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Comment: Really silly (Score 2) 413

Now only is 192 kHz/24 bit silly in general, it's even more silly for a portable music player, that's usually used in places with a higher background noise than your living room. Listening to music above 100 dB SPL in a cafe with noise at 50 dB SPL means you only need an SNR of 50 dB, just slightly more than 8 bits.

Comment: Re:So what's the mass then? (Score 1) 59

by jmv (#46299177) Attached to: Scientists Calculate Most Precise Measurement of Electron's Mass

Consider this, if an electron were to transition from "really far" down to the first energy level of the hydrogen atom, then the photon emitted would have an energy of 13.6 eV, and the mass of the resulting hydrogen atom would be 13.6 eV less than the sum of the original masses.

Comment: Re:So what's the mass then? (Score 4, Informative) 59

by jmv (#46292821) Attached to: Scientists Calculate Most Precise Measurement of Electron's Mass

Actually, the mass of a hydrogen atom isn't equal to the sum mass of the proton and that of the electron. There's a 13.6 eV binding energy (good 'ol E-mc^2) that needs to be taken into account. Considering that the 511 eV rest mass of the electron and the fact that we're taking about measurements that are supposed to be accurate to less than 1 part per billion, then the binding energy is pretty significant. I suspect there are other effects that also need to be taken into account.

Comment: Re:Except for the fact that... (Score 1) 114

by jmv (#46121931) Attached to: Engineers Invent Acoustic Equivalent of One-Way Glass

More generally, any device that lets energy (light, sound, heat, ...) only flow in one direction has to spend energy to avoid violating the laws of thermodynamics. That's true of this device just like for a heat pump. You could probably also create a real one-way mirror, but again it could not be a passive device and would require energy to operate.

Comment: Re:Thermodynamics (Score 1) 312

by jmv (#45648037) Attached to: Life Could Have Evolved 15 Million Years After the Big Bang, Says Cosmologist

Actually, I thought the whole idea of the "Goldilocks universe" was that life could develop anywhere without the need for a star at the right distance (otherwise there's no advantage). The problem then is exactly as you pointed out. There's no way for life to extract energy, no matter what the temperature is, because everything is at thermal equilibrium. The only way to get energy is through a star. And if you have a star, then having the microwave background doesn't help and is just likely to just make your planet too hot.

Comment: Re:This is frightening (Score 1) 312

by jmv (#45648003) Attached to: Life Could Have Evolved 15 Million Years After the Big Bang, Says Cosmologist

do you mean that they wipe themselves out using nuclear weapons or do you mean something else?

I use "nuclear fission" as a sort of "technological landmark". But I was thinking both in terms of "actively" wiping itself out (i.e. wars of some kind) and "passively" destroying itself just like we're currently doing by polluting everything and depleting resources at an insane rate.

Comment: Re:This is frightening (Score 1) 312

by jmv (#45647669) Attached to: Life Could Have Evolved 15 Million Years After the Big Bang, Says Cosmologist

A few things to consider here. First, I don't see a way any of that life at T+15M would have become intelligent before the background got too cold. Second, we do not know if it's even possible for life to actually colonize other star systems and even if it is, what's the percentage of intelligent civilizations that achieve that. Of course, the really interesting question is how long an intelligent civilization can last before either destroying itself or depleting all its resources. Personally, I would suspect the half-life of a civilization is less than 1000 years after discovery of nuclear fission.

Comment: Re:before anybody pops pills (Score 1) 670

by jmv (#45631383) Attached to: Diet Drugs Work: Why Won't Doctors Prescribe Them?

Most of these diets just make eating inconvenient in some way. Either because there's half the stuff you can't eat, or because you can't eat X with Y, ... I'm sure the "eat anything you like as long as you're up side down" diet would work too. The problem is that you can't keep doing it for years.

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