n*******d
发帖数: 650 | 1 No. It is impossible. This is called second kind of "Yong Dong JI", which
absorb heat and gives out work. The point is there should be no "low
temperature source", which means there should be no temperature difference.
If there exists temperature difference in the environment, it is possible. But
it is not called "yong dong ji" of course. | q**i
发帖数: 174 | 2
How about this following machine:
in an isolated system (no exchange of matter, energy, or anything with
the outside world), you establish a magnatic field using a magnet. In
the magnetic field, there is a heat source placed on a metal prob (the
primary prob, P), and a 2nd metal prob nearby (S). As P gets hot
enough, it emits electrons. Those electrons, under the direction of the
magnetic field, get collected at prob S.
If you wire P and S together, you see a current (flowing from P to S).
Note
【在 n*******d 的大作中提到】
: No. It is impossible. This is called second kind of "Yong Dong JI", which
: absorb heat and gives out work. The point is there should be no "low
: temperature source", which means there should be no temperature difference.
: If there exists temperature difference in the environment, it is possible. But
: it is not called "yong dong ji" of course.
| l**n
发帖数: 67 | 3
The heat sink is S i guess. Or in other word, if you keep P and S at the same
temperature, your system won't work. And i cannot see any use of
the magnetic field here.???
【在 q**i 的大作中提到】
:
: How about this following machine:
: in an isolated system (no exchange of matter, energy, or anything with
: the outside world), you establish a magnatic field using a magnet. In
: the magnetic field, there is a heat source placed on a metal prob (the
: primary prob, P), and a 2nd metal prob nearby (S). As P gets hot
: enough, it emits electrons. Those electrons, under the direction of the
: magnetic field, get collected at prob S.
: If you wire P and S together, you see a current (flowing from P to S).
: Note
| a**u
发帖数: 99 | 4 Hi,man. What we said is the same point.
What I said is that "the machine that absorb heat from environment and
transfter it to mechanical energy" is possible. I did not say that the
"Yong Dong Ji" is possible.
【在 n*******d 的大作中提到】
: No. It is impossible. This is called second kind of "Yong Dong JI", which
: absorb heat and gives out work. The point is there should be no "low
: temperature source", which means there should be no temperature difference.
: If there exists temperature difference in the environment, it is possible. But
: it is not called "yong dong ji" of course.
| q**i
发帖数: 174 | 5
the magnetic field is there to direct electrons emitted by P to S.
How about this minor modification: coat P with a material that emits
electrons at a lower temprature (like those used in a vaccum tube), and
put both P and S on that heat source, but insulate P slightly so it has a
lower temprature (but still emits electrons).
In this setup, the electrons still come out of P, get collected at S. Yet
S is hotter (at a higher temprature) than P.
the same question ->
【在 l**n 的大作中提到】
:
: The heat sink is S i guess. Or in other word, if you keep P and S at the same
: temperature, your system won't work. And i cannot see any use of
: the magnetic field here.???
| b****d
发帖数: 30 | 6
that would be too much trick. simply say S is a sphere surrounding P.
if your whole device is in the same temprature, then you can't expect
a directed current. if there's different temprature, the heat will flow
from high and emitted through low temprature pole - there is heat sink.
it doesn't help. Say the material is P'. the potential between P'P will
cancel the potential between P'S.
【在 q**i 的大作中提到】
:
: the magnetic field is there to direct electrons emitted by P to S.
: How about this minor modification: coat P with a material that emits
: electrons at a lower temprature (like those used in a vaccum tube), and
: put both P and S on that heat source, but insulate P slightly so it has a
: lower temprature (but still emits electrons).
: In this setup, the electrons still come out of P, get collected at S. Yet
: S is hotter (at a higher temprature) than P.
: the same question ->
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