Re: Want to prove E=mc²? University labs should try this!

On Tue, 19 Nov 2024 18:04:04 +0000, gharnagel wrote:

On Tue, 19 Nov 2024 16:41:15 +0000, ProkaryoticCaspaseHomolog wrote:

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On Tue, 19 Nov 2024 16:06:10 +0000, gharnagel wrote:

Exactly.  I didn't realize how complex the LIGO optical train was,
nor the "power recycling" concept:
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https://arxiv.org/pdf/1105.0305
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I'm still quite certain, however, that when you throw 750 kW
into a 10 cm ball with walls that are 0.999999 reflective,
the losses will, as you say, cause serious problems.
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For one, that's a loss of 0.75 W/bounce, and bounces will happen
c/0.1 = 3x10^9 times per second -- IF one could supply the power
to keep it operating.  In which case, the whole thing would make
a beautiful incendiary display.  With only 5 W input to drive
the system, however, it would heat up to about 300 C, according
to my radiation slide rule.

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No. Your loss per bounce calculation is off.
Think conservation of energy.

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Prok, Prok, Prok!  Did you not read the above sentence that begins
with "-- IF"?
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At steady state, 5 W input equals 5 W output, which is not
incendiary.
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It _is_ warm enough, however, that the whole shebang needs to be
run in ultra-high vacuum to avoid convective effects.

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The 300 degree temperature rise I calculated was under such
condition, based upon 300 cm^2 of surface area radiating with
no convection.
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The point is, though, that with 3x10^9 bounces/second, it would
take much less than a second to whittle 5 W down to nothing:
1E5 bounces: 0.905Po
1E6 bounces: 0.368Po
2E6 bounces: 0.135Po
3E6 bounces: 0.050Po (in the first msec)
4E6 bounces: 0.018Po

5 watts is approximately the energy output of an old-style
incandescent nightlight run off a Powerstat variable transformer
set to 100 volts. Even if I plugged the nightlight into 120 volt
mains, I can still hold the nightlight in my hand without it being
too uncomfortable. How did you calculate 300 C? Are you sure you
didn't mean 300 K?
Your bounce attenuation calculation is a bit off.