What's all this universe stuff

[Gary.Lowe]

It amazes me how everyone goes on about parrelell universes and time travel etc etc, when 3 quaters of our planet is covered in water in which we know approx only half of what we know about outer space and such.

There are more astouding things found only a few hundred miles from most of our homes and easier to see and explore.

Give me a wetsuit anyday!

[SteveCRM]

I think its just the thrill of imagining things so wild that actually might be true. Like life on other planets, to me, thats more exciting than some new fish in the ocean. Just a view.

[Gary.Lowe]

Stevie

I can understand imagining these things but to move along side something that is as alien as most of us will ever get close to is an amazing thrill.

If there are any divers out there you can back me up as what feeling is like.

My main point was that you can imagine these sort of things but you have the added advantage of being able to do these things.

[Gen-X]

I think one of the main problems is that its more hospitable in space than it is in our own back yard.

While a spaceship (shuttle) needs to provide its crew protection from the elements and a source of air etc...

A DSV (Deep Sea Vessel) needs to be reenforced to withstand extreme depths and human beings were never designed to go down to those depths (ie Astronaughts don't have to "Depressurize")

We can travel 200,000 km from the surface of the earth... but travelling 20km below Sea Level is enough to crush anything.

[Michael]

"Astronaughts (your spelling, genx) don't have to Depressurize" ...

... but don't they have to breathe?

I have never been diving, neither have I been into space, but nature - whether it is 10 miles from home or 10 million miles from home - fascinates me.

[ElectroTism]

umm..just pointing out the flaw in your logic Gen-x:
you are saying that Divers need special gear/prep to go down deep and Astronauts just hop into the space shuttle with no training/no prep and take off.

" We can travel 200,000 km from the surface of the earth... but travelling 20km below Sea Level is enough to crush anything."

Yes, and 20km above earths crust is enough to freeze your butt in a second
Not to mention you'd probably explode due to your such a low air pressure.

Yes DSV's must withstand tremendous outside pressure, but Space shuttles must withstand tremoundous temperature differences.

[Gen-X]

Michael

and a source of air etc...

Had to quote myself so you could read

ElectroTism

Just to point out major flaws in YOUR logic...

1. It wasn't mentioned anywhere Astronauts didn't require training or prep, thats your addition

2. You don't explode due to low air pressure (ROFL!!!!) Its called Weightlessness

3. Its easier to insulate against temperature than it is pressure.

[ElectroTism]

Woah now:
Firstly, I was merely saying what you were implying.
Note:
"... human beings were never designed to go down to those depths... "

Well, they were never designed to go into space either.

Number 2:

Yes, you WILL explode. Same reason you would get crushed, or "implode" as you venture deeper into the ocean. Your body is built to handle the air pressure on the Earth's atmosphere already. In other words, thats why you dont get crushed right now. Your body is nuetralizing the air pressure thats "crushing" your body. Your mistake is (I gather) that you think there is zero air pressure at sea level. Since your body is naturally "pushing outwards" when there is no force to push against, ie air pressure, then you will explode. Air pressure has nothing to do with "Weightlessness". "Weightlessness" is a result of the lack of gravity, which also has nothing to do with air pressure.

Thirdly, no comment

Cheers!

p.s. look forward to your reply

[Gen-X]

Air Pressure

Ok, agreed weightlessness has nothing to do with air pressure... I mistakenly joined the 2 because when you have little to no air pressure you are "usually" weightless.

But you are wrong about exploding in low air pressure.


If you go back to beginners chemistry you will know that air pressure is the number of collisions that occur in a given time. If you push more gas into a smaller container the air pressure will be higher.

I think the problem you are talking about is when you go from DEPTH to NORMAL and you explode... That is called "de-pressurization" and it occurs because too much air is in your lungs when you surface too quickly and it expands causing you to explode.

This is totally different from someone who started at "normal" pressure and went to a pressure that is less. No air pressure at all is called a "vaccum" and because of space suits Astronauts are never in a vaccum.


The bottom line is that it is harder for human beings to get to and survive being only 20km below the surface of the ocean than it does 200,000km above.

[ElectroTism]

"...I mistakenly joined the 2 because when you have little to no air pressure you are "usually" weightless."
Umm...no, when you have little to no air pressure, you are dead..hehe, but really, Air pressure has no correlation to whether you are weightless or not. Gravity does. If you say it does, then you are saying Gravity has a correlation w/ air pressure, which it doesnt.


"If you go back to beginners chemistry you will know that air pressure is the number of collisions that occur in a given time. If you push more gas into a smaller container the air pressure will be higher."

Do I sense some sarcasm?


"I think the problem you are talking about is when you go from DEPTH to NORMAL and you explode... That is called "de-pressurization" and it occurs because too much air is in your lungs when you surface too quickly and it expands causing you to explode."

Ok, that has to do with the fact that the gases in your blood will separate (ie come out of the blood, note i'm not an expert in this field so I dont know how to say it the "right" way, but I do know what i'm talking about). Air pressure is (i might be wrong) not really what you are "breathing" (for lack of better term). Air density, mixture is what you are concerned w/. The units for air pressure is commonly PSI, or pounds per square inch, or in other words, how much is the air pushing on your body. Therefore, as I said earlier, when there is a substantially less amount of pressure pushing on your body, you will explode because your body is still pushing out.


"This is totally different from someone who started at "normal" pressure and went to a pressure that is less. No air pressure at all is called a "vaccum" and because of space suits Astronauts are never in a vaccum."

Obviously astronauts are never in a vacuum (w/o space suits) but then again, divers arent 20km below the surface w/o being in a DSV.

"The bottom line is that it is harder for human beings to get to and survive being only 20km below the surface of the ocean than it does 200,000km above. "

Btw, 20km is wrong because the deepest part of the ocean is about 6 miles which is approx 10km if i'm not mistaken. Now comparing distance(s) vs survivability isn't fair (and I dont think is the topic anyway) because ofcourse the survivalbility curse drops more sharply when going down into the ocean.

Also, we are talking about water pressure when we are going down as the factor that "crushes" people.

p.s. I probably made a few typos and diction/grammar errors because I was talking to someone else as I composed this....

oh and also, people *have* been to the deepest parts of the oceans, but people have not even reached the edge of our galaxy (ppl, not manless space vehicles..)

[Edited by ElectroTism on 08-23-2000 at 08:26 PM]

[Ben.Stappleton]

Phew, it's getting technical in here, and all because Mr.Lowe mentioned he liked to go diving.

I'll keep this as simple as I can

Just to clarify - you *can* explode due to pressure differences.

When you're deep down in the sea, the pressure is huge and the human body cannot withstand this. This is why we need to create a strong shell around us which can support the pressure. But you all knew this.

Conversely, take a creature from really deep down in the sea and bring it to the surface - it will explode as its body is structured to withstand the immense pressure down there (measured in "atmospheres") and is not designed to survive in the "low pressure" environment we live in.

Take us into space without protection and we will get very unhealthy, very quickly.

Let me think of an analogy...

Err...

OK - an aerosol can. Contains lots of compressed gas (high pressure). If you suddenly remove the can - the gas expands outwards rapidly until the pressure is equalised.

This is (roughly) what happens to a human if you dump him outside of a spaceships. No pressure to speak of and the human tries to expand. The pressure inside us tries to leave the body (which is reasonable tough) via the quickest exit (commonly the eyes, ears etc). So although the corspse will remain (pretty much) intact most of the fluids and gases inside will have left in a messy way.

Vacuum also has an interesting affect on a body. If we all think back to our school days, we will remember that the amount of energy required to heat something is related to the pressure of its environment. All SHC (specific heat capacity) measurements are given as being at sea level.

In a vacuum, flesh can simultaneously burn and freeze (quite messy).

As this reply has been structured over about an hour with numerous interruptions and interspersed with trotting around the building it's probably fraught with errors and typos.

As me if I care.

Does this answer anything? I tried to use as few big words as possible...

I'd just like to add that Gary has a very valid point. There are large areas of the sea, that we have absolutely no idea what goes on there. In fact, there are some bloody deep trenches out there that the mind boggles at what you might find at the bottom.

Saying that, I intend to go into orbit before I die and have no intention whatsoever to go to the bottom of some of those trenches.

[Gary.Lowe]

Ben

Conversely, take a creature from really deep down in the sea and bring it to the surface - it will explode as its body is structured to withstand the immense pressure down there (measured in "atmospheres") and is not designed to survive in the "low pressure" environment we live in.

There is one sea animal called the Nautilus which is like a Squid in a shell.

This is one of the only creatures that can live miles below the surface of the ocean but can also survive in shallow water.


Hmmmm!

[Ben.Stappleton]

I was speaking generally.

I actually have one living in my bath. It's quite a pest. Keeps trying to eat my rubber duck. Any more behaviour like that and it's going to end up in the pan.

They're not poisonous are they Gary.

Actually, wouldn't it be easier to shout across the office to you?

[ElectroTism]

"This is (roughly) what happens to a human if you dump him outside of a spaceships....So although the corspse will remain (pretty much) intact most of the fluids and gases inside will have left in a messy way..."

Corpse will remain intact? I think not. Same principle you are using with the fish. Why would "fluids and gasses...[leave] in a messy way" in humans, yet the fish would just explode? Its not merely the "fluids and gasses" expanding, its due to the fact that your bone structure and such are constantly applying pressure to neutralize the air presssure around you. So, take away the air pressure, and your body is neutralizing a force that isnt there which creates a net outwards force. (i.e., you go kablooey.)

[V(ery) Basic]

Of course you explode in outer space. I do it all the time. Also, about that shell, that's probably the reason why it doesn't explode in low pressure.

If you want proof about humans exploding outside, watch Armageddon. There, the guy floats away into space, and since the opposite of what happens in Armageddon is true, humans must explode in outer space.


(Oh, and in Armageddon, why did they nearlt deafen the audience with big whoooooshing sequences when there's no sound in space (even Gen-X must know that )

[Gary.Lowe]

It would have made the film shite

[Ben.Stappleton]

Good logic (V)ery. I like the way your mind works (or doesn't as the case may be ;-) ).

Very insightful comment Gary. I expected little more from you.

Right, lets clear some things up...

Your bone structure applies no pressure at all, everything else applies pressure to keep things on your bone structure.

Besides, as the human body is 85% water, the problem is with the way water reacts when in a zero pressure environment. Let's look through the round window boys and girls...

Just for knowledge:
The vapour pressure of water at body temperature (37C) is about 50 mm of Mercury - compare this to the pressure of one atmosphere (760 mm).

At zero pressure, water would begin to boil immediately, but this doesn't happen because it contained by this wonderful thing we call our skin and blood vessels. If the water vapour pressure within our body were at one atmosphere you could pretty much explode. Severe hemorrhaging, ruptures etc. But it isn't, so you don't.

The normal blood pressure in the arteries is about 75 - 160 mm of Mercury to it's not going to boil that easily and they can take up to about 200 for a while without bursting.

The main area of pressure loss is going to be via the lungs as you can't keep much of a pressure by keeping your mouth and nose closed. When it's all gone, your lungs will fill with water vapour at 50mm pressure mixed with gases from your blood stream.

After this inital expulsion of gases, the body will continue to lose vapour and gases and the body will cool off. This cooling will slow the gradual escape of gases from the body further. This process is known as "outgassing".

Eventually, all that is left is a dessicated shell of corpse which is significantly smaller than it was originally.

Sweet dreams.

Any further questions?

[Gary.Lowe]

just what I was thinking