jagadeesh Posted April 3, 2015 Posted April 3, 2015 I recently got interested in our space. While I was watching documentries about Cosmos, I got this question. Scientists are searching for planets which might have water so that it can support life on it. What if some beings evolved to the conditions they have on their planet. For example, take a planet which doesnt have conditions that doesnt support life as we humans know. It is filled with a heavily poisionus gas that would kill us instantly. But what if some beings evolved on that planet and that poisonous gas is like Oxygen to them. Arent we ignoring those planets while searching for extraterrestrial life.
ajb Posted April 3, 2015 Posted April 3, 2015 What searches are you referring to? Anyway, let us assume that we are not looking to intelligent life that has technology that we could detect; say via radio transmission or similar. Then how should we look for life on other planets if not by looking for the signatures that we know life on Earth produces? In particular, looking at the chemical compositions of the atmospheres of certain planets suggest they altered by the presence of life in much the same way Earth was. We also know that water is very important to life on Earth and so it makes sense to look for that. Oxygen also seems to be very important to life as we know it, but the possibility of life exploiting other similar gases is there. The question to you is what else can we do, remembering we only know the signatures of life on our own Planet and cannot actually visit these planets?
pavelcherepan Posted April 3, 2015 Posted April 3, 2015 It is filled with a heavily poisionus gas that would kill us instantly. But what if some beings evolved on that planet and that poisonous gas is like Oxygen to them. It happened here too. Read up on Great Oxygenation event (also sometimes referred to as Oxygen Holocaust). A lot of primitive anaerobic organisms died as a result of cyanobacteria poisoning atmosphere with oxygen. AFAIK, the current search conditions for planets that could support life only includes ability to support liquid water on the surface, not being a gas giant and not being tidally locked to the central star so possibilities are endless. Circumstellar habitable zone
Greg H. Posted April 3, 2015 Posted April 3, 2015 To approach this from another tack - if we found life on a planet so unlike the Earth that humans couldn't survive there, it would be a final indicator that we're really not that special in the grand scheme of things. It might also help give us more insights into how life originates, and the conditions that are required to kick start living organisms on a newly formed planet.
Sensei Posted April 3, 2015 Posted April 3, 2015 (edited) I recently got interested in our space. While I was watching documentries about Cosmos, I got this question. Scientists are searching for planets which might have water so that it can support life on it. What if some beings evolved to the conditions they have on their planet. For example, take a planet which doesnt have conditions that doesnt support life as we humans know. It is filled with a heavily poisionus gas that would kill us instantly. But what if some beings evolved on that planet and that poisonous gas is like Oxygen to them. Arent we ignoring those planets while searching for extraterrestrial life. Are you familiar with chemistry? There is very limited quantity of gases, either poisonous-toxic or inert. There is just 118 elements in periodic table. Majority of them are metals. There is needed enormous amount of energy just to heat them to melt, not to mention making gas from them. Or ionizing them. Poisonous-toxic means that it easily goes into chemical reaction. Unwanted reaction in living organism or non living object (corrosion of car body f.e.). But once it happens, it's done. Element in "locked" in newly produced molecule for thousands or millions years. So toxic substances don't last long in natural environment. Metals, except gold, don't last long either. They're going into reaction with oxygen, chlorine, fluorine etc. If humans would vanish, after couple hundred years there would be no metallic iron. Just FeO, Fe2O3, Fe3O4 etc. molecules. So make a list of all gases, poisonous or not, and analyze how they react with other elements. Edited April 3, 2015 by Sensei 1
John Cuthber Posted April 3, 2015 Posted April 3, 2015 There is very limited quantity of gases, either poisonous-toxic or inert. So make a list of all gases, poisonous or not, and analyze how they react with other elements. As has been pointed out, whether a gas is poisonous or not depends on your point of view. 1
jagadeesh Posted April 3, 2015 Author Posted April 3, 2015 Thanks for your inputs. I was wondering, if life on other planets exists, is it necessary for that planet to have the same conditions like ours. That "poisonous gas" is just an example. Again to take an example..Let me assume there is a planet ABC which is very near to its star and the temperature on that planet is some Billion centigrades. Now generally we would ignore that planet to have any life on it. Now if there is a life form on that planet which has adapted to that "unlivable Conditions". I'm just wondering, if there is a possibility like that!
TheDivineFool Posted April 3, 2015 Posted April 3, 2015 (edited) The possibilities are endless from my point of view. I just learned that the heavier elements are made from Hydrogen and Helium. The elements we know of are those that our star formed. Who knows what other elements formed on other stars? Since we can't be sure of that, we shouldn't limit the universe to 'our' science. @OP : I also wonder the same thing. What if there are life forms inside the sun or in the cold and dark deep space? What if there are life forms living inside our brains that we don't know of? What if life forms exist that live on atoms? Endless possibilities...or maybe I drank too much coffee. Edited April 3, 2015 by TheDivineFool
Sensei Posted April 3, 2015 Posted April 3, 2015 (edited) Thanks for your inputs. I was wondering, if life on other planets exists, is it necessary for that planet to have the same conditions like ours. That "poisonous gas" is just an example. Even on our planet there are organisms that find oxygen to be poisonous to them. And produced by them compounds are poisonous to us. Again to take an example..Let me assume there is a planet ABC which is very near to its star and the temperature on that planet is some Billion centigrades. Planet that has higher temperature than star? Nope. When temperature is high enough there is created plasma (nucleus and electrons are free). To ionize 1 mol of Hydrogen (6.022141*10^23 particles) there is needed 1312 kJ/mol. It's simply 13.6 eV * 6.022141*10^23 * 1.602*10^-19 = 1312 kJ Edited April 3, 2015 by Sensei
jagadeesh Posted April 3, 2015 Author Posted April 3, 2015 (edited) Planet that has higher temperature than star? Nope. Not higher temperature than the star but temperature very near to the star... Edited April 3, 2015 by jagadeesh
Sensei Posted April 3, 2015 Posted April 3, 2015 (edited) Not higher temperature than the star but temperature very near to the star... Sun surface has 4500-6000 K core has estimated to 15-16 mln K See how far it's from your "billions centigrades".. Edited April 3, 2015 by Sensei
John Cuthber Posted April 3, 2015 Posted April 3, 2015 The elements we know of are those that our star formed. Who knows what other elements formed on other stars? No they are not. The elements that you and I are made from were made in other stars. Also, there are only about a hundred stable elements- no matter where you make them. The other planets will be made from the same elements as ours (though the proportions will be different.) 2
Phi for All Posted April 3, 2015 Posted April 3, 2015 The possibilities are endless from my point of view. This is one of those phrases that sounds good, but is actually part of the problem. The possibilities are literally endless, so it seems smarter to look for what's probable, rather than possible.
TheDivineFool Posted April 3, 2015 Posted April 3, 2015 This is one of those phrases that sounds good, but is actually part of the problem. The possibilities are literally endless, so it seems smarter to look for what's probable, rather than possible. Don't be a spoilsport! You need to loosen up! No they are not. The elements that you and I are made from were made in other stars. Also, there are only about a hundred stable elements- no matter where you make them. The other planets will be made from the same elements as ours (though the proportions will be different.) Thanks for the information. Loosen up. You too! Science is not infallible! Free your minds! -3
Sensei Posted April 3, 2015 Posted April 3, 2015 (edited) Don't be a spoilsport! You need to loosen up! Thanks for the information. Loosen up. You too! Science is not infallible! Free your minds! For extraordinary claims (like other stars are making different periodic table elements) there is needed extraordinary proof. We know what other stars are made of for two hundred years because we're analyzing their spectral lines.. And comparing with discharge tubes in lab spectral lines. Edited April 3, 2015 by Sensei
jagadeesh Posted April 3, 2015 Author Posted April 3, 2015 Sun surface has 4500-6000 K core has estimated to 15-16 mln K See how far it's from your "billions centigrades".. Again a question, is it necessary for stars to have the temperatures that we know of?
MigL Posted April 3, 2015 Posted April 3, 2015 (edited) There are life forms on our own planet that don't live in 'earth-like' conditions. Life has evolved around sulfide vents, under the pressure of 20000 ft of water, in the absence of light and oxygen. This is certainly not earth-like, but it is on earth. A variant of this lives in the hot, sulfide/CO2 rich atmospheres in volcanic cones. What would result in a million yrs, if we seeded the atmosphere of Venus with these micro-organisms ? There are even micro-organisms living in the high radiation waters of nuclear reactors. As Jeff Goldbloom's character said in Jurassic Park... "life will find a way" But some of The Devine Fool's claims are just that, divinely foolish . Edited April 3, 2015 by MigL
Delta1212 Posted April 3, 2015 Posted April 3, 2015 The possibilities are endless from my point of view. I just learned that the heavier elements are made from Hydrogen and Helium. The elements we know of are those that our star formed. Who knows what other elements formed on other stars? Since we can't be sure of that, we shouldn't limit the universe to 'our' science. @OP : I also wonder the same thing. What if there are life forms inside the sun or in the cold and dark deep space? What if there are life forms living inside our brains that we don't know of? What if life forms exist that live on atoms? Endless possibilities...or maybe I drank too much coffee. That's not how elements work. They aren't magic substances cooked from Hydrogen and Helium that could come out in an infinite number of ways. A hydrogen atom has one proton. A helium atom has two. Fuse two hydrogen atoms and you get a helium atom, by definition. An element is defined by the number of protons. If it's oxygen, it has eight protons. If it has eight protons, it is oxygen. We have everything covered up to just shy of 120 protons at this point, and elements stop being stable well before that point. The nucleus just starts getting too big and is prone to breaking apart. That's how you get al those radioactive elements with high atomic numbers. It doesn't matter if it's cooked in our start or another start, th number of protons defines the element, and you aren't going to get any novel proton counts unless you go over 120 or invent some new numbers. And a start turning out anything with a proton count that high is going to be difficult, because the higher the proton count, the heavier the nucleus is and the harder to fuse it is. A build up of heavy, difficult to fuse elements is what ultimately kills a star because it's turning part of its mass into material it can no longer use to sustain a fusion reaction. Plus, anything with that high of a proton count is unlikely to last very long, even if it does get produced in small quantities. We understand how elements work, and there isn't a limitless variety. 2
Sensei Posted April 3, 2015 Posted April 3, 2015 Again a question, is it necessary for stars to have the temperatures that we know of? Scientists are making their own stars here on Earth in laboratories. For small time period. Black body emission graph is different depending on temperature of object emitting it. That's why remote thermometer are able to read temperature without touching anything (unlike ordinary Mercury thermometers).
MigL Posted April 3, 2015 Posted April 3, 2015 Stars only fuse elements up to iron ( #26 ). The minute ( in comparison ) amounts of heavier elements are not created in an energy releasing reaction, but energy must be supplied by a supernova explosion. All elements heavier than iron were created by the supernova explosion of some long dead giant, 1st gen , hot, blue star which 'lived fast and died young'. The shock wave of this dead star probably also started the compression which resulted in the formation of our solar system from the resultant mixture of heavier elements ( stardust ) and spiral arm hydrogen. There are islands of ( relative ) stability at atomic numbers higher than 120. I doubt these could be 'naturally' produced. 1
Moontanman Posted April 3, 2015 Posted April 3, 2015 Again a question, is it necessary for stars to have the temperatures that we know of? It depends a lot on how you mean this question, if you are wondering if there stars that have temps different than our own Sun then yes most definitely. Some stars are so hot they are blue 30,000k our own sun is much cooler, about 6,000k http://en.wikipedia.org/wiki/Stellar_classification I recently got interested in our space. While I was watching documentries about Cosmos, I got this question. Scientists are searching for planets which might have water so that it can support life on it. What if some beings evolved to the conditions they have on their planet. For example, take a planet which doesnt have conditions that doesnt support life as we humans know. It is filled with a heavily poisionus gas that would kill us instantly. But what if some beings evolved on that planet and that poisonous gas is like Oxygen to them. Arent we ignoring those planets while searching for extraterrestrial life. Saturn's moon Titan might have an example of life not as we know it. http://www.news.cornell.edu/stories/2015/02/life-not-we-know-it-possible-saturns-moon-titan
Airbrush Posted April 3, 2015 Posted April 3, 2015 (edited) The elements we find on Earth are found anywhere throughout our galaxy. ANY planets or moons with liquid water have a chance for life. Very dry planets probably don't. The best bet is "follow the water" to find life. As for what gases are present is irrelevant. Edited April 3, 2015 by Airbrush
pavelcherepan Posted April 3, 2015 Posted April 3, 2015 Thanks for your inputs. I was wondering, if life on other planets exists, is it necessary for that planet to have the same conditions like ours. That "poisonous gas" is just an example. Again to take an example..Let me assume there is a planet ABC which is very near to its star and the temperature on that planet is some Billion centigrades. Now generally we would ignore that planet to have any life on it. Now if there is a life form on that planet which has adapted to that "unlivable Conditions". I'm just wondering, if there is a possibility like that! The problem is that currently we only know of only a single type of life - carbon-based organics and we have no idea of other pathways life can take. If we let our imagination run wild pretty much any planet could be thought of potentially supporting life but there's much higher chance of success if we search for Earth-like planets and later on if we do discover some other life type we can then widen our search. Carbon chauvinism 1
Airbrush Posted April 5, 2015 Posted April 5, 2015 "...The apparent lack of silane polymers and the abundance of carbon in meteorites would suggest that carbon-based life is much more probable than silicon-based life." "...if we search for Earth-like planets and later on if we do discover some other life type we can then widen our search." That's a sound plan. Our searches should be for Earth-like planets, and if along the way we bump into something very strange, then we can expand our search. Check out "hypothetical types of biochemistry" in wikipedia: "...In 2007, Vadim N. Tsytovich and colleagues proposed that lifelike behaviors could be exhibited by dust particles suspended in a plasma, under conditions that might exist in space.[69][70] Computer models showed that, when the dust became charged, the particles could self-organize into microscopic helical structures capable of replicating themselves, interacting with other neighboring structures, and evolving into more stable forms." http://en.wikipedia.org/wiki/Hypothetical_types_of_biochemistry 1
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