Do you think we will discover life somewhere other than earth in my lifetime? I'm 39 years old. Would love to see this occur in my lifetime. When I say life I do not mean little green men running around but at least life at a Bacterial level that I would imagine may exist in liquid water on Europa for example.
I really hope we do. Preferably in the next 20 years as I'm 57. Instrumentation will be the key, in particular spectrometers and precesses that allow the light passing through the atmosphere of an exoplanet to be analysed in detail. The gas composition of a planet can be an indicator of the presence life processes. As far as intelligent aliens are concerned that's a whole different ball game.
What do you think will happen?
I look forward to hearing an oxygen rich atmosphere has been found on another planet - an almost certain indicator of life.
Quote from: Tank on June 29, 2017, 06:40:56 AM
I really hope we do. Preferably in the next 20 years as I'm 57. Instrumentation will be the key, in particular spectrometers and precesses that allow the light passing through the atmosphere of an exoplanet to be analysed in detail. The gas composition of a planet can be an indicator of the presence life processes. As far as intelligent aliens are concerned that's a whole different ball game.
What do you think will happen?
Do you have any idea how likely it is this type of Instrumentation will be developed in the near future? I'm not familiar with that technology at all.
It's not very likely. But it gets more likely with each advance in space observation technology.
Put me on the "hope it happens" list... not sure how probable it is, though...
Well, life is extremely unpredictable and can end in the blink of an eye. So, anyone's lifetime can end in the next few seconds, which almost certainly ensures that life outside of earth would not be discovered in said lifetime.
Also, alien life be discovered, and that discovery being disclosed to the general population, are two entirety different things.
Quote from: Davin on June 29, 2017, 02:53:48 PM
It's not very likely. But it gets more likely with each advance in space observation technology.
This is my opinion as well.
I think that in order to say that life exists with some degree of certainty in our lifetime we would have to send an uncontaminated probe to another planet or moon in our very own solar system, capable of analysing soil, water or air samples and sending the data of positive results back to Earth. That would be the quickest, and even so, it could take many years depending on where the probe is sent.
You can analyse atmospheres of interstellar bodies or calculate the probability of exoplanets or exomoons harbouring life but they'd just be possibilities until some more substantial evidence is found.
*Edited for clarity.
I kind of hope I'm proved wrong but I don't think we will. The problem is the massive size of space and the time it takes to explore.
Quote from: Gloucester on June 29, 2017, 06:50:55 AM
I look forward to hearing an oxygen rich atmosphere has been found on another planet - an almost certain indicator of life.
Is it? :notsure:
If a planet is so close to it's star then it could be heavily radiated with ultraviolet light, which breaks water (relatively abundant in the universe) into oxygen and hydrogen. Planets may exist where hydrogen, with less mass than oxygen, can escape an atmosphere but the oxygen can't, leaving an oxygen-rich atmosphere but with no life.
Also, when simple life arose on planet Earth they were most likely oxygen-intolerant anaerobes. O
2 is such a vicious molecule that it takes a bit of evolving in order to deal with it, and even so, it eventually gets the best of us.
Quote from: xSilverPhinx on June 29, 2017, 05:34:22 PM
Quote from: Gloucester on June 29, 2017, 06:50:55 AM
I look forward to hearing an oxygen rich atmosphere has been found on another planet - an almost certain indicator of life.
Is it? :notsure:
If a planet is so close to it's star then it could be heavily radiated with ultraviolet light, which breaks water (relatively abundant in the universe) into oxygen and hydrogen. Planets may exist where hydrogen, with less mass than oxygen, can escape an atmosphere but the oxygen can't, leaving an oxygen-rich atmosphere but with no life.
Also, when simple life arose on planet Earth they were most likely oxygen-intolerant anaerobes. O2 is such a vicious molecule that it takes a bit of evolving in order to deal with it, and even so, it eventually gets the best of us.
Oxygen is obviously very reactive and gets removed from the atmosphere by reacting with iron and such. But you're quite right there would be circumstances where oxygen would not be a reliable indicator. Methane is another element associated with life processes.
The future of spectroscopic life detection on exoplanets (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4156723/)
Quote from: Tank on June 29, 2017, 07:10:18 PM
Methane is another element associated with life processes.
And volcanoes?
Quote from: xSilverPhinx on June 29, 2017, 07:15:49 PM
Quote from: Tank on June 29, 2017, 07:10:18 PM
Methane is another element associated with life processes.
And volcanoes?
Don't know. Apparently methane is quickly absorbed chemically and has to be replenished by life processes.
I posted elsewhere, in the what are you reading thread, a rather scholarly exposition about this subject. The book: Goldilocks and the Water Bears by Louisa Preston is brimming with this kind of subject matter. The difference is that ms. Preston is a highly credentialed British Astrobiologist. This is her field of endeavor.
^^ Oxygen is not necessary for life forms, nor is a narrow range of temperatures or radiation limitations. We humans have a bit of difficulty imagining life forms that do not comply with that which earthlings can conceive of.
Besides all that; God works in mysterious ways....... :not worthy:
Yes, we are mesophiles, which means we like to live in medium conditions. I think my favourite extremophile (which live in extreme conditions) would the the hyperthermophiles, mostly Archea and some strains of bacteria who thrive in temperatures ranging from ~ 60 to 100 degrees Celsius.
In biotechnology some of their enzymes are used in PCR because they can stand such high temperatures.
Quote from: xSilverPhinx on June 29, 2017, 05:34:22 PM
Quote from: Gloucester on June 29, 2017, 06:50:55 AM
I look forward to hearing an oxygen rich atmosphere has been found on another planet - an almost certain indicator of life.
Is it? :notsure:
If a planet is so close to it's star then it could be heavily radiated with ultraviolet light, which breaks water (relatively abundant in the universe) into oxygen and hydrogen. Planets may exist where hydrogen, with less mass than oxygen, can escape an atmosphere but the oxygen can't, leaving an oxygen-rich atmosphere but with no life.
Also, when simple life arose on planet Earth they were most likely oxygen-intolerant anaerobes. O2 is such a vicious molecule that it takes a bit of evolving in order to deal with it, and even so, it eventually gets the best of us.
As Tank said oxygen is very reactive and, in our current models, needs plant life to repleish it.
Your heavily UV irradiated planet, Silver, would surely have to be so far out of the "Goldilocks zone" for that particukar star that life (as we know it, Jim) would be pretty unlikely. But, since UV seems to be highly mutagenic and light is the energy driving photosynthesis . . . .
But supposing there is high IR as well, or does this star radiate "cool'" UV only? Hmm, high UV star further away? So the other factors, if measurable, would mitigate against deciding life was present.
Speculation is the enemy of sleep! Too bloody early!
Quote from: Gloucester on July 01, 2017, 06:41:58 AM
As Tank said oxygen is very reactive and, in our current models, needs plant life to repleish it.
The problem with extrapolating what we know is that it's just a
sample of one (planet Earth). In any other field that would be statistical nightmare.
QuoteYour heavily UV irradiated planet, Silver, would surely have to be so far out of the "Goldilocks zone" for that particukar star that life (as we know it, Jim) would be pretty unlikely. But, since UV seems to be highly mutagenic and light is the energy driving photosynthesis . . . .
So what if it's out of the Goldilocks zone? :P Take Jupiter's moon Europa, for instance, it's speculated that there could be simple life below its ice sheets due to the gravitational heating that Jupiter provides, even if it's outside our habitable zone.
It's not just UV radiation that ionises molecules. A magnetosphere could direct charged particles into a planet's or orbiting moon's atmosphere and that could be the source of oxygen in the atmosphere, such is the case with Saturn's moon Rhea and Jupiter's moons Europa and Ganymede.
While it's true that ionising radiation does destroy molecules such as DNA there are lifeforms that can resist such processes, such as the extremophile
Deinococcus radiodurans (https://en.wikipedia.org/wiki/Deinococcus_radiodurans#Ionizing-radiation_resistance). Maybe if somehow life got jumpstarted on another planet and managed to evolve into something resistant it could have resulted in an organism that could survive such high UV radiation.
:notsure: As far as I know plant life on Earth does not use UV radiation for photosynthesis...they use mostly wavelengths corresponding to red and blue light.
QuoteBut supposing there is high IR as well, or does this star radiate "cool'" UV only? Hmm, high UV star further away? So the other factors, if measurable, would mitigate against deciding life was present.
Speculation is the enemy of sleep! Too bloody early!
Yes, it's too early for this! It's not even 4 in the morning yet! :P
Silcer said:
QuoteSo what if it's out of the Goldilocks zone? :P Take Jupiter's moon Europa, for instance, it's speculated that there could be simple life below its ice sheets due to the gravitational heating that Jupiter provides, even if it's outside our habitable zone.
Hmm, but taking a "cold" body and warming it, by whatever means, untill we think life might be possible seems more likely than its possibility on a heavily irradiated one to me. But then...
OK, we are working on a definition of conditions required for life that fit our current understanding - which has been stretched somewhar from that of a hundred years ago!
Yes, forgot thst UV is not used in photosynthesis, but it is a very energetic form of radiation in terms of a star's long distance output for creating chemical change. As with splitting water rather than merely vaporising it!
And I suppose that energetic radiation is energetic radiation, no matter its source, nature or wave-length!
http://photobiology.info/Albarracin.html
Quote from: Tank on June 29, 2017, 07:11:43 PM
The future of spectroscopic life detection on exoplanets (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4156723/)
Thanks. Great article.
I would "like" for life to be discovered elsewhere than our planet, but that doesn't mean it will happen. A very unlikely circumstance is we explore the entirety of the universe, finding that we are alone.
I am going to wholeheartedly disagree with that, the universe is far too large for humans to be alone.
Quote from: No one on July 08, 2017, 05:47:57 PM
I am going to wholeheartedly disagree with that, the universe is far too large for humans to be alone.
It's unlikely for humans to be alone according to the Fermi Paradox->
Yet we found nothing.
People said Trump would never be elected, look at where we are now...
Hence the enormity of the universe. The distances are fantastically vast. Our nearest star other than the sun, is 4.3 light years away. And there are roughly 70 billion trillion other stars out there. Earth can not be the only planet with life.
Quote from: No one on July 08, 2017, 08:27:05 PM
Hence the enormity of the universe. The distances are fantastically vast. Our nearest star other than the sun, is 4.3 light years away. And there are roughly 70 billion trillion other stars out there. Earth can not be the only planet with life.
I'm not saying there aren't. I never said that. All I was saying is if that somehow it was empty, that would be disappointing.
Anything involving humans is disappointing.
Quote from: No one on July 08, 2017, 08:42:59 PM
Anything involving humans is disappointing.
Bahahaha
I don't think so. Bee-ing a physicist I'd say highly unlikely but possible you'd be around. I'm sure they're out there but the distance is to great. I was thinking of this just the other day coincidentally.
I based my reply on the vastness of the universe. I thought of --if (in my opinion) they came into existence around the same time we did, and considering the speed of electromagnets at the speed of light, and if it hasn't gotten here as yet, they would have to be a very long way from here. In this case it would of course, depend upon the rate of evolution they developed under. The change you have being here my be minimal, and as it is the distance has already proven the be very very great between us. But, there's no exact telling and I'm sure you already understood that. You can calculate how far the magnetics would have to be from here to reach in time for when you are still here.
The speed of light times this, that and the other. If picking a time in history, IE 10000 bc to now, how long would it take for their radio waves to be here. But, evolution can take millions of years.
Quote from: No one on June 29, 2017, 04:38:08 PM
Well, life is extremely unpredictable and can end in the blink of an eye. So, anyone's lifetime can end in the next few seconds, which almost certainly ensures that life outside of earth would not be discovered in said lifetime.
Also, alien life be discovered, and that discovery being disclosed to the general population, are two entirety different things.
Wow, I didn't think of that. They could have been and already blew themselves to smithereens. But they're radio waves would still be on the way.
Also something that crossed my mind - how do we even know they evolve? What if they just came into existence and stayed that way??? We could be sending messages to an alien version of a bacteria. Because I mean there is no guarantee that they have sex so how could they evolve??
Is there a reason why a species which reproduces asexually (through for example cloning) would not evolve?
DNA is disgustingly good at self-replicating well, and yet mistakes do happen. If one such mistake led to better being able to produce the most viable offspring in a lifetime... Evolution.
Yes?
That's true asmo. Some plants reproduce asexually and they evolve. I was just curious about life that does not reproduce at all. And like a bacteria, they just absorb whatever is near them to change that way maube? Idk, I'm just of the thought that life on other planets is nothing as we know it on earth.
Of course as we know life, it has to reproduce to be called life. But that's still biased towards us only finding life here.
Intriguing thought...
A life form, which does not reproduce - it just is.
I suppose, on the macro-est of levels, the Universe is one such. Still, "respires, replicates and expires" is more along the lines of what we define as life. It is a system which takes in some input in order to replicate itself and then... Succumbs to entropy?
I wonder if we found something not-precisely-dead, yet foreign to that half-baked definition, if it would not be more prudent to... Think up a new word for it? Sort-of like intelligence? Would we even recognize it if we saw it in a form so foreign to ourselves as an alien world might produce?
Hmm... Something "living" at a very (age of the Universe to a second type of very) slow pace... Yes. Maybe. I can see how such life forms could hypothetically exist.
Quote from: Arturo on July 26, 2017, 12:42:42 AM
Also something that crossed my mind - how do we even know they evolve? What if they just came into existence and stayed that way??? We could be sending messages to an alien version of a bacteria. Because I mean there is no guarantee that they have sex so how could they evolve??
Sexual reproduction is not required for organisms to evolve. Evolution is the change over time of allele frequency in a population. Mutations occur during reproduction, sexual or otherwise. Populations have variation and selection pressures effect survival/reproduction. Where you have reproduction, mutation, variation and selection pressures you get evolution.
And don't forget genetic drift.
Quote from: Asmodean on July 26, 2017, 02:18:03 PM
Intriguing thought...
A life form, which does not reproduce - it just is.
...
How did it arrive in the first place?
Emerged as a result of whatever passes for chemistry at the scales we are talking about.
I'm not talking about life that always was, but about life that just is. It takes a fair bit of imagination, but is there a reason why there would not exist some (let's say very simple for the purpose of this discussion) system out in space, which uses surrounding molecules and particles and the energy of, say, stray photons and what have you to replicate itself over the course of billions of years? Would such a system not be alive in the broad sense of the word?
Have you heard about those um... Fractal whatchamacallems, which lived like... At the time of early multicellular life? I wonder why those died out... Eaten by more complex things? Some mass extinction event they just couldn't recover from..?
Books. I need to raid me a university library or something.
Quote from: Tank on July 28, 2017, 10:26:14 AM
Quote from: Arturo on July 26, 2017, 12:42:42 AM
Also something that crossed my mind - how do we even know they evolve? What if they just came into existence and stayed that way??? We could be sending messages to an alien version of a bacteria. Because I mean there is no guarantee that they have sex so how could they evolve??
Sexual reproduction is not required for organisms to evolve. Evolution is the change over time of allele frequency in a population. Mutations occur during reproduction, sexual or otherwise. Populations have variation and selection pressures effect survival/reproduction. Where you have reproduction, mutation, variation and selection pressures you get evolution.
And don't forget genetic drift.
Okay so let's forget the sex part. Let's just say they came into existence and don't evolve. Let's say they are the way they always have been since they appeared. What would that be like?
(https://www.happyatheistforum.com/forum/proxy.php?request=http%3A%2F%2Fwww.trackie.com%2Ftrack-and-field%2Fimg%2Flayout%2Ficon_quote.jpg&hash=c5a9d5ac5c9c0366d813e18a50510fe9aa16bfc2)Asmodean:
Intriguing thought...
A life form, which does not reproduce - it just is.
...
(https://www.happyatheistforum.com/forum/proxy.php?request=http%3A%2F%2Fwww.trackie.com%2Ftrack-and-field%2Fimg%2Flayout%2Ficon_quote.jpg&hash=c5a9d5ac5c9c0366d813e18a50510fe9aa16bfc2)Tank:
How did it arrive in the first place?
Magic Sky Fairies, of course. (https://web.stardock.net/images/smiles/themes/digicons/Thumbs%20Up.png)
Quote from: Arturo on July 28, 2017, 04:05:28 PM
Quote from: Tank on July 28, 2017, 10:26:14 AM
Quote from: Arturo on July 26, 2017, 12:42:42 AM
Also something that crossed my mind - how do we even know they evolve? What if they just came into existence and stayed that way??? We could be sending messages to an alien version of a bacteria. Because I mean there is no guarantee that they have sex so how could they evolve??
Sexual reproduction is not required for organisms to evolve. Evolution is the change over time of allele frequency in a population. Mutations occur during reproduction, sexual or otherwise. Populations have variation and selection pressures effect survival/reproduction. Where you have reproduction, mutation, variation and selection pressures you get evolution.
And don't forget genetic drift.
Okay so let's forget the sex part. Let's just say they came into existence and don't evolve. Let's say they are the way they always have been since they appeared. What would that be like?
It looks like we're discussing a 'organism' that arrives by some kind of abiogenesis and then remains unchanging in perpetuity? Would that be what you're describing?
Quote from: The Grey OneI'm not talking about life that always was, but about life that just is. It takes a fair bit of imagination, but is there a reason why there would not exist some (let's say very simple for the purpose of this discussion) system out in space, which uses surrounding molecules and particles and the energy of, say, stray photons and what have you to replicate itself over the course of billions of years? Would such a system not be alive in the broad sense of the word?
Have you read
The Black Cloud by Fred Hoyle?
Quote from: Tank on July 29, 2017, 09:00:15 AM
Quote from: Arturo on July 28, 2017, 04:05:28 PM
Quote from: Tank on July 28, 2017, 10:26:14 AM
Quote from: Arturo on July 26, 2017, 12:42:42 AM
Also something that crossed my mind - how do we even know they evolve? What if they just came into existence and stayed that way??? We could be sending messages to an alien version of a bacteria. Because I mean there is no guarantee that they have sex so how could they evolve??
Sexual reproduction is not required for organisms to evolve. Evolution is the change over time of allele frequency in a population. Mutations occur during reproduction, sexual or otherwise. Populations have variation and selection pressures effect survival/reproduction. Where you have reproduction, mutation, variation and selection pressures you get evolution.
And don't forget genetic drift.
Okay so let's forget the sex part. Let's just say they came into existence and don't evolve. Let's say they are the way they always have been since they appeared. What would that be like?
It looks like we're discussing a 'organism' that arrives by some kind of abiogenesis and then remains unchanging in perpetuity? Would that be what you're describing?
Correct.
Quote from: Arturo on July 29, 2017, 05:20:04 PM
Quote from: Tank on July 29, 2017, 09:00:15 AM
Quote from: Arturo on July 28, 2017, 04:05:28 PM
Quote from: Tank on July 28, 2017, 10:26:14 AM
Quote from: Arturo on July 26, 2017, 12:42:42 AM
Also something that crossed my mind - how do we even know they evolve? What if they just came into existence and stayed that way??? We could be sending messages to an alien version of a bacteria. Because I mean there is no guarantee that they have sex so how could they evolve??
Sexual reproduction is not required for organisms to evolve. Evolution is the change over time of allele frequency in a population. Mutations occur during reproduction, sexual or otherwise. Populations have variation and selection pressures effect survival/reproduction. Where you have reproduction, mutation, variation and selection pressures you get evolution.
And don't forget genetic drift.
Okay so let's forget the sex part. Let's just say they came into existence and don't evolve. Let's say they are the way they always have been since they appeared. What would that be like?
It looks like we're discussing a 'organism' that arrives by some kind of abiogenesis and then remains unchanging in perpetuity? Would that be what you're describing?
Correct.
Do you think tardigrades could be an example?
Quote from: Arturo on July 29, 2017, 05:20:04 PM
Quote from: Tank on July 29, 2017, 09:00:15 AM
....
It looks like we're discussing a 'organism' that arrives by some kind of abiogenesis and then remains unchanging in perpetuity? Would that be what you're describing?
Correct.
How complex does this 'organism' have to be.
Quote from: OldGit on July 29, 2017, 09:41:48 AM
Quote from: The Grey OneI'm not talking about life that always was, but about life that just is. It takes a fair bit of imagination, but is there a reason why there would not exist some (let's say very simple for the purpose of this discussion) system out in space, which uses surrounding molecules and particles and the energy of, say, stray photons and what have you to replicate itself over the course of billions of years? Would such a system not be alive in the broad sense of the word?
Have you read The Black Cloud by Fred Hoyle?
No. Having read a couple of reviews, however, that is something I mean to remedy.
Quote from: Tank on July 30, 2017, 08:54:39 AM
Quote from: Arturo on July 29, 2017, 05:20:04 PM
Quote from: Tank on July 29, 2017, 09:00:15 AM
....
It looks like we're discussing a 'organism' that arrives by some kind of abiogenesis and then remains unchanging in perpetuity? Would that be what you're describing?
Correct.
How complex does this 'organism' have to be.
Leave it up to imagination I guess.
Quote from: Arturo on July 30, 2017, 01:13:07 PM
Quote from: Tank on July 30, 2017, 08:54:39 AM
Quote from: Arturo on July 29, 2017, 05:20:04 PM
Quote from: Tank on July 29, 2017, 09:00:15 AM
....
It looks like we're discussing a 'organism' that arrives by some kind of abiogenesis and then remains unchanging in perpetuity? Would that be what you're describing?
Correct.
How complex does this 'organism' have to be.
Leave it up to imagination I guess.
In that case I would have to say that for an organism to reach a state of evolutionary equilibrium would be vary rare. They do exist though. The horsetail, Ceolocanth and immortal jellyfish get pretty close.
Quote from: Tank on July 30, 2017, 08:02:35 PM
Quote from: Arturo on July 30, 2017, 01:13:07 PM
Quote from: Tank on July 30, 2017, 08:54:39 AM
Quote from: Arturo on July 29, 2017, 05:20:04 PM
Quote from: Tank on July 29, 2017, 09:00:15 AM
....
It looks like we're discussing a 'organism' that arrives by some kind of abiogenesis and then remains unchanging in perpetuity? Would that be what you're describing?
Correct.
How complex does this 'organism' have to be.
Leave it up to imagination I guess.
In that case I would have to say that for an organism to reach a state of evolutionary equilibrium would be vary rare. They do exist though. The horsetail, Ceolocanth and immortal jellyfish get pretty close.
:thumbsup: