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Comment Re:From TFA: bit-exact or not? (Score 1) 160

There used to be a web page called "Your Eyes Suck at Blue". You might find it on the Wayback machine.

You can tell the luminance of each individual channel more precisely than you can perceive differences in mixed color. This is due to the difference between rod and cone cells. Your perception of the color gamut is, sorry, imprecise. I'm sure that you really can't discriminate 256 bits of blue in the presence of other, varying, colors.

Comment Re:From TFA: bit-exact or not? (Score 5, Insightful) 160

Rather than abuse every commenter who has not joined your specialty on Slashdot, please take the source and write about what you find.

Given that CPU and memory get less expensive over time, it is no surprise that algorithms work practically today that would not have when various standards groups started meeting. Ultimately, someone like you can state what the trade-offs are in clear English, and indeed whether they work at all, which is more productive than trading naah-naahs.

Comment That would be penny wise and pound foolish (Score 5, Insightful) 366

If this is actually a credible report, then the U.S. government needs to stop funding the rebuilding/construction of areas that are CURRENTLY under sea level like New Orleans and the dikes and berms around it. No more federal funds of any kind for regions currently under water!

By that logic we should just write off large swathes of the Netherlands. Dykes and berms work just fine, and we have the engineering means to keep portions of land we consider valuable dry even if the waters rise 10 or 20 feet. New Orleans would fit in this category in my opinion. It is a unique part of American heritage and a cultural gem (one of not-so-many the US possesses), well worth the investment of Federal dollars to keep around.

Not to mention that it is by far less expensive to retain land by shoring up or building new dykes, than it is to reclaim land already submerged. Not as cheap as ditching it of course, but in places where it is worthwhile (New York City, Hoboken, New Orleans, Holland, and various other places) it is much smarter to keep existing places dry than leave them to be inundated and then realize our mistake later and either lose them forever, or pay even more to reclaim them.

Comment Wait until the terrorists get hold of this tech. (Score 1) 179

It would be useful both for disrupting "business as usual" that they don't like and herding crowds into range of a more lethal device.

I can imagine several of them being flown into, and triggered in, sessions of a legislature that authorized them. But I somehow doubt that would actually happen, even in tyrannical foreign regimes. If the legislature is giving the tyrant and his security forces what they want, why use it on them? And if the opposition can get them in there with "less than lethal" weapons packages, "more than lethal" would be even easier, and have a more lasting effect on future legislation. (Realpolitik is a bitch.)

Comment Re:Not that far when you think "voltage" (Score 1) 96

It looks to me like the field-reversed configuration does the same sort of thing, compressing the plasma in a way that maps the electric fields (both directly applied and created by the magnetic field change) into particle acceleration during the compression, and thus into temperature.

Then again, this machine also builds TWO plasma donuts and crashes them into each other (where they combine) at "a million kph" - no doubt also by electrical-field acceleration. Another opportunity to scale up the heating by scaling up the voltage (or its magnetic equivalent).

Comment Re:Not that far when you think "voltage" (Score 4, Informative) 96

First off, there is a big difference between something like a fusor which is basically accelerating a beam of particles to some amount of eV that is similar to the applied voltage, and something going for a thermal distribution with same amount of eV spread out with a tail of the distribution that does most of the reactions

Fusors and polywells aren't about beams. They're about assembling a plasma object that is already hot, by compressing it during the assembly.

The fusor does this by having two concentric spherical electrodes, the inner one skeletal, with a large voltage between them. Positive ions fall inward essentially radially, accelerated by the field until they pass through the inner electrode, and fly on orbits that pass through the center of the spheres. They "pile up" as they pass through the center, thus mapping the acceleration voltage directly into compression temperature as well as high average density. (Unfortunately a small number of ions hit the inner electrode on each pass and are lost. So though it's a great fusion-neutron source breakeven isn't in the cards.)

The polywell does the same thing to electrons - with the added tweak that the inner electrode contains a set of magnet coils that get the electrons to travel in paths that mostly miss the electrode. As they orbit through the center the high average density there is effectively a third high-voltage negative electrode, producing a radial electric field between this "virtual electrode" at the center and the inner physical electrode. Positive ions fall in toward the virtual electrode (nearly neutralizing it) and again you get a high density and inward velocity, mapping the electric field into temperature.

It looks to me like the field-reversed configuration does the same sort of thing, compressing the plasma in a way that maps the electric fields (both directly applied and created by the magnetic field change) into particle acceleration during the compression, and thus into temperature. Unlike Tokamaks and similar devices, you don't "put a low-density plasma in a (magnetic) can" and then have to heat it up. You heat it by squeezing it when you initially assemble it, accelerating the particles toward each other, and that maps your compression forces into temperature - which turns a moderately high voltage into a relative particle speed that has a hysterically high number when expressed as temperature (at the same time that you're also raising the density) Hold it together long enough, don't let it interact with solid matter to cool it, and you've got the holy trinity for fusion. No ongoing heating required.

Also, you don't just easily scale up voltage past several 10s of kV, as you start reaching a lot of material limits for break down (even in vacuum), and engineering gets more difficult for 100+ kV in a small space.

  - Expand the space (which also gives you more plasma volume and thus more power output at a given density), and
  - Keep anything but ionized, under-control, gasses out of the working region

100+ kV is not all THAT difficult to handle in an industrial-sized volume. Air at atmospheric pressure has a breakdown of about 40,000 v/in (though this drops as pressure is lowered). A clean vacuum (except for the working plasma itself) isn't too tough either: Television picture tubes worked fine with no arc-over at acceleration voltages of about a kilovolt per diagonal inch (i.e. 25 kV for a 25" picture tube) and far more than a kV per inch inside the tube. A machine twenty feet across would have substantially lower electric field at 200 kV.

Which is not to say that there won't be issues trying to scale this. But I wouldn't expect anything insurmountable from what you've alluded to here.

Comment Re:This looks familiar from 37 years ago (Score 1) 96

As far as I can tell from the article this looks familiar from 37 years ago.

As I read the article in your (corrected) link, the project 37 years ago got the plasmid to form and last for 5 MICROseconds, then ran out of money and got mothballed for a couple decades and had their equipment reactivated in a (never heard from again) lab around the turn of the millenium.

Maybe if they'd had funding to keep going, and figured out what these guys did (or something else) to keep things stable for three orders of magnitude more time and beyond, we'd have fusion power by now. It's been the perpetual 30 years and then some. B-b

Comment Not that far when you think "voltage" (Score 3, Interesting) 96

to do what they want means they need 3 billion degrees to ignite and they are at 10 million

Each electronvolt is equivalent to 11,500 degrees Kelvin. So they need to run at about 200 kV instead of 870V. Piece of cake.

This is whyFarnsworth fusors are tabletop "gassy vacuum tubes" and the issues with polywell machines are things like geometry and electromagnet wiring rather than applying excitation energy.

Kelvin is the same size degree as celsius but offset by a couple hundred degrees so zero is absolute zero. At 3 billion degrees the difference between water freezing and absolute zero is noise. If TFA's degrees are fahrenheit the offset is still noise but scale the voltage back to 144 kV.

Comment Start expecting it in five. (Score 5, Insightful) 96

We have been expecting cold fusion in 30 years for about 50 years now.

Actually it's HOT fusion we've been expecting in 30 years for a long time. (Cold fusion, other than the apparently useless muon-catalyzed form, was a "maybe it's possible - no apparently not" flash in the pan)

But THIS one is big: It's not that it lasted 5 ms. It's that it lasted 5 ms WITHOUT DECAYING. That almost certainly means that:
  - either they've completely solved the instability issues and it's just a matter of scaling up (and using superconductors or adequate cooling so they can run continuously),
  - or they've solved them well enough to hold the plasma ball together until it's paid for itself several times over, then make another one (repeat continuously) and it's just a matter of scaling up (and using superconductors or adequate cooling so they can putt-putt-putt continuously).

Now if other problem show up (but aren't a fundamental refutation of this indication of stability) we might end up expecting fusion in five years for another fifteen or so. But I think the "30 years forever" thing has just been evicted from fusion and is living with its brother in copyright extension.

Comment Re:"Smokers" (Score 1) 102

Bird deaths caused by wind and solar are minimal compared to the bird deaths caused by traditional fossil fueled infrastructure.


I was already aware that wind power, despite the "bird kill" hype, was not all that large a problem. (I'd also thought it might be overestimated, too: Birds die where they live, and wind farms are good hunting sites for raptors and feeding sites for other birds.) It's good to have references to studies actually comparing it to other sources of power - and the comparison to power TRANSMISSION is a really big deal - and might swamp any bird-death issues with heliostats.

Unfortunately, that article seems to be addressing only wind power and not large central-focus collection systems.

I'd be happy to see a study estimating the magnitude of the problem (and whether it IS a substantial problem), and will be overjoyed if the problem is trivial, or at least no more than on a par with "traditional" power sources.

Meanwhile I just wanted to caution that there MAY BE a problem, which needs to be examined.

Comment Re:Autism claims appear to have been lawsuit fraud (Score 1) 94

Why people keep repeating that nonsense is beyond me.

Because rumor spreads fast, with screaming headlines, and retractions spread slower, are low-key, and often aren't believed or discounted.

A lot of people don't trust the "medical establishment" and won't believe "its pronouncements". If they've even heard that this is a fraud, they'll believe that the debunking research was comparable to the stuff the tobacco companies put out for decades.

Unfortunately, this has resulted in substantial numbers of uninoculated children. (The article I cited claims it's as high as 20% for measles innoculations in some areas.) This has lead to the resurgence of dangerous childhood diseases. (What counts for disease spread is not the percentage of uninoculated hosts, but the absolute density of susceptible individuals.)

Now you might think of it as evolution in action, with the children of those susceptible to the fraud being selectively infected, with a non-trivial number of them being crippled and/or killed. Unfortunately, immunizations are not 100% effective, by a long shot. If there is an infection hot-spot or an epidemic, some of the kids who got their shots (along with the immune-compromised) will still get the disease, and take damage.

Part of the drill is to produce "herd immunity" - reducing "k" in the exponential function to below one, so hot-spots of infection tie out, rather than explode into a calamity. The large number of people who don't let their kids be immunized have now prevented this, and (apparently thanks to a few starter cases that came in during the border crisis) we're now seeing a resurgence of measles and several other diseases.

Comment Autism claims appear to have been lawsuit fraud (Score 4, Informative) 94

Sure, having universal flu protection would be nice. But I don't know how I would feel about having THAT many autisms injected into me.

Ha ha. But seriously... As I understand it:

A large number of researchers (many funded by sources with no connection to drug companies) attempted to reproduce the research claiming to find a link between vaccinations and autism. They were not able to do so.

It was discovered that the original researcher who claimed the connection was funded by a consortium of trial lawyers.

The journal (BMJ), in which the original research was published, retracted it, investigated the study, and concluded that the author had "misrepresented or altered" the medical histories of the 12 subjects in question, in what appears to be a deliberate hoax.

More in this CNN article.

Prototype designs always work. -- Don Vonada