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Comment Not illegal, but perhaps detrimental (Score 1) 223

The "border search exception" has been well vetted legally: http://en.wikipedia.org/wiki/Border_search_exception (Note that the ACLU's implication that this exception extends to 100 miles from the border is incorrect: http://news.yahoo.com/does-constitution-free-zone-really-exist-america-195813138.html) But I would guess this search exercise does more harm than good. It can be easily circumvented (encrypted data over networks), so the question is empirical: Have criminals adapted to the law yet, in which case it becomes useless, and detrimental to the innocent (mostly for psychological reasons, but also for practical reasons if the government were to abuse the info it obtains).

Comment Been done in superconductors (Score 4, Informative) 265

Similarly macroscopic quantum states have been achieved in superconductors. So the significance of this work is that macroscopic superposition is accomplished with a mechanical system, not an electronic one. The Nature article that the BBC is referring to: http://www.nature.com/nature/journal/vaop/ncurrent/full/nature08967.html The BBC removed the scale bar, which shows that the resonator is about 70 microns long, with an "active region" 40 microns long. But the resonant frequency is still up in the GHz, so they only have to cool to 0.1K, which is not so hard these days.

Comment 80 watts for 80K (Score 3, Interesting) 124

Yes, you can insulate a device, so that in almost all cases (definitely in the case of a fast-switching transistor) the main heat source is the device itself.

Here's a commercial box that cools a 2-inch wafer of high-temperature superconductor to around 80K. This box uses 80 watts including whatever other signal processing stuff is in there.

Another source (Cryogenics 42 (2002) 705-718) says that 1W of cooling power at 4K will cost you 5kW of input power using a straightforward helium compressor. This scales as 1/temperature^2 for higher temperatures, but for lower temperatures you'd switch to a different type of refrigerator.

0.3K refrigerators using helium 3 would not use more than 10kW, but this is already too much for most applications.

So the practical significance of this research is that it may be reproduced with higher temperature materials, not that we will build THz DSPs at 0.3K.

Games

Professor, ECA Dispute Video Game Aggression Study 78

Earlier this week, we discussed research which linked aggression in children with video games. The Entertainment Consumer Association responded with a statement criticizing the research, as did Christopher Ferguson, a professor at Texas A&M. PCWorld sat down with Ferguson for a more in-depth discussion of the flaws with the study. In addition to bringing up the correlation vs. causation fallacy, he notes: "Even if you took it at face value, which I don't, video game violence overlaps somewhere between, based on their own statistics, a half a percent to two percent, with a variance in aggression. If you woke up tomorrow and you were half a percent more aggressive than you were today, would you notice that? It's just not much of an effect. If the author said look, there's a little effect here, maybe video games increase aggression a tiny bit, but it's not going to make anyone into a serial murderer, yeah, alright, we may argue a little bit over the methodology, though I'd still say they should've controlled for other stuff. "

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