Paul wrote:
> Hi,
>
[ snip bits on Steorn ]
>
> > > > It's type-1 perpetual motion: violation of he
> > > > first law, which is conservation of energy. If
> > > > the Steorn otor works, then a Steorn motor
> > > > operating in a closed nvironment will warm up
> > > > that environment.
> > > >
> > > > You're talking about type-2 perpetual motion:
> > > > iolation of the second law, with energy moving
> > > > "uphill" gainst a thermal gradient. If your idea
> > > > for diode arrays orks, then when it's operating
> > > > in a closed environment, it will ake no net
> > > > difference to the temperature of that
> > > > environment.
> > >
> > > That's simply not true. An LED connected to a
> > > resistor generates photons.
> >
> > Energy is conserved in this scenario;
>
> Indeed, which is why I stated, " you are essentially
> converting the kinetic energy in ambient temperature to
> potential energy in the battery"
Right. I wasn't thinking when I said the temperature would
be unchanged (or rather I was thinking of total energy
rather than temperature).
> > the energy from the photons comes from the "noise"
> > electric current, and the esistor cools slightly as the
> > photons are generated due to the et slowing of the
> > conduction electrons, but the photons are carrying
> > nergy, which when converted back to heat warms the
> > environment up gain.
>
> Perhaps you missed the part regarding the photons being
> focused on the solar cell, which is connected to a
> battery. Again, kinetic ambient energy is being converted
> to potential energy in the battery and the net temperature
> drops.
>
> > And pulling useful energy from a single thermal pool is
> > absolutely a violation of the second law of
> > thermodynamics.
>
> ... Sorry, I become unglued when discussing the 2nd
> law. :-( Wikipedia has a nice quote from Physicists
> P.W. Bridgman, (1941) "There are almost as many
> formulations of the second law as there have been
> discussions of it."
Whatever -- I didn't say it couldn't be done. I just
observed that it violates the second law.
Certainly that last bit is true, claims that the second law
is too vague to mean anything notwithstanding. Gibbs free
energy is reasonably well defined and the second law says
that in a closed system, you can't increase it; this scheme
increases it.
In fact, IIRC a diode and noisy resistor in parallel is a
standard example in EE classes in college. Since I never
took such classes -- just heard about them from friends who
were in the EE program -- I don't know what the "textbook
explanation" of why it "can't work" happens to be.
> It depends how rigid you adhere to the 2nd law. It's a
> "works most of the time" law. The law should only apply
> to random unintelligence such as natural thermal
> occurrences, etc. By means of intelligence the 2nd law is
> breakable-- for example, the design of LED's.
AFAIK LEDs are not normally considered to break the second
law.
As energy runs downhill over the junction, carried by an
electron flow, some of it is converted to light. If it
didn't come out as light it would come out as heat. If it
didn't have a voltage gradient to run down nothing would
happen (or so goes the conventional wisdom).
If, instead of an LED, you put a normal diode in parallel with
a resistor, the diode should get warmer and the resistor
cooler, as noise from the resistor is rectified and the
electrons give up the 0.6 volts of junction energy when they
fall down across the junction. LEDs have a somewhat higher
junction voltage than a common P/N silicon diode --
typically a couple volts IIRC rather than 0.6 volts -- but
it's the same deal: noise in the resistor carries energy
from the resistor to the diode.
In fact, you might do better to use Schottky diodes; they
have a lower forward voltage drop and should be able to
rectify smaller levels of noise energy. With an LED with
its high forward drop, very few of the noise crests are
going to make it "over the wall", or so I would expect.
> Although that's not to suggest there are no natural 2nd
> law violations. No offense intended to anyone, but it's
> the most ridiculous and blind sighted thought to believe
> one cannot extract usable energy from moving and vibrating
> objects regardless if they are planets, basketballs,
> molecules, or even atoms.
>
> > > All LED's dissipate energy below the forward oltage,
> > > as there's no lower limit. Furthermore, there's no
> > > upper rest voltage limit to *real* noise. The
> > > photon energy emitted from he LED comes from the
> > > resistors ambient energy. If you focus the hotons
> > > on a solar cell, and connect the solar cell to a
> > > battery then you re essentially converting the
> > > kinetic energy in ambient emperature to potential
> > > energy in the battery, which does *indeed* drop he
> > > overall temperature with in the closed system. :-)
> >
> > OK, you're right about that. Until the energy in he
> > battery is used again, the average temperature of the
> > system will e lower. You're converting thermal energy
> > to chemical energy.
> In the case of most batteries, sure, although it's still
> PE. In the case of say a capacitor, which is essentially
> a battery, it's not chemical.
True enough. And if you just wire a noisy resistor in a
loop with a diode and a capacitor the capacitor should
eventually get charged up, or so one might think.
