Asteroid cores are not cold

[Morbad]

Getting to the Moon seemed fundamentally impossible 200 years ago.

Travel to the moon was a practical impossibility 200 years ago, but the fundamental understanding was there, the energies involved were tangible. That's more than can be said for the current state of Alcubierre's concept.

Progress happens. What we know now is not all there is to know.

All it takes is a single breakthrough sometimes.

This all goes without saying. However, banking on a breakthrough that is currently completely beyond our understanding doesn't solve any actual problems, it simply closes one off to more mundane possibilities. In the case of interstellar exploration, waiting for FTL travel could mean we never leave this system, when other, slower means to start exploring the stars may be viable in our lifetimes.

In the realm of science fiction, relying on stuff that cannot be extrapolated from current knowledge or processes shifts the material closer to the fantasy side of the spectrum and further from hard sci-fi. Useful for gameplay or plot reasons, but it's not on the same level of science as more concrete mechanisms.

I believe it depends on the type of decay. Alpha and Beta are, Gamma not necessarily.

True enough and good point.

Gamma decay can occur outside fission, but it usually occurs as a byproduct of it, and the overwhelming bulk of radioactive decay in radioactive isotopes in Earth involves fission.

So, I may indeed have been technically mistaken. All fission involves radioactive decay, but not every case of radioactive decay involves fission.

 

[Schmack]

not the immersion. ANYTHING BUT MY IMMERSIUON!! SCIENCE MUST BE ACCURATE IN VIDEO GAMES EEEEEEE




for what i gather: The heat generated by the ship isn't from the outer hull, but from the moving parts required to move a giant mass of metal and electronics through space. Space is inherently cold enough (-455F/-270C) i doubt the heat from the engines will conduct far enough away to be a real problem for the rest of the ship. Your ship is probably measuring general engine temperature vs the temperature of the entire ship from the outer hull to the climate controlled quarters behind the bulkhead.

Think about it this way: If you put your hand close to an exposed lightbulb, your hand will heat up, but the rest of your arm will stay fairly cool (talking about an average household incandescent lightbulb). But if you put your hand over an open fire, your hand, wrist, forearm and shoulder will probably start to heat up and burn you. Engines warming up vs sitting too close to a White Dwarf.

And water is wet btw....

The hull does nothing to generate heat. The comment was that it would be required to act as a super conduit to dump the heat. It's the hull that comes into contact with the vapor inside a wrecked asteroid.

If your hull didn't heat extremely based on ship temps, you could not burn off contamination while fighting the bugs.

 

[M0rty]

well hang on then, how are we generating water vapor then? Certainly not through the use of explosives as that would could probably vaporize any liquid substances down to the molecular level.

Blowing up an Ice-teroid might generate enough residual liquid water to cause icing on the windows and hull, but space is pretty darn cold so i suspect it would become ice again very quickly. Remember, space is 2 degrees above Absolute Zero. I don't believe it's vapor that supercools the hull of a ship when flying through a broken ice-teroid. That said, i don't really have much of a theory that could support this, only the fact that space is cold

 

[Schmack]

I'd expect the entire skin of the vessel to be tied into the coolant loop and used to cool or heat the skin as necessary, as well as for supplemental radiative cooling when appropriate.

THere would be no 'dripping'. Any ice that hit the radiators would be vaporized on contact (they are glowing hot, probably several thousand C) and remove all the heat required to transform them from solid gas in that short perdiod of time and be violently pushed away from the ship.

Anything that came into contact with the skin, which would be much cooler, would either sublimate, or melt and stick to it via surface tension until it was boiled off.

It would be neat to see ice collect on the ship if silent running were engaged (with the heatpumps reversing to cool the skin) during the wash of ice, but that's probably too much detail to expect.



Conduct to the ship's skin and radiators.



Most of a ship's heat is going to be contained within it's primary coolant loop (which would probably be water, for heat capacity reasons). This heat would normally be removed from the ship by circulating it through the skin (which would actually pick up heat and cool the skin in close proximity to a hot object), and via heatpumps that actively moved heat to the much hotter radiator loop (which might be some sort of molten salt, metal, or something more exotic) for the radiators to dissipate (they can work with such a small area because of how hot they are...radiative cooling gets radically more efficient as temperature increases).

All that would have to occur for a heatsink to work would be for the coolant loops and heatpumps to handle moving that amount of energy at that rate (I've seen setups that could freeze a dozen metric tons of water in about twenty second by moving heat to something that was already warmer than the water), and the material the heatsink is made out of to be heated sufficiently to absorb that energy before it was ejected. This would be a challenge with current materials, but isn't anywhere near as far fetched as other things taken for granted in Elite.

The actual rate of transfer through the whole system doesn't necissarily need to be quite so rapid as it appears either; there are plenty of ways it could be buffered along the way, and almost certainly reserve capacity built into the system to absorb rapid shifts that would be necessary.

Unless you can conjure up a heat check valve, then the heat would be shared along the way, the heatsink itself would have an astronomically low heat conduction value (thus heat slowly) and the heat would be distributed along the main feeds of the cooling loops, and throughout the ship. You could not create insta-freeze in seconds unless you had some magical material in the sink that acts as a check valve for heat (insulator) while at the same time accepting massive amounts of it (conductor). Unless mankind found a way around the 2nd Law, I don't see how it's possible. (and I wouldn't consider water the best coolant. I'd think compression and expansion of certain rare gases would facilitate heat transfer faster, like in modern day cold heads and cryogenic systems - helium compressors and zeolite arrays.)

 

[Morbad]

Unless you can conjure up a heat check valve, then the heat would be shared along the way

Each discrete system would have it's own loop that only connected to the primary loop or any others, by the heatpumps, which are heat checks.

the heatsink itself would have an astronomically low heat conduction value (thus heat slowly)

Not sure what you think implies this.

The heatsink is probably just a slug of tungsten heated to near it's boiling point before being ejected. The energy required to do this would come from the heat in the coolant loop via way of heatpumps as well as whatever was required for the pumps themselves (which is accounted for in the SYS draw of a heatsink launch, the standing power consumption of the heatsink laucher, and probably a significant fraction of the power of the ship's power plant that is reserved for cooling). The rate of heating of the heatsink and cooling of the loop would only be limited by the capacity of the heatpumps and the flow rates available.

Unless mankind found a way around the 2nd Law, I don't see how it's possible.

Heat pumps explicitly exist to allow heat to be moved to hotter areas. This doesn't violate the 2nd law of thermodynamics, because entropy of a closed system is not decreasing. A ship is not a closed system.

(and I wouldn't consider water the best coolant. I'd think compression and expansion of certain rare gases would facilitate heat transfer faster, like in modern day cold heads and cryogenic systems - helium compressors and zeolite arrays.)

The heatpumps themselves may use refrigerants such as these, or more exotic means like thermoelectric or magnetic cooling, to move heat, but water would be a good option for the primary loop and main heat storage, because of it's thermal capacity. It can also be pumped efficiently at high flow rates, and is thus a nearly ideal way to move bulk heat energy within it's practical temperature ranges (-43C, for extremely pure water that's been supercooled, to 374C for supercritical water in a high-pressure system).

 

[aRJay]

It'd require a super conductive hull material to make that kind of heat transfer as quickly.

Probably true but space ships are designed to lose heat as fast as possible so there is an accumulation of effects happening to speed things up.

 

[Soron Silin]

well hang on then, how are we generating water vapor then? Certainly not through the use of explosives as that would could probably vaporize any liquid substances down to the molecular level.

Blowing up an Ice-teroid might generate enough residual liquid water to cause icing on the windows and hull, but space is pretty darn cold so i suspect it would become ice again very quickly. Remember, space is 2 degrees above Absolute Zero. I don't believe it's vapor that supercools the hull of a ship when flying through a broken ice-teroid. That said, i don't really have much of a theory that could support this, only the fact that space is cold

We crack the rock, not vaporise it. There would be plenty of dust around. And I'm not talking much about liquid water, I'm talking about solid water -- the stuff the "rock" is made of -- and other bits such as methane, ammonia and liquid oxygen. When that touches the ship's hull and especially the radiators, it will melt and probably boil. The changes of state require a large amount of energy, ie heat, which it takes from the ship and that cools the ship.

Space is neither cold, nor is that relevant. Read the OP again. There is no heat transfer by conduction in space.
The temperature between galaxies only gets down to 3 kelvin, not 2. But that doesn't matter to us because all our game-play takes place in solar systems. Around a star the temperature of space is incredibly high, like hundreds of thousands to millions of degrees. But there are only maybe five sub-atomic particles in a cubic centimetre, there isn't enough stuff to cause any heating. In a debris field that is not true and the debris is very cold.

[ref: https://eportfolios.macaulay.cuny.edu/sciencefordessert/2013/02/02/is-space-cold-or-hot/ ]

 

[obliterator]

Travel to the moon was a practical impossibility 200 years ago, but the fundamental understanding was there, the energies involved were tangible. That's more than can be said for the current state of Alcubierre's concept.

It wasn't seen as a practical impossibility, it was seen as scientifically, physically impossible. Hell, just 130 years ago, most scientists were still positive that aeroplanes were physically 100% impossible too. Less than 20 years later, the first airplane flight happened. The first non-manned space flight happened 55 years later, and 12 years after that we had reached the moon.

 

[Morbad]

It wasn't seen as a practical impossibility. It was seen as scientifically impossible.

Not by Newton or anyone else who grasped his laws of motion.

Hell, about 130 years ago, scientists were positive that aeroplanes were scientifically 100% impossible too.

No scientist would have mistaken an airplane as a scientific impossibility, given that the very existence of birds and other such creatures is proof that heavier than air flight is possible.

Maybe you're referencing Lord Kelvin's infamous opinions? He thought they'd never be practical and that experiments with heavier than air aircraft would never pan out...not that they were scientifically impossible and even his actual opinion wasn't remotely a universal one. Kelvin's original quote was from a letter rejecting an invitation to the Aeronautical Society, which was, at the time, a sixty-something member organization of scientists that spent a large part of their time working on the problem of heavier than air flight.

 

[M0rty]

i think 455 degrees below Zero Fahrenheit constitutes as "cold."

If you think it's anything but, you're smoking some really special. I think the whole "so cold it's hot" is a bunch of hooey and a placebo to explain a trick on the human mind. Of course it's gonna be warmer around a star, it's a flaming ball of gas. but outside of the couple million mile perimeter around the star, it's pretty fricken cold.

Source: https://www.youtube.com/watch?v=VkmBXwOrQCM

Just based on this, these explosions will generate a level of heat that could vaporize resources within a roid. And if we're getting really picky as to the exact science of what happens when a giant space rock explodes, there would be no flashy explosion when the charges detonate. the rock would simply break apart in the same way, just no flash. I'm sure there are explosions that occur in space that would produce a flash like a supernova, but a man-made controlled detonation? that's ridiculous

 

[Schmack]

Each discrete system would have it's own loop that only connected to the primary loop or any others, by the heatpumps, which are heat checks.



Not sure what you think implies this.

The heatsink is probably just a slug of tungsten heated to near it's boiling point before being ejected. The energy required to do this would come from the heat in the coolant loop via way of heatpumps as well as whatever was required for the pumps themselves (which is accounted for in the SYS draw of a heatsink launch, the standing power consumption of the heatsink laucher, and probably a significant fraction of the power of the ship's power plant that is reserved for cooling). The rate of heating of the heatsink and cooling of the loop would only be limited by the capacity of the heatpumps and the flow rates available.



Heat pumps explicitly exist to allow heat to be moved to hotter areas. This doesn't violate the 2nd law of thermodynamics, because entropy of a closed system is not decreasing. A ship is not a closed system.



The heatpumps themselves may use refrigerants such as these, or more exotic means like thermoelectric or magnetic cooling, to move heat, but water would be a good option for the primary loop and main heat storage, because of it's thermal capacity. It can also be pumped efficiently at high flow rates, and is thus a nearly ideal way to move bulk heat energy within it's practical temperature ranges (-43C, for extremely pure water that's been supercooled, to 374C for supercritical water in a high-pressure system).

The fundamental difference between the examples you mentioned and the ED heatsink is the fact the ship is in a vacuum, and though it can pick up radiated heat, it cannot quickly dump it without making some sort of surface contact. If there was some mystical material that absorbs massive amounts of heat, past the equilibrium point and even robs heat in the process, then can hold it like holding a breath of air until released, then that could be one narrative.

If you put the heatpump inside the home, how effective would it be? It would overheat everything, because energy required to run it creates heat, and the room would become hotter and hotter until the pump stopped working.

The heatsink is basically inside the home since it's either inside the ship or attached to it.

 

[Schmack]

well hang on then, how are we generating water vapor then? Certainly not through the use of explosives as that would could probably vaporize any liquid substances down to the molecular level.

Blowing up an Ice-teroid might generate enough residual liquid water to cause icing on the windows and hull, but space is pretty darn cold so i suspect it would become ice again very quickly. Remember, space is 2 degrees above Absolute Zero. I don't believe it's vapor that supercools the hull of a ship when flying through a broken ice-teroid. That said, i don't really have much of a theory that could support this, only the fact that space is cold

Vaporizing is creating a vapor, nebulization of sorts. The heated water would have already outgassed, so it would not rapidly cool since there's nothing to transfer heat to, but it might disperse so space entropy of sorts. Since ours is contained in a small region, we have a partial pressure anomaly since the gas isn't expanding.

 

[Soron Silin]

i think 455 degrees below Zero Fahrenheit constitutes as "cold."

Do you have a reference for that figure? I believe you will find it's the temperature that an object reaches in shadow. That's clearly around -200C, because the rocks are that temperature. That's not the same as the temperature of space, and both are still irrelevant because there is no conduction in a vacuum; heat is lost only very slowly through radiation.

I found some interesting videos on blasting.

This one shows what we are trying to do, how the rock fractures and how much dust is produced:

Spoiler

This one shows actual opal mining, on a rather smaller scale than we are doing and the blasts that they do are a little too small to show the dust. All he's wanting is to break the rock, not cleanly fracture it:

Spoiler

 

[JetsonRING]

Space is not a "perfect" vacuum and not a perfect insulator. We can feel the sun's heat on our faces from over 90 million miles away across space. As I understand thermodynamics an object does not so much "push" heat into space but rather space draws heat out of the object (nature abhors a [energy] vacuum). Nearby, super-cold objects would tend to help draw more heat out of an object. Seems to me that mountain-sized chunks of super-cold asteroid surrounding and in close proximity to a ship could draw heat out of the ship very nicely.

 

[Schmack]

First, space is not a "perfect" vacuum and not a perfect insulator. We can feel the sun's heat on our faces from over 90 million miles away. As I understand thermodynamics an object does not so much "push" heat into space but rather space draws heat out of the object (nature abhors a [energy] vacuum). Nearby, super-cold objects would tend to help draw more heat out of an object. Seems to me that mountain-sized chunks of super-cold asteroid surrounding and in close proximity to a ship could draw heat out of the ship very nicely.

Push or pull is irrelevant. Electricians believe the space in the valance shell moves (hole theory) while electronics practitioners believes the electron moves. One says current moves pos to neg, the other neg to pos. It depends on what you're looking at. Radiated heat doesn't, in any way, detract from the concept of vacuum.

 

[Morbad]

The fundamental difference between the examples you mentioned and the ED heatsink is the fact the ship is in a vacuum

My examples take the vacuum into account.

and though it can pick up radiated heat, it cannot quickly dump it without making some sort of surface contact

At ~6200K it can.

If you put the heatpump inside the home, how effective would it be? It would overheat everything, because energy required to run it creates heat, and the room would become hotter and hotter until the pump stopped working.

All heat that leaves the ship is ultimately emitted via radiation, or ejection of heated matter.

In both cases, heatpumps are used to raise the temperature of the raidative area or object to levels high enough where radiation can handle all the energy involved.

An ejected heatsink is likely a high-melting point material raised nearly to boiling, then fired into space where it cools...rapidly at first, then more slowly. The game has them disappear after a short while, but even a small area can loose heat via radiation quickly at extreme temperatures.

The ships radiators are always glowing at least orange hot and often yellow or white hot and the game actively has them close or retract before they glow any cooler, likely to make sure that all exposed radiator area is operating at sufficient efficiency. Heatpumps are needed to reach these temperatures and these high temperatures are needed for radiators of such size to work. All of this is why there has to be stages of cooling loops...it's not plausible for a single stage to reach the temperature deltas required or for the coolant that's in contact with more sensitive system to be outside a certain and almost certainly rather low range of temperatures.

If there was a vacuum outside my home, and I only had a small area of radiator to work with, a series of heatpumps sufficiently high temperature capacity could cool my house just fine, provided I had the energy to run them.

 

[IndigoWyrd]

I'm not nerd enough to care?

Simulated realities just aren't that much fun. I'd rather have more fun and less simulated reality to be dead honest. If I want realism, I'll fire up Take on Mars.

Reality is four hours fun.

 

[Schmack]

My examples take the vacuum into account.



At ~6200K it can.



All heat that leaves the ship is ultimately emitted via radiation, or ejection of heated matter.

In both cases, heatpumps are used to raise the temperature of the raidative area or object to levels high enough where radiation can handle all the energy involved.

An ejected heatsink is likely a high-melting point material raised nearly to boiling, then fired into space where it cools...rapidly at first, then more slowly. The game has them disappear after a short while, but even a small area can loose heat via radiation quickly at extreme temperatures.

The ships radiators are always glowing at least orange hot and often yellow or white hot and the game actively has them close or retract before they glow any cooler, likely to make sure that all exposed radiator area is operating at sufficient efficiency. Heatpumps are needed to reach these temperatures and these high temperatures are needed for radiators of such size to work. All of this is why there has to be stages of cooling loops...it's not plausible for a single stage to reach the temperature deltas required or for the coolant that's in contact with more sensitive system to be outside a certain and almost certainly rather low range of temperatures.

If there was a vacuum outside my home, and I only had a small area of radiator to work with, a series of heatpumps sufficiently high temperature capacity could cool my house just fine, provided I had the energy to run them.

So you think you could use electromagnetic energy transfer to cool your home, while basically living in a vacuum chamber where no thermal conduction is happening? Just to be clear, you're talking about EM, not convection based energy transfers, right?

You said "provided I had enough energy" when energy is what you're trying to get rid of.

 

[Soron Silin]

First, space is not a "perfect" vacuum and not a perfect insulator. We can feel the sun's heat on our faces from over 90 million miles away. As I understand thermodynamics an object does not so much "push" heat into space but rather space draws heat out of the object (nature abhors a [energy] vacuum). Nearby, super-cold objects would tend to help draw more heat out of an object. Seems to me that mountain-sized chunks of super-cold asteroid surrounding and in close proximity to a ship could draw heat out of the ship very nicely.

Five sub-atomic particles per cubic centimetre is a pretty good vacuum.
Your view of thermodynamics is flawed because it is based on simplified descriptions of the behaviour of bodies that are not in a vacuum. Conduction could be said to work like that, although it is over-simplified to the point of being arguably wrong, but there is no conduction without a medium. Conduction doesn't happen in a vacuum.
Feeling the sun's heat is through radiation. Radiation is the only way to transfer heat in a vacuum.
Radiation is through infra-red light being emitted from the hot body. There is no form of radiation that transfers cold; it is a physical imposibility since it would have to contain negative energy. Cold does not radiate. You cannot get colder from a nearby cold body in a vacuum.
Radiation is much less efficient than conduction, especially if the body is not very hot. So a warm body in a vacuum will remain warm for a considerable time, no matter how cold it will eventually get or how cold surrounding objects are, so long as it is not touching them. For a spaceship, or for the ISS, with a temperature of only 20C, there is sufficient heat generated within it to easily overcome the small losses from radiated heat; being too cold is never a problem.

Even a lone astronaut needs only a cooling system: https://en.wikipedia.org/wiki/Liquid_cooling_and_ventilation_garment

 

[Schmack]

Five sub-atomic particles per cubic centimetre is a pretty good vacuum.
Your view of thermodynamics is flawed because it is based on simplified descriptions of the behaviour of bodies that are not in a vacuum. Conduction could be said to work like that, although it is over-simplified to the point of being arguably wrong, but there is no conduction without a medium. Conduction doesn't happen in a vacuum.
Feeling the sun's heat is through radiation. Radiation is the only way to transfer heat in a vacuum.
Radiation is through infra-red light being emitted from the hot body. There is no form of radiation that transfers cold; it is a physical imposibility since it would have to contain negative energy. Cold does not radiate. You cannot get colder from a nearby cold body in a vacuum.
Radiation is much less efficient than conduction, especially if the body is not very hot. So a warm body in a vacuum will remain warm for a considerable time, no matter how cold it will eventually get or how cold surrounding objects are, so long as it is not touching them. For a spaceship, or for the ISS, with a temperature of only 20C, there is sufficient heat generated within it to easily overcome the small losses from radiated heat; being too cold is never a problem.

Even a lone astronaut needs only a cooling system: https://en.wikipedia.org/wiki/Liquid_cooling_and_ventilation_garment

The ISS reaches -250F in the dark and up to 250F in the light, externally. They use ammonia radiators (massive ones) to bleed the heat.

I could see a large ship like a cutter having skin made of capillaries that act as radiators, so that an even more advanced, perhaps even organic substance could collect heat and spread it evenly across the surface, for purposes of radiation cooling.