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Comment Re:It could be worse (Score 1) 247


Simple fix: don't ever set your voicemail password.

I went over 10 years without enabling my dreaded voicemail, some people complained but I never budged. My current Director told me to set it up about six months ago. I did and used a random integer set from random.org as the password.

I can honestly say "I forgot my voicemail password" and let the thing fill up.

Comment silentpcreview.com (Score 1) 720

silentpcreview.com is a web site dedicated to quiet and silent computing, with extensive reviews and forums. They have very recently posted a sample build of a quiet gaming PC.

You can take that as a base and adjust according to taste. (For example, I'm more obsessed by quiet and less by frames per second, so my gaming PC has a single GTX760Ti GPU.) If you have questions, take them to the forums.

Comment Re:Some details from the paper (Score 1) 145

Emissivity and absorptivity are the same thing. One way to look at this is the time-reversibility of physics on a microscopic scale, another is that something that was really absorptive but not emissive or vice-versa would give you a really easy way to beat the 2nd law of thermodynamics. Emissivity can, however, vary with wavelength, which is the trick here.

Comment Re:Some details from the paper (Score 2) 145

Not really - the 40Wm^2 of cooling is only useful if it is in contact with something that can move that cold to where it is needed. (Hand-wavy explanation, really we are shifting heat to the film.) It also needs to see mostly sky, which windows usually don't.
You'd put it on your roof and run water behind it to shift the heat around.

Comment Re:the law (Score 2) 145

Would you care to be more specific? My explanation is pop-science simplified, but I don't see an error in it.

More detailed explanation:
In the 8-13 micron (wavelength) window, atmospheric transmittance averages about 80% (estimated from a plot in the paper.) So the energy received is about 20% of what you'd get from a black body at atmospheric temperature (plus 80% of what you'd get from space, which is negligible in comparison.) So the brightness temperature at 8-13 microns is lower than ground level atmospheric temperature. How much lower depends on the average temperature of the atmosphere along the line of sight, and where 8-13 microns falls on the black body curve at that temperature (even this is oversimplifying) and I can't be bothered figuring that out. However, if we can reflect/insulate all energy except 8-13 micron radiation, then our thermal equilibrium temperature will be the brightness temperature at 8-13 microns to which we are exposed. This is, as noted, less than atmospheric temperature at ground level.

Comment Re:the law (Score 1) 145

It is possible, because the environment is not in thermal equilibrium. In particular, the film 'sees' colder temperatures at some wavelengths than at others.

Did you not think before you posted that just maybe a bunch of scientists publishing in this area and the reviewers for one of the worlds top scientific journals might possibly have a better understanding of thermodynamics than you do?

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