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Comment: Re:Conveyor belt problem... (Score 1) 60

Why? The only issue is the belt convexity. If the new pulley would pull the belt away from the intermediate pulley if it ran on the outside one can simply switch it to the inside. It cannot be pulled away on both sides. The point is that the run of the belt can be made topologically equivalent to a line drawn between all of the pulley centers in the configuration generated by a distance-ordered recursion from any starting point. All one has to prove is that for a trivial set of local geometries, one can always find a side of the pulley that maintains tension upon addition. The diameter of the pulley ends up being functionally irrelevant.

Perhaps I'm not being sufficiently clear. Take a configuration of N points/pulleys presumed to be spanned by a belt that was systematically structured by starting on the pulley closest to the center of the bounding circle. Add one pulley outside or on the bounding circle of the configuration (one can always reorder the problem to ensure that the N+1 pulley is outside or on this bounding circle). Pick the two (most distant from the center, if there are more than two) pulleys that bracket the new pulley inside rays drawn from the center of the circle through the pulley center. One can always loop in the new pulley in between the two thus selected, and one always does so without adding a loop that "occludes" a future distance-ordered addition. The insistence of maintaining rank order and radially ordered convexity as one proceeds suffices to ensure that one can always add a pulley to a suitably developed set of N pulleys.

Or, maybe I'm missing something, but when I draw sequences of points in this way there aren't really a lot of cases to consider on the addition. The convexity requirement eliminates, I think, your assertion of "distant points" for the nearest neighbors. They cannot be more distant than the diameter of the bounding N circle, and the construction ensures that one does not build a loop that twists around in some snaky way across angles. By posing the solution in this way, I simply avoid having to consider going back to do nonlocal rearrangements of some arbitrary looping selected from the (probably quite large) set of loopings that would work for any set of N pulleys. One really only needs to consider the two bracketing pulleys and the two next neighbors of those pulleys with the comfortable constraint that the next nearest neighbor has a belt that run at an angle of pi or less relative to the exterior of the radius of a/the bracketing pulley in question. Four permutations of possible side swap to consider, done, induction proven.

Comment: Re:So - who's in love with the government again? (Score 1) 356

by hey! (#46796433) Attached to: Beer Price Crisis On the Horizon

I don't know if this is nuts. I'd have to see the full arguments on both sides, and so far what we have to go on is a one-sided summary.

If the *only* effect of the proposed regulation would be to increase beer prices, then sure, I agree with you 100%: government is being stupid. But if there's a good reason for the regulation, then I'd disagree with you.

Reading the article, it seems like the idea that this regulation will cause beer prices to spike dramatically seems a bit alarmist. The regulations would require brewers who send waste to farmers as animal feed to keep records. It seems hard to believe that this would significantly raise the price of beer or whiskey given that alcohol production is already highly regulated. On the other hand, it seems like there is no specific concern related to breweries. They were just caught up in a law that was meant to address animal feed.

If you want an example of a regulation free utopia, look no further than China, where adulteration of the food chain is a common problem. If the choice were a regulatory regime that slightly complicates brewers lives, and a regime that allows melamine and cyanuric acid into human food, I'd live with higher beer prices.

Fortunately, we don't have to live with either extreme. We can regulate food adulteration and write exceptions into the regulations for situations that pose little risk. Since presumably the ingredients used in brewing are regulated to be safe for human consumption, the byproducts of brewing are likely to pose no risk in the human food chain.

Comment: Re:Ivy League Schools (Score 2, Funny) 98

by ShieldW0lf (#46792269) Attached to: Minerva CEO Details His High-Tech Plan To Disrupt Universities

The Ivy League was basically a formal gentleman's agreement (you know, back from the good old days where they banned women and blacks from campus and had strict quotas on Jews) that they would mutually agree to be terrible at sports in order to maintain high academic standards.

Everyone who attends an Ivy League school to play sports is someone who would have been a serious consideration for admission without their athletic ability.

Of course they're going to be terrible at sports. They don't have any black people on their team!

Comment: Re:I hate personal definitions (Score 1) 173

by ShieldW0lf (#46792191) Attached to: 'Thermoelectrics' Could One Day Power Cars

Dude, you're the worst sort of person to argue with. You've demonstrated poor reading comprehension and a willingness to hand-wave away the distinction between similar words if you don't think they are relevant to you or serve your position. You seriously make me wonder why I even bother trying to express myself precisely

I never used the word explosion. I used the word detonation. I contrasted it with the deflagration that occurs in internal combustion engines like we see in cars.

A detonation occurs when the shock wave expanding out of the reaction zone compresses the unburnt fuel ahead of the wave, and the compressive heating raises the temperature in the unburnt fuel above it's autoignition temperature.

10 m/s is well below the threshold. Try 2000 m/s.

Detonation produces a more efficient combustion than deflagration, gives higher yields, and generates more kinetic force relative to the thermal energy released. It's a whole different kettle of fish.

Comment: Re:do they have a progressive view? (Score 0) 326

by Zordak (#46791393) Attached to: Detroit: America's Next Tech Boomtown
I don't know what you think you're responding to, but that I do not favor Democrats most certainly does not mean I'm a Republican. The GOP is only marginally more conservative than the DNC, and only on some issues. They are all the party of big government and statism, and both parties are rotting from within from graft and corruption. But the trope about Texas being a haven of racist, ignorant rednecks is most certainly a Democrat thing that the OP obviously bought. (It's amusing to watch, considering how intensely racists so many Democrats are.) It's bad enough to have to deal with Rick Perry-style crony Republicanism here in Texas. A bunchy of left-wing Democrats who want even bigger government would only make things worse, so the OP is free to stay wherever he is. He won't be missed.

Comment: Re:LaserJet II and LaserJet 3 (Score 1) 672

by hey! (#46791117) Attached to: Ask Slashdot: What Tech Products Were Built To Last?

The most wear sensitive part of a laser printer is the copy drum. If I recall correctly the old LaserJets had the drum integrated with the toner cartidge, so you replace to most quickly wearing part of the printer four or five thousand pages. It's no wonder they lasted so long. The mechanical parts that move the paper through the printer are pretty robust, so I wouldn't be surprised if the printers go until the capacitors in the electronics dry up, or the internal power connectors go bad.

Comment: Re:A bit of background for slashdotters (Score 4, Informative) 339

by hey! (#46790777) Attached to: VA Supreme Court: Michael Mann Needn't Turn Over All His Email

This isn't a case "insisted upon by a conservative group". This is Mann suing a journalist for libel, and the journalist requesting info from the university under FOIA to prove his case.

That would be interesting, if it were true. Here's what TFA says:

The ruling is the latest turn in the FOIA request filed in 2011 by Del. Robert Marshall (R-Prince William) and the American Tradition Institute to obtain research and e-mails of former U-Va. professor Michael Mann.

"Del." I assume is short for "delegate". According to their website, the American Tradition Institute's tag line is "Free Market Environmentalism through *Litigation*" I assuming this means they aren't pals with Greenpeace, or even The Sierra Club, any more than the National Socialists in Germany were pals with the socialist Republicans in 1930s Spain.

Comment: Re:Why do these people always have something to hi (Score 4, Insightful) 339

by hey! (#46790657) Attached to: VA Supreme Court: Michael Mann Needn't Turn Over All His Email

Depends on what you consider "hiding the research". A fishing expedition through a scientist's personal correspondence is an invitation to judge his work on *political* grounds.

In science your personal beliefs, relationships, and biography are irrelevant. There are evangelical Christian climate scientists who believe climate won't change because that would contradict God's will as expressed in the Bible. These scientists may be regarded as religious crackpots by their peers, but that hasn't prevented them from publishing in the same peer-reviewed journals as everyone else. Since their papers invariably are climate-change skeptic, clearly they are publishing work which supports their religious beliefs. But their motivations don't matter. What matters is in their scientific publications.

In 1988, Gary Hart's presidential bid and political career were ruined when he was photographed cavorting on a yacht named "Monkey Business" with a woman that wasn't his wife. Now I didn't care how many bimbos he was boinking, but a lot of people *did*, which made it a political issue (albeit a stupid one in my opinion). Do we really want to use the coercive power of the state to dig through the private lives of controversial scientists?

It's a pretense that that would serve any scientific purpose. Maybe Mann is intent on overthrowing capitalism and creating a socialist utopia. That would be relevant if he were running for dogcatcher, but it's irrelevant to what's in his scientific papers. Scientists publish papers all the time with ulterior motives, not the least of which is that they're being paid to do research that makes corporate sponsors happy. As long as what's in the paper passes muster, it's still science.

Comment: Re:authenticity (Score 1) 55

by hey! (#46789973) Attached to: Lying Eyes: Cyborg Glasses Simulate Eye Expressions

What about acting? Or fiction? These are artificial experiences that evoke real emotional responses. Once the right buttons in your brain are pushed, most of your brain can't tell the difference between what is real and what is synthetic.

Granted, authenticity in human interactions is important, but it's overrated. Fake engagement often is a perfectly acceptable substitute. Situations where people put considerable effort into *seeming* pleasant usually *are* more pleasant than they would be if everyone felt free to paste their indifference to you right on their faces.

So this is a very interesting technology. What's disturbing about it isn't that people might be fooled into thinking the user is truly interested; it's that the user himself no longer puts any effort into creating that illusion. What if that effort is in itself something important? What if fake engagement is often the prelude to real engagement? Maybe you have to start with polite interest and work your way up to the real thing; I suspect the dumber parts of your brain can't tell the difference. If that's true, taking the user's brain out of the interaction means that interaction will automatically be trapped on a superficial level. This already happens in bureaucratic situations where employees are reduce to rules-following automatons. Take the brain out of the equation and indifference follows.

I suspect that the researchers are well aware of these issues; I believe that I discern a certain deadpan, ironic puckishness on their part. People who truly view engagement with other people as an unwelcome burden don't work on technologies that mediate between people.

Comment: Re:do they have a progressive view? (Score 0) 326

by Zordak (#46788867) Attached to: Detroit: America's Next Tech Boomtown

I would die first before moving to texas. most of my friend also feel the same.

That's fine with us. We'd just as soon you not come.

the outright racism and bible-belt feel just is not compatible with many techies' view of what a good living area should offer.

I like how you gobble up tropes fed to you by your Democratic overlords, and then accuse others of bigotry. It's cute.

Comment: Conveyor belt problem... (Score 1) 60

Interesting article, but I don't understand why the conveyor belt problem (as described) is unsolved. Start with one pulley. Obviously a band around it works. Assume a solution exists for some finite number of pulleys, N. Since the support of the pulley locations is compact, one can always and uniquely determine the exterior of the spanning belt. Place an additional pulley exterior to this belt. There are only three topologically relevant cases -- (an pair of in the case of more than two of) the "nearest neighbor" exterior pulleys carry a belt that is "convex" (outside both), "concave" (inside both), or "mixed" (inside one, outside the other). In all three cases it can be shown that one can add the pulley and still satisfy the conditions of the problem. Hence one has 1, N and N+1, a proof by topological induction. The only additional bit of work on the proof is to note that one can avoid problems with pathological interior loopings (if necessary -- I don't really think that it is) or adding the N+1 pulley INSIDE the belt by simply reordering the inductive process for any given pattern to maintain the belt in a maximally convex state as one proceeds, that is starting with any belt and then adding the pulleys ordered by their distance from the original pulley. Not only is there "a" spanning belt, but there will be in most cases an enormous permutation of spanning belts. As in, all of the permutations one can construct by adding pulleys in circular distance order from any pulley treated as the original pulley until they are all entrained.

Comment: Re:Switching from Mercedes to Tesla after $12K bil (Score 1) 352

by hey! (#46786709) Attached to: Mercedes Pooh-Poohs Tesla, Says It Has "Limited Potential"

First you bought an SUV which only an idiot would buy

My late father-in-law designed inertial guidance systems. He worked on the Apollo program and the Trident missile. And he bought a Mercedes SUV, so it's clear it isn't an SUV that only an idiot would buy. He needed a vehicle that could pull a small boat trailer but had reached an age where he wanted a vehicle that was a little easier on the tuckus than a pickup truck. As such it wasn't a bad choice for him, especially as he had the dough to pay the eye-popping maintenance costs.

I prefer small cars myself, but I've driven a few SUVs and the Mercedes wasn't a bad choice for someone who wanted a truck that drives more or less like a car and doesn't care about the cost.

Life is difficult because it is non-linear.