Quote from: Munch on July 12, 2018, 03:11:21 PMThat would be no shit spooky.
Spooky. I remember watching a documentary that explained the physics of Satan and Jupiter, ...
Quote from: Cavebear on July 13, 2018, 03:45:58 AM
It seems that all the planets bey9nd Earth have some body of liquid water in or at their moons due to internal or tidal forces. That increases the possibility of simple life everywhere unless our solar system is unique and I doubt that.
Quote from: Gawdzilla Sama on July 15, 2018, 10:12:15 AM
BTW, I told that to one of my cousins and he replied that he'd heard of billionaires, but not trillionaires, so I must be making that one up.
Quote from: Blackleaf on July 15, 2018, 09:44:38 AMEverything we know about life just from our own one example here on Earth is that once it gets started, it gets into everything. Think about some of the extreme environments that even within the last twenty five years or so, biologists would have all but ruled out as habitats -- and yet they host microorganisms. Where we used to have a very specific list for life: CHONPS (https://en.wikipedia.org/wiki/CHON), liquid water, temperatures within a particular range, solar/tidal/geothermal energy sources. Now it's beginning to look like a solvent (not necessarily water) and an energy source could be all it takes to build an environment.
I'm almost completely certain that there is alien life somewhere out there in this vast universe. The question is, can we find it or is the hay stack too big for us to find the needle? And even if we could find a life-bearing planet, could we even observe or interact with it? Because of how long it takes for light to reach us, any life bearing planet we discover could already be desolate by the time we see it.
Quote from: trdsf on July 16, 2018, 01:24:13 PM
Everything we know about life just from our own one example here on Earth is that once it gets started, it gets into everything. Think about some of the extreme environments that even within the last twenty five years or so, biologists would have all but ruled out as habitats -- and yet they host microorganisms. Where we used to have a very specific list for life: CHONPS (https://en.wikipedia.org/wiki/CHON), liquid water, temperatures within a particular range, solar/tidal/geothermal energy sources. Now it's beginning to look like a solvent (not necessarily water) and an energy source could be all it takes to build an environment.
So I'm bullish on (very simple) life within our own solar system. I'm optimistic for the depths of Hellas Basin, where Martian atmospheric pressures just allow for the presence of liquid water. I'm also optimistic about the remains of the Martian Oceanus Borealis (if it proves to have existed; there are tantalizing clues but nothing definitive), and Martian permafrost, and the Martian polar caps. Got to go where the water is, at least on Mars.
But Mars is kind of low-hanging fruit, life-wise. Enough material has transferred between the Earth and Mars over geologic time that it would not be surprising to find Martian life is DNA based either because it was contaminated by Earth life... or that Earth life started on Mars and found a more stable and suitable environment here.
So the really interesting places are Ganymede and Europa at Jupiter, and Enceladus at Saturn, because any life there would almost have had to independently start there. While it's relatively easy to get impact ejecta from Earth to Mars, it's all but impossible to get it much further out, or get it from there to here. I know I had an article on that, but I can't find it and I will keep up the search until I do.
Target Number One must be Enceladus. It's effectively isolated from interplanetary contamination from Earth (and Mars), and thanks to Cassini's flythrough of the Enceladan geysers, we're confident there should be active black or white smokers (https://en.wikipedia.org/wiki/Hydrothermal_vent) there (or something very like them), and we know those are viable habitats. Europa is close enough to Jupiter that it is expected to have them too, as a result of tidal flexing, but Enceladus so far as I know is the only extraterrestrial place we have direct evidence to indicate them.
Quote from: Gawdzilla Sama on July 17, 2018, 06:11:53 AM
Nobody is saying you can't have life unless liquid water is present, just that everywhere we've studied we've found that liquid water has life in it.
Quote from: Gawdzilla Sama on July 17, 2018, 06:11:53 AM
Nobody is saying you can't have life unless liquid water is present, just that everywhere we've studied we've found that liquid water has life in it.
Quote from: Gawdzilla Sama on July 21, 2018, 07:23:15 AM
I don't get the "but". I wasn't preaching water exclusivity.
Quote from: Baruch on July 21, 2018, 10:28:48 AM
Both of you are "all wet" ;-)
Quote from: Cavebear on July 21, 2018, 12:21:59 PM
Ah, grasshopper, not all that is liquid is "wet" in the way you think...
Quote from: Unbeliever on July 22, 2018, 05:52:47 PM
What a coincidence that hydrogen, helium, carbon and oxygen are the four most abundant elements in the interstellar medium! Fancy that!
Quote from: Baruch on July 21, 2018, 02:42:11 PM
Polywater? Only when your parrot takes a piss.
Quote from: Cavebear on July 25, 2018, 11:30:32 AMMethanol or ethanol? I think you're right about CO2
Put a potato chip in pure alcohol and it doesn't get "wet" (I think). Might be liquid CO2. Or both. I forget.
Quote from: trdsf on July 25, 2018, 01:22:44 PM
Methanol or ethanol? I think you're right about CO2
Quote from: Cavebear on July 25, 2018, 03:15:58 PMI think silicon is unlikely as an analogue for carbon -- it doesn't chain in quite the same way. However, carbon chains in ammonia, ethane, methane, or any other clement liquid remain a perfectly reasonable option. Carbon really is an element like no other; that's why we have organic chemistry based on carbon, but no analogous chemistry for silicon.
Which-Ever (LOL!) The point was that not everything has to revolve around water. Silicon with ammonia and ethane or methane has chemical possibilities. Also, there are possibilities for silicon or geranium. Farter along (literally, there is sulphur involved), there are silicon oxides which has some flexible connections to hydrogen. Call it "bad water" but if that's all you have, it might works. And that's as far as I can push my college chemistry.
Quote from: trdsf on July 25, 2018, 11:23:30 PM
I think silicon is unlikely as an analogue for carbon -- it doesn't chain in quite the same way. However, carbon chains in ammonia, ethane, methane, or any other clement liquid remain a perfectly reasonable option. Carbon really is an element like no other; that's why we have organic chemistry based on carbon, but no analogous chemistry for silicon.
Quote from: Baruch on July 26, 2018, 12:20:47 AM
Silicon and carbon can have 4 bonds ... but the carbon bonds lie flat, but the silicon bonds are at odd angles. DNA works because of the flatness of the components of the helix.
Quote from: Cavebear on August 01, 2018, 03:38:46 AM
When you talk serious like that, you are great! Stick to it. So the carbon bonds lay flat for us. Could a non-flat silicon 3-helix silicon structure replicate?
Quote from: Cavebear on August 01, 2018, 03:38:46 AMIn principle, maybe? It would require a very odd planetary chemistry, though. Using the principle of mediocrity, let's take the elemental abundances in our own stellar system as being representative:
When you talk serious like that, you are great! Stick to it. So the carbon bonds lay flat for us. Could a non-flat silicon 3-helix silicon structure replicate?
Element | Mass fraction (ppm) | Atom fraction (ppm) |
Hydrogen | 705,723 | 909,979 |
Helium | 275,235 | 88,729 |
Oxygen | 9,592 | 477 |
Carbon | 3,069 | 330 |
Neon | 1,756 | 112 |
Nitrogen | 1,105 | 102 |
Silicon | 710 | 33 |
Quote from: Unbeliever on August 02, 2018, 07:53:26 PMExplains the "Floridaman" phenomenon nicely.
Yeah, he just held a rally in Floriduh.
Quote from: trdsf on August 02, 2018, 01:42:34 PM
In principle, maybe? It would require a very odd planetary chemistry, though. Using the principle of mediocrity, let's take the elemental abundances in our own stellar system as being representative:
Element Mass fraction
(ppm)Atom fraction
(ppm)Hydrogen 705,723 909,979 Helium 275,235 88,729 Oxygen 9,592 477 Carbon 3,069 330 Neon 1,756 112 Nitrogen 1,105 102 Silicon 710 33
Assuming this is typical of a planetary system around a third-generation star, it's pretty clear that there's going to be a lot more carbon to work with than silicon, even though both are essentially trace elements compared to hydrogen and helium (99.87% of all atoms in our solar system being one of these two). Silicon is also likely to be tied up in very stable rocks, from which it's not easy to liberate, unlike carbon, which has multiple sources, not all of which are tightly bound.
So biological silicon is likely to be special purpose, as in diatom shells (seashells are calcium carbonate, not any form of silicate) or as a trace mineral. It would take a very different sort of local elemental makeup for silicon to do more than that in a biosystem.
Quote from: Cavebear on August 04, 2018, 03:26:44 AM
Well perhaps there are planets here conditions are different and other elements are more adherent to others than on Earth. I'm not proposing that, just keeping my thoughts open.
I'm still expecting that, if we ever find life elsewhere, it will be similar to what we know. But, you never know...
Quote from: Blackleaf on August 04, 2018, 10:08:19 AM
Well, even here on Earth, we have evidence of convergent evolution. That is, multiple species in similar environments independently developing similar traits. It's especially apparent after a mass extinction leaves most of Earth's species extinct. At that point, new species come and fill the void. It seems there are certain niches in nature, and when a niche is unclaimed, nature quickly finds a new species to fill it. I expect if we ever discover alien life, it'll follow the same rules and they'll be both similar and different.
What would be really interesting, though, would be to see if any species like humans ever independently evolved. We're the only ones like us on Earth that have ever existed, so we may just be a cosmic fluke.
Quote from: Blackleaf on August 04, 2018, 10:08:19 AM
Well, even here on Earth, we have evidence of convergent evolution. That is, multiple species in similar environments independently developing similar traits. It's especially apparent after a mass extinction leaves most of Earth's species extinct. At that point, new species come and fill the void. It seems there are certain niches in nature, and when a niche is unclaimed, nature quickly finds a new species to fill it. I expect if we ever discover alien life, it'll follow the same rules and they'll be both similar and different.
What would be really interesting, though, would be to see if any species like humans ever independently evolved. We're the only ones like us on Earth that have ever existed, so we may just be a cosmic fluke.
Quote from: Cavebear on August 04, 2018, 10:28:13 AM
Nature abhors a vacant niche. A pair of parrots night become an ostritch... Well, a falcon. Yes, actually, a falcon... Parrots and falcons are on the same bird branch.