SETI Astronomer: Aliens Probably Look Like Robots

The scoop: Ever imagined what that first moment of alien contact might be like? Perhaps a slimy green creature descending from a saucer-shape spaceship, or maybe just a repeating radio beacon.

To find out what the experts think, Discovery Space linked up with Seth Shostak -- senior astronomer at the Search for Extraterrestrial Intelligence (SETI) institute who consulted on "The Day the Earth Stood Still" movie remake.

Dave on Earth (1:01 PM): Hi Seth. How are you?

SethHeartsAliens (1:02 PM): Just peachy-keen, Dave!

Dave on Earth (1:03 PM): Great. So we're here to chat about aliens... but before we start, what do you have to do with extraterrestrial life?

SethHeartsAliens (1:03 PM): Well, my day job is to look for them.
Not here on Earth, but aliens that might be on other worlds, sending us a radio broadcast.

Dave on Earth (1:04 PM): I know some would beg to differ, but so far I assume we haven't talked to aliens yet. Correct?

SethHeartsAliens (1:05 PM): That's correct. We still haven't received any radio signals that we believe were sent by extraterrestrials.
We're looking, of course, and our search is speeding up, too.

Dave on Earth (1:05 PM): What about the "Wow!" signal?

SethHeartsAliens (1:05 PM): Well, that was a strange signal received in 1977 with an antenna in Ohio.
No one yet knows for sure what it was, but it was only picked up once. So... if you can't see it again, if you only hear it a single time, then you can't claim that it was ET.
You just don't know.

Dave on Earth (1:06 PM): Thanks. If we did make contact, do you have any idea what the aliens might look like?

SethHeartsAliens (1:07 PM): That's a question that everyone asks!
In the movies they often look a lot like us -- two arms, two legs, a head, two eyes, and so forth.
But really, if you go down to the local zoo, and check out the critters there, THEY don't look like us.
So I don't think aliens would, either.
But my personal opinion is that if we find a signal...
... it will be coming from a society that's more advanced than ours.
So they may have already invented thinking machines.

Dave on Earth (1:08 PM): Thinking machines?

SethHeartsAliens (1:09 PM): Yep. I'm willing to bet you a lunch that any signal we eventually find will be coming from ...
... you said it, thinking machines!

Dave on Earth (1:09 PM): So my computer could be an alien?

SethHeartsAliens (1:09 PM): Well, I don't know how smart your computer is. When it's clever enough to take over your job, I'll be willing to admit that it might be like an alien!

Dave on Earth (1:09 PM): The one I'm working from is pretty dumb, but it has a few tricks up its silicon sleeves.

SethHeartsAliens (1:10 PM): Glad to hear it has sleeves!
But this would be the kind of machine that could teach high school chemistry, or write that Great American Novel.

Dave on Earth (1:10 PM): Honestly, I don't think of machines when I think of aliens.
Why do you think it will be a machine and not, well, a living thing?

SethHeartsAliens (1:11 PM): I think this is just a matter of time scales.
Imagine an alien society that invents radio, similar to the way we did 100 years ago.
Within a century, they've invented computers.
And within a century after that, maybe, they've invented thinking machines.
So: if any aliens we hear are as much as a few centuries ahead of us, they've already invented their successors.

Dave on Earth (1:12 PM): I see... don't you think that's a little depressing?

SethHeartsAliens (1:12 PM): I think we're just subjecting ourselves to wishful thinking when we imagine that the aliens will be protoplasm blobs the way we are!

Dave on Earth (1:12 PM): True... I suppose I just never like that robot from "Lost in Space."
I wouldn't want to meet that kind of "thinking machine" -- too annoying. I'd rather meet other protoplasm blobs.

SethHeartsAliens (1:12 PM): Machines don't bug me that much. And we could be their pets!
Robert May... Yes, I met that fellow once! But he was a very limited robot.
All he could do is roll around the landscape saying "Danger, Will Robinson!" A dog can do more than that.
The machines we'll have a century from now will be rather more sophisticated, I think.

Dave on Earth (1:14 PM): Ok, so let me rephrase my big question:
What might an alien "thinking machine" look like? Obviously this is speculative territory, but it's your job to think about these things :)

SethHeartsAliens (1:14 PM): Well, it may not matter much what it LOOKS like.
What counts is what it is doing that we might detect, even from light-years away. And as you implied, we don't know.
But maybe it's sending out light or radio signals that our telescopes could pick up.
That's one way to find them .. maybe the best way.
Another possibility is that they are building giant structures that we could see.

Dave on Earth (1:15 PM): Is there a chance SETI and everyone else is looking for the wrong thing?

SethHeartsAliens (1:15 PM): Of course there's a chance that we're doing the wrong thing, but if you don't know, then I think you should do SOMETHING.
We'll never find the aliens by just throwing up our hands and saying "we don't know how to look!"
Better to explore and not find them, than to not explore and be guaranteed not to find them!

Dave on Earth (1:17 PM): Thanks. Now another question...
Do you ever ponder why they would want to contact us -- and would you be afraid of ever making contact?

SethHeartsAliens (1:17 PM): Well, I'm certainly not afraid of hearing them on the radio. After all, they won't know that we picked up their signal.

Dave on Earth (1:18 PM): What if their politically correct greeting is to chew off one of our arms or something?

SethHeartsAliens (1:18 PM): If aliens ever came to Earth --- well, that might be a bit different!
Indeed, usually when an advanced society visits a less-advanced society, it's bad news for the less-advanced.
Frankly, I don't know why we'd be visited. I think it's unlikely that the aliens even know we're here.

Dave on Earth (1:19 PM): I see. Here's another depressing thought:
What if they know about us, but are completely avoiding us?
Maybe they know that we smell bad. Or that we're jerks to our planet

SethHeartsAliens (1:19 PM): Gosh, no one likes to be a social outcast!
But as I say, I don't think they know about how we smell or how we treat our planet.
And that's because signals that would tell them that -- for example, our TV shows -- haven't reached them yet, most likely.
They may know about the oxygen in our atmosphere, and that might tell them about plants on Earth. But I doubt any of them know about humans!
Maybe they'll come to Earth to save the chestnut trees, but I doubt it.

Dave on Earth (1:22 PM): So to touch on something you typed a moment ago...
If no aliens probably know about us yet, why are we looking for signs of them?