Quake3World

Wizard .3 wrote:

Sanction wrote:

ToxicBug wrote:You can't compress a liquid unless you heat it and turn it into a gas.

Why must divers come back up to the surface slowly and why do submarines have crush depth ratings if liquids can't be compressed?


:icon27:

Divers need to come to the surface slowly so they don't get the bends. This is from gases in the body forming bubbles in the blood and has nothing to do with compression of liquid.
Actually, both result from pressure and have nothing to do with incompressibility :icon32:

your bladder, however, can contain more urine when you're deep underwater. #1 reason you have to pee when you get back to the surface

mjrpes wrote:I remember reading somewhere an interesting fact about the universe. The amount of space between matter is so great, that if all the matter in the (visible) universe were squeezed together as tightly as possible (to the planck level), it would take up less space than the nucleus of an atom.

universe.zip

Ctrl+c
Ctrl+v

deleted a post about deletion, fancy that

ToxicBug wrote:You can't compress a liquid unless you heat it and turn it into a gas.

Lol, yeah, that’s why they use water for hydraulic rams

mjrpes wrote:I remember reading somewhere an interesting fact about the universe. The amount of space between matter is so great, that if all the matter in the (visible) universe were squeezed together as tightly as possible (to the planck level), it would take up less space than the nucleus of an atom.

You couldn't, it would become a singularity long before it got down to that size. Even hypothetically I doubt it could occupy a volume as small as a nucleus as a nucleus is already pretty much solid matter (from a nucleon point of view, you could try going down to quarks but I'm not aware that anyone's managed to measure the physical volume of a quark). Maybe you could compress it into the volume of an atom (though I'm still VERY sceptical, but not a nucleus.)

Actually, bag of fag-packet calculation:-

Diameter of proton = 10^-15m
Number of atoms in observable universe= 10^80

Assume all atoms in universe are hydrogen (fair assumption, volume of other atomic elements varies very little anyway) so we have 10^80 protons to cram together.

Volume of a single proton (4/3*pi*r^3) = 5 * 10^-46 m3
Therefore Volume of all the protons in the universe = 5 * 10^34 m3

That would be solid sphere of protons (assuming perfect packing) 232079441680m in radius, or roughly 230 million kilometres.

That's a LOT bigger than a nucleus!

(Sorry, there's few things worse than a bored scientist...) :icon25:

You fucking nerd.

I'm curious....where did you get this number from?

Number of atoms in observable universe= 10^80

[Edit] Forget it. Found it.

MKJ wrote: your bladder, however, can contain more urine when you're deep underwater. #1 reason you have to pee when you get back to the surface

Fun fact aha. Never been diving.. would love to go sometime.

never mind fellas. i found the answer to both my questions.

j/k.

as far as what happens to the water. i wonder if some sort of fusion process would occur.

edit: bigger!

shadd_ wrote:never mind fellas. i found the answer to both my questions.

Don't bother posting the fucking answer, thanks!

i was just fucking around. having a bit of fun. see my prev post.

SIK wrote:

mjrpes wrote:I remember reading somewhere an interesting fact about the universe. The amount of space between matter is so great, that if all the matter in the (visible) universe were squeezed together as tightly as possible (to the planck level), it would take up less space than the nucleus of an atom.

You couldn't, it would become a singularity long before it got down to that size. Even hypothetically I doubt it could occupy a volume as small as a nucleus as a nucleus is already pretty much solid matter (from a nucleon point of view, you could try going down to quarks but I'm not aware that anyone's managed to measure the physical volume of a quark). Maybe you could compress it into the volume of an atom (though I'm still VERY sceptical, but not a nucleus.)

Actually, bag of fag-packet calculation:-

Diameter of proton = 10^-15m
Number of atoms in observable universe= 10^80

Assume all atoms in universe are hydrogen (fair assumption, volume of other atomic elements varies very little anyway) so we have 10^80 protons to cram together.

Volume of a single proton (4/3*pi*r^3) = 5 * 10^-46 m3
Therefore Volume of all the protons in the universe = 5 * 10^34 m3

That would be solid sphere of protons (assuming perfect packing) 232079441680m in radius, or roughly 230 million kilometres.

That's a LOT bigger than a nucleus!

(Sorry, there's few things worse than a bored scientist...) :icon25:

I think people get confused because we talk of the big bang originating from a single 'point' of sorts, a very small volume, much smaller than the 230 million km...but what was 'blown out of' the big bang was not all of the elementary particles in the form they are today...the compression of matter and energy at the big bang was much greater than the 230 million km radius calculated for the volume of all the protons in the universe today.

SIK wrote:
Even hypothetically I doubt it could occupy a volume as small as a nucleus as a nucleus is already pretty much solid matter (from a nucleon point of view, you could try going down to quarks but I'm not aware that anyone's managed to measure the physical volume of a quark).

OK, I found a site that mentions this.

http://www.ncsu.edu/felder-public/kenny ... ation.html

Skip down to where it says

The Planck density is enormous. It corresponds to the mass of 100 billion galaxies being squeezed into a space the size of an atomic nucleus. If we could extrapolate general relativity all the way back to the big bang the universe would have gone from infinite density to the Planck density in roughly 10-43 seconds. So saying something happened, say, three minutes after the big bang is equivalent to saying it happened three minutes after the time the universe was at Planck density.

Part of the problems is I wasn't clear... I wasn't talking as much about matter (protons, neutrons) as I was the parts that make up matter.... and at the most basic level that seems to be quantum fluctuations, working at the plank level.