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## Comment Re:Spiral filter, and a Tardis (Score 4, Informative)122

Frankly, I am still confused as to why it's not (more simply) "circular polarisation" that has been known about since the early days of radio.

Since you linked to Wikipedia, I'm going to assume that Wikipedia didn't do a very good job at explaining the difference. While OAM and circular polarisation both describe some sort of spinning, they correspond to different phenomena. As you may know, electromagnetic waves are oscillations of the electric (and magnetic) field, with the field at each spatial position varying over time. You may also recall from your high school physics class that the electric field at any position is a vector quantity --- it has both a strength and a direction. The polarisation of a electromagnetic field is a description of the direction that the electric field points, and circular polarisation can be roughly seen as the electric field direction rotating as you travel in the direction of propagation. What OAM is describing is the phase relationship between the oscillations of the field at different positions (whether the oscillation at one point is lagged or ahead compared to a different point); it can be roughly thought of as a spinning motion in the transfer of energy inside an electromagnetic field.

For a rather inaccurate, but perhaps intuitive, analogy, try imagining a giant stream of asteroids coming your way in outer space. If the rocks are following a spiral trajectory as they come at you, then this corresponds to the rocks having "orbital angular momentum". If the rocks are themselves spinning, then this corresponds the rocks being "circularly polarised".

## Comment Re:I wonder who they would have blamed (Score 2)586

Well, at the time the air base near the crash site was the home of a B-52 bomber wing. The Strategic Air Command had dispersed its bombers among a bunch of smaller wings scattered across the country; obviously that made the bombers harder to destroy, but it also increased the number of potential strategic targets.

## Comment Re:**what caused the plane to 'drop' the bombs?** (Score 4, Informative)586

Others have already linked to Wikipedia's article about the crash, with one guy saying "sounds like a wing fell off". Reading the article, that seems fairly close to the mark, though not quite right. Here's a summary of what happened to the bomber:

The bomber was on an "airborne alert mission", meaning that it was carrying live nukes while flying on a route and schedule that would make it ready to perform a nuclear attack on the Soviet Union on short notice. (This was part of a program called Operation Chrome Dome.) While it was refueling from a tanker over North Carolina, the tanker crew told the bomber crew that the bomber's right wing was leaking fuel. The bomber broke off from the refueling, informed ground control, and were ordered to fly offshore and hold to burn off most of their fuel load, to reduce the risk of an emergency landing. However, on the way to the holding point, the fuel leak rapidly worsened and became critical, and the plane was then ordered to land immediately. During the descent toward the field, while passing through 10,000 feet altitude, the pilots found they could no longer keep the aircraft under control. The captain ordered the crew to eject; those who survived reported that the plane was still intact when they last saw it. Once the airplane went out of control, it must have gone into an uncontrolled spiral dive, a "tailspin"; that's what frequently happens to a flying airplane when control is lost. Such a dive is often fatal for the airplane long before it reaches the ground; the aerodynamic stresses increase so fast that it breaks up in the air.

From the sound of it, there was some sort of structural failure in the right wing which got rapidly worse. The wing did not actually fall off while the pilots were inside, but the failure became so bad that they couldn't maintain control and were forced to bail out. Unfortunately, even this article puts so much focus on what happened to the nukes that the important question of what caused the bomber accident in the first place is ignored. It would be nice to see what the Air Force's accident report has to say on this.

## Comment This problem may affect more than just Xerox... (Score 4, Informative)163

An earlier blog posting from Kriesel on this issue says that a reader reported similar behavior from a Brother copier:

http://www.dkriesel.com/en/blog/2013/0808_number_mangling_not_a_xerox-only_issue

And one of the comments to that posting says:

I have experimented with the open source jbig2enc library available at http://github.com/agl/jbig2enc, which has a encoding parameter called the “threshold”, described like this:

“sets the fraction of pixels which have to match in order for two symbols to be classed the same. This isn't strictly true, as there are other tests as well, but increasing this will generally increase the number of symbol classes”

The included command tool accepts values for this parameter between 0.4 and 0.9, with 0.85 as the default.

I have found replaced digits in single-page numerical tables encoded with this parameter set as high as 0.82. As with the other examples you have found, the errors are not in any ways obvious to the eye which is, of course, the real problem.

Since JBIG2 has been supported in PDF since 2001, it would be surprising if only Xerox have fallen into this trap.

## Comment Re:You pray if you like (Score 4, Informative)147

Yeah they serve all right.. I'm guessing it's not too terribly dangerous to fly about in an armored helicopter shooting at a bunch of asiatic hillbillies with AK-47s.

With AK-47s, and heavy machine guns, and RPG launchers, and portable surface-to-air missiles and such. Oh, and there's always the risks of bad weather and mechanical failure inherent to helicopter flight. Helicopters are dangerous, period, and the Apaches are far from invulnerable. A number have been lost in Afghanistan and Iraq, and some crews have died.

In general, when a piece of military hardware is heavily protected, it also faces powerful threats that make that protection necessary. Otherwise it'd just be carrying extra dead weight that would better be replaced with useful equipment. The military isn't in the business of building invulnerable weapons or letting soldiers fight in "god mode".

And don't you think their opponents wouldn't love to have the coup of bringing down a royal? Just by being in the combat zone, they put themselves at risk.

## Comment Re:You pray if you like (Score 3, Insightful)147

Because you know if there's ever an imminent threat the members of the Royal Family aren't going to be sat at Buck House with a cuppa tea counting down the seconds...they'll be on their merry way to the other three corners of the globe.

Any member of the Royal Family who did that would rightly be disowned by the rest of the family and the British public, and would probably be looked down upon by much of the rest of the world as well. If the monarch herself did it (and I can't imagine Elizabeth II doing it in a thousand years--she may look like a little granny, but she has far too much backbone for that), she would effectively have abdicated. In the face of such a selfish, craven act, Britain would either find itself a new monarch with more spine, or get rid of the monarchy entirely.

The Royal Family enjoys a lot of privileges, but in the end they exist to serve the British state, as its personification. Their lives are far more controlled and circumscribed than ordinary people.

Just look at the case of Edward VIII to see how Britain might treat a monarch who doesn't take his duty seriously.

## Comment Re:Why is it a sealed criminal complaint? (Score 1)442

Easiest thing is to see what comes up under the "Glenn Greenwald" tag in LGF's archives. (You have to scroll to the bottom repeatedly for the page to load older posts, but there's stuff there going back to 2006.) Johnson has spoken contemptuously of Greenwald as dishonest for years, well before Johnson's falling out with the right. A past incident where Greenwald was supposedly caught "sockpuppeting" as commenters defending him on other blogs certainly didn't help matters. Anyway, I get the feeling that once Johnson makes up his mind like that about someone, there's not much that will change it, regardless of ideology.

## Comment Re:Why is it a sealed criminal complaint? (Score 1)442

If you read LGF's take on it more closely, it seems to have a lot to do with Charles Johnson's relationship with Glenn Greenwald, who's been the main guy other than Snowden himself pushing the Snowden story. Johnson himself has remarked that there are indeed very troubling issues with today's overgrown surveillance apparatus, but he has zero trust for Greenwald.

## Comment Re:10 years later and it still looks the same (Score 1)88

If you actually believe that, try actually comparing his earliest comics with his latest ones, and see if you still think so.

## Comment Re:Is that still being updated? (Score 4, Informative)88

It wasn't the heart operation itself that was the problem, it was the heart condition he needed the operation for. He'd known about it for a long time, but had previously believed it to be harmless. Actually, it had gradually been getting worse. While the long pauses between comics had been bad for quite a while, his situation really became terrible the last half year, because he was *completely* sapped of energy. That's when he saw a doctor and found out the state of things, which led him to have the operation. Sounds like he's been feeling vastly improved.

## Comment Re:Hmm... (Score 1)88

Because kids in their basement have parents paying for their expenses, while Fred has a family to provide for? Did you realize Megatokyo has been his livelihood for years?

## Comment Re:Scope creep (Score 1)326

Or a less well-known but more catastrophic (and less excusable) example, the capsizing in a storm of the British sailing turret ironclad HMS Captain in 1870, in which nearly all aboard her drowned, almost 500 people. Among the victims was her designer, Captain Cowper Coles, an early advocate of warships with turreted main guns. Due to poor supervision during Captain's construction, she was about 10% heavier than planned, and since the design already sat low in the water and had limited stability, the extra weight proved to be her undoing.

## Comment Re:why does your phone need software running on yo (Score 1)519

Yes, this is indeed a known bug which I've encountered myself. In my case, the culprit was some free version of VMware. (Note that VMware is listed among the problematic software on the Apple support page linked to by the parent.) Uninstalling the VMware version solved the problem.

## Comment i386 >> mini :) (Score 1)256

(That ">>" in my subject is a "much greater than", not a right shift. :)

To me, the dividing line between a minicomputer and a microcomputer is the capability for virtual memory. Desktop computers have been architecturally minis since the 68030 and i386.

That's kind of funny to me, since the term "minicomputer" came into vogue in the later 1960s to describe computers like the original PDP-8 (the "Straight 8"). Far from being a virtual memory machine, the PDP-8 was a 12-bit architecture with a minimal instruction set and a very limited address space. Later PDP-8s used bank-switching to expand their addressable memory, as did the later 16-bit PDP-11. In many ways the early minis were architecturally similar to 8-bit and 16-bit microcomputers. Compared to them, the 80386 and 68030 look like ultra-powerful monsters.

## Comment 40 feet *long*, not 40 feet tall (Score 1)69

The story says it was estimated to be 40 feet *long*. 40 feet *tall* would have been mind-boggling huge for a predatory dinosaur. Only the very largest of dinosaurs, all plant-eating sauropods, reached such heights.

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