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alien life possibility is pathetic

Belz--I don't think the Bri quote in your sig is as bad as it sounds. Maybe it's not so well worded, but I think Bri's point here is valid as it pertains to statements like, "There are alien intelligences in the universe."

You can't falsify that claim until you have somehow searched every last corner of the universe. You can falsify the complementary claim, "There are no alien intelligences in the universe" by finding one instance of an alien intelligence.

My own take is that even if alien intelligences are relatively abundant, we're not likely EVER to find one (just because stuff is so spread out in space and time). Failing to find one does not disprove the statement, "There are alien intelligences in the universe."

My issue with Bri is that I don't know of anyone who is making the statement, "There are alien intelligences in the universe." As with Sagan's statement, I'd be surprised if there weren't, but we have no evidence, so that statement is not substantiated.

Also, it differs markedly from the statement, "God exists" because while we do have one certain example of intelligent life in the universe (perhaps more than one depending on how you define "intelligent"), we have absolutely no certain examples of gods. The one statement assumes that something that has happened at least once will or has happened more than once. The other statement assumes something there is no reason to think has ever happened.

They're both assumptions, but the former is based on the assumption that the laws of physics and whatnot that led to our existence probably work the same way through in other places, while the latter is based on nothing.

ETA: Maybe this belongs on one of the Bri-threads. I dunno. It has to do with the topic here too. I think I'll copy it over to the "can theists be rational" thread.
 
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There is a recent New Scientist blog article titled How many intelligent civilisations are in our galaxy? It discusses a research paper for a computer simulation of ETI in the galaxy (pdf).

The paper states

The output data will only be as useful as the input data will allow (the perennial “garbage in, garbage out” problem). Current data on exoplanets, while improving daily, is still insufficient to explore the parameter space in mass and orbital radii, and as such all results here are very much incomplete.
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JoeTheJuggler said:
Belz--I don't think the Bri quote in your sig is as bad as it sounds. Maybe it's not so well worded, but I think Bri's point here is valid as it pertains to statements like, "There are alien intelligences in the universe."
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He says the claim of "whether or not" aliens exist is unfalsifiable. It isn't.
 
Lonewulf said:
Thanks for the info, Cuddles.

Might I ask how you know all of this? Self-study also, or are you "officially" an expert in the field? :)
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I'm afraid I have to admit that I am, in fact, a physicist.

Lonewulf said:
Sorry, but according to astronomers, that's the wrong answer. Light doesn't actually "fade"; the particles that make up light do spread, which makes it seem to "fade" to the casual observer, but the particles never stop, they just keep going at the speed c. If there was an infinite amount of light, there would still be an infinite amount of particles, so no amount of fading would stop the overall spread.
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JoeTheJuggler's point about only seeing a limited distance is correct, however, there is also another solution to [/url="http://en.wikipedia.org/wiki/Olbers'_paradox"]Olber's Paradox[/url]. Since the universe is expanding, all light is redshifted, with light from more distant sources having a greater redashift. Note that this is not a simple Doppler shift due to the apparent motion of the source and reciever, it is a separate effect due to the expansion of the space the light is in while it is travelling. This means that even in an infinitely old, infinitely big universe, light from distant sources would be shifted to much lower energies and the sky would still look mostly dark.

JoeTheJuggler said:
As far as I know that's not testable.
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It is. As I noted earlier, we can tell a bit about what is outside the observable universe by looking at what happens close to the edge. The important thing to remember is that there isn't a real boundary, it is simply perceptual boundary due to our fixed observation point. While we can't see anything past what we percieve as the edge, objects closer to that edge can, and by looking at how they behave compared to how they would be expected be behave, we can determine whether the universe carries on going, has some kind of actual boundary, wraps around on itself or whatever.

In addition, the point raised about whether we could see the same galaxy in opposite directions due to light from it going in a circle and coming back around is a good one. Howvever, you get one assumption wrong. While the light from a galaxy close to us would take longer to reach us depending if it goes straight or the long way around, light from a galaxy close to the edge of the observable universe would take just as long no matter which way it got to us, if the observable universe were all there was, and so we would expect to see identical galaxies in different parts of the sky.

Observations of both these things - light wrapping around the universe and coming back and the effects of things that are too far away for us to see - show that the physical universe must be many times larger than the observable universe, and that things outside the observable universe are pretty much the same as they are within it, at least for the distance we are able to draw inferences about.
 
And IIRC the minimum size of the universe is about 80 Gly (24+ Gparsec) otherwise some lensing effects would be observable (which are not observed).
But the math of this is beyond my reach.
 
I knew someone with more expertise would be able to help us out!
Cuddles said:
While we can't see anything past what we percieve as the edge, objects closer to that edge can, and by looking at how they behave compared to how they would be expected be behave, we can determine whether the universe carries on going, has some kind of actual boundary, wraps around on itself or whatever.
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I should've been able to think of that. Sure, that makes perfect sense as a way of inferring more stuff beyond the "edge".

In addition, the point raised about whether we could see the same galaxy in opposite directions due to light from it going in a circle and coming back around is a good one. Howvever, you get one assumption wrong. While the light from a galaxy close to us would take longer to reach us depending if it goes straight or the long way around, light from a galaxy close to the edge of the observable universe would take just as long no matter which way it got to us, if the observable universe were all there was, and so we would expect to see identical galaxies in different parts of the sky.
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Oh--I think I see. Galaxies that were right on an edge should be the same to us seen from either way. That is, if we imagine the universe is 2-D disk (for simplicity's sake), and there's something right there on the Eastern edge, I should see the same galaxy on the Western edge. The distances to the center of the universe (my eye) are the same. However, wouldn't we be seeing it from the other side? So if there were any assymetry, it would be flipped? Or if one side were occluded by dust, the other side would look different?
 
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Belz... said:
He says the claim of "whether or not" aliens exist is unfalsifiable. It isn't.
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I think you're right. Chances are that given the overall size of even our own galaxy that we would never know. I just play the statistical odds on this one and say that Aliens exist, but we will more than likely never encounter them.
 
To me I sometimes wonder if we are trying to Guesstimate something that has always been. But is forever changing.
The edge may be just another limit of our observation. I think this edge might always elude us, as we tend to be nosy and poke out even farther into the Universe. So really it could be the edge of our observation, our limits and mathematical theories. This can apply to trying to set an age to it all.
If I were to make a guess that beyond the observable, is more space yet to be seen. Plenty of room for this "speculative extrapolating" out beyond our known Universe.
We could have been a Big Bang of many.
I do believe looking at the very small and tiny things, tells us a big story.
 
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I still find it very hard to imagine either a finite universe (what is outside it, and is that finite also etc.?) or infinite universe (I can't convert the ball-surface analogy to 3D, can't imagine how the universe would wrap around itself).

Another question that comes to mind when I think about this... why is there ANYTHING in the first place?
 
Bell said:
I still find it very hard to imagine either a finite universe (what is outside it, and is that finite also etc.?) or infinite universe (I can't convert the ball-surface analogy to 3D, can't imagine how the universe would wrap around itself).

Another question that comes to mind when I think about this... why is there ANYTHING in the first place?
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Because His Noodly Holiness hath ordained it so.

My guess is that something had to happen. Now that sorta leads to, well what cosmos construct (where 2 + 2 = 5) didn't happen? I've pondered that question, and now thanks to you, I have a headache and a nihilistic nervous breakdown. :mad:
 
Mitchell314 said:
Because His Noodly Holiness hath ordained it so.

My guess is that something had to happen. Now that sorta leads to, well what cosmos construct (where 2 + 2 = 5) didn't happen? I've pondered that question, and now thanks to you, I have a headache and a nihilistic nervous breakdown. :mad:
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Blame the universe. If it didn't excist, you wouldn't have the headache.
 
Well, isn't nothing taken in context of the lacking of something? So if there's nothing, what makes that nothing possible?

I think something in my head just imploded.
 
There was nothing until something occupied nothing.
Can a nothing occupy space?
My coffee cup has nothing in it, so I will fill it :D
 
Of course the silly answer is that you couldn't ask the question, "Why is there something?" if something didn't exist.

Another way of looking at it is that if you add up everything, in a way that is probably beyond my ability to explain, it comes to nothing. (Similarly, some things pop in and out of existence even in the vacuum of intergalactic space, I'm given to understand.)

I get it mathematically--that you can start with 0 and rewrite it as +7 and -7, but it will probably take a genuine physicist to explain it better than that.
 
Bell said:
I still find it very hard to imagine either a finite universe (what is outside it, and is that finite also etc.?) or infinite universe (I can't convert the ball-surface analogy to 3D, can't imagine how the universe would wrap around itself).
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I know it's back to a 2-D example, but do you see how a Moebius Strip has only one infinite surface? If you imagine yourself to be one of Escher's ants walking along it, at any given spot, it sure seems like the ant on the other side of the paper from you (directly below your 6 little feet) is on "the other side", but it really is continuous with the surface you're walking on. If you keep on walking, you'll be on that side without ever having encountered an edge or terminus.

Maybe an easier way of thinking of it is that whatever you think exists on the "outside" of the universe, if it exists is actually part of the universe.
 
JoeTheJuggler said:
Of course the silly answer is that you couldn't ask the question, "Why is there something?" if something didn't exist.

Another way of looking at it is that if you add up everything, in a way that is probably beyond my ability to explain, it comes to nothing. (Similarly, some things pop in and out of existence even in the vacuum of intergalactic space, I'm given to understand.)

I get it mathematically--that you can start with 0 and rewrite it as +7 and -7, but it will probably take a genuine physicist to explain it better than that.
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That's because space is a false vacuum. If what you're talking about is virtual particles, there is something there to begin with.
 
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Mitchell314 said:
That's because space is a false vacuum. If what you're talking about is virtual particles, there is something there to begin with.
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I confess, I have no idea what I'm talking about! :)

I'm pretty sure the standard model has some provision for something from nothing. As I said, the only way I've ever understood it is that everything sums up to nothing somehow, so there's nothing to prevent nothing from sort of exploding into everything.

Still--I don't have much existential anxiety. The universe certainly exists, and I accept that it does. If it didn't exist, there would be nothing I could do about that anyway.

The Big Bang seems like the inevitable result of whatever the initial conditions were. Before that (or rather before a time shortly after that), causality as we know it didn't exist, so it's not very meaningful to ask what happened "before" that, I suppose.
 
Space and compaction always makes me think of the
story of the Elephant who hears a who!
 
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