What's the next window into our universe?
-
0:01 - 0:05So in 1781, an English composer,
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0:05 - 0:08technologist and astronomer called William Herschel
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0:08 - 0:09noticed an object on the sky that
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0:09 - 0:12didn't quite move the way the rest of the stars did.
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0:12 - 0:15And Herschel's recognition
that something was different, -
0:15 - 0:17that something wasn't quite right,
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0:17 - 0:19was the discovery of a planet,
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0:19 - 0:21the planet Uranus,
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0:21 - 0:23a name that has entertained
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0:23 - 0:26countless generations of children,
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0:26 - 0:28but a planet that overnight
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0:28 - 0:31doubled the size of our known solar system.
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0:31 - 0:33Just last month, NASA announced the discovery
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0:33 - 0:35of 517 new planets
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0:35 - 0:37in orbit around nearby stars,
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0:37 - 0:39almost doubling overnight the number of planets
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0:39 - 0:42we know about within our galaxy.
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0:42 - 0:44So astronomy is constantly being transformed by this
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0:44 - 0:47capacity to collect data,
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0:47 - 0:49and with data almost doubling every year,
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0:49 - 0:51within the next two decades, me may even
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0:51 - 0:53reach the point for the first time in history
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0:53 - 0:56where we've discovered the majority of the galaxies
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0:56 - 0:58within the universe.
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0:58 - 1:00But as we enter this era of big data,
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1:00 - 1:02what we're beginning to find is there's a difference
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1:02 - 1:05between more data being just better
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1:05 - 1:07and more data being different,
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1:07 - 1:10capable of changing the questions we want to ask,
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1:10 - 1:13and this difference is not about
how much data we collect, -
1:13 - 1:15it's whether those data open new windows
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1:15 - 1:17into our universe,
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1:17 - 1:19whether they change the way we view the sky.
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1:19 - 1:23So what is the next window into our universe?
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1:23 - 1:26What is the next chapter for astronomy?
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1:26 - 1:28Well, I'm going to show you some
of the tools and the technologies -
1:28 - 1:31that we're going to develop over the next decade,
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1:31 - 1:32and how these technologies,
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1:32 - 1:34together with the smart use of data,
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1:34 - 1:37may once again transform astronomy
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1:37 - 1:39by opening up a window into our universe,
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1:39 - 1:41the window of time.
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1:41 - 1:44Why time? Well, time is about origins,
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1:44 - 1:45and it's about evolution.
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1:45 - 1:47The origins of our solar system,
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1:47 - 1:49how our solar system came into being,
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1:49 - 1:53is it unusual or special in any way?
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1:53 - 1:55About the evolution of our universe.
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1:55 - 1:58Why our universe is continuing to expand,
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1:58 - 2:00and what is this mysterious dark energy
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2:00 - 2:02that drives that expansion?
-
2:02 - 2:05But first, I want to show you how technology
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2:05 - 2:08is going to change the way we view the sky.
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2:08 - 2:09So imagine if you were sitting
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2:09 - 2:11in the mountains of northern Chile
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2:11 - 2:13looking out to the west
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2:13 - 2:15towards the Pacific Ocean
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2:15 - 2:17a few hours before sunrise.
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2:17 - 2:21This is the view of the night sky that you would see,
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2:21 - 2:22and it's a beautiful view,
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2:22 - 2:25with the Milky Way just peeking out over the horizon.
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2:25 - 2:27but it's also a static view,
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2:27 - 2:30and in many ways, this is the
way we think of our universe: -
2:30 - 2:32eternal and unchanging.
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2:32 - 2:34But the universe is anything but static.
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2:34 - 2:37It constantly changes on timescales of seconds
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2:37 - 2:39to billions of years.
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2:39 - 2:41Galaxies merge, they collide
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2:41 - 2:43at hundreds of thousands of miles per hour.
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2:43 - 2:45Stars are born, they die,
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2:45 - 2:48they explode in these extravagant displays.
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2:48 - 2:50In fact, if we could go back
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2:50 - 2:52to our tranquil skies above Chile,
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2:52 - 2:55and we allow time to move forward
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2:55 - 2:59to see how the sky might change over the next year,
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2:59 - 3:01the pulsations that you see
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3:01 - 3:06are supernovae, the final remnants of a dying star
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3:06 - 3:10exploding, brightening and then fading from view,
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3:10 - 3:11each one of these supernovae
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3:11 - 3:14five billion times the brightness of our sun,
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3:14 - 3:17so we can see them to great distances
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3:17 - 3:19but only for a short amount of time.
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3:19 - 3:22Ten supernova per second explode somewhere
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3:22 - 3:23in our universe.
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3:23 - 3:25If we could hear it,
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3:25 - 3:28it would be popping like a bag of popcorn.
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3:28 - 3:32Now, if we fade out the supernovae,
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3:32 - 3:35it's not just brightness that changes.
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3:35 - 3:37Our sky is in constant motion.
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3:37 - 3:40This swarm of objects you
see streaming across the sky -
3:40 - 3:43are asteroids as they orbit our sun,
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3:43 - 3:45and it's these changes and the motion
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3:45 - 3:47and it's the dynamics of the system
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3:47 - 3:50that allow us to build our models for our universe,
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3:50 - 3:54to predict its future and to explain its past.
-
3:54 - 3:57But the telescopes we've used over the last decade
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3:57 - 4:01are not designed to capture the data at this scale.
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4:01 - 4:02The Hubble Space Telescope:
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4:02 - 4:05for the last 25 years it's been producing
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4:05 - 4:07some of the most detailed views
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4:07 - 4:09of our distant universe,
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4:09 - 4:11but if you tried to use the Hubble to create an image
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4:11 - 4:15of the sky, it would take 13 million individual images,
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4:15 - 4:19about 120 years to do this just once.
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4:19 - 4:21So this is driving us to new technologies
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4:21 - 4:23and new telescopes,
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4:23 - 4:25telescopes that can go faint
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4:25 - 4:26to look at the distant universe
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4:26 - 4:29but also telescopes that can go wide
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4:29 - 4:32to capture the sky as rapidly as possible,
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4:32 - 4:35telescopes like the Large Synoptic Survey Telescope,
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4:35 - 4:37or the LSST,
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4:37 - 4:40possibly the most boring name ever
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4:40 - 4:42for one of the most fascinating experiments
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4:42 - 4:44in the history of astronomy,
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4:44 - 4:46in fact proof, if you should need it,
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4:46 - 4:49that you should never allow
a scientist or an engineer -
4:49 - 4:54to name anything, not even your children.
(Laughter) -
4:54 - 4:56We're building the LSST.
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4:56 - 4:59We expect it to start taking data
by the end of this decade. -
4:59 - 5:01I'm going to show you how we think
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5:01 - 5:04it's going to transform
our views of the universe, -
5:04 - 5:07because one image from the LSST
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5:07 - 5:09is equivalent to 3,000 images
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5:09 - 5:11from the Hubble Space Telescope,
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5:11 - 5:14each image three and a half degrees on the sky,
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5:14 - 5:17seven times the width of the full moon.
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5:17 - 5:20Well, how do you capture an image at this scale?
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5:20 - 5:24Well, you build the largest digital camera in history,
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5:24 - 5:27using the same technology you find
in the cameras in your cell phone -
5:27 - 5:31or in the digital cameras you
can buy in the High Street, -
5:31 - 5:34but now at a scale that is five and a half feet across,
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5:34 - 5:36about the size of a Volkswagen Beetle,
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5:36 - 5:39where one image is three billion pixels.
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5:39 - 5:41So if you wanted to look at an image
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5:41 - 5:44in its full resolution, just a single LSST image,
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5:44 - 5:48it would take about 1,500
high-definition TV screens. -
5:48 - 5:51And this camera will image the sky,
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5:51 - 5:54taking a new picture every 20 seconds,
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5:54 - 5:56constantly scanning the sky
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5:56 - 5:59so every three nights, we'll get a completely new view
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5:59 - 6:02of the skies above Chile.
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6:02 - 6:05Over the mission lifetime of this telescope,
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6:05 - 6:08it will detect 40 billion stars and galaxies,
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6:08 - 6:09and that will be for the first time
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6:09 - 6:12we'll have detected more objects in our universe
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6:12 - 6:15than people on the Earth.
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6:15 - 6:16Now, we can talk about this
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6:16 - 6:18in terms of terabytes and petabytes
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6:18 - 6:20and billions of objects,
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6:20 - 6:22but a way to get a sense of the amount of data
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6:22 - 6:24that will come off this camera
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6:24 - 6:28is that it's like playing every TED Talk ever recorded
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6:28 - 6:31simultaneously, 24 hours a day,
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6:31 - 6:34seven days a week, for 10 years.
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6:34 - 6:36And to process this data means
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6:36 - 6:38searching through all of those talks
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6:38 - 6:41for every new idea and every new concept,
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6:41 - 6:43looking at each part of the video
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6:43 - 6:45to see how one frame may have changed
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6:45 - 6:46from the next.
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6:46 - 6:49And this is changing the way that we do science,
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6:49 - 6:51changing the way that we do astronomy,
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6:51 - 6:53to a place where software and algorithms
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6:53 - 6:55have to mine through this data,
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6:55 - 6:58where the software is as critical to the science
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6:58 - 7:02as the telescopes and the
cameras that we've built. -
7:02 - 7:05Now, thousands of discoveries
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7:05 - 7:07will come from this project,
-
7:07 - 7:08but I'm just going to tell you about two
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7:08 - 7:11of the ideas about origins and evolution
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7:11 - 7:13that may be transformed by our access
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7:13 - 7:16to data at this scale.
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7:16 - 7:18In the last five years, NASA has discovered
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7:18 - 7:20over 1,000 planetary systems
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7:20 - 7:22around nearby stars,
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7:22 - 7:24but the systems we're finding
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7:24 - 7:27aren't much like our own solar system,
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7:27 - 7:28and one of the questions we face is
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7:28 - 7:31is it just that we haven't been looking hard enough
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7:31 - 7:32or is there something special or unusual
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7:32 - 7:35about how our solar system formed?
-
7:35 - 7:37And if we want to answer that question,
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7:37 - 7:38we have to know and understand
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7:38 - 7:41the history of our solar system in detail,
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7:41 - 7:43and it's the details that are crucial.
-
7:43 - 7:47So now, if we look back at the sky,
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7:47 - 7:51at our asteroids that were streaming across the sky,
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7:51 - 7:55these asteroids are like the
debris of our solar system. -
7:55 - 7:57The positions of the asteroids
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7:57 - 7:59are like a fingerprint of an earlier time
-
7:59 - 8:01when the orbits of Neptune and Jupiter
-
8:01 - 8:03were much closer to the sun,
-
8:03 - 8:06and as these giant planets migrated
through our solar system, -
8:06 - 8:10they were scattering the asteroids in their wake.
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8:10 - 8:11So studying the asteroids
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8:11 - 8:13is like performing forensics,
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8:13 - 8:16performing forensics on our solar system,
-
8:16 - 8:18but to do this, we need distance,
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8:18 - 8:20and we get the distance from the motion,
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8:20 - 8:25and we get the motion because of our access to time.
-
8:25 - 8:27So what does this tell us?
-
8:27 - 8:29Well, if you look at the little yellow asteroids
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8:29 - 8:31flitting across the screen,
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8:31 - 8:34these are the asteroids that are moving fastest,
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8:34 - 8:37because they're closest to us, closest to Earth.
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8:37 - 8:38These are the asteroids we may one day
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8:38 - 8:42send spacecraft to, to mine them for minerals,
-
8:42 - 8:44but they're also the asteroids that may one day
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8:44 - 8:46impact the Earth,
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8:46 - 8:47like happened 60 million years ago
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8:47 - 8:49with the extinction of the dinosaurs,
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8:49 - 8:51or just at the beginning of the last century,
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8:51 - 8:53when an asteroid wiped out
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8:53 - 8:56almost 1,000 square miles of Siberian forest,
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8:56 - 8:59or even just last year, as one burnt up over Russia,
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8:59 - 9:03releasing the energy of a small nuclear bomb.
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9:03 - 9:07So studying the forensics of our solar system
-
9:07 - 9:09doesn't just tell us about the past,
-
9:09 - 9:12it can also predict the future,
including our future. -
9:15 - 9:17Now when we get distance,
-
9:17 - 9:20we get to see the asteroids
in their natural habitat, -
9:20 - 9:22in orbit around the sun.
-
9:22 - 9:25So every point in this visualization that you can see
-
9:25 - 9:27is a real asteroid.
-
9:27 - 9:31Its orbit has been calculated
from its motion across the sky. -
9:31 - 9:35The colors reflect the composition of these asteroids,
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9:35 - 9:37dry and stony in the center,
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9:37 - 9:39water-rich and primitive towards the edge,
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9:39 - 9:42water-rich asteroids which may have seeded
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9:42 - 9:45the oceans and the seas that we find on our planet
-
9:45 - 9:48when they bombarded the
Earth at an earlier time. -
9:50 - 9:53Because the LSST will be able to go faint
-
9:53 - 9:55and not just wide,
-
9:55 - 9:56we will be able to see these asteroids
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9:56 - 10:00far beyond the inner part of our solar system,
-
10:00 - 10:03to asteroids beyond the
orbits of Neptune and Mars, -
10:03 - 10:06to comets and asteroids that may exist
-
10:06 - 10:09almost a light year from our sun.
-
10:09 - 10:12And as we increase the detail of this picture,
-
10:12 - 10:15increasing the detail by factors of 10 to 100,
-
10:15 - 10:17we will be able to answer questions such as,
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10:17 - 10:21is there evidence for planets
outside the orbit of Neptune, -
10:21 - 10:23to find Earth-impacting asteroids
-
10:23 - 10:26long before they're a danger,
-
10:26 - 10:28and to find out whether, maybe,
-
10:28 - 10:31our sun formed on its own or in a cluster of stars,
-
10:31 - 10:34and maybe it's this sun's stellar siblings
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10:34 - 10:37that influenced the formation of our solar system,
-
10:37 - 10:43and maybe that's one of the reasons why
solar systems like ours seem to be so rare. -
10:43 - 10:48Now, distance and changes in our universe —
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10:48 - 10:51distance equates to time,
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10:51 - 10:53as well as changes on the sky.
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10:53 - 10:56Every foot of distance you look away,
-
10:56 - 10:59or every foot of distance an object is away,
-
10:59 - 11:02you're looking back about a
billionth of a second in time, -
11:02 - 11:05and this idea or this notion of looking back in time
-
11:05 - 11:08has revolutionized our ideas about the universe,
-
11:08 - 11:10not once but multiple times.
-
11:10 - 11:13The first time was in 1929,
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11:13 - 11:15when an astronomer called Edwin Hubble
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11:15 - 11:17showed that the universe was expanding,
-
11:17 - 11:20leading to the ideas of the Big Bang.
-
11:20 - 11:22And the observations were simple:
-
11:22 - 11:24just 24 galaxies
-
11:24 - 11:27and a hand-drawn picture.
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11:29 - 11:34But just the idea that the more distant a galaxy,
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11:34 - 11:36the faster it was receding,
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11:36 - 11:39was enough to give rise to modern cosmology.
-
11:39 - 11:42A second revolution happened 70 years later,
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11:42 - 11:44when two groups of astronomers showed
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11:44 - 11:46that the universe wasn't just expanding,
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11:46 - 11:48it was accelerating,
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11:48 - 11:51a surprise like throwing up a ball into the sky
-
11:51 - 11:54and finding out the higher that it gets,
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11:54 - 11:55the faster it moves away.
-
11:55 - 11:57And they showed this
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11:57 - 11:59by measuring the brightness of supernovae,
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11:59 - 12:01and how the brightness of the supernovae
-
12:01 - 12:03got fainter with distance.
-
12:03 - 12:06And these observations were more complex.
-
12:06 - 12:09They required new technologies and new telescopes,
-
12:09 - 12:13because the supernovae were in galaxies
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12:13 - 12:15that were 2,000 times more distant
-
12:15 - 12:18than the ones used by Hubble.
-
12:18 - 12:23And it took three years to find just 42 supernovae,
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12:23 - 12:25because a supernova only explodes
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12:25 - 12:28once every hundred years within a galaxy.
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12:28 - 12:30Three years to find 42 supernovae
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12:30 - 12:34by searching through tens of thousands of galaxies.
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12:34 - 12:36And once they'd collected their data,
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12:36 - 12:40this is what they found.
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12:40 - 12:42Now, this may not look impressive,
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12:42 - 12:46but this is what a revolution in physics looks like:
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12:46 - 12:49a line predicting the brightness of a supernova
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12:49 - 12:5111 billion light years away,
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12:51 - 12:55and a handful of points that don't quite fit that line.
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12:55 - 12:59Small changes give rise to big consequences.
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12:59 - 13:02Small changes allow us to make discoveries,
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13:02 - 13:05like the planet found by Herschel.
-
13:05 - 13:07Small changes turn our understanding
-
13:07 - 13:09of the universe on its head.
-
13:09 - 13:13So 42 supernovae, slightly too faint,
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13:13 - 13:15meaning slightly further away,
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13:15 - 13:18requiring that a universe must not just be expanding,
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13:18 - 13:21but this expansion must be accelerating,
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13:21 - 13:23revealing a component of our universe
-
13:23 - 13:26which we now call dark energy,
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13:26 - 13:28a component that drives this expansion
-
13:28 - 13:31and makes up 68 percent of the energy budget
-
13:31 - 13:33of our universe today.
-
13:35 - 13:39So what is the next revolution likely to be?
-
13:39 - 13:41Well, what is dark energy and why does it exist?
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13:41 - 13:44Each of these lines shows a different model
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13:44 - 13:46for what dark energy might be,
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13:46 - 13:49showing the properties of dark energy.
-
13:49 - 13:53They all are consistent with the 42 points,
-
13:53 - 13:55but the ideas behind these lines
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13:55 - 13:57are dramatically different.
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13:57 - 13:59Some people think about a dark energy
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13:59 - 14:01that changes with time,
-
14:01 - 14:03or whether the properties of the dark energy
-
14:03 - 14:06are different depending on where you look on the sky.
-
14:06 - 14:08Others make differences and changes
-
14:08 - 14:11to the physics at the sub-atomic level.
-
14:11 - 14:14Or, they look at large scales
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14:14 - 14:17and change how gravity and general relativity work,
-
14:17 - 14:20or they say our universe is just one of many,
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14:20 - 14:23part of this mysterious multiverse,
-
14:23 - 14:26but all of these ideas, all of these theories,
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14:26 - 14:29amazing and admittedly some of them a little crazy,
-
14:29 - 14:33but all of them consistent with our 42 points.
-
14:33 - 14:35So how can we hope to make sense of this
-
14:35 - 14:38over the next decade?
-
14:38 - 14:41Well, imagine if I gave you a pair of dice,
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14:41 - 14:43and I said you wanted to see whether those dice
-
14:43 - 14:45were loaded or fair.
-
14:45 - 14:48One roll of the dice would tell you very little,
-
14:48 - 14:50but the more times you rolled them,
-
14:50 - 14:52the more data you collected,
-
14:52 - 14:54the more confident you would become,
-
14:54 - 14:56not just whether they're loaded or fair,
-
14:56 - 15:00but by how much, and in what way.
-
15:00 - 15:04It took three years to find just 42 supernovae
-
15:04 - 15:07because the telescopes that we built
-
15:07 - 15:11could only survey a small part of the sky.
-
15:11 - 15:14With the LSST, we get a completely new view
-
15:14 - 15:17of the skies above Chile every three nights.
-
15:17 - 15:20In its first night of operation,
-
15:20 - 15:23it will find 10 times the number of supernovae
-
15:23 - 15:26used in the discovery of dark energy.
-
15:26 - 15:28This will increase by 1,000
-
15:28 - 15:30within the first four months:
-
15:30 - 15:351.5 million supernovae by the end of its survey,
-
15:35 - 15:38each supernova a roll of the dice,
-
15:38 - 15:42each supernova testing which theories of dark energy
-
15:42 - 15:46are consistent, and which ones are not.
-
15:46 - 15:50And so, by combining these supernova data
-
15:50 - 15:52with other measures of cosmology,
-
15:52 - 15:55we'll progressively rule out the different ideas
-
15:55 - 15:57and theories of dark energy
-
15:57 - 16:04until hopefully at the end of this survey around 2030,
-
16:04 - 16:06we would expect to hopefully see
-
16:06 - 16:09a theory for our universe,
-
16:09 - 16:11a fundamental theory for the physics of our universe,
-
16:11 - 16:14to gradually emerge.
-
16:15 - 16:17Now, in many ways, the questions that I posed
-
16:17 - 16:22are in reality the simplest of questions.
-
16:22 - 16:23We may not know the answers,
-
16:23 - 16:27but we at least know how to ask the questions.
-
16:27 - 16:30But if looking through tens of thousands of galaxies
-
16:30 - 16:33revealed 42 supernovae that turned
-
16:33 - 16:37our understanding of the universe on its head,
-
16:37 - 16:40when we're working with billions of galaxies,
-
16:40 - 16:42how many more times are we going to find
-
16:42 - 16:4742 points that don't quite match what we expect?
-
16:47 - 16:50Like the planet found by Herschel
-
16:50 - 16:52or dark energy
-
16:52 - 16:56or quantum mechanics or general relativity,
-
16:56 - 16:59all ideas that came because the data
-
16:59 - 17:02didn't quite match what we expected.
-
17:02 - 17:05What's so exciting about the next decade of data
-
17:05 - 17:07in astronomy is,
-
17:07 - 17:09we don't even know how many answers
-
17:09 - 17:11are out there waiting,
-
17:11 - 17:15answers about our origins and our evolution.
-
17:15 - 17:16How many answers are out there
-
17:16 - 17:19that we don't even know the questions
-
17:19 - 17:21that we want to ask?
-
17:21 - 17:23Thank you.
-
17:23 - 17:27(Applause)
- Title:
- What's the next window into our universe?
- Speaker:
- Andrew Connolly
- Description:
-
Big data is everywhere — even the skies. In an informative talk, astronomer Andrew Connolly shows how large amounts of data are being collected about our universe, recording it in its ever-changing moods. Just how do scientists capture so many images at scale? It starts with a giant telescope …
- Video Language:
- English
- Team:
- closed TED
- Project:
- TEDTalks
- Duration:
- 17:39
Morton Bast approved English subtitles for What's the next window into our universe? | ||
tom carter accepted English subtitles for What's the next window into our universe? | ||
Morton Bast edited English subtitles for What's the next window into our universe? | ||
Morton Bast edited English subtitles for What's the next window into our universe? | ||
Morton Bast edited English subtitles for What's the next window into our universe? | ||
Morton Bast approved English subtitles for What's the next window into our universe? | ||
Morton Bast edited English subtitles for What's the next window into our universe? | ||
Morton Bast edited English subtitles for What's the next window into our universe? |