Is it still an open question whether the universe is finite?
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APOD is cool.
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Depending how you plug in some more or less plausible numbers into the grand formula for estimating the distribution of life in the galaxy*, you can easily get answers ranging from <1 to 1,000,000+ technologically advanced civilizations, and you can argue for an even more extreme range as many of the values are based on unknown quantities like incidence of earthlike planets.
The formula suggests there are zillions of alien civs in the universe, but quirky German research notwithstanding, odds are most of them are too far away to communicate even if they wanted to, and are infinitely less likely to visit. Intergalactic distances are too big for anything reasonable to travel without FTL. So if the plausible low end of the estimation formula pays off and we’re the only civ in the galaxy this eon, that’s the way it goes.
Fermi’s paradox has always seemed like bullshit to me. I can come up with half a dozen arguments why it is inoperative, which I won’t waste space with here (as they are too big for the margin).
*I forget the name of the formula or I’d link it – somewhere there is a calculator site that lets you enter your own values to see how the numbers work out.
We’re all missing that Dinosaurs didn’t die out, they evolved brains, became worldwide (hence the mass extinctions) made spaceships, removed all trace of their cultures, and left. That’s why “V” is a docu-drama.
Wasn’t that an episode of ST:Voyager?
Depends what you mean by finite. IIRC, an infinite universe was just one that expanded forever, constantly increasing the amount of space between the actual objects in space. I don’t think that they meant that the number of stars/planets were infinite.
And it’s very easy to think we’re alone. All you have to do is think that the probability of life forming x number of stars is well below one. Hardly a stretch.
Throwing up a picture of stars and goo-gaaing about “Oooh, there’s SO MANY goddamn stars, those people who think we’re alone in the universe are just loonies!” commits at least two fallacies. First it’s an emotional appeal, because really, believing that there are other people out there is a highly attractive concept for a social species. Second, it’s taking advantage of the fact that people intuitively deal very poorly with astronomical-level numbers.
In this case, the shit bonerz option is there is ‘life’ out there, only it’s all emissions conscious machine life that will seek out and eradicate competing organic life!
Thankfully I’ll be long gone before any hard sci-fi authors prove prescient and Gilligan’s Island results in the destruction of humanity. Mmm. Coconuts.
Just the fact that suggested ranges are so broad suggests that the estimates are basically worthless. Garbage in, garbage out.
Also, as I recall the age of the universe is guesstimated at…14 billion years, right (I’ve heard as high as 20)? I have to figure that the first few billion years are spent just getting enough heavy elements together (results of supernovae) to be able to make life, so the clock ticking on “when life can begin” doesn’t start at the beginning of the universe - I wonder how long after the big bang do you have enough matter that’s not hydrogen/helium in sufficient quantities to make an environment hospitable to life?
~14 is the accepted number now. It might go up or down another .5, but that’s about it.
As for when life forms, it depends on when the planet stabilizes. On Earth, life arose pretty much immediately after the surface settled down.
However, one fallacy that most commit is to assume that evolution works towards complexity; it does not. Looked at one way, the odds of intelligence arising from life are many billions to one, if life is assumed, based on the number of non-intelligent species we can estimate have lived on the Earth, our only real data source. Looked at another, the odds are 100%, since life itself arose once in our knowledge, and produced intelligence.
Long story short, we don’t know jack shit about the odds of life or intelligence anywhere. Alien visitors we can dismiss due to a rather thorough understanding of physics, but remote dark life, who can say?
H.
Yeah, but my point was that you don’t get widespread numbers of planets until you’ve got enough heavy elements out there to form them (you need enough supernovae to go off to create oxygen, carbon, iron, etc) in high enough quantities/concentrations to allow planets to form.
Of course, I’m being biased here - who am I to say that hydrogen-based life can’t form? Although I don’t see how given that there are limited ways for hydrogen/helium atoms to interact with one another.
The universe is too big for us to be the only “intelligent” life. I just don’t believe they’re inserting anal probes in humans right here and now.
You think we have a rather thorough knowledge of physics? That’s what people thought 100 years ago too. We still know shit about physics, most likely. We also have no idea what new models will be developed that will enable us to do things we can’t even imagine right now.
I also think Phil’s equation is wrong. Surely the number of stars is a multiplier, not an exponential.
And then some Newton/Hawkings guy will come around, laugh in the face of all known science and prove the existence of the W dimension, where all matter connects to the same node.
Then, just to keep the same running joke going, we’ll go to another civilization out there and fuck around with their orifices.
I think that’s right. At least as regards rocky planets. I think it’s generally agreed that only Population I stars have these elements in any quantity. Population III stars would have been too huge and short-lived to support life at all, and Population II stars would have life-not-as-we-know-it if they have life at all, not having much in the way of heavy elements until they are ready to blow up.
But of course there are an awful lot of Population I stars out there…
I know you’re trolling, but…
We have observed that life exists, and therefor it is reasonable to hypothesize that it might exist elsewhere, and that the sheer number of other stars in the universe arguably increases the statistical likelihood. God either exists or he doesn’t–we have no data either way, so any hypothesis is baseless speculation. The fact that there are billions of stars in the Tarantula nebula speaks neither for nor against the existence of god, unless you mean to argue that god is incapable of creating a small universe.
Here’s what I wrote:
I made a small error in the above - I forgot to subtract the whole thing from 1. The correct equation is
1- ((1 - probability of intelligent life, per star) ^ (# of stars))
It’s easier to conceptualize this with small numbers.
Imagine you have 10 lottery tickets, each with an independent 10% chance of being a winner. Initially it may look like you have a 100% chance of holding a winner (10 x 10%), but of course, this isn’t true. The odds are in fact (1-((1.00-.10) ^ 10)) = ~.65 (i.e. a 65% chance of holding at least one winner).
If you double the number of tickets, the odds are (1-((1.00-.10) ^ 20)) = ~.88 (88% chance of holding at least one winner).
I don’t think any scientists believe the universe is infinite in terms of normal matter and energy – steady state is pretty much dead so far as I understand it. I qualify that because if the curvature is open, there may be some amount of virtual energy basically pervading all of space even outside the 14 or however many billion light year radius the big bang may have expanded to, and virtual particles can randomly fluctuate into real existence whenever they feel like, to my limited understanding. But that would be incredibly low energy density if true, not enough to form galaxies and stuff, and anyhow the curvature may be closed so in that case it has to be finite.
Actually, I’ve never heard anyone discuss what lies outside the light cone of the big bang in an open-curvature universe. Kind of messes with Mach’s paradox, I guess.
And by “universe” of course we’re talking about our own space created by our own big bang, not any other random concentric or displaced big bangs that we can’t access anyway even if they exist.
Yeah, Phil, I think most people here are talking expected value rather than overall probability.
Designate any sequence of ten numbers. Now get a random number generator to spit out two sequences of numbers: one sequence that’s a million numbers long, and another that’s a hundred trillion numbers long. Are the odds that your ten-number sequence will appear larger in one of those sequences than it is in the other?
I think he’s referring to the per star probability, Ben.