What Sagan missed.

What Sagan missed.
There is a mathematical meaning to this principle. An extraordinary claim is not one that is merely surprising; it is one that is assigned a very low prior probability. The argument is statistical: if a claim is highly improbable, then the evidence required to overcome that improbability must be correspondingly strong. Within its proper domain, this makes perfect sense. But what are the odds of a visitation? And more importantly—how would we know? Fermi’s paradox arises precisely because, given the age of the universe, there should exist civilizations vastly older than ours—perhaps by hundreds of millions or even billions of years. Such civilizations would have had more than enough time to spread throughout the galaxy without ever exceeding the speed of light. Galactic colonization does not require exotic propulsion; it only requires time. This is why Fermi asked, “Where is everyone?” His point was that, under reasonable assumptions, extraterrestrial presence should be expected. If that is true, then why would a claimed sighting be considered an extraordinary claim? Now consider superluminal travel. While we currently lack a practical mechanism for exceeding the speed of light, General Relativity does not strictly forbid all forms of effective faster‑than‑light motion. And it remains possible that some future physics—unknown to us but not to a civilization millions of years ahead—could make such travel feasible. But here is the crucial point: either faster‑than‑light travel is physically possible, or it is not. This is not a probabilistic question. It is binary. We may guess that it is unlikely based on our current understanding, but that is not a statistical inference. There is no meaningful “10% chance” or “0.1% chance” that superluminal travel is possible. The truth value exists independently of our knowledge. If the speed of light is an absolute limit, then the probability of interstellar visitation may indeed be 0%. But if it is not an absolute limit—if some advanced civilization, or perhaps many thousands, have discovered a viable method—then visitation may be not merely possible but common. We might live adjacent to an interstellar thoroughfare, with travelers passing by routinely and occasional visitations being entirely expected. Thus, the probability of visitation spans the full range from 0% to nearly 100%. Without knowing the underlying physical truth, we cannot meaningfully assign a prior probability. And if we cannot assign a prior, we cannot declare the claim “extraordinary” in the statistical sense. The event might be vanishingly unlikely—or it might be the most natural thing in the world. We simply lack the information needed to classify it. submitted by /u/Observer_042 [link] [comments]