So, I've been tossing this idea around about a planet with

>>8534790
gas is a state, under pressure it becomes a liquid.

vapor is gas, water is its liquid

>>8534790

Hm I guess you could get a hydrosphere if there's a moon small enough that could maintain water but at the same time have a planet surrounding with strong enough gravity that would pull the water from it. If the forces cancel out at one point perhaps the water would float in a "hydrosphere". Pulling ideas out of my ass btw.

>>8534790
There aren't any gases denser than liquid water

>>8534821
That would be an unstable configuration.

I once heard you can get a "smoke ring" stable, just as in the science fiction story. Will that fit your idea?

>>8534790
are you that guy writing the book?

>>8534863
im not necessarily writing the book yet, ive got it started, sort of, but i was wondering if there was a way to make it scientifically sound

>>8534821
what if this planet was a moon?
is there any record of moons ever containing water?
if so, i think that could work, it being the larger of two moons, and the planet and second moon working to create a hydrosphere using gravity, as you stated

gases are hundreds of times less dense than water, its not like liquid to solid being roughly the same density

>>8534853
>>8534941
http://physics.stackexchange.com/questions/45140/is-it-possible-to-have-a-gas-heavier-than-a-liquid

If you can put Xenon under enough pressure, it looks like it's gas state can be denser than water's liquid state.

>>8534790
no, but you could have a core of super critical fluid which has gas like characteristics.

>>8535375
neat! so, follow up i suppose, could an atmosphere both maintain this pressure and simultaneously sustain life? im guessing not, as all life we can imagine is carbon based.

>>8535381
i dont have a strong understanding of super critical fluids (i just skimmed wikipedia, and they sound awesome) care to enlighten me?

>>8535375
The pressure from the downwards force of the water would have to be strong enough to counteract the force due to gravitational differentiation. Meaning you'd need a significant amount of water to generate that pressure, and as few rotational forces as possible so that mixing doesn't occur which would decrease the pressure on the Argon and ruin the entire system.

It also would require a gas giant so that planet's g is high; the gas giant would have to be at the right distance from the Sun so that the water remains liquid; and plenty of advanced aliens to build it because this would never form naturally.

>>8535405

Maybe if you had a large planet with a large Argon atmosphere, then took two thick, hollow half-spheres made of H2O ice and collapsed it around the planet, thereby simultaneously creating the pressure needed for the Argon to hold against the water, and providing the water by ice which will melt slow enough that it wouldn't rip through the atmosphere.

>>8535423
OR, maybe a more realistic idea (none of this is realistic) you generate an enormous magnetic field around the planet, then you decrease its size pulling the Argon in closer while making sure the magnetic field is super powerful so that it's strong enough to hold the super dense Argon close to the planet.

Then simply apply water and hope you can turn the magnetic field off without the planet getting destroyed.

Actually you couldn't use Argon, you'd have to use a more much electron dense gas so that it interacts with the magnetic fields (plasma hydrogen should work, but at that point it's not really an atmosphere anymore).

>>8535398
>could an atmosphere both maintain this pressure and simultaneously sustain life

Life is only formed in oceans, and it would need the ability to slowly adapt and evolve at higher and higher pressures, but ultimately yes, life can exist under extreme conditions (again however, life will not form under extreme conditions).