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  • So, my question:

  • are we alone?

  • The story of humans is the story of ideas --

  • scientific ideas that shine light into dark corners,

  • ideas that we embrace rationally and irrationally,

  • ideas for which we've lived and died and killed and been killed,

  • ideas that have vanished in history,

  • and ideas that have been set in dogma.

  • It's a story of nations,

  • of ideologies,

  • of territories,

  • and of conflicts among them.

  • But, every moment of human history,

  • from the Stone Age to the Information Age,

  • from Sumer and Babylon to the iPod and celebrity gossip,

  • they've all been carried out --

  • every book that you've read,

  • every poem, every laugh, every tear --

  • they've all happened here.

  • Here.

  • Here.

  • Here.

  • (Laughter)

  • Perspective is a very powerful thing.

  • Perspectives can change.

  • Perspectives can be altered.

  • From my perspective, we live on a fragile island of life,

  • in a universe of possibilities.

  • For many millennia, humans have been on a journey to find answers,

  • answers to questions about naturalism and transcendence,

  • about who we are and why we are,

  • and of course, who else might be out there.

  • Is it really just us?

  • Are we alone in this vast universe

  • of energy and matter and chemistry and physics?

  • Well, if we are, it's an awful waste of space.

  • (Laughter)

  • But, what if we're not?

  • What if, out there, others are asking and answering similar questions?

  • What if they look up at the night sky, at the same stars,

  • but from the opposite side?

  • Would the discovery of an older cultural civilization out there

  • inspire us to find ways to survive

  • our increasingly uncertain technological adolescence?

  • Might it be the discovery of a distant civilization

  • and our common cosmic origins

  • that finally drives home the message of the bond among all humans?

  • Whether we're born in San Francisco, or Sudan,

  • or close to the heart of the Milky Way galaxy,

  • we are the products of a billion-year lineage of wandering stardust.

  • We, all of us,

  • are what happens when a primordial mixture of hydrogen and helium

  • evolves for so long that it begins to ask where it came from.

  • Fifty years ago,

  • the journey to find answers took a different path

  • and SETI, the Search for Extra-Terrestrial Intelligence,

  • began.

  • So, what exactly is SETI?

  • Well, SETI uses the tools of astronomy

  • to try and find evidence of someone else's technology out there.

  • Our own technologies are visible over interstellar distances,

  • and theirs might be as well.

  • It might be that some massive network of communications,

  • or some shield against asteroidal impact,

  • or some huge astro-engineering project that we can't even begin to conceive of,

  • could generate signals at radio or optical frequencies

  • that a determined program of searching might detect.

  • For millennia, we've actually turned to the priests and the philosophers

  • for guidance and instruction on this question of whether there's intelligent life out there.

  • Now, we can use the tools of the 21st century to try and observe what is,

  • rather than ask what should be, believed.

  • SETI doesn't presume the existence of extra terrestrial intelligence;

  • it merely notes the possibility, if not the probability

  • in this vast universe, which seems fairly uniform.

  • The numbers suggest a universe of possibilities.

  • Our sun is one of 400 billion stars in our galaxy,

  • and we know that many other stars have planetary systems.

  • We've discovered over 350 in the last 14 years,

  • including the small planet, announced earlier this week,

  • which has a radius just twice the size of the Earth.

  • And, if even all of the planetary systems in our galaxy were devoid of life,

  • there are still 100 billion other galaxies out there,

  • altogether 10^22 stars.

  • Now, I'm going to try a trick, and recreate an experiment from this morning.

  • Remember, one billion?

  • But, this time not one billion dollars, one billion stars.

  • Alright, one billion stars.

  • Now, up there, 20 feet above the stage,

  • that's 10 trillion.

  • Well, what about 10^22?

  • Where's the line that marks that?

  • That line would have to be 3.8 million miles above this stage.

  • (Laughter)

  • 16 times farther away than the moon,

  • or four percent of the distance to the sun.

  • So, there are many possibilities.

  • (Laughter)

  • And much of this vast universe,

  • much more may be habitable than we once thought,

  • as we study extremophiles on Earth --

  • organisms that can live in conditions totally inhospitable for us,

  • in the hot, high pressure thermal vents at the bottom of the ocean,

  • frozen in ice, in boiling battery acid,

  • in the cooling waters of nuclear reactors.

  • These extremophiles tell us that life may exist in many other environments.

  • But those environments are going to be widely spaced in this universe.

  • Even our nearest star, the Sun --

  • its emissions suffer the tyranny of light speed.

  • It takes a full eight minutes for its radiation to reach us.

  • And the nearest star is 4.2 light years away,

  • which means its light takes 4.2 years to get here.

  • And the edge of our galaxy is 75,000 light years away,

  • and the nearest galaxy to us, 2.5 million light years.

  • That means any signal we detect would have started its journey a long time ago.

  • And a signal would give us a glimpse of their past,

  • not their present.

  • Which is why Phil Morrison calls SETI, "the archaeology of the future."

  • It tells us about their past,

  • but detection of a signal tells us it's possible for us to have a long future.

  • I think this is what David Deutsch meant in 2005,

  • when he ended his Oxford TEDTalk

  • by saying he had two principles he'd like to share for living,

  • and he would like to carve them on stone tablets.

  • The first is that problems are inevitable.

  • The second is that problems are soluble.

  • So, ultimately what's going to determine the success or failure of SETI

  • is the longevity of technologies,

  • and the mean distance between technologies in the cosmos --

  • distance over space and distance over time.

  • If technologies don't last and persist,

  • we will not succeed.

  • And we're a very young technology

  • in an old galaxy,

  • and we don't yet know whether it's possible for technologies to persist.

  • So, up until now I've been talking to you about really large numbers.

  • Let me talk about a relatively small number.

  • And that's the length of time that the Earth was lifeless.

  • Zircons that are mined in the Jack Hills of western Australia,

  • zircons taken from the Jack Hills of western Australia

  • tell us that within a few hundred million years of the origin of the planet

  • there was abundant water and perhaps even life.

  • So, our planet has spent the vast majority of its 4.56 billion year history

  • developing life,

  • not anticipating its emergence.

  • Life happened very quickly,

  • and that bodes well for the potential of life elsewhere in the cosmos.

  • And the other thing that one should take away from this chart

  • is the very narrow range of time

  • over which humans can claim to be the dominant intelligence on the planet.

  • It's only the last few hundred thousand years

  • modern humans have been pursuing technology and civilization.

  • So, one needs a very deep appreciation

  • of the diversity and incredible scale of life on this planet

  • as the first step in preparing to make contact with life elsewhere in the cosmos.

  • We are not the pinnacle of evolution.

  • We are not the determined product

  • of billions of years of evolutionary plotting and planning.

  • We are one outcome of a continuing adaptational process.

  • We are residents of one small planet

  • in a corner of the Milky Way galaxy.

  • And Homo sapiens are one small leaf

  • on a very extensive Tree of Life,

  • which is densely populated by organisms that have been honed for survival

  • over millions of years.

  • We misuse language,

  • and talk about the "ascent" of man.

  • We understand the scientific basis for the interrelatedness of life

  • but our ego hasn't caught up yet.

  • So this "ascent" of man, pinnacle of evolution,

  • has got to go.

  • It's a sense of privilege that the natural universe doesn't share.

  • Loren Eiseley has said,

  • "One does not meet oneself

  • until one catches the reflection from an eye other than human."

  • One day that eye may be that of an intelligent alien,

  • and the sooner we eschew our narrow view of evolution

  • the sooner we can truly explore our ultimate origins and destinations.

  • We are a small part of the story of cosmic evolution,

  • and we are going to be responsible for our continued participation in that story,

  • and perhaps SETI will help as well.

  • Occasionally, throughout history, this concept

  • of this very large cosmic perspective comes to the surface,

  • and as a result we see transformative and profound discoveries.

  • So in 1543, Nicholas Copernicus published "The Revolutions of Heavenly Spheres,"

  • and by taking the Earth out of the center,

  • and putting the sun in the center of the solar system,

  • he opened our eyes to a much larger universe,

  • of which we are just a small part.

  • And that Copernican revolution continues today

  • to influence science and philosophy and technology and theology.

  • So, in 1959, Giuseppe Coccone and Philip Morrison

  • published the first SETI article in a refereed journal,

  • and brought SETI into the scientific mainstream.

  • And in 1960, Frank Drake conducted the first SETI observation

  • looking at two stars, Tau Ceti and Epsilon Eridani,

  • for about 150 hours.

  • Now Drake did not discover extraterrestrial intelligence,

  • but he learned a very valuable lesson from a passing aircraft,

  • and that's that terrestrial technology can interfere

  • with the search for extraterrestrial technology.

  • We've been searching ever since,

  • but it's impossible to overstate the magnitude of the search that remains.

  • All of the concerted SETI efforts, over the last 40-some years,

  • are equivalent to scooping a single glass of water from the oceans.

  • And no one would decide that the ocean was without fish

  • on the basis of one glass of water.

  • The 21st century now allows us to build bigger glasses --

  • much bigger glasses.

  • In Northern California, we're beginning to take observations

  • with the first 42 telescopes of the Allen Telescope Array --

  • and I've got to take a moment right now to publicly thank

  • Paul Allen and Nathan Myhrvold

  • and all the TeamSETI members in the TED community

  • who have so generously supported this research.

  • (Applause)

  • The ATA is the first telescope built from a large number of small dishes,

  • and hooked together with computers.

  • It's making silicon as important as aluminum,

  • and we'll grow it in the future by adding more antennas to reach 350

  • for more sensitivity and leveraging Moore's law for more processing capability.

  • Today, our signal detection algorithms

  • can find very simple artifacts and noise.

  • If you look very hard here you can see the signal from the Voyager 1 spacecraft,

  • the most distant human object in the universe,

  • 106 times as far away from us as the sun is.

  • And over those long distances, its signal is very faint when it reaches us.

  • It may be hard for your eye to see it,

  • but it's easily found with our efficient algorithms.

  • But this is a simple signal,

  • and tomorrow we want to be able to find more complex signals.

  • This is a very good year.

  • 2009 is the 400th anniversary of Galileo's first use of the telescope,

  • Darwin's 200th birthday,

  • the 150th anniversary of the publication of "On the Origin of Species,"

  • the 50th anniversary of SETI as a science,

  • the 25th anniversary of the incorporation of the SETI Institute as a non-profit,

  • and of course, the 25th anniversary of TED.

  • And next month, the Kepler Spacecraft will launch

  • and will begin to tell us just how frequent Earth-like planets are,

  • the targets for SETI's searches.

  • In 2009, the U.N. has declared it to be the International Year of Astronomy,

  • a global festival to help us residents of Earth

  • rediscover our cosmic origins and our place in the universe.

  • And in 2009, change has come to Washington,