25.77,Default,,0000,0000,0000,,the same size to us as an orange\Non the surface of the moon.
Dialogue: 0,0:03:26.33,0:03:29.15,Default,,0000,0000,0000,,That makes taking a picture of it\Nextremely difficult.
Dialogue: 0,0:03:30.22,0:03:31.52,Default,,0000,0000,0000,,Why is that?
Dialogue: 0,0:03:32.08,0:03:35.27,Default,,0000,0000,0000,,Well, it all comes down\Nto a simple equation.
Dialogue: 0,0:03:35.29,0:03:37.71,Default,,0000,0000,0000,,Due to a phenomenon called diffraction,
Dialogue: 0,0:03:37.73,0:03:39.09,Default,,0000,0000,0000,,there are fundamental limits
Dialogue: 0,0:03:39.11,0:03:41.78,Default,,0000,0000,0000,,to the smallest objects\Nthat we can possibly see.
Dialogue: 0,0:03:42.36,0:03:46.03,Default,,0000,0000,0000,,This governing equation says\Nthat in order to see smaller and smaller,
Dialogue: 0,0:03:46.06,0:03:48.64,Default,,0000,0000,0000,,we need to make our telescope\Nbigger and bigger.
Dialogue: 0,0:03:48.67,0:03:51.74,Default,,0000,0000,0000,,But even with the most powerful\Noptical telescopes here on Earth,
Dialogue: 0,0:03:51.76,0:03:54.18,Default,,0000,0000,0000,,we can't even get close\Nto the resolution necessary
Dialogue: 0,0:03:54.20,0:03:56.40,Default,,0000,0000,0000,,to image on the surface of the moon.
Dialogue: 0,0:03:56.42,0:04:00.04,Default,,0000,0000,0000,,In fact, here I show one of the highest\Nresolution images ever taken
Dialogue: 0,0:04:00.06,0:04:01.46,Default,,0000,0000,0000,,of the moon from Earth.
Dialogue: 0,0:04:01.49,0:04:04.04,Default,,0000,0000,0000,,It contains roughly 13,000 pixels,
Dialogue: 0,0:04:04.07,0:04:08.12,Default,,0000,0000,0000,,and yet each pixel would contain\Nover 1.5 million oranges.
Dialogue: 0,0:04:08.97,0:04:10.94,Default,,0000,0000,0000,,So how big of a telescope do we need
Dialogue: 0,0:04:10.96,0:04:13.73,Default,,0000,0000,0000,,in order to see an orange\Non the surface of the moon
Dialogue: 0,0:04:13.75,0:04:15.96,Default,,0000,0000,0000,,and, by extension, our black hole?
Dialogue: 0,0:04:15.99,0:04:18.33,Default,,0000,0000,0000,,Well, it turns out\Nthat by crunching the numbers,
Dialogue: 0,0:04:18.35,0:04:20.96,Default,,0000,0000,0000,,you can easily calculate\Nthat we would need a telescope
Dialogue: 0,0:04:20.99,0:04:22.38,Default,,0000,0000,0000,,the size of the entire Earth.
Dialogue: 0,0:04:22.40,0:04:23.43,Default,,0000,0000,0000,,(Laughter)
Dialogue: 0,0:04:23.45,0:04:25.57,Default,,0000,0000,0000,,If we could build\Nthis Earth-sized telescope,
Dialogue: 0,0:04:25.60,0:04:28.52,Default,,0000,0000,0000,,we could just start to make out\Nthat distinctive ring of light
Dialogue: 0,0:04:28.54,0:04:30.73,Default,,0000,0000,0000,,indicative of the black\Nhole's event horizon.
Dialogue: 0,0:04:30.75,0:04:33.67,Default,,0000,0000,0000,,Although this picture wouldn't contain\Nall the detail we see
Dialogue: 0,0:04:33.69,0:04:35.27,Default,,0000,0000,0000,,in computer graphic renderings,
Dialogue: 0,0:04:35.29,0:04:37.70,Default,,0000,0000,0000,,it would allow us to safely get\Nour first glimpse
Dialogue: 0,0:04:37.73,0:04:40.21,Default,,0000,0000,0000,,of the immediate environment\Naround a black hole.
Dialogue: 0,0:04:40.81,0:04:42.42,Default,,0000,0000,0000,,However, as you can imagine,
Dialogue: 0,0:04:42.44,0:04:46.07,Default,,0000,0000,0000,,building a single-dish telescope\Nthe size of the Earth is impossible.
Dialogue: 0,0:04:46.09,0:04:47.98,Default,,0000,0000,0000,,But in the famous words of Mick Jagger,
Dialogue: 0,0:04:48.00,0:04:49.79,Default,,0000,0000,0000,,"You can't always get what you want,
Dialogue: 0,0:04:49.82,0:04:52.00,Default,,0000,0000,0000,,but if you try sometimes,\Nyou just might find
Dialogue: 0,0:04:52.03,0:04:53.24,Default,,0000,0000,0000,,you get what you need."
Dialogue: 0,0:04:53.27,0:04:55.73,Default,,0000,0000,0000,,And by connecting telescopes\Nfrom around the world,
Dialogue: 0,0:04:55.76,0:04:59.29,Default,,0000,0000,0000,,an international collaboration\Ncalled the Event Horizon Telescope
Dialogue: 0,0:04:59.32,0:05:02.43,Default,,0000,0000,0000,,is creating a computational telescope\Nthe size of the Earth,
Dialogue: 0,0:05:02.45,0:05:03.99,Default,,0000,0000,0000,,capable of resolving structure
Dialogue: 0,0:05:04.01,0:05:06.21,Default,,0000,0000,0000,,on the scale of a black\Nhole's event horizon.
Dialogue: 0,0:05:06.54,0:05:09.92,Default,,0000,0000,0000,,This network of telescopes is scheduled\Nto take its very first picture
Dialogue: 0,0:05:09.95,0:05:11.76,Default,,0000,0000,0000,,of a black hole next year.
Dialogue: 0,0:05:13.94,0:05:17.28,Default,,0000,0000,0000,,Each telescope in the worldwide\Nnetwork works together.
Dialogue: 0,0:05:17.31,0:05:20.02,Default,,0000,0000,0000,,Linked through the precise timing\Nof atomic clocks,
Dialogue: 0,0:05:20.04,0:05:22.70,Default,,0000,0000,0000,,teams of researchers at each\Nof the sights freeze light
Dialogue: 0,0:05:22.72,0:05:25.69,Default,,0000,0000,0000,,by collecting thousands\Nof terabytes of data.
Dialogue: 0,0:05:25.71,0:05:30.73,Default,,0000,0000,0000,,This data is then processed in a lab\Nright here in Massachusetts.
Dialogue: 0,0:05:32.63,0:05:34.42,Default,,0000,0000,0000,,So how does this even work?
Dialogue: 0,0:05:34.45,0:05:37.85,Default,,0000,0000,0000,,Remember if we want to see the black hole\Nin the center of our galaxy,
Dialogue: 0,0:05:37.88,0:05:40.86,Default,,0000,0000,0000,,we need to build this impossibly large\NEarth-sized telescope?
Dialogue: 0,0:05:40.88,0:05:43.11,Default,,0000,0000,0000,,For just a second,\Nlet's pretend we could build
Dialogue: 0,0:05:43.14,0:05:44.98,Default,,0000,0000,0000,,a telescope the size of the Earth.
Dialogue: 0,0:05:45.00,0:05:47.46,Default,,0000,0000,0000,,This would be a little bit\Nlike turning the Earth
Dialogue: 0,0:05:47.48,0:05:49.23,Default,,0000,0000,0000,,into a giant spinning disco ball.
Dialogue: 0,0:05:49.25,0:05:51.45,Default,,0000,0000,0000,,Each individual mirror would collect light
Dialogue: 0,0:05:51.48,0:05:54.08,Default,,0000,0000,0000,,that we could then combine\Ntogether to make a picture.
Dialogue: 0,0:05:54.10,0:05:56.76,Default,,0000,0000,0000,,However, now let's say\Nwe remove most of those mirrors
Dialogue: 0,0:05:56.78,0:05:58.76,Default,,0000,0000,0000,,so only a few remained.
Dialogue: 0,0:05:58.78,0:06:01.66,Default,,0000,0000,0000,,We could still try to combine\Nthis information together,
Dialogue: 0,0:06:01.68,0:06:03.67,Default,,0000,0000,0000,,but now there are a lot of holes.
Dialogue: 0,0:06:03.70,0:06:08.07,Default,,0000,0000,0000,,These remaining mirrors represent\Nthe locations where we have telescopes.
Dialogue: 0,0:06:08.10,0:06:12.17,Default,,0000,0000,0000,,This is an incredibly small number\Nof measurements to make a picture from.
Dialogue: 0,0:06:12.20,0:06:16.04,Default,,0000,0000,0000,,But although we only collect light\Nat a few telescope locations,
Dialogue: 0,0:06:16.06,0:06:19.48,Default,,0000,0000,0000,,as the Earth rotates, we get to see\Nother new measurements.
Dialogue: 0,0:06:19.51,0:06:23.33,Default,,0000,0000,0000,,In other words, as the disco ball spins,\Nthose mirrors change locations
Dialogue: 0,0:06:23.35,0:06:26.25,Default,,0000,0000,0000,,and we get to observe\Ndifferent parts of the image.
Dialogue: 0,0:06:26.27,0:06:30.29,Default,,0000,0000,0000,,The imaging algorithms we develop\Nfill in the missing gaps of the disco ball
Dialogue: 0,0:06:30.32,0:06:33.35,Default,,0000,0000,0000,,in order to reconstruct\Nthe underlying black hole image.
Dialogue: 0,0:06:33.37,0:06:36.01,Default,,0000,0000,0000,,If we had telescopes located\Neverywhere on the globe --
Dialogue: 0,0:06:36.03,0:06:37.97,Default,,0000,0000,0000,,in other words, the entire disco ball --
Dialogue: 0,0:06:37.100,0:06:39.38,Default,,0000,0000,0000,,this would be trivial.
Dialogue: 0,0:06:39.40,0:06:42.73,Default,,0000,0000,0000,,However, we only see a few samples,\Nand for that reason,
Dialogue: 0,0:06:42.75,0:06:45.14,Default,,0000,0000,0000,,there are an infinite number\Nof possible images
Dialogue: 0,0:06:45.16,0:06:48.13,Default,,0000,0000,0000,,that are perfectly consistent\Nwith our telescope measurements.
Dialogue: 0,0:06:48.75,0:06:51.77,Default,,0000,0000,0000,,However, not all images are created equal.
Dialogue: 0,0:06:52.21,0:06:56.67,Default,,0000,0000,0000,,Some of those images look more like\Nwhat we think of as images than others.
Dialogue: 0,0:06:56.69,0:06:59.91,Default,,0000,0000,0000,,And so, my role in helping to take\Nthe first image of a black hole
Dialogue: 0,0:06:59.94,0:07:02.71,Default,,0000,0000,0000,,is to design algorithms that find\Nthe most reasonable image
Dialogue: 0,0:07:02.73,0:07:04.95,Default,,0000,0000,0000,,that also fits the telescope measurements.
Dialogue: 0,0:07:06.49,0:07:10.43,Default,,0000,0000,0000,,Just as a forensic sketch artist\Nuses limited descriptions
Dialogue: 0,0:07:10.45,0:07:13.97,Default,,0000,0000,0000,,to piece together a picture using\Ntheir knowledge of face structure,
Dialogue: 0,0:07:13.99,0:07:17.31,Default,,0000,0000,0000,,the imaging algorithms I develop\Nuse our limited telescope data
Dialogue: 0,0:07:17.33,0:07:21.65,Default,,0000,0000,0000,,to guide us to a picture that also\Nlooks like stuff in our universe.
Dialogue: 0,0:07:22.18,0:07:25.83,Default,,0000,0000,0000,,Using these algorithms,\Nwe're able to piece together pictures
Dialogue: 0,0:07:25.85,0:07:28.03,Default,,0000,0000,0000,,from this sparse, noisy data.
Dialogue: 0,0:07:28.06,0:07:32.58,Default,,0000,0000,0000,,So here I show a sample reconstruction\Ndone using simulated data,
Dialogue: 0,0:07:32.61,0:07:34.54,Default,,0000,0000,0000,,when we pretend to point our telescopes
Dialogue: 0,0:07:34.56,0:07:37.15,Default,,0000,0000,0000,,to the black hole\Nin the center of our galaxy.
Dialogue: 0,0:07:37.17,0:07:41.63,Default,,0000,0000,0000,,Although this is just a simulation,\Nreconstruction such as this give us hope
Dialogue: 0,0:07:41.65,0:07:45.11,Default,,0000,0000,0000,,that we'll soon be able to reliably take\Nthe first image of a black hole
Dialogue: 0,0:07:45.13,0:07:47.72,Default,,0000,0000,0000,,and from it, determine\Nthe size of its ring.
Dialogue: 0,0:07:50.18,0:07:53.38,Default,,0000,0000,0000,,Although I'd love to go on\Nabout all the details of this algorithm,
Dialogue: 0,0:07:53.40,0:07:55.58,Default,,0000,0000,0000,,luckily for you, I don't have the time.
Dialogue: 0,0:07:55.60,0:07:57.60,Default,,0000,0000,0000,,But I'd still like\Nto give you a brief idea
Dialogue: 0,0:07:57.62,0:07:59.93,Default,,0000,0000,0000,,of how we define\Nwhat our universe looks like,
Dialogue: 0,0:07:59.95,0:08:03.74,Default,,0000,0000,0000,,and how we use this to reconstruct\Nand verify our results.
Dialogue: 0,0:08:05.18,0:08:07.68,Default,,0000,0000,0000,,Since there are an infinite number\Nof possible images
Dialogue: 0,0:08:07.70,0:08:10.06,Default,,0000,0000,0000,,that perfectly explain\Nour telescope measurements,
Dialogue: 0,0:08:10.09,0:08:12.73,Default,,0000,0000,0000,,we have to choose\Nbetween them in some way.
Dialogue: 0,0:08:12.76,0:08:14.60,Default,,0000,0000,0000,,We do this by ranking the images
Dialogue: 0,0:08:14.62,0:08:17.45,Default,,0000,0000,0000,,based upon how likely they are\Nto be the black hole image,
Dialogue: 0,0:08:17.48,0:08:19.96,Default,,0000,0000,0000,,and then choosing the one\Nthat's most likely.
Dialogue: 0,0:08:19.98,0:08:22.38,Default,,0000,0000,0000,,So what do I mean by this exactly?
Dialogue: 0,0:08:22.40,0:08:24.38,Default,,0000,0000,0000,,Let's say we were trying to make a model
Dialogue: 0,0:08:24.40,0:08:27.59,Default,,0000,0000,0000,,that told us how likely an image\Nwere to appear on Facebook.
Dialogue: 0,0:08:27.61,0:08:29.31,Default,,0000,0000,0000,,We'd probably want the model to say
Dialogue: 0,0:08:29.34,0:08:32.89,Default,,0000,0000,0000,,it's pretty unlikely that someone\Nwould post this noise image on the left,
Dialogue: 0,0:08:32.92,0:08:35.34,Default,,0000,0000,0000,,and pretty likely that someone\Nwould post a selfie
Dialogue: 0,0:08:35.36,0:08:36.69,Default,,0000,0000,0000,,like this one on the right.
Dialogue: 0,0:08:36.72,0:08:38.36,Default,,0000,0000,0000,,The image in the middle is blurry,
Dialogue: 0,0:08:38.38,0:08:41.02,Default,,0000,0000,0000,,so even though it's more likely\Nwe'd see it on Facebook
Dialogue: 0,0:08:41.04,0:08:42.40,Default,,0000,0000,0000,,compared to the noise image,
Dialogue: 0,0:08:42.43,0:08:45.39,Default,,0000,0000,0000,,it's probably less likely we'd see it\Ncompared to the selfie.
Dialogue: 0,0:08:45.71,0:08:48.00,Default,,0000,0000,0000,,But when it comes to images\Nfrom the black hole,
Dialogue: 0,0:08:48.03,0:08:51.53,Default,,0000,0000,0000,,we're posed with a real conundrum:\Nwe've never seen a black hole before.
Dialogue: 0,0:08:52.01,0:08:54.30,Default,,0000,0000,0000,,In that case, what is a likely\Nblack hole image,
Dialogue: 0,0:08:54.33,0:08:57.26,Default,,0000,0000,0000,,and what should we assume\Nabout the structure of black holes?
Dialogue: 0,0:08:57.79,0:09:00.42,Default,,0000,0000,0000,,We could try to use images\Nfrom simulations we've done,
Dialogue: 0,0:09:00.44,0:09:02.98,Default,,0000,0000,0000,,like the image of the black hole\Nfrom "Interstellar,"
Dialogue: 0,0:09:02.100,0:09:05.94,Default,,0000,0000,0000,,but if we did this,\Nit could cause some serious problems.
Dialogue: 0,0:09:07.46,0:09:10.84,Default,,0000,0000,0000,,What would happen\Nif Einstein's theories didn't hold?
Dialogue: 0,0:09:10.86,0:09:14.88,Default,,0000,0000,0000,,We'd still want to reconstruct\Nan accurate picture of what was going on.
Dialogue: 0,0:09:14.90,0:09:18.27,Default,,0000,0000,0000,,If we bake Einstein's equations\Ntoo much into our algorithms,
Dialogue: 0,0:09:18.30,0:09:21.05,Default,,0000,0000,0000,,we'll just end up seeing\Nwhat we expect to see.
Dialogue: 0,0:09:21.07,0:09:23.35,Default,,0000,0000,0000,,In other words,\Nwe want to leave the option open
Dialogue: 0,0:09:23.37,0:09:26.30,Default,,0000,0000,0000,,for there being a giant elephant\Nat the center of our galaxy.
Dialogue: 0,0:09:26.32,0:09:27.47,Default,,0000,0000,0000,,(Laughter)
Dialogue: 0,0:09:27.94,0:09:30.93,Default,,0000,0000,0000,,Different types of images have\Nvery distinct features.
Dialogue: 0,0:09:30.96,0:09:34.50,Default,,0000,0000,0000,,We can easily tell the difference\Nbetween black hole simulation images
Dialogue: 0,0:09:34.53,0:09:36.80,Default,,0000,0000,0000,,and images we take\Nevery day here on Earth.
Dialogue: 0,0:09:36.83,0:09:39.93,Default,,0000,0000,0000,,We need a way to tell our algorithms\Nwhat images look like
Dialogue: 0,0:09:39.96,0:09:43.20,Default,,0000,0000,0000,,without imposing one type\Nof image's features too much.
Dialogue: 0,0:09:43.76,0:09:45.65,Default,,0000,0000,0000,,One way we can try to get around this
Dialogue: 0,0:09:45.67,0:09:48.73,Default,,0000,0000,0000,,is by imposing the features\Nof different kinds of images
Dialogue: 0,0:09:48.76,0:09:52.89,Default,,0000,0000,0000,,and seeing how the type of image we assume\Naffects our reconstructions.
Dialogue: 0,0:09:54.54,0:09:58.03,Default,,0000,0000,0000,,If all images' types produce\Na very similar-looking image,
Dialogue: 0,0:09:58.06,0:10:00.11,Default,,0000,0000,0000,,then we can start to become more confident
Dialogue: 0,0:10:00.14,0:10:04.34,Default,,0000,0000,0000,,that the image assumptions we're making\Nare not biasing this picture that much.
Dialogue: 0,0:10:04.36,0:10:07.36,Default,,0000,0000,0000,,This is a little bit like\Ngiving the same description
Dialogue: 0,0:10:07.38,0:10:10.38,Default,,0000,0000,0000,,to three different sketch artists\Nfrom all around the world.
Dialogue: 0,0:10:10.40,0:10:13.26,Default,,0000,0000,0000,,If they all produce\Na very similar-looking face,
Dialogue: 0,0:10:13.28,0:10:15.08,Default,,0000,0000,0000,,then we can start to become confident
Dialogue: 0,0:10:15.10,0:10:18.72,Default,,0000,0000,0000,,that they're not imposing their own\Ncultural biases on the drawings.
Dialogue: 0,0:10:20.04,0:10:23.36,Default,,0000,0000,0000,,One way we can try to impose\Ndifferent image features
Dialogue: 0,0:10:23.38,0:10:25.82,Default,,0000,0000,0000,,is by using pieces of existing images.
Dialogue: 0,0:10:26.37,0:10:28.53,Default,,0000,0000,0000,,So we take a large collection of images,
Dialogue: 0,0:10:28.56,0:10:31.28,Default,,0000,0000,0000,,and we break them down\Ninto their little image patches.
Dialogue: 0,0:10:31.30,0:10:35.58,Default,,0000,0000,0000,,We then can treat each image patch\Na little bit like pieces of a puzzle.
Dialogue: 0,0:10:35.61,0:10:39.89,Default,,0000,0000,0000,,And we use commonly seen puzzle pieces\Nto piece together an image
Dialogue: 0,0:10:39.91,0:10:42.36,Default,,0000,0000,0000,,that also fits our telescope measurements.
Dialogue: 0,0:10:46.60,0:10:50.34,Default,,0000,0000,0000,,Different types of images have\Nvery distinctive sets of puzzle pieces.
Dialogue: 0,0:10:51.37,0:10:54.17,Default,,0000,0000,0000,,So what happens when we take the same data
Dialogue: 0,0:10:54.20,0:10:58.33,Default,,0000,0000,0000,,but we use different sets of puzzle pieces\Nto reconstruct the image?
Dialogue: 0,0:10:58.35,0:11:02.08,Default,,0000,0000,0000,,Let's first start with black hole\Nimage simulation puzzle pieces.
Dialogue: 0,0:11:03.94,0:11:05.53,Default,,0000,0000,0000,,OK, this looks reasonable.
Dialogue: 0,0:11:05.56,0:11:08.25,Default,,0000,0000,0000,,This looks like what we expect\Na black hole to look like.
Dialogue: 0,0:11:08.27,0:11:09.47,Default,,0000,0000,0000,,But did we just get it
Dialogue: 0,0:11:09.49,0:11:12.80,Default,,0000,0000,0000,,because we just fed it little pieces\Nof black hole simulation images?
Dialogue: 0,0:11:12.83,0:11:14.71,Default,,0000,0000,0000,,Let's try another set of puzzle pieces
Dialogue: 0,0:11:14.73,0:11:17.24,Default,,0000,0000,0000,,from astronomical, non-black hole objects.
Dialogue: 0,0:11:18.27,0:11:20.40,Default,,0000,0000,0000,,OK, we get a similar-looking image.
Dialogue: 0,0:11:20.42,0:11:22.66,Default,,0000,0000,0000,,And then how about pieces\Nfrom everyday images,
Dialogue: 0,0:11:22.68,0:11:25.47,Default,,0000,0000,0000,,like the images you take\Nwith your own personal camera?
Dialogue: 0,0:11:26.67,0:11:28.79,Default,,0000,0000,0000,,Great, we see the same image.
Dialogue: 0,0:11:28.81,0:11:32.18,Default,,0000,0000,0000,,When we get the same image\Nfrom all different sets of puzzle pieces,
Dialogue: 0,0:11:32.20,0:11:34.25,Default,,0000,0000,0000,,then we can start to become more confident
Dialogue: 0,0:11:34.27,0:11:36.24,Default,,0000,0000,0000,,that the image assumptions we're making
Dialogue: 0,0:11:36.26,0:11:39.18,Default,,0000,0000,0000,,aren't biasing the final\Nimage we get too much.
Dialogue: 0,0:11:40.05,0:11:43.30,Default,,0000,0000,0000,,Another thing we can do is take\Nthe same set of puzzle pieces,
Dialogue: 0,0:11:43.32,0:11:45.81,Default,,0000,0000,0000,,such as the ones derived\Nfrom everyday images,
Dialogue: 0,0:11:45.84,0:11:49.44,Default,,0000,0000,0000,,and use them to reconstruct\Nmany different kinds of source images.
Dialogue: 0,0:11:49.46,0:11:50.73,Default,,0000,0000,0000,,So in our simulations,
Dialogue: 0,0:11:50.76,0:11:54.53,Default,,0000,0000,0000,,we pretend a black hole looks like\Nastronomical non-black hole objects,
Dialogue: 0,0:11:54.55,0:11:58.40,Default,,0000,0000,0000,,as well as everyday images like\Nthe elephant in the center of our galaxy.
Dialogue: 0,0:11:58.43,0:12:01.60,Default,,0000,0000,0000,,When the results of our algorithms\Non the bottom look very similar
Dialogue: 0,0:12:01.62,0:12:03.72,Default,,0000,0000,0000,,to the simulation's truth image on top,
Dialogue: 0,0:12:03.74,0:12:07.08,Default,,0000,0000,0000,,then we can start to become\Nmore confident in our algorithms.
Dialogue: 0,0:12:07.11,0:12:08.98,Default,,0000,0000,0000,,And I really want to emphasize here
Dialogue: 0,0:12:09.00,0:12:10.93,Default,,0000,0000,0000,,that all of these pictures were created
Dialogue: 0,0:12:10.96,0:12:13.89,Default,,0000,0000,0000,,by piecing together little pieces\Nof everyday photographs,
Dialogue: 0,0:12:13.92,0:12:16.35,Default,,0000,0000,0000,,like you'd take with your own\Npersonal camera.
Dialogue: 0,0:12:16.38,0:12:19.82,Default,,0000,0000,0000,,So an image of a black hole\Nwe've never seen before
Dialogue: 0,0:12:19.85,0:12:24.33,Default,,0000,0000,0000,,may eventually be created by piecing\Ntogether pictures we see all the time
Dialogue: 0,0:12:24.68,0:12:27.33,Default,,0000,0000,0000,,Imaging ideas like this\Nwill make it possible for us
Dialogue: 0,0:12:27.35,0:12:29.97,Default,,0000,0000,0000,,to take our very first pictures\Nof a black hole,
Dialogue: 0,0:12:29.100,0:12:32.44,Default,,0000,0000,0000,,and hopefully, verify\Nthose famous theories
Dialogue: 0,0:12:32.47,0:12:34.89,Default,,0000,0000,0000,,on which scientists rely on a daily basis.
Dialogue: 0,0:12:35.73,0:12:38.34,Default,,0000,0000,0000,,But of course, getting\Nimaging ideas like this working
Dialogue: 0,0:12:38.36,0:12:41.68,Default,,0000,0000,0000,,would never have been possible\Nwithout the amazing team of researchers
Dialogue: 0,0:12:41.71,0:12:43.60,Default,,0000,0000,0000,,that I have the privilege to work with.
Dialogue: 0,0:12:43.92,0:12:45.08,Default,,0000,0000,0000,,It still amazes me
Dialogue: 0,0:12:45.11,0:12:48.46,Default,,0000,0000,0000,,that although I began this project\Nwith no background in astrophysics,
Dialogue: 0,0:12:48.48,0:12:51.10,Default,,0000,0000,0000,,what we have achieved\Nthrough this unique collaboration
Dialogue: 0,0:12:51.12,0:12:53.88,Default,,0000,0000,0000,,could result in the very first\Nimages of a black hole.
Dialogue: 0,0:12:54.41,0:12:57.11,Default,,0000,0000,0000,,But big projects like\Nthe Event Horizon Telescope
Dialogue: 0,0:12:57.13,0:12:59.94,Default,,0000,0000,0000,,are successful due to all\Nthe interdisciplinary expertise
Dialogue: 0,0:12:59.97,0:13:01.76,Default,,0000,0000,0000,,different people bring to the table.
Dialogue: 0,0:13:02.18,0:13:03.89,Default,,0000,0000,0000,,We're a melting pot of astronomers,
Dialogue: 0,0:13:03.91,0:13:06.14,Default,,0000,0000,0000,,physicists, mathematicians and engineers.
Dialogue: 0,0:13:06.17,0:13:08.04,Default,,0000,0000,0000,,This is what will make it soon possible
Dialogue: 0,0:13:08.07,0:13:10.58,Default,,0000,0000,0000,,to achieve something\Nonce thought impossible.
Dialogue: 0,0:13:10.60,0:13:12.86,Default,,0000,0000,0000,,I'd like to encourage all of you to go out
Dialogue: 0,0:13:12.88,0:13:14.98,Default,,0000,0000,0000,,and help push the boundaries of science,
Dialogue: 0,0:13:15.00,0:13:18.90,Default,,0000,0000,0000,,even if it may at first seem\Nas mysterious to you as a black hole.
Dialogue: 0,0:13:18.93,0:13:20.10,Default,,0000,0000,0000,,Thank you.
Dialogue: 0,0:13:20.13,0:13:25.69,Default,,0000,0000,0000,,(Applause)