life elsewhere in the universe?

Question

if the universe is infinite then even if the probability of life existing elsewhere is infinitesimally small, does this mean that logically that must be life elsewhere?

Answer 1

"If there isn't, it's an awful waste of space!"

Answer 2

Infinity times an infinitesimal quantity is an undefined number, so that argument is meaningless.

Besides, the universe is not infinite; it is staggeringly large (about 80 billion light years across, and expanding faster than the speed of light) but it nevertheless has a finite size.

However, judging by the preliminary surveys finding planets, it seems reasonable to assume that there is probably life within, say, only 100 light-years of Earth. The Kepler space telescope, due to be launched in a couple of years, should have some definitive data on that within a decade.

That being said, there is NO reason to assume, just because evidence of life is found, that there will be intelligent alien species in that radius. I remain deeply skeptical that there will be contact with an intelligent alien race in the lifespan of anyone living today. That's because the odds are not just stretched by the incomprehensible vastness of space, but also by the astounding vastness of TIME. Humans have only been capable of radio communication (even only in principle) for 100 years; the universe is about 14,000,000,000 years old and our planet's 4,300,000,000 years old. That implies there is no reason to assume there should be an alien civilization at a compatible technological level within a sane distance.

Answer 3

I've had the same thought many times and have come to the same conclusion. However, what if the universe isn't infinite? There was a time when we thought the universe as big as the country we live in. We found that wasn't true when we found other countries. then we thought our world must be the only one. Nope. Then we thought the galaxy was as big as it got. Well we were wrong again. I wouldn't be surprised if we eventually find the universe is just one of many contained in something else.

Answer 4

Even if you say that life needs exactly the same conditions are here on Earth, exactly the same position in a solar system, exactly the same stellar formation and position in a galaxy....

Then there must be billions upon billions of possibilities out there.... with figures like that you can even say that, what if life needs such perfect conditions as here on Earth... and by probability the universe should be packed full of life.

And then of course you must think, what if there is life that does not need conditions like ours? We cannot imagine what else could be created as we are looking through tinted glasses so to speak.

Answer 5

Hello and thanks for bringing this question to Yahoo Questions and Answers for the 11,534 Th Time.

Your particular question is incorrectly asked, Mam.
True the Universe is very, very, very big...
But, not true, that the possibility of life elsewhere is
very, very small. It is a possibility but we have no idea of
the size of the probability.

Look at it this way...

In the Milky Way Galaxy, alone, there are 200 Billion Stars, just like our Sun. Each of those stars could have from 0 to 10 or more planets (with all their associated moons) circling around them. That is a huge number of possible locations for one or more "Earth equivalent" planets.

Now, beyond the Milky Way Galaxy there are Tens of Thousands of other galaxies. Each of those galaxies contain Billions of stars. And, each of those stars might have from 0 to 10 (or more) planets (with their associated moons) circling around them. ...So, the number of possible locations for Earth Equivalent Planets is quite big, but exactly how big is not known at this time.

The problem is that stars give off intense light (shine) and planets do not. Planets only reflect light from their local star
(sun). So when we look at distant galaxies and distant stars, it is rather like looking into the headlights of an automobile late at night. The auto's headlights blind your ability to see anything else around or behind the headlights. Only when a large object, such as a big planet, passes between our view
and the star we are viewing do we get some indication of an object's presence. Light from the star sort of blinks or changes color slightly as the planet passes through the light rays. If observers are watching closely when this happens, a record may be made of the event and continued observations might record when it happenes again, etc. From that series of observations one might calculate the orbital period of the distant planet swinging around its parent star. The actual science to do this is quite a bit more complex than I have suggested, but in general that is how it is done.

At this time there are more than 200 extrasolar (not within our solar system) planets that have been discovered and cataloged which are circling distant stars. More are being discovered each day. It is very unfortunate that those planets are only the biggest ones because they are big enough to cause this "blinking" or color shift change as they pass in between the star and our line of sight. Smaller planets, close to the star, might go undetected for a very long time due to their minimal effect on the star's emitted light. Small planets of solid mass which lack a big gas atmosphere, and are far away from their parent star might also go undetected for a long time for the same reason.

With all of the many possible locations for an Earth Equivalent Planet, it would not seem unreasonable to suggest that there might be from 1,000 to 100,000 Earthlike
planets. We will only know where and how many in the distant future when we develop new techniques to better observe the distant galaxies. The nearest star (not including our Sun) is at least 4 Light Years away from us. Other stars in the most distant galaxies are some 40 Billion Light Years away. A huge, huge number of stars lay inside this range of our ability to see with present optical and radio observation equipment.

I hope I have answered your question. Please tell all your friends to come look at it, so that they will not ask the same question tomorrow. Thanks in advance...

Regards, Zah

Answer 6

well your reasoning is strong but your facts are incorrect, the universe is not infinite. although it is really HUGE and im sure that there has to be life out there somewhere considering everywhere astronomers look everything is made of the same elements and the same physical processes apply throughout the universe then surley this cant be the only place with life. if it is it sure would be a big waste of space!!!!!

Answer 7

I say yes. I am not a scientist, but logically thinking it would make sense that there is other intelligent life out there somewhere. Probably they are wondering the same thing.

Answer 8

I don't really see how there can't be life elsewhere in the universe. I would have thought it physically impossible that we are the only lifeform in the universe.

Answer 9

I personally feel, a priori, that life does exist in our solar system and in the greater part of the universe. This life will probably be bacterial or protozoan or algae, but I feel it does exist.

Answer 10

Within our own galaxy, the probability of life is very high, possibly many thousands of systems supporting some life forms.

Answer 11

It might be that no one out there is bothered about talking to us.

The idea of life being out there is very widesperead now. Personally, I don't think it would make a big difference to me to know we are not alone. It would be amusing to see how others react though.