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Comment Re:Test Team (Score 1) 166

Yes there was significant energy outside the plane. (But anything near an airport that systematically fouled the planes' avionics would have been detected, hunted down, and suppressed.)

On the other hand, inverse-square makes for a LOT of signal right next to the phone. So does being inside a conductive can (along with the avionics), where the energy just accumulates in a handy resonance until it is pumped up enough that the absorption and leakage equals the input. (See the recent article on how hard it is to actually build an effective Faraday cage, due to the latter phenomenon.)

Comment Re:Private Aircraft? It's Their Rules. (Score 1) 166

So here's the thing: It's their plane.

When you buy the ticket and board the plane, you agree to play by their rules. They have the property rights and have sold you limited rights to your seats with stipulations.

If that were true, they'd be able to chose to let you use your equipment on takeoff and landing. Some of them would likely do so, to attract more customers in the highly competitive market, or to make it easier on their flight staff (and maybe get away with less flight staff).

But that's NOT the case. This is a federal regulation. The government tells them to do this. It's not a matter of contract between them and you, it's a matter of the government running the show as a dominating third party.

Comment Re:Facebook Status: going to emergency depart plan (Score 1) 166

What about having people ready to MOVE during an emergency? Isn't that why bags, tables, and everything is put away during takeoff and landing?

I thought it was about avoiding/reducing injuries from flying luggage or hitting the seat or table in front of you with your head or adam's apple if the plane bumped into something, ran off the runway into the dirt beside it, or otherwise decelerated or experienced strong G-forces during some mishap.

Same reason they ask you to go back to your seat and belt in if the run into turbulence midflight - though the latter (almost always) has less extreme forces.

Comment Re:Test Team (Score 5, Insightful) 166

The ban on electronics, with the claim that it interferes with the plane's electronics, has always been bullshit.

The old analog phones put a strong, continuous, signal in a narrow band. This was both an interference problem for communications and navigation equipment (due to effects like front-end quieting and intermodulation, even though the plane's gear wasn't operating on the same frequency) and a signal corruption problem for any electronic device with a metallic structure in its wiring that picked up enough signal to drive the electronics out of proper operating conditions.

Digital cellphone signals, whether CDMA or OFDM based (as well as the OFDM based WiFi) are spread-spectrum. The energy is spread out over a broad band and looks like background radio noise to equipment that isn't designed to collect and concentrate it. This is much less of a problem. Any electronics that would be interfered with it (if the phone wasn't within inches of it) would also be interfered with by so much other stuff that it wouldn't be suitable for aircraft at all.

Now that the Analog cellphone network is shut down (and most analog-capable cellphones are retired), and most modern portable computer gear is also designed with spread-spectrum clocks internally (to avoid generating narrowband radio interference due to all those gates switching simultaneously and periodically), these devices are much less of a source of problematic radio interference.

Meanwhile, the avionics has gone through a couple more generations of engineering, with avoiding dangerous failures from passenger electronics interference as a design criterion.

So now is a much safer time to let the passengers play with their toys than even a few years ago.

If that were true the ban would be for the entire duration of the flight, and it would be pretty scarey if flight electronics were so delicate that anyone with a cell phone turned on could screw it up.

"You can do anything you want [when flying] a plane, as long as you don't do it near the ground." This is doubly true for operating a not-designed-for-air-flight radio transmitter in the plane:

  - When flying "up there" you have a lot of room to manouver and a lot of time to correct errors or switch modes if something goes wrong with a system. When taking off or landing you have only seconds to react, and have to be accurate with a couple inches vertically, feet right-left, and tens of yards fore-aft to land ON, rather than under, beside, or off-the-end-of the runway (and avoid all the other planes, buildings, trees, antennas, etc.)

  - When taking off and landing you're using a LOT of additional electrical, and radio, systems.

Comment Easier way to test it. (Score 2) 213

Of course, Gorhamâ(TM)s ideas will need to be tested by actually measuring the charge on gossamer spider silk as it is generated.

Rather than trying to test it directly, just modulate the field in a room containing such a spider.

If the spider and its silk has a net charge you should be able to steer it around the room, land it where you want it, and measure the charge by the spider's response to the ambient field you're modulating. The attitude of the spider/silk system in the modified field will also give you the distribution of charge vs. weight on the spider and its silk.

If the spider and its silk doesn't have a net charge it will just hang there and blow around in the air currents.

(Of course the fanning out of the silk already proves the silk itself has a substantial charge.)

Comment Tents and shade structures. (Score 1) 228

Back when I was tent camping, my wife and I had (serially) more than one commercially-made, high-quality, camping tent. These were strong synthetic cloth structures that hung from a framework.

One was a little dome tent with bent fiberglass poles, a couple others were big stand-up tents that hung from aluminum poles that formed hockey-stick shapes that joined at the center.

All of them had (or had available) a shade cover. This was a shaped cloth structure that went OVER the supports and had bungi-cord fasteners at each pole to hold them in place. The curved or pyramidal shape of the tent roof, along with the couple inches of clearance between the cover and the tent proper, caused any slight breeze to clear the hot air under the cover. (Some of them also had a small hole at the center so they'd change air by convection even in a dead calm.)

Result: Tent WITH shade structure as a single, strong, unit, suitable for quick setup and stable shape even when subjected to strong winds.

Caveat: I'm NOT a Burning Man attendee. So I don't know if there's some reason this won't work or would be unacceptable.

Comment Re:Uh...wasn't Burning Man last month? (Score 1) 228

Because Burning Man is a recurring annual event, and many on here, such as myself, have not been, but want to go, and so found some of the advice useful.

It also takes a while to prepare for it.

Just AFTER an instance is the best time to pick the brains of the attendees, while memories are still fresh, for helpful information on what to build.

Starting now also gives you nearly a year to get your stuff ready for the next one - at a leisurely pace, with time for debugging and remakes, before you have to stress-test it in a desert for a week - while your life depends on it working adequately. B-)

Comment Re:old news (Score 1) 110

GI in Japan after surrender of Japan in WWII, picked up gut bacteria and whenever he ate carbs he got drunk.

That may be the one my parents told me about, back in the '60s or so (but as a war story which probably puts it in WWII.

In the one I heard about the GI was thrown in the brig and put on bread and water - which of course made him even more intoxicated. Then they mounted an investigation to see how he was getting the booze smuggled in. That finally showed it was a medical problem.

Turns out he had diverticulosis - one or more failures in the intestinall muscle wall where the gut membrane bubbles out into a little appendix-like pocket and is prone to infections - and one of these became home to a culture of brewer's yeast.

Comment Old and kludgy makes it harder to port. (Score 2) 157

Not only does it cost a LOT to port this stuff and risk errors in doing so, but the cruftier it is the harder (and more expensive and error-prone) it is to port it.

If, instead, you can get the new machines to run the old code, why port it? Decades of Moore's Law made the performance improve by orders of magnitude, and the behavior is otherwise unchanged.

If you have an application where most of the work is done in a library that is largely parallelizable, and with a few tiny tweaks you can plug in a modern multiprocessor-capable library and run it on a cluster, you get another factor of almost as-many-processors-as-I-decide-to-throw-at-it, with small effort and negligible chance of breaking the legacy code.

What a deal!

And it's one less reason to touch the tarbaby of the rest of the working legacy code.

Let the COMPUTER do the work. People are for setting it up - with as little effort as practical - and moving on to something else that is important and can't yet be automated.

Eventually somebody will teach the computers to convert the Fortran to a readable and easily understandable modern language - while both keeping the behavior identical and highlighting likely bugs and opportunities for refactoring. Until then, keeping such applications in the legacy language (unless there's a really good reason to pay to port them) is often the better approach - both for economy and reliability.

Comment Re:Summary seems to be somewhat misleading. (Score 1) 81

Not at all. The size (spacing) of the pixels relative to the wavelength limits the angle through which you can (first-order) diffract the beam,

A hologram of a scene where only a small region, very near the spot the reference beam is aimed at, i.e. one that leaves most of the light nearly parallel to the reference beam on reconstruction, is a very low-resolution, big-blobby thing.

Comment Re:Summary seems to be somewhat misleading. (Score 1) 81

60 Hz would be terrible. Let's imagine they can IQ modulate 64 symbols (6 bits per symbol) with a samplerate of 60 Hz, that gets you 6 * 30 (Nyquist) = 180 bits per second.

That's per pixel in the modulator. Now multiply by the number of (mega) pixels.

The modulator is essentially the guts of an LCD display so you get the same bandwidth as the video image it could display. What's new is:
  - You're modulating the(many) modes of the cavity itself, rather than shaping the beam after it emerges.
  - You're modulating the modes rapidly, rather than by hand-replacing components (call it one symbol per hour if you're good at it).

Comment Summary seems to be somewhat misleading. (Score 4, Informative) 81

My impression is that, because the mirror is "replaced" with the LCD, the LCD is inside the cavity, with each pixel modulating either the Q or the polarization of a particular chunk of the cross-section of the cavity. This amounts to adjusting the gain of the various modes of the cavity and thus switching which one(s) oscillate and consume the energy from the amplifier in the cavity.

Though the modes that are selected would not be mapped one-to-one onto the pixels, , you can control a lot of modes with the ciquid crystal display - probably all of them available, or up to the number of pixels in the liquid crystal device.

You can also switch them as fast as the liquid crystal switches. With modern drivers (which remember the previous state of the liquid crystal in each pixel and temporarily overdrive those that must change more in order to switch them rapidly, rather than just letting them settle passively into the new state) you can switch it at 60 Hz or better.

You might use holographic techniques to change the angle of the beam, or emit a number of beams of various intensities in various directions. Result: Scanning and image formation without moving parts (other than the molecules in the display).

I think the computation to turn it into a (one-color) projector would be pretty much a straight 2-D FFT times a nonliinear tweak to deal with energy-stealing among modes.

I'd like to see versions of this with array-of-Kerr-cells in place of the liquid crystal device (for more rapid modulation, at the cost of high voltage drivers), or digital light processors for the mirrors (though the latter are more on/off than continuously adjustable so they might be more limited on what beams they can form).

Comment So they don't by them AS THEMSELVES. (Score 3, Interesting) 81

for the life of me I don't know why Cisco, Microsoft and other big players just don't pay up to get at least some insight into how these guys are finding exposures in their systems

I would assume that VUPEN would refuse to sell to Microsoft and Cisco on account of it diminishing the value of the zero-days they're holding.

Or at least not sell them the best stuff.

Obviously, if Cisco, Microsoft, etc. were going to buy this service, they wouldn't do it (only) as themselves, acting directly. They'd do it through a front, to insure they got the same things the bad guys were getting.

Just as a startup did, about a decade ago, when I was designing a next-generation routing chip, and we needed to obtain equipment from Cisco for testing it for function and compatibility.

It took two half-rack, 3/4 megabuck, top-of-the-line Cisco routers to drive it properly. We bought them through another company on a very hush-hush basis, just to be sure Cisco wouldn't be tempted to send us defective or gimmicked equipment, not support it properly, or hold up shipment and slip our schedule.

Comment Commercial vs. government control rooms. (Score 1) 94

Anybody knows how the new commercial space launchers do in comparison?

Don't know about the current crop. But back in the late '80s AMROC controlled their launches without the classic room-full-of-custom-consoles. Instead they hacked up their "consoles" as a GUI on one instance of the state-of-the-art windowing interface computer of the time - a Macintosh (what they'd now call a "Macintosh Classic").

I hear that, when they showed up at Goddard for their test shot, the usual control room crew was standing around with their jaws dropped as the whole thing was run from the little screen on the little box on the single desk. B-)

If you never heard of AMROC: They were the ones that were working with the hybrid rocket: Solid fuel (synthetic tire rubber), liquid oxidizer (liquid oxygen). Controllability of a liquid fuel, complexity halfway between solid and liquid fuel (only ONE set of plumbing, not too that must be synchronized), safety better than either (turn off the LOX and the fuel just smolders and goes out.

They lost their mover-and-shaker founding-team member days before their first flight attempt. Then, though the engines had many successful tests, the actual flight attempt failed in about the worst possible failure modes for a hybrid: The LOX valve iced up (due to ambient moisture) and stuck at about 30% open: Not enough thrust to get off the pad, but enough slow burn energy to destroy much of the rocket and pad equipment, and they couldn't either launch or shut down. Then they went bankrupt, so there wasn't a second shot. (Their tech was sold and some of it is used in space ship one.)

Comment It's just automation doing its job. (Score 1) 85

Now I can record even more TV that I'll never get around to watching. Technology is great and progress is divine.

Ha ha, but seriously....

Letting the automation pull the the needles out of the hundreds-of-channels vast wasteland haystack is a classic example of using automation to do the drudgery, leaving you to do the interesting stuff.

There's two hundred channels of crud and 20 minutes per day of stuff of interest? Let the computer watch the junk sieve out the jems for you. That way you don't need to be rich enough to hire an army of interns to do the same.

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