Are WE the only life in the Universe?

[Freethinker]

Originally posted by: TeleMad

Our solar system is one that has the potential for there being a person who goes by the name FreeThinker, who... It therefore automatically becomes one that has the good chance for more than one planet having such a person. Doesn’t quite work:

FreeThinker: You may not understand it yet but in fact statistically it DOES work. Do I need to explain it to you or can you figure it out for yourself?

Sure, go ahead and try.

TRY has nothing to do with it. And I have posted basically this a number of times. That is why I did not just post it again. I was hoping people had caught on by now. Try to follow this time.

 

We have to start with the "set of all things". This set would be infinitely large and would include an infinitely large "set of things that are not possible". However in our set of "an infinite number of things", there is a finite subset of "things that ARE possible". An even smaller subset is that of "things that ARE possible and DO exist".

 

Thus once something is a part of the finite smaller set of "things that ARE possible and DO exist", the chances of another one of those is INFINITELY greater than the "set of things that are not possible" out of the "set of all things".

But note that it could be argued that having one instance of something highly improbable makes it LESS LIKELY that there would be more.

Since the example given is ME, and *I* exist, we are NOT discussing "something highly improbable". We are discussing something that is 100% probable. 100% probable compared to "infinitely impossible". Thus the chances of TWO things that are each "100% probable" is infinitely greater than the "set of things that are not possible".

 

Consider the time immediately after the BB. As particles formed, it is obvious that the probablity of mutiples of the SAME particle forming is infinitely greater than each particle being unique. Just as there are a FINITE number of probable elements. And those that DO exist are infintiely more likely to be repeated than those that CAN'T exist.

I'll resuse something I said earlier. Take a standard deck of 52 playing cards

This is a failed analogy as the 52 cards are a very finite selection. But it does still hold if you were to take a "deck of all cards" and select 52 in a series. As while the repetition of an actual series of cards is less probable than a new series of cards, it is infinitely more probable than an impossible series of cards. Such as an Ace, Queen, Zork.

 

So the reality is, once something, a particle, an element, a series of cards or genes, DOES exist, the probablity of it happening again is infinitely greater than the existence of something that CAN'T exist.

[Freethinker]

Originally posted by: TeleMad

But just finding life on Mars or even Titan wouldn’t show that life arose elsewhere, it could have traveled there via “planet hopping”…

Just as finding life on earth "wouldn’t show that life arose" HERE. it could have traveled (here) via “planet hopping”.

 

What's your point?

[Freethinker]

Originally posted by: TeleMad

I like how when people try to use logic to show that there simply must be more X out there, they always use an example for which we ... They pretend to be convincing but their logic is preloaded to deliver the result they are trying to show comes about when we DON’T know that other Xs are out there.

We don't need to "KNOW there are more X out there". We just need to understand that if X exists, the chance of "more X" is infinitely greater than "can't exist".

 

Unless you can PROVE that no two same particles exist? There is only ONE photon, electron, ...

[Freethinker]

Originally posted by: TeleMad

Now, let's follow through on that logic. If life's arising is as improbable as I believe,

Interesting. So just how high is the probablity of something that exists, to exist?

 

If something DOES exist, the PROBABLITY of it's existing is 100%.

[Tormod]

Originally posted by: TeleMad

Tormod: Telemad, it is impossible to stick to your actual position because it is always unclear.

 

Only for people who think there are only two completely opposite positions and forget that other positions exist between the two extremes.

 

You've stuffed words of impossibility into my mouth....you've tried to push me way over to an extreme where my statements themselves simply don't put me.

 

Oh my. Well. Let me rephrase: "It is impossible for ME (as you requested) to stick to your 'actual' position because it is always unclear TO ME".

 

 

Tormod: I may appear to be refuting you, but my aim is to show that there is no reason to argue that life is something that happened on Earth only.

 

So you are trying to show something that is wrong...I thought so.

 

My point was that I was taking part in the discussion, not refuting YOU but making a point. These discussions always end up in a fight between TeleMad and The Rest Of Us because you lay claim to the rules of logic. We end up playing ping pong, which is fruitless. We may all be to blame for that.

 

I'l drop my participation in this thread here because of that. TeleMad, you are a valuable member and please don't get me wrong. I'd really like to see you start a thread on what logic is. That should be an interesting discussion. We seem to disagree on many basic things - maybe it would help to discuss them in a "logic" thread.

[Tormod]

Originally posted by: TeleMad

Tormod: The carbon-based life "as we know it" mantra is perhaps the simplest solution in our part of the universe. But life could equally well be silicon-based.

 

No, it couldn't. We don't even know that it could be based on silicon at all, let alone equally well. And there are reasons to doubt that silicon life is even possible.

 

(Good quotes from TeleMad offering evidence removed, they are in his original post)

 

I've been thinking about this for a while. I have read many times that silicon-based life forms may be possible, so I wanted to follow up this particular aspect of the thread.

 

I found one paper to support this idea, although I am not sure how reliable the source is. It agrees with TeleMad that silicon based life would be very unlikely in a terrestrial setting, but it does allow for silicon-based life forms given other circumstances:

 

Edited for brevity

 

Tormod

[Freethinker]

As a note, the "What is life" thread was closed to keep it's discussion here exclusively. Thus stopping duplicating the effort and diluting everyone's efforts.

[Tormod]

Just found an interesting story in Nature which is highly relevant to our discussion here:

 

Alien microbes could survive crash-landing

http://www.nature.com/news/2004/040830/full/040830-10.html

 

Bacteria could survive crash-landing on other planets, a British team has found. The result supports to the idea that Martian organisms could have fallen to Earth in meteorites and seeded life.

[Freethinker]

This would not only dramatically increase the possibility of life elsewhere in the universe, but would also potejtially resolve any Abiogenesis issues. "Life" did not have to START here.

 

Plus it would mean intelligent life, life in fact which nearly duplicates "human", would be very likely elsewhere.

 

But why do they promote Mars as a better initial source of life?

[Tim_Lou]

remember that i had seen a show talking about the same thing.

 

people used guns to target directly at the bacteria, and a pretty good amount survived......

[Tormod]

Originally posted by: Freethinker

But why do they promote Mars as a better initial source of life?

 

Yeah, puzzling.

[TeleMad]

Uhm, didn't I already bring up the "planet hopping" possibility for bacteria way back on 08/04/2004...

 

TeleMad: But just finding life on Mars or even Titan wouldn’t show that life arose elsewhere, it could have traveled there via “planet hopping”…

 

 

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“Because planetary systems are formed by accretion, I think it unlikely that life on another body in the solar system arose independently of terrestrial life. It is now clear from meteorite studies that bodies can be transported from one planet to another, for instance from Mars to Earth, without excessive heating that would sterilize microbial organisms. Although such transfer events are now rare, they must have been far more frequent during the accretion of the planets. Large-scale infall, blasting ejecta throughout the forming solar system, probably extended until at least about 4 billion years ago and so probably overlapped with the processes that resulted in the origin of life. In principle, life, regardless of where it arose, could have survived interplanetary transport and seeded the solar system wherever conditions occur that are permissible to life. So, if we go to Mars or Europa and find living creatures there, and read their rRNA genes, we should not be surprised if the sequences fall into our own relatedness group, as articulated in the tree of life.” (Normal R Pace, The Universal Nature of Biochemistry, PNAS, January 30, 2001, vol. 98, no. 3, p805-808)

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So if we find life elsewhere, we first have to confirm that it is sufficiently different from life here on Earth to warrant the conclusion that it arose independently.

 

 

I didn't explicitly mention it at the time, since it wasn't the topic of discussion at the time I made the post, but the opposite is implied: that life could have arisen on Mars or elsewhere and then "hopped" here. In fact, I've been suggesting this possibility for years on the net.

[Freethinker]

Seems we should run the Abiogenesis thread in sync with this one.

 

The need to even ultimately examine how life could start based on early earth is irrelevant once panspermia steps in.

[Tormod]

Originally posted by: TeleMad

Uhm, didn't I already bring up the "planet hopping" possibility for bacteria way back on 08/04/2004...

 

...snip...

 

I didn't explicitly mention it at the time, since it wasn't the topic of discussion at the time I made the post, but the opposite is implied: that life could have arisen on Mars or elsewhere and then "hopped" here. In fact, I've been suggesting this possibility for years on the net.

 

Yes. Although you were hardly the first and will not be the last. But you spend a lot of time here and elsewhere (like this thread) refuting our (obviously futile) attempts to suggest that life may have arisen elsewhere in the universe, sticking to your point that since we have no proof of life elsewhere, it cannot have happened (like your refutation Amir Aczel's book because it is full of "unsupported assumptions").

 

Then some evidence turns up favoring planet hopping - which suggest two things (At least) - a) life on Earth may come from elsewhere and B) life may be all over the solar system. And suddenly this is "your" idea. Cool. Well, then I have supported you since I was 10.

 

But there is also evidence - no, for the sake of argument let's call it hints - (planets in "habitable zones", for example) that conditions favorable to life exist elsewhere in the universe. And if planethopping is possible, who knows if starhopping may be. I think that to maintain that life can only have arisen here (which still is a "shots" argument, only in denial ) simply because we haven't shook hands with Mr ET is a tad uninspiring, to say the least. Scientists are working hard to bring up solid evidence and I for one would NOT ague that they are failing to do so.

 

The Astrobiology web at NASA Ames is a good source for those who are interested in this:

http://astrobiology.arc.nasa.gov/index.cfm

 

Here is a classroom exercise which puts the Drake equation to use:

http://imagine.gsfc.nasa.gov/docs/teachers/lessons/lotto/lotto.html

 

Although Drake himself admits that his theory is faulty, because it bases it's number of technlogical civilzations on their use of detectable electromagnetic communication (which we now realize will only be true for a fraction of the civilaztion's existence) the theory is a numbers game which does indeed come out in favor of life arising elsewhere.

[BlameTheEx]

There are arguments in favour of mars being the original source of life.

 

1) Assuming it was transferred by a meteorite hitting the planet so hard that bits of the planet were knocked into space with life hitching a lift. We know for a fact that bits of mars have arrived on earth a meteorites, but did it work the other way round? The escape velocity of earth is higher.

 

2) Mars is smaller, and thus cooled down earlier. If life is just about inevitable for both planets, then life would have got started on mars first. Perhaps true Earth life never got the chance to start, or failed to compete, because more evolved martian life arrived.

[IrishEyes]

Yep, that explains a lot, Blame. I always KNEW FreeT was really from another planet!

[Freethinker]

Originally posted by: BlameTheEx

There are arguments in favour of mars being the original source of life.

 

1) Assuming it was transferred by a meteorite hitting the planet so hard that bits of the planet were knocked into space with life hitching a lift. We know for a fact that bits of mars have arrived on earth a meteorites, but did it work the other way round? The escape velocity of earth is higher.

I don't see where this would promote Mars as the source of life on earth.

2) Mars is smaller, and thus cooled down earlier. If life is just about inevitable for both planets, then life would have got started on mars first. Perhaps true Earth life never got the chance to start, or failed to compete, because more evolved martian life arrived.

This does give a mechanism, Mars cooling down first

 

But I still don't see why, if we assume for discussion panspermia, then we need to set ALL of the universe as the potential original donor. I don't see where Mars becomes a favorite on this level.