Extraterrestrial life virtually has to exist

[Hypercube]

Why is it that some people are still skeptical that extraterrestrial life is more than science fiction? I mean in a sense, it is impossible that it doesn't exist.

 

To prove my point, let's assume (even though this is not always the case) that each of the universes 100 billion galaxies has 200 billion stars. Now, there are two possibilities for each of these stars; either they have planets with life or they don't. That means that the odds of every star in the universe besides the Sun having no planets with life on them is;

 

2 ^ (200 000 000 000 stars X 100 000 000 000 galaxies) : 1

 

There is no calculator that can even do that calculation. In my opinion that basically proves the existance of life beyond the earth.

[Klaynos]

But the probability of a star having a planet that has life is not (probably) 50%, so your equation is fundamentally flawed. Although I do agree the universe is so massive that there just has to be other life, whether we'll ever find it or find evidence for it is another thing.... again because the universe is just so mindbogglingly huge!

[Hypercube]

True, but even if you eliminate 99.9% of all stars from the equation, the result will still be a massive number.

[timo]

The question whether a pocket calculator can handle a number is completely irrelevant for nature.

[insane_alien]

my laptop can calculate it.(okay it takes friggin ages but it'll do it)

[Phi for All]

What are the odds that extraterrestrial life could form and evolve to our present level, survive the discovery of uranium, and then venture off-planet, managing to find Earth in all that massive space, within the fifty-year window of our current interplanetary capabilities? I too believe there MUST be extraterrestrial life, but I don't think we've encountered any of it yet. It would be like threading a microscopic needle with a thread several thousand light-years long.

[Dark matter]

most physicists and Astro-physicists believe that there is intelligent life in the universe because of the massive numbers of galaxies and planets. However; some biologists refuse to believe intelligent life exists because of how many things have to be perfectly right for a planet to hold intelligent life.

In my opinion, I think the thought of intelligent life is a very real fact.

[ecoli]

most physicists and Astro-physicists believe that there is intelligent life in the universe because of the massive numbers of galaxies and planets. However; some biologists refuse to believe intelligent life exists because of how many things have to be perfectly right for a planet to hold intelligent life.

It's an important point, because we would like to assume that conditions need to in such a way and stable enough that life could evolve. For example, The formation of our moon is an astronomical event that was very unlikely, and probably doesn't happen very often in our universe.

 

That tends to suggest, that the evolution of life on other planets is a rare, almost impossible thing.

However, we are limited in our imagination, to think of ways in which life could evolve, that is no way like how life evolved on our own planet.

My inclination, is that there really is no way to guess using strict probability. But, that if life has evolved elsewhere, it is a rare thing, with distance and time limiting our ability to meet other species. I'm not planning on holding my breathe about it.

 

In my opinion, I think the thought of intelligent life is a very real fact.

I don't quite understand this sentence.

[antimatter]

What Dark matter means is that he believes that the idea that there are extra-terrestrials is true, and should be considered a fact, rather than a belief.

Am I correct?

 

There is however the Drake equation...which does predict intelligent life in our own galaxy.

[ecoli]

What Dark matter means is that he believes that the idea that there are extra-terrestrials is true, and should be considered a fact, rather than a belief.

Am I correct?

If that's true, it seems like a silly thing to believe. Even if it was highly probably, it's still not a fact, without evidence.

 

There is however the Drake equation...which does predict intelligent life in our own galaxy.

It attempts to predict intelligent life. Which is, different than the OP (which is not necessarily intelligent life).

Also, it fails, in the respect that there are still too many unknowns. It gives a potential quantification, that's pretty much useless if you cannot accurately define the terms.

[antimatter]

If that's true, it seems like a silly thing to believe. Even if it was highly probably, it's still not a fact, without evidence.

 

I just rephrased it...and yet I get the odd feeling you're attacking me there...

Edited May 28, 2008 by antimatter
multiple post merged

[ecoli]

I just rephrased it...and yet I get the odd feeling you're attacking me there...

nope, sorry. I was refuting whatever darkmatter said. I didn't mean to "attack" anyone.

[djeinstine]

Has anyone even considered outside the visible universe? Possibility still lies there...remember light hasn't even had time to reach us yet

[iNow]

I'm confident that life of some sort exists beyond earth in this vast universe.

I'm confident that none of that life has visited earth in little spinning metal discs or frisbies.

I don't know what "outside" of the universe even means, since the universe is, by definition, everything.

[Reaper]

I don't think we will know how likely life is on other worlds until we actually find it elsewhere. Until then, all of this is pure conjecture....

 

Even if life exists on more than 50% of all star systems, it would still take quite a bit of time to actually find it because of the huge size of the Universe. Also note that the vast majority of all the solar systems found so far are not likely to have planets that support life; the super-Jupiter's tend to get in the way.

[Dark matter]

It's an important point, because we would like to assume that conditions need to in such a way and stable enough that life could evolve. For example, The formation of our moon is an astronomical event that was very unlikely, and probably doesn't happen very often in our universe.

 

That tends to suggest, that the evolution of life on other planets is a rare, almost impossible thing.

However, we are limited in our imagination, to think of ways in which life could evolve, that is no way like how life evolved on our own planet.

My inclination, is that there really is no way to guess using strict probability. But, that if life has evolved elsewhere, it is a rare thing, with distance and time limiting our ability to meet other species. I'm not planning on holding my breathe about it.

 

 

I don't quite understand this sentence.

 

I'm saying I believe that there is intelligent life elsewhere in the universe

 

What Dark matter means is that he believes that the idea that there are extra-terrestrials is true, and should be considered a fact, rather than a belief.

Am I correct?

 

There is however the Drake equation...which does predict intelligent life in our own galaxy.

 

Yes, that is correct. I do have to admit though, I don't completely understand how the drake equation works, and hate to say I really don't trust it very much..

 

Has anyone even considered outside the visible universe? Possibility still lies there...remember light hasn't even had time to reach us yet

 

Be careful using "outside the universe" as a general term, however, I do understand what you're getting at. I don't think that there would be anything where light hasn't reach yet because light is the fastest thing in the universe... headache...

Edited May 29, 2008 by Dark matter
multiple post merged

[BumFluff]

If clues of the existence of life on the bodies within our solar system that may be able to support it besides Earth, namely under the surface of Mars and under the ice sheets of Europa, are found to support or to once have supported life I'm fairly certain that there are quite a lot more possibilities of intelligent life elsewhere in the universe. Until we discover what exactly makes a lifeform and under what specific conditions a lifeform can exist I think that anyone saying one way or the other is merely a guess. If life can form 4.5 billion years ago on Earth under those harsh conditions and if life can live near the heat ducts of the ocean it can survive almost anywhere. Living microbes have also been tested and have been found to be able to survive in the extreme cold of space.

 

All animals need is some type of little shove to get going and they can easily adapt to their surroundings. To think that life couldn't evolve aside from how it evolved on Earth is just ludicrous. I'm actually reading a book right now that deals with exactly this sort of thing. It states that non-Earth like life is probably very abundant in the universe. When people speak about how there is probably very few worlds with life on it they probably mean Earth-like life.

[foodchain]

We only have life on earth in which to guess how other life could have formed, or what it could look like. Going from natural selection which is abotic and biotic variables I would think it would be easy to surmise that gravity would have an effect on the evolution of life. I don’t see how you can say gravity would only have X for an effect though, maybe on some planet business organisms need suits that can hold eight limbs along with proper and stylish aspects for the fact they may hover for some reason.

 

I say this because looking at life and natural selection you do have an evolution from microbes to human type life as a possibility that can occur.

[Klaynos]

If clues of the existence of life on the bodies within our solar system that may be able to support it besides Earth, namely under the surface of Mars and under the ice sheets of Europa, are found to support or to once have supported life I'm fairly certain that there are quite a lot more possibilities of intelligent life elsewhere in the universe. Until we discover what exactly makes a lifeform and under what specific conditions a lifeform can exist I think that anyone saying one way or the other is merely a guess. If life can form 4.5 billion years ago on Earth under those harsh conditions and if life can live near the heat ducts of the ocean it can survive almost anywhere. Living microbes have also been tested and have been found to be able to survive in the extreme cold of space.

 

All animals need is some type of little shove to get going and they can easily adapt to their surroundings. To think that life couldn't evolve aside from how it evolved on Earth is just ludicrous. I'm actually reading a book right now that deals with exactly this sort of thing. It states that non-Earth like life is probably very abundant in the universe. When people speak about how there is probably very few worlds with life on it they probably mean Earth-like life.

 

Even if we find life (or evidence of life) on other solar system planets it is not evidence that life has formed more than once, as there's quite alot of evidence about single cell life forms surviving in space and feasibly travelling planet -> planet....

[BumFluff]

Even if we find life (or evidence of life) on other solar system planets it is not evidence that life has formed more than once, as there's quite alot of evidence about single cell life forms surviving in space and feasibly travelling planet -> planet....

 

Chances are if we find life in other Solar Systems those lives would have evolved independantly. The possibility that a living organism being transported from one planet in one solar system to another planet in another solarsytem is so remote I don't even have the words to describe how remote the chances are. It has absolutely nothing to do with how often a living microbe is transported via asteroid from a planet, it has more to do with the distance between the planets and how unlikely it is that an asteroid would travel millions of miles across space only to crash into another planet orbiting some distant star and have that still living organism begin to adapt and breed in it's new surroundings.

 

The possibilities of life originating within our solar system and being spread out, still within oru solar system is more likely but it is still a long shot.

[Klaynos]

By "other solar system plants" I meant other plants in our solar system, not extrasolar planets.

[waitforufo]

Intelligent life, to me, seems impossibly remote. Consider how many life forms exist and have existed on this planet. How many were intelligent? How many of them can or could meaningfully modify their surroundings?

 

Finding life elsewhere? Well, if it's not in our solar system our best bet is SETI. Again, such life would have to be intelligent. Even with SETI, I don’t see much possibility of picking up radio signals outside the Milky Way.

 

Perhaps one day we will have telescopes powerful enough to detect some kind of probability of life signature from another planet. I imagine the spectrum of light reflected from our planet is unique. I can't imagine that such a method would ever produce certainty. Again, limited to the Milky Way.

 

If we were to find life elsewhere I would not be surprised if we were a bit disappointed with the results of the discovery. Carbon based, DNA, and so on. The same rules apply everywhere so similar results should be expected. I think it would be similar to discovering an unknown chain of islands on this planet. That would be very cool but I wouldn't expect something radically different.

 

That last paragraph was quite the flight of fancy. It supposes that one day a human being will actually be able to walk on such a newly discovered planet. I see nothing in our current understanding that suggests we will ever visit any planet outside our own solar system. Along those same lines, I don't see humans ever creating a self sustaining breading population on any planet other than this one. But who knows, we are stubborn and persistent.

[Edtharan]

Intelligent life, to me, seems impossibly remote. Consider how many life forms exist and have existed on this planet. How many were intelligent? How many of them can or could meaningfully modify their surroundings?

Actually if there were any species that had a technology as complex as our own that came before us, it is actually unlikely that we would ever find any evidence of them.

 

In just a few thousand years, evidence of human activity is hard to come by. In a few hundred thousand years it would almost be wiped of the face of the Earth. In a few million years we wouldn't expect anything to remain.

 

It the proverbial Needle in a Haystack, but where the Needle has a high chance that it has dropped out and fallen through the cracks in the floorboards.

[Dark matter]

Actually if there were any species that had a technology as complex as our own that came before us, it is actually unlikely that we would ever find any evidence of them.

 

In just a few thousand years, evidence of human activity is hard to come by. In a few hundred thousand years it would almost be wiped of the face of the Earth. In a few million years we wouldn't expect anything to remain.

 

It the proverbial Needle in a Haystack, but where the Needle has a high chance that it has dropped out and fallen through the cracks in the floorboards.

 

Hmmm.. that sounds oddly familiar, did you quote/paraphrase that from somewhere?

[Ophiolite]

We still do not know exactly how life arose. Many argue - from positions of considerable knowledge - that life is inevitable whenever the conditions are right. Thus, Christian de Duve, Nobel Laureate, speaks of 'the Universe, pregnant with life', while Steve Kaufman complexity theorist, sees life as an inevitable emergent property of the Universe.

 

But these views are, at best, well informed opinions. Until we have demonstrated in detail a mechanism by which life could readily have arisen in the course of a hundred million years or so (or have solid evidence for pan spermia) then we cannot be sure that the Earth is not unique. Consequently, I would have to disagree with the op. Is there life elsewhere in the Universe? Probably. Is it virtually certain? We just don't know.

 

On the subject of the Drake equation, remember it was not designed to predict or calculate the probable number of intelligent civilisations in the galaxy, or Universe. It was intended to provide a framework or skeleton around which to build a meeting on extraterrestrial life held at the Greenbank observatory in the early 60s. It was a discussion tool, not a real algorithm.