If I go down seven kms the water is rather heavy, what with the weight of all that water on top of it.

If I take a litre of water from 7km down trapped in an airtight metal box and bring up that litre of water still enclosed in the box but now on the deck of my science wessel is the pressure inside the box seven kms down or surface pressure?

Depends on how strong the box is.

This is another question- water doesn't compress under pressure, right?
So that litre of water at 7km depth when the box is opened is that now still the same one litre or does like seventeen litres of water rush out?

When you ask how strong the box is, is that because the pressure of the water inside the box is so great that the 1 atmosphere at sea level doesn't press enough pressure against the box and it literally explodes?

Somebody with a science degree and knowledge of tv should make a pot head asks science questions show; it'll make millions.. or at least do as well as drunk history.

(Explodes minus the fire, obviously)

too bad that mythbusters ended.

Pure water is very difficult to compress under pressure. Impure water less so.

Hypothetically, with pure water, the pressure in the box would virtually remain the same to an extent, depending on the strength of the container. But that isn't realistic.

There's no such thing as a wrong answer, ford.
Especially in science.

I misread the entire post and edited my comment lol.

James Cameron could tell you.

And for the record, everything is compressible. Some things are just much harder than others. So I suppose with enough compression the water would expand upon ascension. I need another beer to fluff with this fluff.

This is an interesting question, and I've been sitting here thinking about it, without cheating and looking on Google. Suppose you took a Kilo of steel from a mile under the earth, and carried it up all the way to the vacuum of space. Would it explode? No. If an object isn't physically compressed so its size is reduced, no force is transferred to it by the pressure on all sides.

So, if the box of water isn't compressed at all it won't expand when the the box is taken to the surface, and nothing will happen.

The debate is if the water is compressed at depth.

Water is compressible, but it is extremely difficult.

Water at depth is more dense than water at the surface because of pressure, but additionally temperature.

There are a few variables at play here.

Humans have to decompress after diving deep or get Benz correct? Are submarines made to expand and contract?

Submarines do expand and contract. I am sure there are vids out there of submariners tying taught strings between bulkhead at the surface and they sag at depth. I have heard plenty of stories.

But like previously stated, water is much harder to compress.

I know water can be compressed, because solving for water compression expansion is a thing when doing calculations in oil field applications, but it cannot be compressed very much - maybe 1% of its volume at depths encountered in oil drilling.

The steel from the ocean floor to space would compress and expand somewhat, but because of the strength of metallic molecular bonding it will stay together.

The bends is because nitrogen normally found in air becomes much more soluable at higher pressures and gets dissolved in blood. If you depressurize the blood too fast the nitrogen comes out quickly aka a cold boil and then you have gas bubbles in your veins, which I hear is bad for you.

water weighs 1 gram / cubic centimeter, so a 7 Km column of water would exert 700000 grams/cm3 of pressure, or almost 10K psi

I skimmed through op's post and didnt read any replies so I will only contribute that regardless of depth or pressure the water will be wet.

But can I take water at the bottom of that column, at 10kpsi, capture it so no air gets in or water out, pull it up to the surface, and is that water pressure 10kpsi without any of the 7km worth of weight still physically pressing down on it?

Why cant men pee in a virgina then?

Technically, yes you should be able to. 10k psi is a lot but it's a workable engineering problem to contain it.

Water is compressible depending on temperature. It is just less compressible than most other liquids.

There are obviously diagrams describing this at the end of a google search but if my memory serves me right you got about 2-4% higher density of pure water at the pressures in the deepest waters on earth. Ofc it is not pure water there, it is salt water so Im not exactly sure what happens then to the compressibility. I would guess most impurities increase the compressibility of water as it is one of the least compressible liquids.

My course in molecular dynamics is about 8-9 years behind me now.

So if you make an extemely hard glass container, with no room for expansion, open it and lower it to 7km down into the ocean and then close it and transport it back up, it will explore when and if the container is no longer strong enough to hold the pressure differential between the inside and the outside of the container, which at sea level would be ~700 bar.

Can I trap that 10k psi and use it to move a turbine that creates energy such as in a hydro electric dam?

This might be hydro electric engineering but I never made it that far in high school so I really don't know.

Salt water freezes at a lower temperature than fresh water, yes?
Obviously once you add salt, more mass, it becomes heavier.

Is 7km deep in fresh water (I know it doesnt exist), lighter than 7km deep in salt water? The salt becomes into the water but two things can't exist as one so does the added salt push out water, being more salinated, but weighing the same?

If I take a cup of fresh water and a cup of salt water, remove the salt, desalination, am I left with one cup of fresh water or a cup less the volume the salt occupied?


Drunk and high science will at least double drunk history's ratings. fluff the game. Pang and qz should hire me, retain ya'll, and sell this fluff to Jay Ingram. (Who did read live on Canadian television a question I emailed in when I was twelve, ha I'm famous!)

salt water is slightly more dense than fresh water (around 2%, depending on concentration), so yes pressure would be slightly higher.

the expansion of pressurized water would release a fair bit of energy and could be made to do work . . . BUT - not as much work as would be required to fetch it from the bottom of the sea. Lord Kelvin is a harsh task master and he gives up very little ground when you start meddling with his laws

Absolute zero is just an extrapolation of the gas law, PV=nRT. If we could go below Absolute zero, maybe entropy would no longer be in effect. We could then have a heat transfer mechanism more efficient than a Carnot engine, and we would be able to reach the stars.

Dude, join weedylar - we visit the stars all the time

Pressure-volume work is calculated as deltaP*deltaVol... since the deltaVol is very small the work would be small.

That's what I was going to say. Meh

I've always thought that we have been trapped by the paradigms of Steam Age thermodynamics. This gas law equation, and the assumption that that there is an Absolute Zero Kelvin just because the graph of PV vs T ends there, is an example of how our entire energy system has been paralyzed by Lord Kelvin!

Plus of course all the other Lords who control the energy systems, and who are happy with the status quo because it maintains their obscene wealth and control. And so, great thinkers and experimenters such as Wilhelm Reich, who's writings were burned, his orgone accumulators destroyed, and he himself abducted by the CIA never to be seen again, are monitored and kept in check by the system.

In my youth I considered pursuing a Doctorate in thermodynamics. I was also invited to work in an underground lab in the Berkshire Hills, close to the site of Reich's experiments that shut down the entire Eastern Seaboard energy grid in the 1950's prior to his disappearance. A trove of his original journals had been protected and saved.

But I declined, since the holders of these writings were what you might call Right Wing Born Again Survivalists, and I didn't feel I could join such a group. The pressure to conform to the social norms of such a group would have been impossible for me to withstand.

But I still wonder what my life might have been like if I had become a mad scientist. Oh well.

A real thousand year Reich?

.

didn't some scientist go beyond absolute zero and found absolute heat?

http://s2.quickmeme.com/...4565856d44f61a87d8987.jpg

http://www.tgdaily.com/...o-temperatures-get-hotter

Thank you Marshal.

And, fluff you, Lord Kelvin!!

but superman can go beyond absolute zero and still its cold not heat.

Just throw fluff in the harddon collider and see what happens

*hadron

besides you getting arrested not much would happen.

Hawkwind, "Orgone Accumulator"

https://www.youtube.com/watch?v=MPISXvQwm_E

You all ruined my thread.

What is worse is you all did not give me an answer.

What's even worse than that, is all ya'll science private place touching but still no answer?

Science and star trek made up science have the same result: maybe; we don't know. Let us get back to you?

And I failed science or my science teachers failed me? Educate yourself with tdsb, so drkprince, am I dumb or is the tdsb below par?

(I was also mike Harris so maybe ask your parents?)

if you want answers then ask from scientists not earthers since i really doubt that any scientist plays this game.

Sorry the water in the box will just be water in a box. It will not explode with pressure from the inside as you bring it up. It will just have less pressure pushing on the exterior of the box as it rises.

I think its far more common to find scientist and engineers in EE than in the general public. The reason is that it is a math game.

If the box is sealed and does not expand as the outer pressure decreases the pressure in the box will be the same as where it was sealed.

Finding a container that does not expand as the delta pressure bewteen inside and outside increases to 700 bar will be more difficult.