Can life exist without using water as a solvent?

[daniel l.]

It has been theorized that life could exist based on some other liquid solvent; perhaps nitrogen or methane? Now, neither of these liquids are believed to be particularly good at being a solvent, but is it possible that, with some finagling and lots of Trial & Error, these liquids could support a lifeform?

And, if so, would it be somehow possible to port the genome of ordinary water-based life over to a non-water platform? Could we make methane or nitrogen-based human beings? If so, worlds like Titan could be colonized without the need for bulky spacesuits or any sort of protective infrastructure other than a source of oxygen to breathe.

[p1t1o]

38 minutes ago, daniel l. said:

It has been theorized that life could exist based on some other liquid solvent; perhaps nitrogen or methane? Now, neither of these liquids are believed to be particularly good at being a solvent, but is it possible that, with some finagling and lots of Trial & Error, these liquids could support a lifeform?

And, if so, would it be somehow possible to port the genome of ordinary water-based life over to a non-water platform? Could we make methane or nitrogen-based human beings? If so, worlds like Titan could be colonized without the need for bulky spacesuits or any sort of protective infrastructure other than a source of oxygen to breathe.

The biochemistry of water-based life is finely tailored to the solubility profiles of things in water, so "porting" over genomes would be problematic. Proteins will not fold the same way in a different solvent and god knows what other effects there would be for gene expression, I think the whole thing would have to be re-written.

Having said that, there isnt any fundamental reason why life couldnt exist in other chemistry systems. Ammonia is a good example, it shares many of the properties of water that makes water so conducive to life.

Silicon is also considered a viable alternative to carbon, in that its electronic structure and bonding is quite similar, a similar range of compounds can be constructed from it at similar energies.

[Green Baron]

55 minutes ago, daniel l. said:

It has been theorized that life could exist based on some other liquid solvent; perhaps nitrogen or methane?

First, the search function here and it the web will give you some answers.

tl,dr: while other bases than carbon (e.g. sulphur, silicon) are imaginable (though by for not as effective as carbon), a replacement for water is improbable. Of course, much can be fantasized if you stretch the definition of life. This describes possible pre-life conditions:

https://www.nature.com/articles/s41598-017-18483-8

55 minutes ago, daniel l. said:

Now, neither of these liquids are believed to be particularly good at being a solvent, but is it possible that, with some finagling and lots of Trial & Error, these liquids could support a lifeform?

Not in a way that is possible with highly reactive materials that are used on earth and are hypothesized for being the base elsewhere as well, because they are abundant and "easy to use". It is for a cause that people search for possible liquid water.

55 minutes ago, daniel l. said:

And, if so, would it be somehow possible to port the genome of ordinary water-based life over to a non-water platform?

Is it possible to port a genome between species on earth ? ;-) It is too early to ask that question because nothing is known about life in different expressions.

55 minutes ago, daniel l. said:

Could we make methane or nitrogen-based human beings?

No. We can't "make" normal human beings (yet) except through the natural processes :-)

55 minutes ago, daniel l. said:

If so, worlds like Titan could be colonized without the need for bulky spacesuits or any sort of protective infrastructure other than a source of oxygen to breathe.

If you say so :-)

[cubinator]

Well, Titan already can be colonized without bulky spacesuits - you just need an oxygen mask and a very heavy jacket.

[Starman4308]

To answer the thread title: Maybe. We don't know. It's possible you might have a situation where you have a hydrophobic solvent such as methane, and those organisms' proteins or protein-equivalents utilize a hydrophilic core instead of a hydrophobic core to fold up. To answer that sort of question, though, we'd need either to get more than n=1 on planets harboring life, or an extraordinary simulation effort that would probably mean sci-fi-level AI.

Porting the genome of a water-based organism is going to be essentially impossible. The function of proteins, functional RNAs, etc, is all predicated on the existence of water as a solvent. Many enzymes do not function without coordinated waters. Biochemically, basically nothing works without the solvent it is predicated around.

[Technical Ben]

Can you build a robot out of X?

Theoretically a robot or a Turing machine (computer) can be built out of anything.

Can you build a self replicating machine/robot/thing out of anything that is also a robot/Turing machine? That is a harder question.

Can such things self organise? Even harder.

[sevenperforce]

You could have self-sustaining, replicating sentient plasma vortices populating the surface of the sun and we'd never know.

[magnemoe]

Think problems with life based on other liquids than water is that water is so common. 
leaving only temperatures there you don't have liquid water, but it still has to be an common  enough material for you to get lakes. 
Low temperatures will also give low energy biochemistry, things will go slow so don't think we will get much evolution 
 

[YNM]

4 hours ago, daniel l. said:

... but is it possible that, with some finagling and lots of Trial & Error, these liquids could support a lifeform?

Yes and No, I'd say.

Yes things could try.

No it maybe not.

 

I'd say that the only way to tell is to go and keep searching for one.

[mikegarrison]

You have to define "life" before you can answer such a question.

[kerbiloid]

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