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Where are the Space Aliens?!

2010-09-09 · Hank · watch on YouTube · Science & nature · explainer learning

Continuing his Hubble Ultra Deep Field video, Hank explains the Fermi Paradox and its possible resolutions (self-destruction, transformation, hiding, a zoo, our short broadcasting history), concluding that the one civilization we know must be protected from itself.

What is said

00:00:00 — Continuation of the Hubble Ultra Deep Field video; 100-400 billion stars; Enrico Fermi asks 'Where are they?'

  • ★★ Hank says this video continues his video from a couple of months ago meant to blow John's mind, about the Hubble Ultra Deep Field, and tells viewers to watch that first. — 00:00:00
  • ★★ Hank says there are between 100 billion and 400 billion stars in our galaxy. — 00:00:00
  • ★★ Hank recounts that the physicist Enrico Fermi, discussing civilization and the size of the universe with fellow scientists, asked 'Where are they?' — 00:00:00 > «Where are they?»
  • ★★★ The description says Hank believes we don't hear aliens because it is foolish to assume other civilizations communicate, think or act as we do, and if they do, they probably don't last long, as we probably won't. (hedged) — 00:00:00

00:00:29 — The reasoning: planets, life and civilizations should be common and should have colonized or at least broadcast; we hear nothing: the Fermi Paradox

  • ★★★ Hank reasons that among 400 billion stars many should have planets, life and advanced civilizations that, if interstellar travel is possible, would have colonized the galaxy. — 00:00:29
  • ★★★ Even if they don't expand, Hank says, we should at least hear them, assuming other civilizations broadcast as ours does. — 00:00:58
  • ★★ Hank says our civilization has been broadcasting ultra-high-frequency broadband signals that can be detected tens of thousands of light years away. — 00:00:58
    • number check: tens of thousands of light years — doubtful
  • ★★ Hank says we have detected nothing: as far as we can tell, aliens either aren't out there or aren't watching TV. (playful) — 00:01:28
  • ★★★ Hank names the problem: the Fermi Paradox asks why we don't hear aliens if there should be so many of them. — 00:01:28
  • ★★ Hank says examining the Fermi Paradox helps him think more about humanity and our civilization than about alien civilizations. — 00:01:28

00:01:58 — Possible answers: civilizations destroy themselves or change beyond recognition, hide (Prime Directive), keep us in a zoo, or our signals have barely left home

  • ★★★ Hank says it is possible, and it constantly worries him, that advanced civilizations tend to destroy themselves, through atomic winter, big natural events or losing interest in procreation. (hedged) — 00:01:58
  • ★★ Hank suggests civilizations may change into something we can't understand, such as consciousnesses downloaded into sun-powered planet-wide computers that emit no signals. (hedged) — 00:01:58
  • ★★ Other options, Hank says: aliens may be hiding, like Star Trek's Prime Directive against interfering with non-spacefaring civilizations, or keeping us in a zoo and watching us. (hedged) — 00:02:27
  • ★★★ Hank says we've broadcast radio for barely a hundred years; if the nearest listening civilization is 50,000 light years away, our signals won't arrive for another 49,900 years. — 00:02:56
  • ★★ Hank says the first civilization to hear our radio signals might not exist yet, and by the time it does, we might not exist anymore. (hedged) — 00:02:56

00:03:25 — We know one civilization and must protect it from itself; question to Nerdfighteria; sign-off

  • ★★★ Hank concludes that we know of one advanced civilization, unique or one of millions, which we must observe carefully and protect from its greatest enemy: itself. — 00:03:25
  • ★★ Hank asks Nerdfighteria whether they think there is life out there in the galaxy, whether we'll ever see it, and whether it would kill us or be friendly. — 00:03:25 · Nerdfighteria

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