Someone Clever tell me why this isn't possible.
Discussion
Why hasn't a material been manufactured that takes all its heat energy and transfers it to electrical current.
So you have a material that is close to absolute 0 all the time pumping out current, and it just keeps taking energy from heat to do this. This would mean that the material would be constantly be cold, and the area around it.
Like a solar panel does with light, why not a material with heat??
You could also maybe solve global warming this way ?
So you have a material that is close to absolute 0 all the time pumping out current, and it just keeps taking energy from heat to do this. This would mean that the material would be constantly be cold, and the area around it.
Like a solar panel does with light, why not a material with heat??
You could also maybe solve global warming this way ?
Wikipedia is your friend. Pyroelectricity (from the Greek pyr, fire, and electricity) is the ability of certain materials to generate a temporary voltage when they are heated or cooled.[1] The change in temperature modifies the positions of the atoms slightly within the crystal structure, such that the polarization of the material changes. This polarization change gives rise to a voltage across the crystal. If the temperature stays constant at its new value, the pyroelectric voltage gradually disappears due to leakage current (the leakage can be due to electrons moving through the crystal, ions moving through the air, current leaking through a voltmeter attached across the crystal, etc.).
Long time since I've had to think about this, but you seem to be describing a perpetual motion machine of the second kind?
http://en.wikipedia.org/wiki/Perpetual_motion#Clas...
http://en.wikipedia.org/wiki/Perpetual_motion#Clas...
BrassMan said:
Long time since I've had to think about this, but you seem to be describing a perpetual motion machine of the second kind?
http://en.wikipedia.org/wiki/Perpetual_motion#Clas...
Seem like quite a complicated subject, but basically using heat to move material or in my case electrons.http://en.wikipedia.org/wiki/Perpetual_motion#Clas...
okay, here goes as an attempt to explain the second law of thermodynamics, and a carnot engine (google those):
what you are proposing is that you have a 'hot' body (the air at room temperature, or whatever your material is getting energy from) and a 'cold' body (your material). You're moving heat energy from hot to cold, and changing some of that energy into electricity (a piston engine works on the same principle, only it converts heat energy into mechanical energy, with the 'hot' being the hot gas in the cylinder and 'cold' the air in the crankcase). But some heat must flow into the cold body (if this was not the case, you could cause heat 'to flow of its own accord from a cold body to a hotter body' - in other words, cold things getting colder and vice versa), warming it - this ends up setting a limit on the efficiency of a heat engine. Since some heat is warming your cold body, you must use some energy running an air-conditioner to keep it cold - inevitably this air-conditioner will require more power to run than your material will produce.
what you are proposing is that you have a 'hot' body (the air at room temperature, or whatever your material is getting energy from) and a 'cold' body (your material). You're moving heat energy from hot to cold, and changing some of that energy into electricity (a piston engine works on the same principle, only it converts heat energy into mechanical energy, with the 'hot' being the hot gas in the cylinder and 'cold' the air in the crankcase). But some heat must flow into the cold body (if this was not the case, you could cause heat 'to flow of its own accord from a cold body to a hotter body' - in other words, cold things getting colder and vice versa), warming it - this ends up setting a limit on the efficiency of a heat engine. Since some heat is warming your cold body, you must use some energy running an air-conditioner to keep it cold - inevitably this air-conditioner will require more power to run than your material will produce.
I've also got a great idea. Someone should just work out some magic solutions to all our problems. Like a pile of food that doesn't go down when you eat it and never goes off. And a kind of plastic that turns into petrol when you expose it to sunlight.
Both these ideas would work really well, people are so stupid that they don't just do them.
Both these ideas would work really well, people are so stupid that they don't just do them.
There are devices that convert a temperature gradient directly in to electricity;
http://en.wikipedia.org/wiki/Thermoelectric_effect
As someone explained above, to extract useful work, you need a hot place and a cold place, and thermal energy to flow from one to the other. Other examples might include;
Coal (etc) fired power station (hot furnace as coal releases chemical potential energy, cold cooling tower)
Solar power (hot sun, cool solar panel)
Wind power (Hot sun + cool atmosphere --> weather)
Nick
http://en.wikipedia.org/wiki/Thermoelectric_effect
As someone explained above, to extract useful work, you need a hot place and a cold place, and thermal energy to flow from one to the other. Other examples might include;
Coal (etc) fired power station (hot furnace as coal releases chemical potential energy, cold cooling tower)
Solar power (hot sun, cool solar panel)
Wind power (Hot sun + cool atmosphere --> weather)
Nick
otherman said:
I've also got a great idea. Someone should just work out some magic solutions to all our problems. Like a pile of food that doesn't go down when you eat it and never goes off. And a kind of plastic that turns into petrol when you expose it to sunlight.
Both these ideas would work really well, people are so stupid that they don't just do them.
That plastic to petrol thing could be possible.Both these ideas would work really well, people are so stupid that they don't just do them.
Unfortunately, the basic laws of our universe seem to be broadly speaking uni-directional. Generally, everything would rather "decay" to a lower energy lever, rather than er, grow to a high energy. So the electrical property of a material that results in resistance, can easily and efficienty convert electric current to heat, "antiresistance" that coverts heat to electric current is much much more in-efficient / difficult to achieve (but it IS achievable). This is reflected in simple things like whilst it is easy for example to smash a tea cup in mear miliseconds, it takes much much longer to unsmash or repair it.
This is repeated time and time again for example, making light from electricity is much easier than electricity from light, and is seen in physics, chemistry (try to "unexplode" gun powder for example!), and all scientific arenas
This is repeated time and time again for example, making light from electricity is much easier than electricity from light, and is seen in physics, chemistry (try to "unexplode" gun powder for example!), and all scientific arenas
Max_Torque said:
Unfortunately, the basic laws of our universe seem to be broadly speaking uni-directional. Generally, everything would rather "decay" to a lower energy lever, rather than er, grow to a high energy. So the electrical property of a material that results in resistance, can easily and efficienty convert electric current to heat, "antiresistance" that coverts heat to electric current is much much more in-efficient / difficult to achieve (but it IS achievable). This is reflected in simple things like whilst it is easy for example to smash a tea cup in mear miliseconds, it takes much much longer to unsmash or repair it.
This is repeated time and time again for example, making light from electricity is much easier than electricity from light, and is seen in physics, chemistry (try to "unexplode" gun powder for example!), and all scientific arenas
It's easy to get a current from light. and if you want to unexplode gunpowder you will need a sThis is repeated time and time again for example, making light from electricity is much easier than electricity from light, and is seen in physics, chemistry (try to "unexplode" gun powder for example!), and all scientific arenas
t load of energy, just like you can re-form petrol from carbon monoxide and water from the air, you need a lot of energy to do it because the reverse reaction has a large activation energy.There are fans that you put on top of woodstoves that use the differential in heat to create electricity.
http://www.fluesystems.com/sundries/info/ecofan.ht...
Cool stuff.
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