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Should we try to talk to aliens? | 91TV

5 mins watch 27 November 2025

Transcript

  • STAR 1: Hello? STAR 2: Can you hear us?
  • STAR 1: I can hear you. Can you hear me?
  • STAR 2: Hello?
  • ECHOING: Is there anybody out there?
  • NARRATOR: Well, that's the question, isn't it?
  • Has been for as long as anyone can remember.
  • Are we alone?
  • It might sound like science fiction,
  • but the Universe is so vast,
  • many scientists think it's unrealistic to imagine
  • we're the only form of life in it.
  • Alien life may also be what we would consider intelligent.
  • But as the physicist Enrico Fermi asked in 1950,
  • if we're not alone, where is everybody?
  • MIKE GARRETT: The Universe is full of natural radio waves
  • generated by stars and planets and galaxies.
  • But that emission is really very smooth.
  • NARRATOR: That's Mike Garrett, an astrophysicist
  • and active member of SETI -
  • the Search for Extra Terrestrial Intelligence.
  • MIKE: Artificial radio waves are very spiky
  • because they convey information.
  • So we're looking for anomalies - the signature
  • of potentially other intelligent civilisations out there,
  • broadcasting to the Universe.
  • DOUGLAS VAKOCH: What SETI assumes
  • is that the aliens are very motivated,
  • that they're going out of their way to send us intentional signals
  • for our benefit.
  • NARRATOR: And that's Douglas Vakoch, the founder of Meti,
  • which stands for Messaging Extra Terrestrial Intelligence.
  • They think listening is not enough.
  • DOUGLAS: Maybe we should do the heavy lifting by reaching out first.
  • I mean, someone has to take the first move.
  • NARRATOR: Making the first move in any relationship has its risks -
  • opening oneself up to rejection, or worse.
  • Stories of alien fleets visiting Earth with the sole intention
  • of wiping us out are common ground for science fiction.
  • But there is a theory that, if we're not careful,
  • this could become science fact.
  • MIKE: I think one of the things that Stephen Hawking,
  • famous cosmologist,
  • said about this idea of transmitting signals
  • is that it might not turn out very well for us here on this planet -
  • just like it didn't turn out very well for the Native Americans
  • when Columbus first settled there.
  • NARRATOR: But Meti is amongst those who see this argument
  • as a red herring.
  • DOUGLAS: It's too late to hide. We're already known in the Universe.
  • NARRATOR: Douglas and his colleagues believe that, through TV
  • and radio broadcasts - not to mention mobile phone towers -
  • Earth has been leaking radiation into space for decades.
  • This "leakage" is exactly what Seti look for
  • as signs of life elsewhere,
  • so it stands to reason that,
  • if aliens are listening, they could probably already hear us.
  • One theory, known as The Zoo Hypothesis,
  • is that aliens already know we exist.
  • But rather than making contact, they're studying us from afar -
  • as if we were animals in a zoo.
  • Douglas thinks that by sending out regular messages,
  • we can demonstrate both our intelligence
  • and desire to communicate.
  • DOUGLAS: If you imagine we go to the zoo
  • and we're walking around and we see a bunch of giraffes,
  • what happens if one of them turns around, looks us in the eye
  • and starts pounding out a series of prime numbers with its hoof?
  • We're trying to be the galactic giraffes here.
  • NARRATOR: But for Seti, and Mike, this remains problematic.
  • Though not against communicating per se,
  • Mike argues that we need to think much more carefully
  • about what we want to say and how we want to say it.
  • MIKE: Who speaks for Earth? And who has the right?
  • When I see a lot of these signals being sent,
  • they don't represent all of this planet.
  • You know, just arbitrarily sending signals out into space
  • is not very democratic.
  • NARRATOR: If humans were to enter a dialogue with an alien species,
  • how would we get them to understand us?
  • This is more than a language barrier.
  • It's a fundamental difference barrier.
  • Because of the enormous distances involved,
  • we're also dealing in difficult timescales.
  • If we send a message to a life form 1,000 light years away,
  • it will take 1,000 years to reach them.
  • And assuming their technology is similar to ours,
  • we'd wait another 1,000 years for the reply.
  • DOUGLAS: It's almost like you get an email from someone ten years ago
  • and they say, "Yes, sounds great."
  • But you don't even remember what it was about.
  • This only works if it's something embraced by generations to come.
  • NARRATOR: The first message sent into space
  • for the benefit of aliens was in 1974 -
  • more than 50 years ago.
  • It became known as the Arecibo Message.
  • And so far, we have received nothing in return -
  • which returns us to Enrico Fermi's question -
  • "Where is everybody?"
  • Meti will continue reaching out to those planets that orbit
  • within what's known as the "Goldilocks Zone" -
  • not too hot, not too cold -
  • just right for potential life.
  • Meanwhile, Mike and Seti will keep an ear to the sky,
  • advancing techniques to pick up signals from other worlds.
  • And maybe one day, just maybe...
  • MIKE: If we detect a signal
  • and we know that we're not alone in the Universe,
  • I think that should make people happy.
  • If we discover another civilisation
  • and they're very different from us,
  • we'll realise actually how similar we are to our neighbours.

Is there human-like alien intelligence out there. Do they already know about us, and what are the risks of trying to make contact? professor Mike Garrett of SETI (The Search for Extra-Terrestrial Intelligence) and Douglas Vakoch of METI (Messaging Extra-Terrestrial Intelligence) answer these questions and more.

made in partnership with @bbcideas


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