Why Can't We See Evidence of Alien Life?
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0:00 - 0:15(Music)
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0:15 - 0:18Somewhere out there in that vast universe
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0:18 - 0:21there must surely be countless other planets teeming with life,
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0:21 - 0:24but why don't we see any evidence of it?
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0:24 - 0:28Well, this is the famous question asked by Enrico Fermi in 1950:
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0:28 - 0:31"Where is everybody?"
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0:31 - 0:35Conspiracy theorists claim that UFOs are visiting all the time
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0:35 - 0:37and the reports are just being covered up,
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0:37 - 0:40but honestly, they aren't very convincing.
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0:40 - 0:42But that leaves a real riddle.
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0:42 - 0:45In the past year, the Kepler space observatory has found
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0:45 - 0:48hundreds of planets just around nearby stars,
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0:48 - 0:50and if you extrapolate that data,
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0:50 - 0:53it looks like there could be half a trillions planets
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0:53 - 0:56just in our own galaxy.
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0:56 - 0:59If any one in 10,000 has conditions
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0:59 - 1:02that might support a form of life, that's still
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1:02 - 1:0450 million possible life-harboring planets
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1:04 - 1:06right here in the Milky Way.
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1:06 - 1:08So here's the riddle.
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1:08 - 1:13Our Earth didn't form until about 9 billion years after the Big Bang.
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1:13 - 1:16Countless other planets in our galaxy
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1:16 - 1:19should have formed earlier and given life a chance to get underway
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1:19 - 1:23billions, or certainly many millions, of years
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1:23 - 1:25earlier than happened on Earth.
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1:25 - 1:28If just a few of them had spawned intelligent life
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1:28 - 1:30and started creating technologies,
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1:30 - 1:33those technologies would have had millions of years
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1:33 - 1:36to grow in complexity and power.
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1:36 - 1:38On Earth,
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1:38 - 1:41we've seen how dramatically
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1:41 - 1:44technology can accelerate in just 100 years.
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1:44 - 1:48In millions of years, an intelligent alien civilization
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1:48 - 1:51could easily have spread out across the galaxy,
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1:51 - 1:54perhaps creating giant energy-harvesting artifacts
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1:54 - 1:57or fleets of colonizing spaceships
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1:57 - 2:00or glorious works of art that fill the night sky.
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2:00 - 2:03At the very least, you'd think they'd be revealing their presence,
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2:03 - 2:05deliberately or otherwise,
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2:05 - 2:08through electromagnetic signals
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2:08 - 2:11of one kind or another. And yet we see no convincing evidence of any of it.
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2:11 - 2:14Why?
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2:14 - 2:17Well, there are numerous possible answers,
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2:17 - 2:19some of them quite dark.
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2:19 - 2:22Maybe a single, super-intelligent civilization
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2:22 - 2:25has indeed taken over the galaxy,
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2:25 - 2:28and has imposed strict radio silence
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2:28 - 2:31because it's paranoid of any potential competitors.
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2:31 - 2:34It's just sitting there ready to obliterate
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2:34 - 2:37anything that becomes a threat.
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2:37 - 2:40Or maybe they're not that intelligent,
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2:40 - 2:43or perhaps the evolution of an intelligence
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2:43 - 2:45capable of creating sophisticated technology
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2:45 - 2:47is far rarer than we've assumed.
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2:47 - 2:52After all, it's only happened once on Earth in 4 billion years.
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2:52 - 2:55Maybe even that was incredibly lucky.
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2:55 - 2:58Maybe we are the first such civilization in our galaxy.
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2:58 - 3:02Or perhaps civilization carries with it
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3:02 - 3:04the seeds of its own destruction
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3:04 - 3:07through the inability to control the technologies it creates.
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3:07 - 3:12But there are numerous more hopeful answers.
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3:12 - 3:16I mean, for a start, we're not looking that hard. And we're spending a pitiful amount of money on it.
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3:16 - 3:20Only a tiny fraction of the stars in our galaxy
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3:20 - 3:23have really been looked at closely for signs of interesting signals.
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3:23 - 3:26And perhaps we're not looking the right way.
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3:26 - 3:29Maybe as civilizations develop,
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3:29 - 3:32they quickly discover communication technologies
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3:32 - 3:35far more sophisticated and useful than electromagnetic waves.
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3:35 - 3:38Maybe all the action takes place
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3:38 - 3:42inside the mysterious recently discovered dark matter,
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3:42 - 3:46or dark energy, that appear to account for most of the universe's mass.
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3:46 - 3:50Or maybe we're looking at the wrong scale.
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3:50 - 3:53Perhaps intelligent civilizations come to realize
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3:53 - 3:56that life is ultimately just complex patterns of information
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3:56 - 3:58interacting with each other in a beautiful way,
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3:58 - 4:01and that that can happen more efficiently at a small scale.
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4:01 - 4:04So, just as on Earth clunky stereo systems
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4:04 - 4:07have shrunk to beautiful, tiny iPods, maybe intelligent life itself,
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4:07 - 4:10in order to reduce its footprint on the environment,
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4:10 - 4:12has turned itself microscopic,
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4:12 - 4:15so the Solar System might be teeming with aliens, and we're just not noticing them.
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4:15 - 4:19Maybe the very ideas in our heads are a form of alien life.
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4:19 - 4:22Well, okay, that's a crazy thought.
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4:22 - 4:24The aliens made me say it.
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4:24 - 4:27But it is cool that ideas do seem to have a life all of their own
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4:27 - 4:30and that they outlive their creators.
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4:30 - 4:35Maybe biological life is just a passing phase.
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4:35 - 4:40Well, within the next 15 years,
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4:40 - 4:42we could start seeing real spectroscopic information
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4:42 - 4:46from promising nearby planets that will reveal just how life-ready they might be.
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4:46 - 4:49And meanwhile SETI, the Search for Extra-Terrestrial Intelligence,
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4:49 - 4:52is now releasing its data to the public
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4:52 - 4:55so that millions of citizen scientists, maybe including you,
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4:55 - 4:58can bring the power of the crowd to join the search.
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4:58 - 5:01And here on Earth, amazing experiments are being done
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5:01 - 5:04to try to create life from scratch,
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5:04 - 5:07life that might be very different from the DNA forms we know.
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5:07 - 5:09All of this will help us understand
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5:09 - 5:12whether the universe is teeming with life
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5:12 - 5:16or whether, indeed, it's just us.
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5:16 - 5:20Either answer, in its own way,
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5:20 - 5:23is awe-inspiring,
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5:23 - 5:25because even if we are alone,
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5:25 - 5:29the fact that we think and dream and ask these questions
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5:29 - 5:33might yet turn out to be one of the most important facts about the universe.
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5:33 - 5:37And I have one more piece of good news for you.
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5:37 - 5:40The quest for knowledge and understanding never gets dull.
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5:40 - 5:43It doesn't. It's actually the opposite. The more you know,
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5:43 - 5:46the more amazing the world seems.
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5:46 - 5:49And it's the crazy possibilities, the unanswered questions,
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5:49 - 5:53that pull us forward. So stay curious.
- Title:
- Why Can't We See Evidence of Alien Life?
- Speaker:
- Chris Anderson
- Description:
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Stand by for an animated exploration of the famous Fermi Paradox. Given the vast number of planets in the universe, many much older than Earth, why haven't we yet seen obvious signs of alien life? The potential answers to this question are numerous and intriguing, alarming and hopeful.
- Video Language:
- English
- Team:
- closed TED
- Project:
- TED-Ed
- Duration:
- 06:04
Krystian Aparta commented on English subtitles for Why can't we see evidence of alien life? | ||
Krystian Aparta edited English subtitles for Why can't we see evidence of alien life? | ||
Sara Bgd edited English subtitles for Why can't we see evidence of alien life? | ||
Jenny Zurawell edited English subtitles for Why can't we see evidence of alien life? | ||
Francesca Pratali edited English subtitles for Why can't we see evidence of alien life? | ||
Francesca Pratali edited English subtitles for Why can't we see evidence of alien life? | ||
Jenny Zurawell approved English subtitles for Why can't we see evidence of alien life? | ||
Jenny Zurawell edited English subtitles for Why can't we see evidence of alien life? |
Krystian Aparta
The English transcript was updated on 10/4/2016.