Does life exist elsewhere in the universe?

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I am personally not sure. As we have no evidence to sway my opinion either which way, I will not make a opinion based on faith or belief. although there are 300 sextillian stars in the observable universe (estimated), odds are, one of them has a planet that has life on it, right? Maybe. I don't know.

But what is your stance on this?

I've heard from reputable sources that there is life in other places than this planet. Human life, even.
http://en.wikipedia.org/wiki/Internatio ... ce_Station

Other than that, I do think there is life elsewhere. However, I doubt we'll discover intelligent life in the next centuries.

I think the notion that Earth is the only planet in the entire cosmos with life on it is absurd. However I have no empirical proof to back up this thinking. So I answered -don't know-.

ruveyn

Last edited by ruveyn on 29 Jul 2012, 10:24 am, edited 1 time in total.

The universe is a pretty big place, in the universe, there are trillions of galaxies, in those galaxies there are trillions of stars, and orbiting some of those stars are planets, some in the habitable zone. There has to be life in the universe and if there isn't, that would be a waste of a universe

The notion of "waste" in this context is a moral notion, not a physical notion. There does not HAVE to be life elsewhere. It is logically possible that Earth is the only place that has life. However logical possibility and physical actuality are two different things.

ruveyn

Logically possible but highly improbable.

Either way you have no empirical proof. It may be improbable, but fact. AKA, a paradox.

There are billions of galaxies, each with billions of stars.
It's a mathamatical certainty that life exists out there.
However,,,,,,,,,,,,,,,,,,,,,the distances to travel are mind blowing and I see no way that we will ever be able to reach them or them us.

I've seen scientists bending pieces of paper to simulate the bending of space but cannot get my head around that theory. If a planet is thousands of light years away then it's thousands of light years away. How can it be possible to get there by "bending" space; absolute nonesense.

Exactly.

Although I cannot prove it YET, I'm pretty sure there is intelligent life that also possesses advanced technology on a world very close to the center of the galaxy.

We have no frequency data on which to base an estimate of probability.

Probability is measure (Kolomogoroff) or relative frequency.

ruveyn

I voted yes because we have found fossilised prokaryotic cells that evolved insanely soon after the Earth formed. Although essentially nothing more than bacteria, Most would class such cells as examples of living things, hence, as we know there's nothing particlarly unique about our solar system, the rapid evolution of such cells is highly suggestive that it would happen elsewhere, under similar conditions.

Having said that, it then took around three billion years for the far more complex eukaryotes (cells that make up animals) to evolve in an apparently cooperative effort between prokaryotes. This appears to have happened on this planet just once during a time-span that is approacing one-quarter the age of the universe itself. Another perspective is that this means complex life only got started roughly half to one-third the way through the life of the planet (depending on how life manages to adapt to the changing environment as the Sun becomes a red-giant). A late start in the order a billions of years is therefore another reason why complex life may be extremely rare.

Have thought something like that for a long time.

There are what I call "noncelluliar" creatures (bacteria, blue green algae- the prokaryotes) on one hand. Then there are the unicellular and multicellular creatures on the other (amoebas, trees, humans)- the eukaryotes.

It took three billion years to get from the bacteria to the amoeba stage. Then things stayed at the amoeba stage for another billion years.

Then around 600 million years ago life vaulted from the amoeba stage to the jellyfish stage ( single cell to multicellular things that you can see with the naked eye) in the space of a few tens of millions of years in the "cambrian explosion".

After the cambrian explosion you had the familiar parts of the fossil record- plants and animals take over the sea, fish take over the sea, bugs invade the land, lobe finned fish invade the land next, the ascent of the dinosaurs and so on.

All of that drama- the trilobites, the dinosaurs, the ascent of man, the ice ages- that was all only the last 13 percent of the earth's history!

So if we we suddenly achieved interstellar space travel ability and could expand our scope outward to our stellar neighbors we might find that say one in a million stars has life. But of the exoplanets that have life- the first hundred have it only at the bacteria stage. We would probably find that only one life-baring planet in a 100 gets beyond the bacteria stage.

Indeed if our own sun had been of the wrong mass or whatever it might have turned surpernova before we even got the amoeba stage ourselves.

So one in a 100 million stars has life more advanced than a bacterium.

Of that- probably most (if they have a billion years before their suns go red giant or snuffs out) go on from there to the sponge and jellyfish stage.

Of those- then how many go on to evolve inteligent species capable of technology and civilization?

Who knows.

I agree with everything you say, but I have a comment on the part I bolded. The Ediacaran biota are really quite unique compared to the familiar configurations of life as we know it. There is a hypothesis that this biota (existing before the Cambrian) was in fact an alternate genesis of life on Earth that was outcompeted by Cambrian life. If this were to be true it opens the possibility there could have been many genesis of life on Earth. There is actually a term for life that exists here, evolved here but is unrelated to any known organisms, though what the term is escapes me right now (if anyone knows it please pipe in!). There are researchers looking for these life forms

Hello Vigilans, don'tcha just love those prototype critters!

The Ediacaran period only pre-dates the Cambrian by around 100 million years, so while there may well have been different "eukaryotic genesis events", they couldn't get started until some major obstacles were overcome. The chief engineering problem for evolution to lick was how to obtain the vast amounts of energy required for the more complex forms of life. Until the efficient eukaryotic mechanisms got going, all life was firmly stuck in the slow lane.

Even though the conditions for life are very strict, any element that can be found on the earth can be found on other planets as well—and with a bizarrely high number of planets out there, many planets will probably be terrestrial planets within the habitable zones of their mother stars.

I hope there is other life out there. I hate to think that we're the Universe's only chance at sapience.