Existance of extraterestrial form of life

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In summary: The problem with this argument is that if even one of the factors in Drake's equation is unknown, then the entire equation fails. I don't mean to say that the equation is entirely useless, only that it fails to predict whether or not we are alone. Here are the factors.-R = the average rate of star formation per year in our galaxy-fp = the fraction of those stars that have planets-ne = the average number of planets that can potentially support life per star that has planets-fℓ = the fraction of the above that actually go on to develop life at some point-fi = the fraction of the above that actually go on to develop intelligent life-
  • #36
Jimmy Snyder said:
You are using the principle that we are not special to answer the question of whether we are special or not.

Yes, I don't see how this is a Copernicus-like situation. Copernicus made a hypothesis based on the observations of the movements of planets which conflicted with geocentricism. The idea that geocentricism wasn't true was based on observation, whether or not we are truly special is irrelevant. If we are special and unique, that's the way it is, we haven't currently got any reason to believe otherwise. It is like the teapot in Saturn's rings, I guess it's possible, but it seems like a worryingly religious approach of "I choose to believe it because there is no evidence against there being other life."

Correct me if I'm wrong but I didn't think science was about proving negatives, we'd be in the same place forever otherwise. We can only base theories and hypotheses on what we do know and see and in this case, there is no evidence for life off of Earth. I have no problem with believing there is life elsewhere in the universe, because I believe this myself, but I do think there is a problem with saying that because life exists on Earth, life in any sense (despite lack of evidence, and I understand that our ability to detect life is likely pretty feeble) has anything like a significant probability of existing, let alone saying it must. Such assertions are not very scientific - and that's coming from someone who is unable to give up a belief in God. Based on evidence and evidence alone, we currently cannot assert anything other than we are sure life as we have defined it exists here on Earth. Everywhere else is currently moot.
 
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  • #37
Ryan_m_b said:
Like Jimmy I'm seeing some circular reasoning here. We're asking the question "how exceptional is the genesis and evolution of life on Earth?" and you're addressing it with "if we assume that we aren't exceptional then it's likely that we aren't exceptional".

But the difference is that we are starting to have a pretty good idea of what is going on in other solar systems in terms of the number of planets, chemistry (based on the type of star) etc. When Drake first came up with his equation no one even had any idea of how common planets are, now we know that they are pretty common. We've also found quite a few different types (i.e. rocky planets etc).
Hence, so far everything points towards the fact that we live in a pretty "typical" system; which supports with the idea that our spot in the galaxy is not very special.

At the moment we are still dealing if probabilies (with very large error bars). But in a few years time we will hopefully be able to do spectroscopy of planets in other systems, and that will reduce the uncertainty quite a bit.
This area has gone from being pure speculation, to a pretty rigorous are of science.
 
  • #38
f95toli said:
But the difference is that we are starting to have a pretty good idea of what is going on in other solar systems in terms of the number of planets, chemistry (based on the type of star) etc. When Drake first came up with his equation no one even had any idea of how common planets are, now we know that they are pretty common. We've also found quite a few different types (i.e. rocky planets etc).
Hence, so far everything points towards the fact that we live in a pretty "typical" system; which supports with the idea that our spot in the galaxy is not very special.
I disagree with your conclusion, whilst we might have a pretty good idea compared to when Drake first came up with his equation it is still not good enough. When you say we have a good idea of chemistry that's being a bit generous but even if we did know that planets with primordial-Earth like chemistry and conditions were common we'd still not know whether or not life was common because we don't have a theory of abiogenesis and so we don't know what the necessary conditions for life are nor the chance that they will give rise to something we'd call life.

It doesn't matter if we start filling in the blanks on the Drake equation it's still can't give us an answer if we don't have a good idea of all the info.
 
  • #39
f95toli said:
But the difference is that we are starting to have a pretty good idea of what is going on in other solar systems in terms of the number of planets
fp = the fraction of those stars that have planets

f95toli said:
chemistry (based on the type of star) etc.
ne = the average number of planets that can potentially support life per star that has planets

f95toli said:
When Drake first came up with his equation no one even had any idea of how common planets are, now we know that they are pretty common.
fp = the fraction of those stars that have planets

f95toli said:
We've also found quite a few different types (i.e. rocky planets etc).
ne = the average number of planets that can potentially support life per star that has planets

Pure speculation:
fℓ = the fraction of the above that actually go on to develop life at some point

If even one of the factors in Drake's equation is unknown, then the entire equation is unknown.
 
  • #40
Why are you being serious Jimmy?
 
  • #41
Now you are saying that we are not special with regard to being a planetary system, therefore we are not special in regard to anything else either.
 
  • #42
I don't really see the issue here. We have NO idea if life has emerged anywhere else in the universe other than Earth. Period. Until we KNOW that life is possible elsewhere, the drake equation is utterly useless. You can put in "what ifs" and whatever assumptions you want, but in the end it's idle speculation for now.

Now you can BELIEVE that life exists elsewhere without having evidence, as many people here do, but you cannot say with ANY certainty that life does or does not exist elsewhere.
 
  • #43
EBENEZR said:
Yes I did and I find it insufficient to suggest that we are entitled to state likelihood is anything but pitiful no matter how much we want to think life out there is likely - this is wishful thinking, not science.

ne
How many have we found that can support life? How do we know it can support life with any degree of certainty? Surely any planet is capable of supporting life until we know what all life of all varieties is and isn't capable of surviving. We only have an idea of the upper and lower limits on Earth and even then we often find a new record breaking living organisms.

f
So far, we only know of one, Earth, out of hundreds of planets. Drake's Equation goes on to civilisations... we're still stuck at "well, we haven't found anything microbial yet." in which case, probability is looking pretty low.

EDIT: Sorry I guess I wasn't clear. What I meant by "how is this worked out?" was "how can people come to such an optimistic conclusion?"

Okay, you're right, it's not actually science. That's why this isn't in one of the "science" fora.

Anyway, the people coming to an optimistic conclusion think along the lines of, "okay, planets with life are probably pretty rare, but them being so rare that Earth is the only one in the observable Universe is just ridiculous." Yes, this is somewhat subject to human though processes.

Anyway, I've always somewhat disliked the Drake Equation. It simply repeatedly states

[tex]\dfrac{a}{b}=\dfrac{a}{c}\cdot\dfrac{c}{b}[/tex]
 
  • #44
So we agree, no science here.

One more thing, I just want to compare this post with ...

micromass said:
Other people can explain it better than me:

https://www.youtube.com/watch?v=9BRDCxNEuyg

Check at about 4:40
 
  • #45
at the same time that it makes sense to say "well there are SO MANY stars out there, that there's just got to be more with life than ours"

I also have to ask the question that Fermi asked as well: "Where are they?"

these two totally contradicting positions both make sense, but like almost totally contradict each other

so I generally put the idea out of my head because it's one of those questions that doesn't really help me in any way
 
  • #46
Andre said:
So we agree, no science here.

Again, it depends on if you are talking about ET visiting us (which is a ridiculous idea) or the possibility of life (of some sort) on other planets. While we can't say anything for sure about the latter it is definately science. There is a reason there is whole discipline called astrobiology.
Moreover, if it was impossible to say anything about the possibility of detecting life Darwin-like space missions would be meaningless. Cleary, there are enough scientist that believe that the probability is somewhat larger than zero for this to be taken seriously.

This is no different than e.g. writing a research proposal where you propose a high-risk project with lots of unknowns, while you can't say anything for sure until the research is actually done you can still use what we DO know to say something about the likelihood of success.
 
  • #47
f95toli said:
Again, it depends on if you are talking about ET visiting us (which is a ridiculous idea) or the possibility of life (of some sort) on other planets. While we can't say anything for sure about the latter it is definately science.

Te reason why I think it's not science is because you can't falsify the idea of ET. If there is no proof now and within the next *fill in any looong era with plenty of zero's* years, you can't say anything.
 
  • #48
Andre said:
Te reason why I think it's not science is because you can't falsify the idea of ET. If there is no proof now and within the next *fill in any looong era with plenty of zero's* years, you can't say anything.

But it IS falsebiable in principle. We can't observe every star in the universe, but the underlying principles are easily able to be studied from here on Earth. The same applies to astrobiology. The physical laws that seem to underpin life are able to be studied and tested. We can verify and falsify these laws.
 
  • #49
Drakkith said:
But it IS falsebiable in principle. We can't observe every star in the universe, but the underlying principles are easily able to be studied from here on Earth. The same applies to astrobiology. The physical laws that seem to underpin life are able to be studied and tested. We can verify and falsify these laws.

Whilst chemical and physical processes should be the same everywhere or not, I don't know, it would allow for ET somewhere sometimes. No doubt about that. But that doesn't mean that we have any idea about it's probability. The Drake Equation could easily end up with an error margin of X digits. Think of a BIG X.

Also interestingly, in the evolution on Earth, nature took many many sidesteps before really evolving brain power of the primates. It took many extinctions, erasing the sort of 'dead ends' in evolution. Drake does not account for that.

Also check this discussion, without recycling carbon due to plate tectonics, carbon based life could tend to terminate itself quickly. All extra restrictions on Drakes equation; apart from why Venus is not like Earth.

Essentially, having an Earth is not enough, you'd also need the happy accidents that led to the brain power evolution of the primates.
 
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  • #50
Andre said:
Whilst chemical and physical processes should be the same everywhere or not, I don't know, it would allow for ET somewhere sometimes. No doubt about that. But that doesn't mean that we have any idea about it's probability. The Drake Equation could easily end up with an error margin of X digits. Think of a BIG X.

Also interestingly, in the evolution on Earth, nature took many many sidesteps before really evolving brain power of the primates. It took many extinctions, erasing the sort of 'dead ends' in evolution. Drake does not account for that.

Also check this discussion, without recycling carbon due to plate tectonics, carbon based life could tend to terminate itself quickly. All extra restrictions on Drakes equation; apart from why Venus is not like Earth.

Essentially, having an Earth is not enough, you'd also need the happy accidents that led to the brain power evolution of the primates.

tsoukalos_aliens_build_everything.jpg

-----------------------------
I told people in chat today that I had a premonition of getting banned tonight.
I would expand on your hypothesis Andre, but then we both might be banned.
ps. how many spare rooms do you have?
 
  • #51
I don't know about you guys, but if I was an alien (hypothetically speaking), then I would not want to interact with human beings.

With the state of human beings at the moment, it would be way too dangerous both for us and for them.

As George Carlin said, we can't even care for each other and be responsible.

I sure would not want to come here and risk the savages nor risk coming and totally screwing things up, having to live with that for the rest of my life.

Whether outside life exists is a debate that has gone on for a long time, but in terms of having a positive answer to that question, I certainly would not expect (or hope for that matter) for a more highly civilized being to show themselves to us as we are at this present time.

It's bad enough now that we have quite a lot of people that want to have free will, but also have someone else do everything for them whether its a religious deity, some other human being or whatever else.

There are a lot of people in this world and sometimes giving people what they want is the worst thing you can do for them if they are expecting it to happen instantaneously without effort and learning.

I say the above because one thing that a significant portion of people express is usually between two distinct polar opposites: the first one is that some advanced alien race is going to save them and make the nightmares go away and the other extreme is that the aliens are going to come and wipe us out.

The militaries of the world would be frightened and everyone would panic, or the religious of the world with all the sick demented cults would hop on the gravy train turning this "opportunity" into something for their own benefit.

So either you have every-one either scared out of their mind or willing to do whatever the hell they were told.

What a choice they would have.
 
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  • #52
There are a lot of people in this world and sometimes giving people what they want is the worst thing you can do for them if they are expecting it to happen instantaneously without effort and learning.

Take a look at the internet. People want knowledge, and they have a means of easily attaining, yet don't seem to be more knowledgeable or wiser given the immense amount of knowledge at their finger-tips. One of the reasons is that certain types of knowledge are not streamlined enough for them to understand it at a moments whim.

But even if it were, it still would not solve any problems that plague the human of today. Wisdom is unattainable without introspection, or a better understanding of one's self. It is also not attainable without knowledge. So even if people got what they wanted in terms of knowledge being just a bunch of conglomerating facts to them, they would be nothing more than a computer without any understanding of those facts.

That is just my opinion though.

In my case, I've learned there is more to understanding than I initially thought. I always felt if it were intuitive enough then I understood it, but I learned of that obvious error. My intuition is at best faulty so I must understand through what is more logical and sometimes, against a more visceral gut reaction. There is no way around that.

No alien can give someone the knowledge and understanding one wants. No amount of technological advancements can do that either. Without having a deeper understanding, a person can never be wise no matter how hard they read up on wisdom. So those who flock to deities, etc..., will just remain in the dark. You can listen to other wise people, but that goes against what I am saying here in that wisdom comes from introspection. "Harkening (as the priest say it)" unto the wise is just another form of listening to those who are wiser, it is more of the external aspect and takes less from the what one needs to focus on.
(opinion)

Even though I do believe in alien life, I don't care too much to see it. There is no longing in me to see an alien. There is a longing to understand more than I do today though, but like I said above, that is more of a life's work than a simple snap of the wrist in my opinion.
 
  • #53
What I was getting at was that a lot of people want everything done for them and sometimes just giving them what they want actually keeps them back instead of helping them develop.

It's not just knowledge academic or otherwise: it can be related to any kind of accomplishment or outcome whatsoever not just the acquisition of some esoteric knowledge.

It reminds of the song by System Of A Down Aerials: "We are the ones who want to choose, always want to play but you never want to lose" and people are really like that.

It's funny because a lot of people talk about the problems that exist, but very few genuinely want to solve them: they'd rather let someone else do it and that's the real point.

Ironically a lot of people wonder why everything is going to hell in a hand-basket in more ways than one.
 
  • #54
chiro said:
I don't know about you guys, but if I was an alien (hypothetically speaking), then I would not want to interact with human beings.

With the state of human beings at the moment, it would be way too dangerous both for us and for them.

As George Carlin said, we can't even care for each other and be responsible.

I sure would not want to come here and risk the savages nor risk coming and totally screwing things up, having to live with that for the rest of my life.

Whether outside life exists is a debate that has gone on for a long time, but in terms of having a positive answer to that question, I certainly would not expect (or hope for that matter) for a more highly civilized being to show themselves to us as we are at this present time.

It's bad enough now that we have quite a lot of people that want to have free will, but also have someone else do everything for them whether its a religious deity, some other human being or whatever else.

There are a lot of people in this world and sometimes giving people what they want is the worst thing you can do for them if they are expecting it to happen instantaneously without effort and learning.

I say the above because one thing that a significant portion of people express is usually between two distinct polar opposites: the first one is that some advanced alien race is going to save them and make the nightmares go away and the other extreme is that the aliens are going to come and wipe us out.

The militaries of the world would be frightened and everyone would panic, or the religious of the world with all the sick demented cults would hop on the gravy train turning this "opportunity" into something for their own benefit.

So either you have every-one either scared out of their mind or willing to do whatever the hell they were told.

What a choice they would have.

You seem to be basing your argument about contact on the premise that they not only know what we are like, but also understand behaviour like we do (or, like we think we do). For them, seeing us, may well be a perfectly ideal situation. We could be their petridish growth. Who knows if they're not doing that already. That they don't choose to interact because they can but are observing us like guinea pigs? They could easily "solve" all our problems, but won't out of an obligation like how naturalists cannot interfere when they see a dying or harmed animal.
 
  • #55
They could well be, but don't you find it ironic how humans think? The fact that we think that every thing is a "petri-dish" and just waiting to not only be examined and observed but completely meddled with?

Why would a benevolent super-race want to help any species like us with this mindset? Do you think such a race at that level lacks any kind of serious conscious capacity to think about what its doing?

We're still trying to learn something called self-control unless it inevitably gets the best of us.
 
  • #56
I absolutely believe that aliens exist. I've watched way to many documentaries to know that the universe is indescribably large. The fact that most humans think we are so special and unique that there couldn't possibly be any other life like us is just plain ignorant.

There are 10x more stars in the observable universe than grains of sand on Earth http://news.bbc.co.uk/1/hi/sci/tech/3085885.stm and that it's highly likely each one of these stars has at least 1 orbital body. Now when you have and uncountable amount of planets, is it really too much to think that there are other intelligent life?

People often say "well if there were other life out there, why have they not found us yet?" Well the answer to this question is the same reason why when a fishing vessal goes missing at sea, there is a 99% chance the rescue helicopter won't find them, because the ocean is just too damn big to look for a tiny boat. Obviously magnify the ocean by 100 trillion trillion times while the fishing vessal stays the same size. Now you have a comparrison.

Many physicists including Stephen Hawking say that there it is much more likely that aliens exist than not existing. Maybe the laws of physics just simply can not be broken, the laws of physics will simply prevent us from ever traveling faster than light, going through a wormhole, teleportation ect. Maybe no matter how smart a species is, the laws of physics simply say no, you can't do that.

Maybe we're the most intelligent life in the universe? Maybe 14billion years is nothing for the age of the universe, maybe they live for trillions of years and so 14billions years is not a long time for things to involve.

Who knows, but hopefully I'll still be alive when aliens land on Earth offically. Even if they kill me, I can die knowing that the second most important question was answered.
 
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