Nuclear Bomb Comparisons

[j.p.bill]

You only have to remember Apollo 13. They almost froze to death with no electricity to spare for heat.

 

[Nigel Goodwin]

You only have to remember Apollo 13. They almost froze to death with no electricity to spare for heat.

The dangers of poor (or no?) insulation - decent insulation would have mostly prevented heat radiating in to space.

Mind you, as the biggest problem is getting rid of excess heat, presumably it was designed to lose heat at a similar rate as it creates it - reducing the amount of heat created then means you are in trouble!.

 

[Oznog]

Ambient, you must have not understood what Nigel was saying. The only method is radiation. Regardless of how well it's insulated the materials the space ship was made of still radiated a lot of energy outwards, and in space there was very little energy hitting the ship (at least when it's in the dark) soo all the energy bleeds off very quickly.

Well that depends, doesn't it?

The sunlight in space near Earth orbit is brighter than noon in Arizona in the summer (no atmospheric losses). It can heat things up fast. There is no loss from contact with cooler air circulating past so the situation is similar to a greenhouse. In contrast the dark side radiates out heat while receiving no external radiation so it can get quite cold.

Many ships are rotated just to keep the temperature even.

 

[Oznog]

If you had a very solid type of balloon, made of thick aluminum or something, and then sucked all the air, everything, out of it, would it float? I guess you could argue that it would collapse under the weight of the atmosphere, but if you took it very high, would it float up there?

It would- but the pressure trying to crush a sphere with a vacuum inside is enormous!

At higher alts, the pressure is less so there is less crushing force. However, since the air density is less there is less boyant force thus the shell weight that can be floated is less. There is no known material which could make a vacuum sphere that could float at any altitude.

 

[Oznog]

I thought that your blood "boiling" always referred to the fact that at lower pressures the nitrogen in your blood simply gathers into bubbles, similar to steam bubbles in boiling water (but not caused by heat). That is why you do not screw around in a decompression chamber!

I have put ordinary water in a vacuum chamber and I assure you it bubbles quite violently for several minutes until it is fully degassed. If you have a strong pump and a small chamber even a 2/3rds full container may overflow.

Eventually the water will be degassed, boils a bit, gets cold and the boiling and evaporation slows down quite a bit.

So you're 100% right. The water itself will not evaporate catastrophically. However the huge volume of gases other than H2O coming out of solution will quickly cause "the bends".

 

[dknguyen]

Okay, here's something else I've been wondering about for a long time now. Hydrogen and Helium are used in balloons because they're low in density, but (I'm presuming here) they provide some component of structure to inflate the balloon. If you had a very solid type of balloon, made of thick aluminum or something, and then sucked all the air, everything, out of it, would it float? I guess you could argue that it would collapse under the weight of the atmosphere, but if you took it very high, would it float up there?

Don't they use this principle in weather balloons? Near sea-level, they're practically droopy because they have a minimal amount of gas inside, but by the time they reach the limits of the atmosphere, the relative lower pressure outside the balloon makes the gas inside expand and fill the balloon to capacity (and then eventually boil?).

It doesn't matter what material you use inside, or the material it's made out of. It depends more on the medium you are trying to float in. So if you found a material that was very stiff and light enough, sure a vacuum would work. The denser the medium you are floating in, the heavier the balloon material can be (and the less pressure you can have inside the material.

 

[Krumlink]

2 Words:

Depleted Uranium

 

[Nigel Goodwin]

Well that depends, doesn't it?

The sunlight in space near Earth orbit is brighter than noon in Arizona in the summer (no atmospheric losses). It can heat things up fast. There is no loss from contact with cooler air circulating past so the situation is similar to a greenhouse. In contrast the dark side radiates out heat while receiving no external radiation so it can get quite cold.

Many ships are rotated just to keep the temperature even.

Because of the poor insulation

Essentially the outside of the craft needs to be mirrored to reflect the suns radiation, but then it needs to be matt black to radiate excess heat from inside - one of those nasty little things to upset designers!.

 

[Krumlink]

This is a cool post apocalyptic picture of some boats that were near the chernobyl site.

 

[JimB]

This is a cool post apocalyptic picture of some boats that were near the chernobyl site.

Are you trying to say that the delapidated state of those boats is due to the Chernobyl event?

I dont think so, they are just half cut up, abandoned, scrapped boats.

JimB

 

[Krumlink]

No not at all, they were cut up BECAUSE of chernobyl and the contamination

 

[Krumlink]

Does anybody like my new avatar