Life elsewhere, thoughts.

[Moontanman]

 

What life forms on Earth are able to survive the conditions you mentioned? They're likely not creatures I've heard of.

 

 

Brine shrimp eggs are pretty tough as well. They can survive decades vacuum packed and out in the deserts locked in salt can survive a very long time. Some desert soils can yield shrimp after a many decades long drought.

[swansont]

Yeah I saw carbohydrates in the table too, although I didn't know the reason for it ranking above TNT. So basically what you're saying is cookies make better bombs than TNT?

No, because bombs need to oxidize quickly to blow up.

[saevitas]

I think that it is almost impossible that life doesn't exists anywhere else in the Universe. The Cosmos is so vast that life cannot be the property of just one of its smallest pixels. Also, the ingredients of life exist everywhere; after all, even the molecules of our bodies are traceable to old stars.

Communication with this life will be very difficult for various reasons; not only the distance between Earth and the possibly inhibited planet would be vast and therefore the communication would be very slow, but it would also take time to learn the language of the other beings, if they have a language. We might also be too developed to establish a communication with the alien beings or the other way round. But I think technology will allow us to do so; we have established a communication with dolphins, the aliencivilidsation won't be the problem.

I think that it is almost impossible that life doesn't exists anywhere else in the Universe. The Cosmos is so vast that life cannot be the property of just one of its smallest pixels. Also, the ingredients of life exist everywhere; after all, even the molecules of our bodies are traceable to old stars.

Communication with this life will be very difficult for various reasons; not only the distance between Earth and the possibly inhibited planet would be vast and therefore the communication would be very slow, but it would also take time to learn the language of the other beings, if they have a language. We might also be too developed to establish a communication with the alien beings or the other way round. But I think technology will allow us to do so; we have established a communication with dolphins, the aliencivilidsation won't be the problem.

[CramBoom]

 

One example: https://en.wikipedia.org/wiki/Tardigrade

 

"For example, tardigrades can withstand temperatures from just above absolute zero to well above the boiling point of water, pressures about 6 times stronger than pressures found in the deepest ocean trenches, ionizing radiation at doses hundreds of times higher than would kill a person, and the vacuum of outer space. They can go without food or water for nearly 120 years, drying out to the point where they are 3% or less water, only to rehydrate, forage, and reproduce."

 

Tardigrades are amazing. They were actually sent in space an brought back after being exposed to radiation, the vacuum of space, etc, and they alive and happy when they were brought back to earth. They even brought some baby tardigrades with them.

 

Also, about the topic, the universe is too big not to have other life. The human race may never meet other life because of the sheer size of the universe, but it is possible that we will.

 

But is life possible in higher dimensions? I mean our definition of life:

1. The condition that distinguishes animals and plants from inorganic matter, including the capacity for growth, reproduction, functional...(from google)

Is it possible that life could follow that definition and live in a higher dimension? Or does that definition only apply to the 3rd dimension?

[Iota]

Tardigrades are amazing. They were actually sent in space an brought back after being exposed to radiation, the vacuum of space, etc, and they alive and happy when they were brought back to earth. They even brought some baby tardigrades with them.

 

Also, about the topic, the universe is too big not to have other life. The human race may never meet other life because of the sheer size of the universe, but it is possible that we will.

 

But is life possible in higher dimensions? I mean our definition of life:

1. The condition that distinguishes animals and plants from inorganic matter, including the capacity for growth, reproduction, functional...(from google)

 

Is it possible that life could follow that definition and live in a higher dimension? Or does that definition only apply to the 3rd dimension?

 

I looked up about dimensions years back, I became none the wiser though. There are videos explaining what the 4th dimension would look like, and a game which plays in a 3D representation of the 4th dimension. I couldn't comprehend it really, and someone else claimed the 4th dimension is light... or something.

 

What I'm most interested in is the potential for life that may occur which we wouldn't expect to. That doesn't conform to the normal definition of life, or life that does... but forms differently.

[MigL]

I've lost all respect for your arguments iota.

 

PERONI ??!!

 

Not that I drink it, but at least go for a Moretti.

[Iota]

I've lost all respect for your arguments iota.

 

PERONI ??!!

 

Not that I drink it, but at least go for a Moretti.

 

You know, I was looking for Moretti the other day, because I've been meaning to try it for ages, but the pub I was in didn't have it.

 

Which one is better is redundant to me as of next month anyway, because I'll be on a university budget again. Pints of Carlsberg all the way.

[MigL]

I like a Carlsberg now and again, paesano.

[SamBridge]

So as I understand it many people are hopeful (except for Stephen Hawking) that there's much life on many different planets. But has anyone stopped to think that the Earth is perfectly suitable for life as we know it, yet in it's 4 billion years of history the base pairs for DNA only spontaneously formed once? I mean if it only happens once in 4 billion years (and still counting) and not even scientists have done it, that's got to make it a pretty improbable event. But I guess we'll have to see what's under Europa to make sure.

Edited August 19, 2013 by SamBridge

[Moontanman]

So as I understand it many people are hopeful (except for Stephen Hawking) that there's much life on many different planets. But has anyone stopped to think that the Earth is perfectly suitable for life as we know it, yet in it's 4 billion years of history the base pairs for DNA only spontaneously formed once? I mean if it only happens once in 4 billion years (and still counting) and not even scientists have done it, that's got to make it a pretty improbable event. But I guess we'll have to see what's under Europa to make sure.

 

 

I don't think the improbability argument is valid Sam, with only one data point we really don't know how improbable abiogenesis really is but I do know that spontaneous formation of DNA base pairs is not the current scientific consensus of how life originated on our planet.

 

Also the idea of the Earth life as we know it being perfectly suited for life is bass ackwards, life evolved to fit the Earth and it is quite easy to speculate about how the Earth or another planet might very well be better suited for life as we know it. Quite a bit of the Earth is not well suited for life as we know it, in fact places like deserts and ice sheets are no where nearly as well suited for life as a rain forest for instance. An Earth like planet with rain forest type conditions all over it's surface might very well be better suited for life as we know it. (just to suggest an easy exception)

 

Of course I'd be remiss if i didn't give a shout out for life not as we know it (personally I have more and more of a problem with this idea) but lets not discount silanes dissolved in liquid methane or boron life, Nitrogen Phosphorous, or other increasingly weird life forms just because we haven't seen them. We have found life as we know it in some pretty unlikely environments just here on the Earth, in fact complex surface life can be said to be the extremophiles here on Earth with a huge ecosystem under ground based on chemical energy rather than EM radiation, this ecosystem has been estimated to be much larger than all complex surface life combined...

 

Any place we find complex chemicals and an energy source is justifiably under suspicion of harboring some sort of self replicating molecular systems...

 

http://en.wikipedia.org/wiki/Astrobiology

 

http://en.wikipedia.org/wiki/Hypothetical_types_of_biochemistry

 

http://www.astrobiology.com/

 

http://www.daviddarling.info/encyclopedia/N/nitrogen-based_life.html

[SamBridge]

 

 

I don't think the improbability argument is valid Sam, with only one data point

No we don't have one data point, we technically have 4 billion data points, 4 billion x365 if you wanna be more specific, though I'm sure the number of days in a year has changed a little bit. Every year or really even every second of every day on Earth, a bunch of random chemicals has the chance to spontaneously create life as it did before. But after 4 billion chances it's only done that once, at least successfully. So even if the chances of life forming is less slim, the chances of it developing and progressing are definitely slimmer.

 

 

 

Also the idea of the Earth life as we know it being perfectly suited for life is bass ackwards, life evolved to fit the Earth and it is quite easy to speculate about how the Earth or another planet might very well be better suited for life as we know it. Quite a bit of the Earth is not well suited for life as we know it, in fact places like deserts and ice sheets are no where nearly as well suited for life as a rain forest for instance. An Earth like planet with rain forest type conditions all over it's surface might very well be better suited for life as we know it. (just to suggest an easy exception)

I'm not really sure what you're trying to say. Obviously one organism cannot be adapted to every environment, but the general properties of carbon based life that we know of, like having cells with a nucleus and cytoplasm, and even common structures like having a mouth and skin and digestive chemicals, cells communicating with each other and DNA structures taking part in evolution, are pretty common here.

Edited August 19, 2013 by SamBridge

[Moontanman]

I absolutely love this picture, i wish i knew if there was a book connected with it...

 

 

 

No we don't have one data point, we technically have 4 billion data points, 4 billion x365 if you wanna be more specific, though I'm sure the number of days in a year has changed a little bit. Every year or really even every second of every day on Earth, a bunch of random chemicals has the chance to spontaneously create life as it did before. But after 4 billion chances it's only done that once, at least successfully. So even if the chances of life forming is less slim, the chances of it developing and progressing are definitely slimmer.

No, in fact this is not true, the conditions on the earth today do not allow for the formation of new life, not only is oxygen a problem for the formation of life any complex organics are immediately eaten by current life forms...

I'm not really sure what you're trying to say. Obviously one organism cannot be adapted to every environment, but the general properties of carbon based life that we know of, like having cells with a nucleus and cytoplasm, and even common structures like having a mouth and skin and digestive chemicals, cells communicating with each other and DNA structures taking part in evolution, are pretty common here.

Yes they are pretty common here in fact it's all we have because that's what evolved here, I think it's likely similar biochemistry has evolved elsewhere but to think that what evolved here is the only way is possible for life to have evolved is a bit more than unsupportable...

[SamBridge]

 

No, in fact this is not true, the conditions on the earth today do not allow for the formation of new life, not only is oxygen a problem for the formation of life any complex organics are immediately eaten by current life forms...

As you implied before, there's a wide variety of conditions on Earth. If life could so easily form, then it definitely would have taken the opportunity to do so somewhere. There could easily be locations without much bacteria in places like concentrations of sulfuric acid, extreme cold temperatures, or lava which only a small amount of life can survive, or just random geographically isolated sections of land and caves. There's been millions of years for other types of life to develop in a constantly changing landscape with new opportunities arising, but it really doesn't seem to happen that often.

 

 

 

Yes they are pretty common here in fact it's all we have because that's what evolved here, I think it's likely similar biochemistry has evolved elsewhere but to think that what evolved here is the only way is possible for life to have evolved is a bit more than unsupportable...

I don't understand where anyone said life as we know it is the only life that can possibly develop. I said life as we knew it could have formed again.

Edited August 20, 2013 by SamBridge

[Moontanman]

As you implied before, there's a wide variety of conditions on Earth. If life could so easily form, then it definitely would have taken the opportunity to do so somewhere. There could easily be locations without much bacteria in places like concentrations of sulfuric acid, extreme cold temperatures, or lava which only a small amount of life can survive, or just random geographically isolated sections of land and caves. There's been millions of years for other types of life to develop in a constantly changing landscape with new opportunities arising, but it really doesn't seem to happen that often.

Um so you've gone from it only happened once to it doesn't happen very often?

 

 

I don't understand where anyone said life as we know it is the only life that can possibly develop. I said life as we knew it could have formed again.

How do you know it didn't?

[EdEarl]

... But has anyone stopped to think that the Earth is perfectly suitable for life as we know it, yet in it's 4 billion years of history the base pairs for DNA only spontaneously formed once? I mean if it only happens once in 4 billion years (and still counting) and not even scientists have done it, that's got to make it a pretty improbable event. ...

We do not know that abiogenesis only occurred once. It could occur from time to time, but with all the biology that exists on Earth, a neophyte life form is unlikely to survive long because something is likely to either eat it or infect and kill it. We know so little about how life formed and began evolution that our assumptions are likely to be incorrect.

 

Recently we have learned that DNA is traded among species. Perhaps, abiogenesis occurred several times and began trading features of life before DNA existed, and that process of trading eventually resulted in DNA. Until we know a process for abiogenesis, we cannot afford to exclude speculations without careful examination. One day such a mind experiment may result in an insight that helps us truly understand abiogenesis.

[SamBridge]

Um so you've gone from it only happened once to it doesn't happen very often?

it's called a compromise, I thought you liked those things.

 

 

How do you know it didn't?

Because there's been thousands of opportunities with diverse arrays of chemicals in various locations every single day for over 4 BILLION years and there's no new life. Maybe you are just not understanding how long a billion years is, just a single billion is a really really really long time for something to not happen.

 

We do not know that abiogenesis only occurred once. It could occur from time to time, but with all the biology that exists on Earth, a neophyte life form is unlikely to survive long because something is likely to either eat it or infect and kill it. We know so little about how life formed and began evolution that our assumptions are likely to be incorrect.

 

Recently we have learned that DNA is traded among species. Perhaps, abiogenesis occurred several times and began trading features of life before DNA existed, and that process of trading eventually resulted in DNA. Until we know a process for abiogenesis, we cannot afford to exclude speculations without careful examination. One day such a mind experiment may result in an insight that helps us truly understand abiogenesis.

Well, we found some very old bacteria called Algae and we can trace its lineage back from various rocks we found to around 3.8 billion years ago, and all life on this planet has the same base pairs as it does. Also, see above response.

Edited August 20, 2013 by SamBridge

[Moontanman]

it's called a compromise, I thought you liked those things.

You were mistaken...

 

 

 

Because there's been thousands of opportunities with diverse arrays of chemicals in various locations every single day for over 4 BILLION years and there's no new life. Maybe you are just not understanding how long a billion years is, just a single billion is a really really really long time for something to not happen.

 

Again, how do you know it did not?

 

 

Well, we found some very old bacteria called Algae and we can trace its lineage back from various rocks we found to around 3.8 billion years ago, and all life on this planet has the same base pairs as it does. Also, see above response.

We have no idea how the biochemistry of those algae worked and gene transfer at the time did indeed negate common decent.

 

There are three domains of life, current thought proposes a fourth but the consensus is that life, before common decent began, was a mishmash of life forms trading genes, out of an unknown number of life forms three basic domains of life emerged all of which more or less shared the same nucleotides the possible forth is RNA based but is parasitical on other life forms.

 

Conditions currently on the Earth are not conductive to abiogenesis and there is good reason not to expect new life to spring up due to current life forms occupying all the places life can form.

 

There is also the possibility that we simply haven't looked the right way as well. Current life detection methods are limited to life as we know it, a shadow biosphere has been proposed but all we ever check for are known nucleotides how can we check for something we do not know what it is? How would a non dna life form look like? How would we know if a bacterium used different chemistry? All we currently look for is life as we know it...

 

http://en.wikipedia.org/wiki/Shadow_biosphere

[SamBridge]

You were mistaken..

Then I'll just stick with what I was saying before.

 

 

Again, how do you know it did not

Because there's been billions of opportunities (literally) and nothing else has showed up, whereas the first microbial life we are related to got one shot and now there's us. We have more reason to doubt that life anything like life we have on Earth has a high chance of developing, and even less support that life unlike what we know can develop on Earth.

 

We have no idea how the biochemistry of those algae worked and gene transfer at the time did indeed negate common decent.

There are three domains of life, current thought proposes a fourth but the consensus is that life, before common decent began, was a mishmash of life forms trading genes, out of an unknown number of life forms three basic domains of life emerged all of which more or less shared the same nucleotides the possible forth is RNA based but is parasitical on other life forms.

Conditions currently on the Earth are not conductive to abiogenesis and there is good reason not to expect new life to spring up due to current life forms occupying all the places life can form.

There is also the possibility that we simply haven't looked the right way as well. Current life detection methods are limited to life as we know it, a shadow biosphere has been proposed but all we ever check for are known nucleotides how can we check for something we do not know what it is? How would a non dna life form look like? How would we know if a bacterium used different chemistry? All we currently look for is life as we know it...

http://en.wikipedia.org/wiki/Shadow_biosphere

But as I keep saying, there's many many many many different places on Earth where there's a diverse array of chemicals with no bacteria we know of. The different nascent genes as you mentioned are still part of the same time period and most likely event of whatever started life. There's no reason to expect that creating a hyperdrive or warp drive will spontaneously make the galaxy like star wars. And if it's so easy to create life forms from a bunch of random organic chemicals how come scientists still haven't created life forms from scratch? It's because it's a lot harder than your giving it credit for and it's not something to take for granted, it's very improbable.

[EdEarl]

Well, we found some very old bacteria called Algae and we can trace its lineage back from various rocks we found to around 3.8 billion years ago, and all life on this planet has the same base pairs as it does. Also, see above response.

Do we actually know that any base pairs except those will make a viable DNA? Even if a form of DNA can be made with different base pairs, it may be weak and unable to survive in the Earth's biosphere. Although, some viruses are able to survive, they are unable to survive without cells, AFAIK. Although, I have seen speculation that some viruses may be able to reproduce without cells.

 

Basically, the biology we have has had 4 Gy to evolve to be strong. Other forms of life that may have once existed have been overwhelmed by superior evolution. A stronger form of DNA seems unlikely, but it is conceivable.

[Moontanman]

Then I'll just stick with what I was saying before.

 

 

Because there's been billions of opportunities (literally) and nothing else has showed up, whereas the first microbial life we are related to got one shot and now there's us. We have more reason to doubt that life anything like life we have on Earth has a high chance of developing, and even less support that life unlike what we know can develop on Earth.

 

 

But as I keep saying, there's many many many many different places on Earth where there's a diverse array of chemicals with no bacteria we know of. The different nascent genes as you mentioned are still part of the same time period and most likely event of whatever started life. There's no reason to expect that creating a hyperdrive or warp drive will spontaneously make the galaxy like star wars. And if it's so easy to create life forms from a bunch of random organic chemicals how come scientists still haven't created life forms from scratch? It's because it's a lot harder than your giving it credit for and it's not something to take for granted, it's very improbable.

I see where the disconnect is coming from Sam, you think life is just a matter of mixing the right chemicals in a test tube and Viola a microbe... Not even close, the chemicals were the entire earth, the test tube was all of earths oceans, the time frame was millions of years billions of chemical reactions per second and the first life forms or protobionts were just the first in a long line of steps to microbes.,..

 

Edited August 20, 2013 by Moontanman

[Ihcisphysicist]

Of course there is life outside. It would be naive to assume that we are the perfect form of existence in the universe .

Edited August 22, 2013 by Ihcisphysicist

[Iota]

So as I understand it many people are hopeful (except for Stephen Hawking) that there's much life on many different planets. But has anyone stopped to think that the Earth is perfectly suitable for life as we know it, yet in it's 4 billion years of history the base pairs for DNA only spontaneously formed once? I mean if it only happens once in 4 billion years (and still counting) and not even scientists have done it, that's got to make it a pretty improbable event. But I guess we'll have to see what's under Europa to make sure.

 

Like Moontanman said, the conditions haven't been constant, so saying in 4billion years it's only occurred once is redundant. As for the Earth being 'perfect' for life, how do you know what the perfect conditions are for life to form? Also, at what point or which time period was Earth 'perfect' for life formation? It's not suitable for life formation now, according to the currently best science theories explaining how life first formed. It's currently good at supporting life, not forming life.

 

I would replace the word 'perfect' with 'viable', and drop the idea that this occurrence has only ever occured once. You can't accurately assert that at all.

 

I'd be interested to know why Hawking is doubtful about extraterrestrial life though.

 

 

Of course there is life outside. It would be naive to assume that we are the perfect form of existence in the universe .

 

I agree.

Edited August 26, 2013 by Iota

[EdEarl]

I just watched a documentary about the moon, again. It explained how the moon stabilizes the rotation of the Earth about its axis, and that without the moon, Earth's axis would sometimes rotate 90 degrees; thus, scorching raising pole temperatures to equatorial level while freezing some equatorial latitudes.

 

I suppose any life that formed in such conditions would have to survive wide swings in temperature, from arctic to temperate. I'm not sure how that would affect evolution other than making life forms able to survive such temperature swings. AFAIK there could be primates able to hibernate or be frozen for long periods and revive, an adaptation that might be useful for long trips in space.

[TransformerRobot]

After seeing the sci-fi epic Pacific Rim I began to wonder about this with regards to alien life forms;

 

Could they be found not on another planet, but in a separate dimension? Maybe even one they long ago created themselves through advanced sciences?