does it imply that getting out into space is a lot harder than it sounds?
It enforces a statement along the lines of “these aliens got space travel recently or getting out into space is a lot harder than it sounds.” That’s weak evidence, at least, for that claim.
But if those are aliens, then aliens must be common. And if aliens are common, then there should have been tons of them that got to the space travel point long enough ago to have reached us by now.
But if those are aliens, then aliens must be common.
Given that the universe started a finite amount of time ago, and supposing there is easy space travel, then there is an interval during which the first colonists have intrastellar space travel but have not visibly done interstellar space travel, and we can estimate how long that interval is. They’re in that interval, or there isn’t easy space travel.
We cannot argue “because there is one, there must have been a previous one,” you can’t do that sort of induction on the natural numbers, eventually you hit one. We can argue it’s unlikely, sure, and we weigh that unlikelihood against the unlikelihood that interstellar travel is hard in order to determine what our posterior ends up being.
They’re in that interval, or there isn’t easy space travel.
But that’s a lot of information. It’s a very short interval. Since it’s so unlikely to be in that interval, this is large evidence against easy space travel.
We can argue it’s unlikely, sure
It’s a probabilistic argument. But what isn’t? There’s no argument that allows infinite certainty. At least, I’m pretty sure there isn’t.
But that’s a lot of information. It’s a very short interval. Since it’s so unlikely to be in that interval, this is large evidence against easy space travel.
I agree that it’s a lot of information. But it’s also the case that we have a lot of information about physics, such that interstellar space travel being difficult is also unlikely. Which unlikelihood is larger? That’s the question we need to ask and answer, not “the left side of the balance is very heavy.”
The general lack of space-going aliens suggests that getting into space is harder than it sounds.
Sure, but we already knew there was a general lack of space-going aliens. Presuming this is aliens, this moves us from “are we the first? Really?” to “are we only shortly after the first? Really?”
Both of those fall under “are we the first? Really?”, or the related hypothesis that we’re shortly after the first. Or did you mean to respond to NancyLebovitz?
Or there are fewer civilizations than we expect, or something is wiping out civilizations once they go to space, or most species for whatever reason decide not to go to space, or we are living in an ancestor simulation which only does a detailed simulation of our solar system. (I agree that all of these are essentially wanting, your interpretation makes the most sense, these examples are listed more for completeness than anything else.)
It enforces a statement along the lines of “these aliens got space travel recently or getting out into space is a lot harder than it sounds.” That’s weak evidence, at least, for that claim.
But if those are aliens, then aliens must be common. And if aliens are common, then there should have been tons of them that got to the space travel point long enough ago to have reached us by now.
Given that the universe started a finite amount of time ago, and supposing there is easy space travel, then there is an interval during which the first colonists have intrastellar space travel but have not visibly done interstellar space travel, and we can estimate how long that interval is. They’re in that interval, or there isn’t easy space travel.
We cannot argue “because there is one, there must have been a previous one,” you can’t do that sort of induction on the natural numbers, eventually you hit one. We can argue it’s unlikely, sure, and we weigh that unlikelihood against the unlikelihood that interstellar travel is hard in order to determine what our posterior ends up being.
But that’s a lot of information. It’s a very short interval. Since it’s so unlikely to be in that interval, this is large evidence against easy space travel.
It’s a probabilistic argument. But what isn’t? There’s no argument that allows infinite certainty. At least, I’m pretty sure there isn’t.
I agree that it’s a lot of information. But it’s also the case that we have a lot of information about physics, such that interstellar space travel being difficult is also unlikely. Which unlikelihood is larger? That’s the question we need to ask and answer, not “the left side of the balance is very heavy.”
And that’s why my conclusion is “that wasn’t made by aliens.”
The general lack of space-going aliens suggests that getting into space is harder than it sounds.
Sure, but we already knew there was a general lack of space-going aliens. Presuming this is aliens, this moves us from “are we the first? Really?” to “are we only shortly after the first? Really?”
That’s one explanation, the other being “intelligent life is harder than it sounds” and another being “any life is harder than it sounds”.
Both of those fall under “are we the first? Really?”, or the related hypothesis that we’re shortly after the first. Or did you mean to respond to NancyLebovitz?
Sorry, that was meant to be a response to Nancy Lebovitz.
Or there are fewer civilizations than we expect, or something is wiping out civilizations once they go to space, or most species for whatever reason decide not to go to space, or we are living in an ancestor simulation which only does a detailed simulation of our solar system. (I agree that all of these are essentially wanting, your interpretation makes the most sense, these examples are listed more for completeness than anything else.)