- So, Dan, you're in charge of
the SETI program here at Berkeley.
Can you tell us a little bit about what SETI is?
- SETI is the Search for Extraterrestrial Intelligence.
We're trying to answer the question: Are we alone?
Is anybody out there?
And one of the ideas is that earthlings are sending off
all this radio and television and radar signals
out into space unintentionally,
like "I Love Lucy," "Ed Sullivan"
have left the Earth 50 years ago,
have gone past 10,000 stars.
The nearby stars have seen "The Simpsons."
So if we're polluting space with radio and television,
maybe other civilizations, if they're out there,
maybe they have something like that that we could detect.
And that's what we're trying to do in SETI,
and see if there are any of these signals out there
and see if we're alone.
- So it's not just-- we're not just
sticking an aerial up on our roof here.
How do you actually detect it?
- The signals are likely to be extremely weak,
so you can't find them with a little, tiny antenna.
So we use the world's largest antenna.
We call it a radio telescope.
It's the Arecibo Radio Telescope in Puerto Rico.
It's 1,000 feet in diameter.
It would hold 10 billion bowls of Corn Flakes.
We haven't actually done that yet,
but we've made that calculation.
- You've put in an NSF grant for that.
- We should try that experiment.
- And so you receive them there, and then--
now you have a recording of all these radio signals
coming from space.
How do you tell the difference between E.T.
and all the other things that are out there?
- We need a lot of computing power
to figure out where the signal might be.
We don't know what frequency it might be at,
so we have to listen to a lot of different frequencies,
lot of different channels.
We don't know where to point the telescope,
where E.T. might be lurking, so we want to point it
to all these different places in the sky.
We don't know what kind of signal it is.
Is it AM, FM? Is it pulsing?
So we have a lot of different things we want to go through
and look at our data in a lot of different ways.
And that takes a huge amount of computing power.
So what we do is, we record the data at the telescope,
and then we send it out to the volunteers
all around the world to help us analyze the data.
- And that's a program that you have called SETI@home.
- Right, it's a free program you can download.
You go--just Google SETI, S-E-T-I,
and you can find the SETI@home website.
You install it on your computer,
and then it behaves like any other kind of screen saver.
It pops up when you go out for a cup of coffee.
But instead of just putting pretty pictures on your screen,
it's actually going through the data,
looking for that faint murmur
of an extraterrestrial civilization.
And your name is attached to the data.
So if you're the lucky one that finds E.T.,
you get the Nobel Prize.
- Along with you.
- With me and maybe 8 million other people.
- Tell us a little bit about that SETI@home receiver
you have at Arecibo.
- Right, so we just got back from the telescope,
where we installed this new instrument that can listen
to 5 billion channels simultaneously.
So the name of the game is to listen to as many channels
as you can because we don't know
what channel E.T. might be broadcasting on.
You don't want to do it one at a time
like a police scanner-- listen here, then here,
then here, then here, then here,
kind of step across the band.
You want to listen to all the channels.
It's like having 5 billion radios,
each one tuned to a different frequency, each one listening.
We're just trying to figure out
if there's something strong there.
So it's like looking at the signal strength meter
and seeing if it peaks up.
It's one of those frequencies.
That's what gets our attention.
Then we'll go back and check it out
and see if it's something really exciting.
So we're trying to look at new frequency bands.
Every year, we try to launch a new SETI program.
We're looking at radio frequencies,
now these super-low frequencies.
We're doing work at visible--
looking for laser signals.
And we're also just starting off something in the infrared,
looking for infrared laser signals.
- Recently we've had a lot of interesting scientific results
given to us from the Kepler mission,
which has discovered thousands of planets
going around other stars.
And that must make you feel really good.
- This is really exciting.
If you extrapolate
from the few thousand planets that they found
by the little patch in the sky that they looked at,
if you extrapolate, it looks like
there's a trillion planets in the Milky Way galaxy.
A trillion planets-- that's five times more planets
than there are stars.
So there's lots of planets out there,
and some of them that they found are like the Earth.
They're little dinky things,
and they're probably rocky,
and a lot of them have liquid water.
So we think that there are lots of places
for life in the universe.
- So, Dan, there's been a history about SETI.
We're not the first ones to think about this.
When did all this thought
about extraterrestrial life begin?
- The first guys to actually do SETI experiments
were the early pioneers of radio: Marconi and Tesla.
These guys were the discoverers.
They invented radio.
And they thought, well,
maybe E.T. would use radio to communicate.
And they actually did experiments
looking for these radio waves.
And they thought they heard this stuff in their headsets.
And they thought they had found E.T.
And they didn't know it at the time,
but there were big headlines in the press,
you know, extraterrestrials,
but it turned out they were
listening to distant lightning bolts.
And when the lightning bolts bounce around
between the ionosphere and the Earth,
they get dispersed,
and you get this kind of whistling noise.
[whistling softly]
- Sort of like our echo tube.
- They're called whistlers. Yeah, like the echo tube.
And, in fact, it's the same process.
[sharp claps, whistling sounds echoing]