Do you believe there are aliens?

[emzie]

http://en.wikipedia.org/wiki/Kepler-22b

Demonstrates that places like earth exist, not that there's life.

What do you need for life ?
For life as we know it (and it may very well be only one kind of life among MANY others), you requires a certain range of temperatures, certain "materials" and time.
The materials themself are rather common in the universe on telluric planets. Moreover, the temperatures required means that a planet which is at the correct distance of its star to fall into the said temperature range, is often a telluric planet with a good chance of having these materials.

As such, the main limiting factor is having a planet in the correct distance range of a star. Even if we limit life to stars like our sun (which is probably not actually required, but I'm playing conservative here), they are a minority, but still a sizeable one that doesn't reduce chances that much. Planets in this correct range are a rarity, but not that much (we know several dozens candidates for such ones in the near vicinity of our solar system, and they tend to be very hard to see, so they may actually be much more numerous).

As such, we can safely consider that even if life is a very rare occurence, even the cumulated restrictions of all the requirements are dwarfed by the size of the universe, making other life elsewhere a certainty.

That's some pretty awful logic. While it certainly may be true (and if you forced me to take a side, I would wholeheartedly agree with your position) there is not enough evidence to say many of your assumptions are true. We do not know enough about the universe, about extra-solar planets, about the origin of life on earth to make any of the far reaching conclusions that you call certainty.

As I said, I wholeheartedly would agree that there are many promising hints towards the possibility of life elsewhere. Habitable areas, the seeming ease that microbial life took hold of this planet, the unimaginable size of the universe.... I am quite optimistic that life exists elsewhere, but it is against everything that was drilled into me by science professors to then say, "it seems probable, therefore it is."

Planets suitable for life we know: 1
Planets suitable for life we know where life evolved: 1

The probability seems pretty high to my knowledge. Stating anything else is ignoring facts.

You cannot extrapolate from one data point.

 

[Maniacal]

Most likely yes, there are other intelligent beings out there. They probably won't want to make contact with us though, I wouldn't recommend it.

 

[Power_of_Beer]

You cannot extrapolate from one data point.

I'm not extrapolating anything, i'm just stating facts.

 

[emzie]

I'm not extrapolating anything, i'm just stating facts.

"The probability seems pretty high to my knowledge. Stating anything else is ignoring facts."

that's extrapolating. You cannot gather a single thing about the probability of life elsewhere based on it being here.

 

[Power_of_Beer]

"The probability seems pretty high to my knowledge. Stating anything else is ignoring facts."

that's extrapolating. You cannot gather a single thing about the probability of life elsewhere based on it being here.

You can say for sure that the probability is >0.
From a pure statistical view we have to assume we are the normal case. Maybe the chance is not 100%, but is probably a lot more likely that a planet capable of life will evolve life at some point.

 

[emzie]

From a pure statistical view we have to assume we are the normal case.

Why? If this is not the case, how would you be able to tell the difference?

 

[Skwink]

I don't know. I'm not totally closed to the idea of intelligent aliens, but I've yet to see any good evidence. If there are aliens, I doubt that we'll ever contact them.

 

[warpus]

To answer the question, I don't believe that aliens exist, but think that they probably do

 

[Power_of_Beer]

Why? If this is not the case, how would you be able to tell the difference?

We coudn't tell the difference. All i say is the chance is higher that we are the normal case.

 

[Antilogic]

I don't know. I'm not totally closed to the idea of intelligent aliens, but I've yet to see any good evidence. If there are aliens, I doubt that we'll ever contact them.

It's annoying because if you say you think there is a possibility of life somewhere else in the universe, you get lumped in with the UFO conspiracy theorists. I'm in (probably) the same boat you are: since I think life has evolved from wholly natural processes, I must conclude the possibility that somewhere else in the universe, the same combination of forces could cause some kind of life to develop.

 

[Theov]

Demonstrates that places like earth exist, not that there's life.
.

Yes, it demonstrates that within 'viewing distance' there are more places like earth.
So there's a big chance one of them contains life.
I thought it was explained by a few people quite well.

 

[Agent Cooper]

To me, the theory that we are alone in the Universe is somewhat shot down for the very simple reason that we exist.

If intelligent life can evolve here in the millions of different variations we've uncovered so far and survived cataclysmic events multiple times, why shouldn't that also be true for many other planets in the Universe? And there's a lot of stars/planets in the Universe - approx. 100 stars for each grain of sand on Earth according to some mathematicians who did a rough calculation.

 

[SG-17]

Statistically impossible for there to not be intelligent life outside of the Earth. Especially with the abundance of rocky planets that have been discovered.

 

[Akka]

Demonstrates that places like earth exist, not that there's life.

What it shows is that even with our very limited capabilities at detecting planets, we know at least two planets which are "candidate for life" in a 1000 ligth-years radius (and taking into account these very limited capabilities, we can safely estimate there is at least some dozens more).
That means the amount of life-candidate planets in the universe is on the same "cosmic size" than the amount of stars (that is, it's about the same "one to one million order").

In other words, there is cosmic numbers of planets that can potentially harbour life.

Then =>

That's some pretty awful logic.

No, that's pretty solid logic built onto something that is a non-absolute but somehow informed guess. The only unknown point is the probability of a "life-giving candidate" planet to give birth to actual life. My take is that it's "rare but not ridiculously microcosmically low" (considering all the elements you've listed).

And the point is that, taking into account the untold numbers of "candidate planets" that do exist in the universe, any probabilities that are not "ridiculously microcosmically low" are sufficient to mean there is millions of planets hosting life somewhere.

 

[Omega124]

Does extraterrestrial life exist? Yes. Is it necessarily like anything like the movies? Probably not.

It seems like a mathmatical certainy that we are not alone in this universe. Each galaxy has billions of billions of stars, each with their own planets. In turn, there is at least 170 billion galaxies. With all of these planets, which is much larger than Graham's Number, there is no way that Earth is the only planet special enough to hold life.

 

[bathsheba666]

So much faith is shown in this thread.

Not at all.
Faith and probabililty are two entirely different things.

 

[emzie]

We coudn't tell the difference. All i say is the chance is higher that we are the normal case.

It's your intuition that it's higher. We have no way of discerning the probabilities.

Yes, it demonstrates that within 'viewing distance' there are more places like earth.
So there's a big chance one of them contains life.
I thought it was explained by a few people quite well.

Vague notions of chance without supporting data do not make for a compelling case.

Statistically impossible for there to not be intelligent life outside of the Earth. Especially with the abundance of rocky planets that have been discovered.

All I'm asking for is some data points to justify such statistical certainty.

What it shows is that even with our very limited capabilities at detecting planets, we know at least two planets which are "candidate for life" in a 1000 ligth-years radius (and taking into account these very limited capabilities, we can safely estimate there is at least some dozens more).
That means the amount of life-candidate planets in the universe is on the same "cosmic size" than the amount of stars (that is, it's about the same "one to one million order").

In other words, there is cosmic numbers of planets that can potentially harbour life.

Then =>

No, that's pretty solid logic built onto something that is a non-absolute but somehow informed guess. The only unknown point is the probability of a "life-giving candidate" planet to give birth to actual life. My take is that it's "rare but not ridiculously microcosmically low" (considering all the elements you've listed).

And the point is that, taking into account the untold numbers of "candidate planets" that do exist in the universe, any probabilities that are not "ridiculously microcosmically low" are sufficient to mean there is millions of planets hosting life somewhere.

Our limited ability to detect shows us we're not a particularly unusual bit of space.

Of everyone in this thread, the Young Earth Creationist said it best. Every reason given that life exists elsewhere is faith-based, but everyone is ignoring the faith part of their conclusions.

 

[Akka]

Our limited ability to detect shows us we're not a particularly unusual bit of space.

That's my point.
So, you agree, but you disagree ? THAT is some awful logic here

Of everyone in this thread, the Young Earth Creationist said it best. Every reason given that life exists elsewhere is faith-based, but everyone is ignoring the faith part of their conclusions.

Let me quote myself :

"his answer is just showcasing a certain kind of ignorance, the unability to distinguish between "faith" (which is based on wishful thinking) and "probability" (which is based on reasoning). "

Faith and probabilities are completely different concepts - in fact, most of the time they are at odds, probabilities being the best proof against the existence of religious beliefs. They can only be equated by someone who lacks the understanding of mathematical mechanisms.

 

[Power_of_Beer]

We have no way of discerning the probabilities.

Our limited ability to detect shows us we're not a particularly unusual bit of space.

You contradict yourself in the same post.

And I have no idea what observation and estimation has to do with faith.

 

[warpus]

It's your intuition that it's higher. We have no way of discerning the probabilities.

Probability of probabilities! That we can figure out, and it points to a conclusion that life only appearing once is very unlikely.