if heat cant transfer through a vacume, why do satalights get cold when in earths shadow. wouldnt they just retain the heat. is their a different way for the the thermal energy to dissapate
125699
Yes, heat can dissipate through radiation, just like a radiator in your house. Each body (Earth, moon, satellite, etc.) has a number called the albedo, the ratio of how much heat it absorbs to how much heat it reflects. And when somethnig passes into the shadow, it radiates out its heat and gets cold.
76921
Is it within a vacuum?\n\nIf not, and if through your above given conditions resulted in air being compressed or what have you then I guess it would.
535492
It's because the thinner atmosphere at the higher altitude holds less heat.  The atmosphere and its greenhouse effect is the reason why the night side of the Earth is not frozen, because the atmosphere holds infrared radiation given off by the Earth after it is irradiated by the sun.  But at altitudes where the atmosphere is thinner, it is able to hold less of that warmth.
377482
Does it have to be a material? the best solution for this would be to have 2 cans one just inside the other with a compleat vacume between them, as there is no air to transmit the heat between them the liquid inside wont change tempreture.\n\nthis is the principle of a thermos flask,\n\nif you need an actual material, somthing that would trap air to stop it from moving and spreading the heat such as glass fiber like you might have in your loft\n\nhope this helps
184132
HAHAHAHA You all forgot about our little friend called drag! Inside or out the ball has a drag force acting on it by the surrounding air. Like stated before the air in the car is moving with you, and the car, and the ball all the same and the drag force on the ball at this point is negligible. This is not the effect of a vacume, a vacume is the absence of air. is it possible for there to be no air in the car? NO, Sooo.. outside on a bike or where ever, you are traveling at a speed where the balls light weight will be significantly affected by this drag force and it will cause it to slow down as you throw it up and while you keep riding on un affected by the static(motionless) air, your ball only has one force acting on it, air drag causing it to slow behind you.   test this by throwing a variety of same shaped objects while riding and you will see that the one with the most density will keep up the best. try a marble V.S. a ping pong ball.  then do it in the car
230727
Different materials conduct heat at different rates.\n\nMetal, for example, is generally an excellent conductor of heat, meaning that when you place your hand on a metal doorknob, the metal conducts heat away from your hand at a much higher rate than of you were to grab an object made of less conductive material, such as wood.  The sensation you're calling "cool" or "cold" is simply heat being conducted away from your skin.  \n\nRemember, just as darkness is nothing more than the absence of light, cold is nothing more than the absence of heat.  So when you're touching a cold object, nothing is being imparted to your skin; all you're feeling is the heating leaving.\n\nRegards,\n\nKevinb671, Ph.D.\nSertufied Science Person
637099
Sorry but darkness is not a measurable thing. the absence of light however is! The absolute absence of light leaves the condition referred to as darkness. likewise cold does not exist only the absence of heat. thermal dissipation is the term I believe so I guess we could call darkness, photonic dissipation? wink wink nudge nudge.
50568
Nuclear energy is not "cold", I am not sure what you meant by that.  The whole principle of how muclear energy is used to generate electrcity relies on the fact that it gives off a lot of heat.\n\nIt is also not too clean either.  The depleted nuclear waste posses a problem of where to dispose of it.  It will stay radio active for hundreds of thousands of years, so whereever you put it it needs to be out of the way and secure.  Right now, the government is planning to store the stock piles of nuclear waste deep underground under Yucca Mountain (in Nevada I think), but there is a lot of debate over this.\n\nAs for sustainable, perhaps not in the long run.  There is only so much fissionable material on Earth, it will run out eventually just like fossil fuels.  A more long term nuclear energy sourse would rely on fusion, not fission, but this has yet to be practical.
63440
True but...\n\nIn the Troposphere it is usually decreasing to about 40,000ft (in the mid latitudes), then in the tropopause it is generally stable, then above that I think it goes back up slightly as you get closer to space, then it gets very cold.  \n\nThe Troposhphere, Tropopause, Stratsosphere, etc are layers of air that have similar charistics.  I do not know them all but thats a littl more infor for you.
630123
In space you are barbecued!\nYour sun side becomes hot and the shadow side is freezing.\nThe same happens to the moon.
551317
It's from radioctivity and friction.  The gas giants also create more heat than they recieve from the sun.  The sun is nowhere the near the only source of energy in the solar system.
9501
Some systems actually cool as they deliver power.  A rubber band is most common example I can think of.  If you expend energy to stretch a rubber band, it actually heats up, but it cools slightly as it contracts, which could potentially power some small device like a toy car.  Why this occurs is a little complicated, but the exact same principle of entropic cooling is used to achieve the lowest temperatures currently possible.\n\n***Response to first answerer***\nWhat basic law of motion are you talking about?  The second law of thermodynamics? Because that deals with entropic differences, and doesn't apply. The "laws of motion" aren't even relevant to this thermodynamics question.  \n\nI used the example of a rubber band because it is a clean example of entropic cooling, but in fact ANY  heat engine will result in a decrease in thermal energy of the system. It's true that there is some heat produced from friction in the engine, but on a whole more MORE heat flows into the engine than flows out.  The average temperature of the system decreases. That's why we can use heat engines to power things.
373333
The short answer is no, a circuit cannot absorb heat. \n\nElectrons don't know which way they are flowing in a wire, and there will always be an ohmic loss. One exception is with superconducting materials, in which case electrical current flow does not generate heat, and its flow is essentially lossless.\n\nHaving said that, there are devices called thermoelectric coolers that work on the Peltier effect. These devices are constructed with chunks of material assembled between two plates, typically made of ceramic. \n\nThe device operates by creating a termperature difference between the two surfaces when you run a DC current through it.\n\nWhen electrical current is run through the material in one direction, it causes one plate to get cold, and the other to get hot. If you run the current in the other direction, the opposite effect occurs. The hot plate now gets cold, and the cold plate now gets  hot.\n\nUsually, current is run in one direction only. The hot surface is attached to a big heatsink to actually prevent it from getting too warm. This causes the cold plate to get even colder.  But even with that, the hot side gets hotter than the cold side gets cold. That is, there is a net consumption of electrical power which gets dissipated as heat throughout the overall circuit.\n\nBut this is also true of a kitchen refrigerator, which also gets cold when electricity is run through the device. (Don't forget though that the cooling coils on the back of the refrigerator get hot.). A TE cooler is simply a solid state refrigerator.\n\nThere are no devices that inherently get colder when electrical current flows through them.\n\nHope this helps,\n\n-Guru
327620
Heat is transferred by conduction, convection and radiation. In medium-temperature applications radiation would only be a small part of the total, and an opaque material will prevent radiative escape of heat in any case. Conduction and convection are minimized by the structure of a typical insulator in addition to the material properties mentioned in the first answer. Styrofoam, for instance, consists of very thin partitions of styrene plastic which enclose gas-filled bubbles. This means each convection cell or mixing space is small and essentially a small proportion of the total insulation thickness, so you don't have the coldest internal gas mixing with the hottest gas. Conduction is low because gas conducts heat more slowly than a solid. The conduction path through the solid styrene is convoluted and of small thickness, both of which minimize conduction. In houses, fiberglass insulation uses similar principles except that the air spaces are connected. This means a larger convection cell potentially exists, but it is baffled by all the glass strands, so circulation and mixing are much slower and smaller-scale.
288355
no...it cant get colder than absolute zero....thats why its called absolute....molecules dont move forward or backward ....you should think of them as energy particles....electrons dont really move around a nucleus either....dont think of them as planets around the sun they are more like energy fields.  the more negative the charge the more "electrons"....if there is any movement....even if it were possible to move backwards it would be warmer....movement causes friction and, therefore, heat.  it you cant get less than nothing.
319290
sure- it's easy- the refrigeration system moves heat out of one area into another- and simple experiment for you to do, is take a can of pressurized spray whatever, and spray it- can gets cold from reduction in pressure, allowing molecules space to "slow down" because they quit "bumping" from being in a tight spot- making room for more heat- or "making" cold- with me so far? now just picture a system with a pump that packs the gas molecules tightly together, and on the other end has a spot for them to expand (making room for more heat)and then runs the "heated" expanded gas through a radiator (heat comes out) and then gets compressed (packed) again- round and round "absorbs heat- moves heat- loses heat" \n hope this helps- if you really need more help email me through answers and I can provide pictures of how it works.
657016
radiation? do you hear yourself?\n\nit looses heat b/c it doesn't get enough energy to keep it warm!  a solar cover is a good way to create that needed energy as it uses the suns rays and not weighing down your electricity bill.