Just How Deep Can we Go ??

[Dominic]

The mask'd be safe... but come to think of it, you'd need a hell of a lot of air to inflate your drysuit down there... Can you imagine a 15L argon cylinder?

One of those hot water suits would probably be the way to go...

[Paul Thomas]

<font color='#000080'>. . . and what mix would you use?

Even if you could breath it the mix would have to be no more than 0.28% oxygen or it would be toxic and I suspect you would be slightly narked even if you were to use hydrogen as the diluent!

(Aren't the atmospheric gasses liquified at that pressure?)

[Beck]

Hey I have hear poseidon regs are good at depth but thats just ridiculous
LOL

I'm game, give me the kit to do it and i'll give it a go
LOL

[jasondrake]

I once read that some people used to believe that at a certain depth the sea's density would be thick enough to stop objects sinking through them. They pictured ship wrecks suspended in the gloopy water all at the same depth above the sea bed. Oh the possibilities!

I think hard atmosphere suits would be the order of the day.

[angus Theape]

Originally Posted by [b

Quote[/b] (Jason Drake @ Mar. 24 2003,18:47)]I once read that some people used to believe that at a certain depth the sea's density would be thick enough to stop objects sinking through them. They pictured ship wrecks suspended in the gloopy water all at the same depth above the sea bed. Oh the possibilities!

I think hard atmosphere suits would be the order of the day.

Ah the floating cannonball theory. This comes from mixing up what happens with a helium filled ballon in the atmosphere and what happens to a solid object in water.

In fact the gravity on the object will increase the deeper you go as you get nearer the centre of the Earth.

[Dominic]

Originally Posted by [b

Quote[/b] ]In fact the gravity on the object will increase the deeper you go as you get nearer the centre of the Earth.

Eh? Gravity DECREASES as you near the center of the Earth - there's less mass below you pulling you down and more mass above you pulling you up.
In theory, the center of the Earth is at zero gravity..

Water density is hardly affected by depth, so an iron cannonball will never be denser than water and stop sinking. There is some increase but not as much as you would think.
&nbsp;A full 232 bar cylinder would not implode on the titanic, 151 bar is not enough to crush it and in fact it would resist compession better than being overfilled on the surface. A steel cylinder would buckle but a ally would implode eventually. TThink on that when you decide which is safer.
&nbsp; &nbsp;
The cylinder would take on water if you opened the valve and yes gravity decreases as you get nearer the core for the reason stated. &nbsp;

[Paul Thomas]

Originally Posted by [b

Quote[/b] (Jason Drake @ Mar. 24 2003,18:47)]I once read that some people used to believe that at a certain depth the sea's density would be thick enough to stop objects sinking through them.

<font color='#000080'>This doesn't happen because water is an incompressible liquid so its density does not change with pressure. (Hence one added atmosphere per 10 metres of depth, due to the weight of the column of water above the immersed object).

On the other hand the atmosphere is a mixture of gasses, which of course are compressible. The deeper you &quot;fall&quot; into the atmosphere the denser the air becomes (because of the variable weight of the column of air above, compressing it). This is an exponential function, as opposed to the linear function seen in liquids.

In consequence the earth's atmosphere does not have a distinct surface, it just continues to get thinner and thinner the higher you go, in an exponential manner (and it gets colder).

15,000 feet 0.70 bar
30,000 feet 0.30 bar
40,000 feet 0.18 bar
50,000 feet 0.11 bar

[JohnR]

Just picked up on this thread and thought about it for awhile.

Originally Posted by [b

Quote[/b] ]Eh? Gravity DECREASES as you near the center of the Earth - there's less mass below you pulling you down and more mass above you pulling you up

Not sure about this as gravity directional and is a function of mass. &nbsp;The centre of the earth is believed to be much more dense than the outer layers -this is why the tectonic plates &quot;float&quot; on the surface. &nbsp;As you get closer to the core the mass is relatively little changed 'cos all the heavy stuff is in the middle, but the distance has decreased. &nbsp;ie you are closer to an object with approximately the same mass. &nbsp;Therefore gravitaional force will be increased. &nbsp;

Once you reach the exact centre the mass/gravitational force in every direction is equal resulting in an equlibrium effect (nett force = zero).

'Course this could be a load of bollox.

Cheers, &nbsp;John

[Finless]

I have been trying to follow and understand the points and comments made with varying degrees of failure.

Just to be on the safe side, this means I will not be able to dive the Titanic on twin 10s + a 3 ltrs pony? Right?

Bear in mind I could get the local dive shop to pump the cylinders to 240 bar in each?

It is an awesome thought that assuming a 25 ltr per min breathing rate whilst diving on the Titanic (might be a little stressed to be at that depth with twin 10s) the cylinders would empty within 30 seconds.

Naturally I am ignoring all other factors BUT if you could breath at that depth .. wow.