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Comment: OK let's see, (Score 2) 327

our "free" markets are a shining example to the rest of the world- at least the part that the mortgage banks didn't steal from just prior to the housing collapse, our "free and democratic" elections are a shining example- offices are sold to the highest bidder and then election boundaries are jiggered by the party in power, our system of taxation is fair to all, but especially fair to people and corporations with the resources to hide money offshore, the same people who were claiming Saddam Hussein had WMDs are at it again, trying to get us into a war in Syria, our government sends people off to war to fight for the oil companies - oops, I mean freedom- and when they come back injured can't be bothered to take care of them, and like the idiots we are, we keep volunteering for military service, our healthcare "system" is a joke, and now our "free and open" internet turns out to be a means of massive government surveillance- but it's OK- it's for our own good.

And dopes in the US wonder why the rest of the world doesn't just follow our examples...

Comment: There is more bullshit involved in marketing wine (Score 1) 206

than any other commodity, except maybe audio equipment. Anything that cuts through some of the bullshit is welcome.

Of course, those of you with sophisticated palates who enjoy fine wines will have no use for such a mechanistic means of judgment and will disregard it. However, this development should please you as it provides yet another reason to turn your noses up at the unwashed masses who would be so ignorant as to select a wine based on chemical composition.

Comment: Get a used Roomba robotic vacuum cleaner (Score 1) 166

by mark_reh (#43899953) Attached to: Ask Slashdot: How To Begin Simple Robotics As a Hobby?

from Craig's list or your local goodwill/SVdP store and then go here: http://www.instructables.com/id/Hacking-Your-iRobot/ and many other sites on the web that deal with modifying Roombas. Most of the mechanical stuff is taken care of for you so you can concentrate on programming and adding/reading/using sensors and actuators.

Comment: Re:Bullshit! (Score 1) 376

by mark_reh (#43882859) Attached to: Too Many Smart People Chasing Too Many Dumb Ideas?

OK, I see you're a literalist. Let me put it this way: if you're trying to sell a product or service that costs $10, how much effort will it take to get $10 from a poor person who has to work for a couple hours to earn $10 (in the US anyway) vs getting $10 from someone who makes $10 in a couple minutes? It is harder to get a poor person to part with their money than a relatively rich person.

Slick Willie Sutton summed it up nicely when someone asked why he robbed banks: "that's where the money is".
(yes, I know, you take things literally and there is some disagreement about the origin of that quote...)

Comment: Duh! The main reason few are focused on helping (Score 2, Insightful) 376

by mark_reh (#43882589) Attached to: Too Many Smart People Chasing Too Many Dumb Ideas?

the less fortunate is that you can't make any money off of them. Guys like Bill Gates, with all the money in the world, can afford to focus on that portion of the human population because they don't have to make money off of them. The rest of us have to eat and feed our families and send our kids to school.

Comment: The reason that supercapacitors are not already (Score 1) 295

by mark_reh (#43767305) Attached to: Charge Your Cellphone In 20 Seconds (Eventually)

powering our cell phones is that in order to get the super high capacitance the "plates" of the capacitor must be microscopically close together which limits the voltage at which they can operate to typically 2.5V. The next problem is that you can't use all the energy stored because you need a DC input converter circuit to regulate (and step up) the ever falling voltage as the capacitor discharges and those circuits require some minimal level of input, maybe a few hundred millivolts, below which they cease to function. While the total energy storage capacity of the capacitor is great, you can't use all of it, so if you compare the usable energy storage of a supercapacitor to a similar sized Li-Ion battery, the battery wins.

Batteries, on the other hand, provide adequate current via a chemical reaction that maintains a more or less constant, higher voltage output until the battery is almost completely discharged, at which point the voltage drops precipitously. This works well with the circuits in a cell phone.

If this student managed to make a supercapacitor that operates at 5V or higher in the same physical volume as current technolofy 2.5V parts, or solved some other problem related to the technology- maybe a voltage converter circuit that efficiently delivers a usable current from the capacitor at 20 mV input, then she made quite a breakthrough.

I think fuel cells are a more promising technology for cell phone battery replacement than supercapacitors. You can have your "instant" charge by squirting in some butane or whatever fuel it uses, but then I'm not sure if they can pack the same energy density as li-ion cells. The other potential game changer for phones, computers, and cars is lithium-air batteries which have much higher energy densities that li-ion cells.

The clothes have no emperor. -- C.A.R. Hoare, commenting on ADA.

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