Do Aliens Exist?

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#1 5 March, 2015 - 12:08
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Do Aliens Exist?


This is in the off-topic chat section, and continued from the discussion over here.

Josh Cohen wrote:

Microbes are possibly a key to everything, and all of these questions are going to get much more interesting and complex when we discover aliens. :)

Bateman wrote:

Re: Josh: They quite possibly are. I don't see how aliens would play a part in it; if they evolved in a different solarsystem/planet, they are likely so completely different from us that their microbes wouldn't affect us. If they got over here, they would however have the technology to do whatever they wished to us practically instantly(ie; destroy the whole planet, cause a lethal plague, etc). This is because of the various limitations of space travel which make it so you would have to be able to literally bend space-time at will.

Have you heard of panspermia?

Panspermia is a hypothesis proposing that microscopic life forms that can survive the effects of space, such as extremophiles, become trapped in debris that is ejected into space after collisions between planets and small Solar System bodies that harbor life. Some organisms may travel dormant for an extended amount of time before colliding randomly with other planets or intermingling with protoplanetary disks. If met with ideal conditions on a new planet's surfaces, the organisms become active and the process of evolution begins. Panspermia is not meant to address how life began, just the method that may cause its distribution in the Universe.

I really like the idea, though I don't know if it is true. Tardigrades can survive in space for at least ten days. Bacteria maybe longer.

I think that when we do encounter aliens it's going to be more like Andromeda Strain than Star Trek. I'm less inclined to believe that aliens fly around in spaceships and think and act like modern humans.

5 March, 2015 - 12:57
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it is one of the very few things that has 100% of chance to be true.
the temperature going from the hot to the cold is not 100%

5 March, 2015 - 15:00
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Maybe there is life out there, but not as "smart" or macroscopic as seen on movies or TV.

Here ( Earth ) there are a lot of bacterias that survive to anything.

The Tardigrade for example:

http://en.m.wikipedia.org/wiki/Tardigrade

5 March, 2015 - 15:38
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Josh Cohen wrote:

Have you heard of panspermia?

Panspermia is a hypothesis proposing that microscopic life forms that can survive the effects of space, such as extremophiles, become trapped in debris that is ejected into space after collisions between planets and small Solar System bodies that harbor life. Some organisms may travel dormant for an extended amount of time before colliding randomly with other planets or intermingling with protoplanetary disks. If met with ideal conditions on a new planet's surfaces, the organisms become active and the process of evolution begins. Panspermia is not meant to address how life began, just the method that may cause its distribution in the Universe.

I really like the idea, though I don't know if it is true. Tardigrades can survive in space for at least ten days. Bacteria maybe longer.

I think that when we do encounter aliens it's going to be more like Andromeda Strain than Star Trek. I'm less inclined to believe that aliens fly around in spaceships and think and act like modern humans.

Of course. The key behind that idea, if I remember correctly, is that when they're trapped inside that debris, they are basically in cryogenic sleep; they don't need much if any energy to continue living, they're protected(unlike the tardigrade, which is unprotected) by the mass around them. Some have proposed that's how life began on earth; a bacteria trapped inside an asteroid. There are also frogs that can survive being frozen(at least for a winter). I'm still unsure of this though; closest star is 8 thousand light-years away(if I remember correctly), so the asteroid would have to travel for at least(realistically) twice as long.

Sure, we might 'meet' aliens by this method. I was thinking more in terms of; if they come to us on purpose, they possess extremely advanced technology. Some of the limitations of space travel; the time it takes, going at that speed a particle the size of a grain of sand would pierce through the ship, there's a phenomenon in which wavelengths of electromagnetism shift into basically being so radioactive as to kill anything on the ship, as well as; why us? Why would they check this average little planet in an average solar system? Really; only if they also have evolved using water. If they, like the tardigrades(who occasionally), use sugar instead, they would have no reason to look for us.

To overcome those obstacles, there comes the theoretical I spoke of earlier, bending space-time in front and behind of the ship, to make the distance a lot shorter. You don't go as fast, and thus no electromagnetic radiation, no grains of sand killing you.

On the title of the post; They are very very likely to exist. As stringent as the Goldilocks zone conditions are, there are many planets that meet them. There is also likely to be other life, from other types of conditions. Obviously they're not abducting cows or sticking things in random farmers.

Taijutsu : "it is one of the very few things that has 100% of chance to be true.
the temperature going from the hot to the cold is not 100%"
It's not a 100% chance, but it is very close to that. The temperature going from hot to cold is just as likely, in terms of the universe. Everything is cooling(very very slowly of course). Unless you're talking about global warming, which has vast amounts of evidence behind it.

Something else that's interesting to me is the idea of an everexpanding universe. Not only is it expanding all the time, it's actually expanding faster and faster. It's not that the 'map' is getting longer, so to speak, but it's stretching. The fabric of spacetime is stretching, everything is getting farther apart from everything else. Like dots drawn on a balloon that's being inflated.

Fascinating. Stephen Hawking(if I remember correctly) spoke on how eventually, in a couple billion years, the universe will be expanding so fast that gravity will be overcome by it; the planets will fall out of orbit, solar systems out of orbit, etc. A couple thousand years after that, the atomic forces will also be overcome by it; the nucleus will be separated from the electrons, etc. After that, absolute zero comes very quickly.

I wouldn't dismiss intelligent life so quickly.

Bateman

5 March, 2015 - 23:00
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Bateman wrote:

...closest star is 8 thousand light-years away(if I remember correctly), so the asteroid would have to travel for at least(realistically) twice as long...

True -- debris from Mars and other sources isn't uncommon though. It's possible that life originates at independent locations and also gets transported. If panspermia is accurate, we could be descendents of "Martians".

Bateman wrote:

Sure, we might 'meet' aliens by this method. I was thinking more in terms of; if they come to us on purpose, they possess extremely advanced technology. Some of the limitations of space travel; the time it takes, going at that speed a particle the size of a grain of sand would pierce through the ship, there's a phenomenon in which wavelengths of electromagnetism shift into basically being so radioactive as to kill anything on the ship, as well as; why us? Why would they check this average little planet in an average solar system? Really; only if they also have evolved using water. If they, like the tardigrades(who occasionally), use sugar instead, they would have no reason to look for us.

Yeah... it seems unlikely to me that "intelligent aliens" are flying around in spaceships, just waiting to make diplomatic contact with us. Who knows...

Bateman wrote:

On the title of the post; They are very very likely to exist. As stringent as the Goldilocks zone conditions are, there are many planets that meet them. There is also likely to be other life, from other types of conditions.

It is hard for me to believe that life only exists on Earth. This is interesting. (tl;dr there may be 15-30 billion "Earths" in the Milky Way)

Bateman wrote:

Obviously they're not abducting cows or sticking things in random farmers.

I can't remember who I was speaking with who joked that the aliens' real purpose is to harvest gut microbes. :)

5 March, 2015 - 23:46
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Don't think so, however I am quite sceptic to things I've never seen.

15 April, 2015 - 10:00
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Josh Cohen wrote:

True -- debris from Mars and other sources isn't uncommon though. It's possible that life originates at independent locations and also gets transported. If panspermia is accurate, we could be descendents of "Martians".

Still, it wouldn't really change much; evolution still works the same way, even if the first bacteria was actually brought here on a comet(asteroid?). The amount of time since then, whatever organisms, wherever the debris came from, would have evolved completely differently from us, would be almost as different from us as aliens from any other planet(that wasn't the source of the debris).

Josh Cohen wrote:

Yeah... it seems unlikely to me that "intelligent aliens" are flying around in spaceships, just waiting to make diplomatic contact with us. Who knows...

Yep. Especially given the limitations of the speed of light; depending on where in the universe they were, they would only see the earth as it used to be, not how it is not(with technology, large life and such).

Depends how broadly you define 'earth-like'.

Gadsila wrote:

Don't think so, however I am quite sceptic to things I've never seen.

Remaining skeptical before sufficient evidence is presented makes sense. After it's presented, it does not. For life on other planets, it's a bit like a lottery; let's say 1 in 10 million chance of winning. With the amount of planets and stars there are, it's like we bought 10 billion tickets. It's possible none of them won, but it's statistically extremely likely that there are many planets that have life on them. What stage that life is at though is questionable.

Bateman

6 May, 2015 - 00:52
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Yes and No.

But, unless proven, the scale is on to 'No'.

If you bring proofs then I am the first to believe it. Till then, no.

My view is solipsistic, but I go with the evidence, which says that nothing has been found so far. 60 years of SETI and nothing so far. Some say "Absence of evidence is not evidence of absence". But okay, you gotta bring the evidence. That's how science and epistemology works. Based on hard pure evidence and not on 'gut feeling'.

Okay we estimate that there are 1 septillion planets, (10^24) but I repeat, nothing has been found.

We on Earth are basically an 1 sample experiment so there are no conclusions. The Drake equation might as well be N=10^(-30) which trivialises the 10^24. But okay. It's all speculations.

6 May, 2015 - 06:08
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You're completely right Nodas. The default position is to disbelieve claims before they have been proven.

'60 years of SETI and nothing so far' It's not that easy to detect life on other planets. Even other planets are difficult to detect on their own, if I remember correctly they're usually identified when they go between earth and their sun(we can see the light bending around them). We have detected several likely water based planets with similar conditions to earth though. It doesn't mean there is life there, but it might be there.

My position is that it's likely there is life on other planets.

Bateman

31 May, 2015 - 19:56
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Basically, we do not know. That's why I said 'Yes and No'.

So without evidence and proofs, it all comes down to personal beliefs.
You believe it's likely. I don't.

But our beliefs don't matter much, because all beliefs stem from the ignorance of facts.
The hard facts are :
- Have we imagined aliens? Yes. (e.g. plenty of fiction movies)
- Have we ever seen real aliens (peer-reviewed)? No.
- Do aliens exist? Maybe yes, maybe no.

Okay, I may assume that right now there is a lifeform crawling somewhere inside Andromeda galaxy M31. But that's 2.5*10^22 meters far away, so I'll never know about that anyway. That's why I mentioned the word solipsistic, and I add another: stoic. These 2 words (stoic and solipsistic) sum up my position concerning this issue.

15 June, 2015 - 03:09
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We may never know the answer, but I suspect that are going to find microbes on Mars. Even NASA is optimistic: Signs of Alien Life Will Be Found by 2025, NASA's Chief Scientist Predicts. This is a field that I really want to get into, so I'm biased. :)

Regarding the size of the universe, make these videos full screen and turn up the resolution:

More here:
http://howfarawayisit.com/

There are hundreds of millions of stars in the Milky Way, and maybe more than 100 billion galaxies. We will most likely never find the aliens beyond our solar system, but I have trouble believing that life only exists on our planet. :)

15 June, 2015 - 09:51
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Nice links and vids. I also have a special map of M31 that shows individual stars and clusters.

Regarding speculations, I think most of us would definitely
wish to find aliens or exo-life.

But that's still only wishful thinking and not proof.
NASA scientists, said they 'will find', but not 'they found'.
That's not science, but speculation and opinion(like mine).

Like I said, there is also a chance that even if there are 1 septillion planets (10^24), the Drake equation may have a Great Filter somewhere along the its factors, that trivialises the probability of intelligent communicating life arising.

E.g. For n=10^24 exoplanets
and probability f(communicating intelligence) =10^(-30)
then a simplified version of Drake equation gives
N = 10^24 x 10^(-30) = 0.0001% that communicating intelligence have arised. So that even makes our existence highly improbable in the first place, because there may be thousands of other universes where interplanetary communicating life like humans, never arose at all.

Basically, all the conditions were favourable in this universe, and we hit the existence lottery. So congratulations to us.

15 June, 2015 - 11:09
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Quote:

Regarding speculations, I think most of us would definitely
wish to find aliens or exo-life.

I will be excited when we find aliens, but I actually hope that we don't find them. I don't think that it will be good for this planet.

I don't expect to find "intelligent" aliens. I think it's possible that the Great Filter is a result of species encountering each other. It could be more like Andromeda Strain than Star Trek (like I mentioned in my original post). One only has to look at the devastation caused by invasive species just from different continents on this planet. With enough food and without natural barriers to reproduction, organisms tend to reproduce in ways that can be devastating for other organisms and the environment.

I recently read an article about the ethics of Mars exploration. The author was worried about the possibility of Earth's microorganisms overrunning the Martian environment. I think that the article had things backwards---I'd be more worried about Martian organisms reproducing without ecological constraints in Earth's environment. The Earth is more habitable than Mars, so it's likely that any flow of invasive microorganisms would come in this direction.

Even though it's just a personal belief, I can't imagine that there isn't alien life out there. "Intelligent" aliens is another story though. I think that our perception of "intelligent life" is clouded by our lack of understanding of what a human is. Complex organisms may not be able to survive outside of their natural environments. A human is not exactly an individual entity, it is more like an ecosystem. Something like 90% of the DNA on a human is not human---it's microbial. Human ego makes us think that it's the age of humanity, but it might be more accurate to consider that microbes have always ruled and probably always will.

16 June, 2015 - 01:48
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Here is another perspective on Mars that I just saw today: New study favors cold, icy early Mars

16 June, 2015 - 20:13
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The US National debt exceeds the number of stars in the milky way.

Alien life does not seem like an extraordinary claim. It is the idea that it may exist within a distance or time that might have any relevance that is extraordinary .

The observable universe is not likely to be the limit of space and quite a few would argue that the universe is not essentially singular.

That photons of light from 13 billion years ago are arriving from the event of the "big bang" make me strongly suspect that our ideas of space and time, despite seeming to be consistent are fundamentally silly.

Quantum mechanics and the unified theories work incredibly well but the whole big ball of something from nothing, gravity, time, and entanglement add up to monkey noises.

Hopefully the aliens will show up soon and sort this out for me :)

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