/sci/ - Science & Math

>>2547719

life doesn't need oxygen even on Earth. Have you ever heard of a fucking plant?

Also water is the best possible substrate through which solutes can move. Life without water would never be able to evolve very much complexity.

you have a point, extremeophiles live in conditions that are utterly impossible for humans to inhabit

op here, i have another question:

how do we know life on other planets would be anything like us. what if they couldn't die, or what if they didn't have anything resembling things we have, like cells or eyes? why do people assume they have to?

>since when was it a rule that everything needed water and oxygen?
It's really just liquid water. All the life we know about requires liquid water to complete its life cycle.

And scientists - the few who spend their time on this question - acknowledge that drastically different life is possible, like in liquid methane or something, but we really have no basis for anything but speculation there, which is worthless.

>>2547736

>mfw you think plants don't require oxygen

>>2547746
> what if they couldn't die
That's just fucking retarded. All patterns encoded by matter can be randomized by an appropriate influx of energy.

>>2547736
>He thinks plants don't need oxygen to live!

Sure is grade school education.

>>2547759
um...what? idiot words please, i'm not really a /sci/entist

>>2547756

plants don't need oxygen gas to live. just because they incorporate oxygen into their cellular structures doesn't negate the imbecility of OP's implied statement "life needs oxygen gas"

>>2547770

anything can be broken.

>>2547736
>life doesn't need oxygen even on Earth.
You're a moron for several, several reasons.

>>2547779
ah. makes sense

to be totally honest, when i think of "intelligent life that isn't human-looking", i picture the angels from NGE. assuming they don't have "powers" like they do on the show, would something like that be possible?

>>2547770
Anything pattern made of matter can be destroyed by heating it up.

>>2547770
Entropy, bro.

>>2547785

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

>>2547774
>implying OP said anything about oxygen gas

>>2547774

Plants need oxygen to survive because of these guys. Pic related. You know these guys, right?
They kind of do the whole "aerobic respiration thing" which allows then to use oxygen as a final electron acceptor in the krebs cycle. Without it you have a net gain of 2 ATP instead of 36-38. Kind of required for an energetically active cell.
Plants fall under the category of organisms composed of cells which require a lot of energy.

Yes they generate their own oxygen.
They also have no way of storing it and release a lot of it as a waste gas.
Which they need to retake during those hours when there's no sun around... what's that time called again... hmm.. it'll come back to me.
Night. Yea that's the one.

>>2547799
You were referring to O2. I was referring to oxygen all together. These are all important clarifications when referring to what does and does not constitute life.

>>2547806

>implying he would mention one substituent in complex organic molecules without mentioning other substituents such as phosphorus, nitrogen, or iron, or for that matter carbon

>implying op isn't clearly a laymen and his meaning wasn't blindingly clear

>>2547746
There are organisms on Earth that are functionally immortal - they either don't age, or can go through their life cycle multiple times. That'd be like one of us becoming a baby and then growing up again. Roughly.

As far as we know, cells are pretty much essential. You could also say that some sort of "package" is essential, if you consider viruses to be alive or you want to generalize. That doesn't mean that alien life would have cells made of the same parts or with the same machinery that we have.

Eyes are not essential. Plenty of organisms either don't have them or don't rely on them extensively. An alien lifeform could be blind, or it could see in a different spectrum, like infrared or microwave.

Some people assume that alien life will be mostly like us; humanoid, oxygen-breathing, fingers and things. Others don't. In a similar environment, maybe evolution would run the same course, and produce something like humans. Maybe it wouldn't. I have no idea.

>>2547825
i see. i've heard of certain jellyfish doing what you're talking about. but i have a question: refer to this >>2547787.

would that be possible?

>>2547824
>OP only mentions water and oxygen
>WELL AKSHULY HE SAID A LOT MORE. WHY? BECAUSE IF HE ONLY SAID WHAT HE ACTUALLY SAID IT WOULD PROVE HOW MUCH OF AN ANALLY RETENTIVE PEDANT I AM

>>2547853
Depends on which Angel you're talking about. Sachiel would need incredibly strong bones to stand and walk in Earth-gravity, since he's so massive. He would also need to eat a hell of a lot to sustain that mass. Shamshel might be at home in a gas giant, if most of his volume held a lifting gas, basically making him a living Zeppelin. Ditto for Ramiel. Gaghiel would be right at home on a prehistoric Earth, since he's basically just a giant fish.

Now, something like Sahaquiel, the space-capable one? I have no idea how something like that would develop. But I suppose it's theoretically possible.

>>2547894
so, theoretically, most of them are possible. and those rules are going by earth "life laws" correct? now, going my problem with using earth as a basis, why would sachiel need to eat? he's a totally different life form than anything on earht (this all sounds really stupid, but the only way i can accurately describe what my thought process is is by using NGE as a medium)

>>2547924
If you're using Earth life as a base for your assumptions (which we usually do), then Sachiel really isn't that different from a dinosaur or a whale. He's very, very large, and very strong, and, like every other living being, he needs a power source. Plants take in water, carbon dioxide, and nutrients from the dirt, and use solar power to convert those resources into food and other byproducts. Carnivores eat meat. Herbivores eat plants. Omnivores can eat both. Simple stuff.

At the cellular level, bacteria can eat damn near anything, depending on their type. But everything eats something. Everything. If Sachiel wants to move, or use energy to do anything, he needs to take in more energy, which means eating. And unless he's mostly hollow, he's going to need a metric asston of food.

WHERE ARE MY SUBS?!

>>2547965
well, that makes things make more sense. but who's to say that sachiel, for example, is made from organic material like that on earth?

>>2547990
If he's not made of organic material, then he's not carbon-based like the rest of us. Silicon-based life is theoretically possible, but I don't know much about the particulars.

It comes to mind that Sachiel could be propelled by a fission reactor. There is no Earth life that uses nuclear power, but nuclear reactors have developed naturally in the past.

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

If Sachiel was nuclear-powered, that would solve a lot of energy issues. He'd still need to eat, but not as much. However, I have no idea if it's even possible for an organism to evolve to use nuclear power. Radioactive isotopes are chemically identical to their non-radioactive counterparts, after all. I'd say if we encountered something like that, we should assume it was engineered.

/tangent

>>2548039
i see. thanks for all the help.

fuck yeah NGE and science!

i came

>>2548053
No problem. Glad to be of help.

Our only examples of life can be found on Earth. It's a pretty good bet to say that if you find something similar to Earth's conditions, you'll find life.

You could, of course, find life in vastly different conditions, but the chances are smaller since we don't have an example of that life.

Basically, some scientists prefer to hedge their bets.

>>2547746
>how do we know life on other planets would be anything like us
no one is claiming that
>what if they couldn't die
they would take in a ridiculous amount of resources and reproduce very little so as to not over populate
>what if they didn't have anything resembling things we have, like cells or eyes
they wouldn't necessarily need eyes, but, they'd be very nice
without cells, they wouldn't be able to heal or grow very quickly and wouldn't be very complex
>why do people assume they have to
I don't know anyone who does

>>2547746
cells is obvious, an outer membrane keeps the internal chemistry safe from the external chemistry and keeps all the essential parts together. Sure, you could go without one, but then the entire thing goes to shit with the slightest disturbance.