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Comment: Re:Inside of cameras (Score 5, Informative) 171

by Animats (#47445151) Attached to: Scientists Have Developed a Material So Dark That You Can't See It

I didn't research so forgive my ignorance

It gets this property from its fine surface structure, which is a forest of tubes. Incoming light has to be reflected many times before it gets back out, so a black material is effectively made even less reflective. It's the optical-scale version of the pointed absorbers used in anechoic chambers.

It probably is not going to retain its blackness when exposed to water, dirt, or wear. Superhydrophobic coatings such as Never Wet have the same problem - they work because they're composed of tiny points, so droplets of liquid don't have a surface they can grab. But after some wear, the effect stops working. (See any of the many "NeverWet fails" videos on YouTube.)

This is likely to be great for protected environments, such as inside optical systems. It should be useful for optical sensors in space, too. But it's probably an inherently fragile surface. That limits its uses. (The "stronger than steel" probably refers to the individual carbon nanotubes, not the bulk material.)

This s a problem with a lot of surface chemistry stuff touted as "nanomaterials". They have interesting surface properties, but the surfaces are fragile, because they're some very thin surface layer with an unusual structure. If you protect that structure with some coating, you lose the effect.

Comment: Hard to tell if it's working. (Score 4, Informative) 323

by Animats (#47438917) Attached to: A Skeptical View of Israel's Iron Dome Rocket Defense System

Here's the promotional video from Rafael, the system's maker. If the Iron Dome launchers are in a position to hit incoming rockets when they're still in boost phase, they're clearly effective. When they hit, the ascending rocket's flare disappears. Israel has Iron Dome launchers both forward postioned near Gaza, for boost phase defense, and near cities, for terminal defense. For terminal defense, it's harder to tell if they worked. The incoming rockets are just falling at that point, and success requires blowing up their warhead, not their rocket engine.

Videos show the missile's warhead exploding. That's triggered by a proximity fuse. There's a spray of shrapnel from the warhead; it doesn't have to be a direct hit. Whether that sets off the incoming rocket's warhead isn't visible from the videos of terminal defense.The Patriot missiles used in the Gulf war were able to hit incoming Scud missiles, but often didn't detonate the warhead.

Comment: Re:There's already a Tesla museum, in Belgrade. (Score 1) 76

It wouldn't have done what he envisioned, but it could well have proven to be the worlds' first VLF radio station.

Marconi already had VLF working, sort of, before Wardenclyffe was built. Marconi's R&D approach was to transmit across short distances, test and improve the hardware, then try longer distances. Over a few years, he slowly worked up from across the room to across the ocean. Less grandiose than Tesla, but more successful.

Tesla is said to have assisted in the construction of the 1913 Telefunken VLF station on Long Island, but the IRE Journal article doesn't mention him. Telefunken built a VLF antenna much the way one would be built today - a simple guyed tower resting on an insulator base, with wires spreading outward to a circle of poles. They only used 35KW, instead of Tesla's 200KW. The station communicated with a similar station in Germany.

Comment: There's already a Tesla museum, in Belgrade. (Score 4, Informative) 76

by Animats (#47428151) Attached to: The Oatmeal Convinces Elon Musk To Donate $1 Million To Tesla Museum

The Tesla Museum already exists.

Tesla did great work with AC generators and motors. Most common AC motors today still use approaches he invented. That's his legacy.

Wardenclyffe, though, is a monument to failure. From his patents, you can read how he thought it would work. He thought the ionosphere was a conductive layer. The Wardenclyffe tower was supposed to punch power through the atmosphere to that conductive layer, so that signals and maybe power could be received elsewhere.

The ionosphere does not work that way. Tesla's tower would have done nothing useful, although with 200KW at 20KHz going in, it probably could have lit up fluorescent lamps and gas tubes for some distance around. Since the location is now surrounded by a housing subdivision, rebuilding the tower and powering it up would annoy the neighbors.

Comment: Self-reported data will never work. (Score 1) 131

by Animats (#47427143) Attached to: How Google Map Hackers Can Destroy a Business

See my 2010 paper "'Places' spam - the new front in the spam wars." As I wrote back then, "The two phases of spamming Google Places are the insertion of fake business locations and the creation of fake reviews. Both are embarrassingly easy." That hasn't changed.

Google doesn't fix this 4-year-old problem because Google makes money from bad search results. If search results take you directly to the business selling whatever it is you want, Google makes no money. If you're detoured through some Demand Media content farm, Google makes ad revenue. If you get fed up with being sent to ad-choked sites and click on a Google ad, Google makes money. Organic search that sucks is a fundamental part of Google's business model.

Technically, it's straightforward to fix this. Business data has to be checked against sources businesses can't easily manipulate, such as business credit rating companies. A business that reports fake store locations to Dun & Bradstreet or Experian will soon have a very low credit rating.

Bing or Yahoo could beat Google at search quality. They have the same spam problem, but it doesn't make them money. That's because Google has most of the third-party advertising market. Web spam on Bing drives traffic mostly to sites with Google ads, not Bing ads.

The real search engines are Google, Bing, Baidu (China) and Yandex (Russia). Everybody else, including Yahoo, is a reseller. Yandex has been doing some interesting stuff lately with linkless search ranking, and Baidu just opened a Silicon Valley office.

Yahoo's Marissa Mayer announced last January that Yahoo was getting back into search. (They've been reselling Bing since 2009.) That appears to have been a bluff to get a better deal from Microsoft. There's no indication of Yahoo actually building a search engine. No relevant job ads, no data center buildout, no increased crawling by Yahoo bots, no high-profile hires, no buzz in Silicon Valley.

Bing ought to be doing better than it is, but they're reported to have management problems. Every year, there's new top management at Bing, and it doesn't help.

Comment: Jurisdiction (Score 3, Informative) 303

I'm listening to the recording of the radio communications. The drone was over 2000' altitude. At first, the cops in the helicopter aren't sure what they're seeing, and they first think it's a fast-moving aircraft in a vertical climb, over the East River. It has red and green lights, like aircraft do. They ask La Guardia ATC radar what they're seeing. ATC isn't seeing it on radar. Then they get closer and see it's a drone of some kind. In a few minutes it's over the George Washington Bridge, miles from the East River.

Once the guys who were operating them were caught, the cops are on the air discussing what to charge them with. The cops on the ground call them "tiny little toys". There's some discussion of "if it's over 1000', it's reckless". The cops aren't quite sure what to charge them with.

The FAA can certainly have them prosecuted. They were operating a drone in class B controlled airspace. That's serious, and dumb. Here's the New York City airspace chart. (Yes, there's actually a VFR corridor over the Hudson River; it's permitted to fly along the river at up to 1300' altitude. There used to be one over the East River, too, but after some jock slammed a light plane into a Manhattan apartment building by going too fast there, it was closed to VFR traffic. These drone operators didn't stay in the VFR corridor, and probably had no clue where it was anyway.)

The drone guys were lucky. LGA has two intersecting runways, 4-22 and 13-31. The one in use depends on wind direction. The approach to 13 and the departure from 31 are over where the drones were operating. LGA happened to be using 4-22 that day. If the other runway had been in use, there would have been a large plane in the area ever 45 seconds or so.

Comment: Mysterious "Aurora" attack not so mysterious. (Score 1) 50

by Animats (#47417787) Attached to: DHS Mistakenly Releases 840 Pages of Critical Infrastructure Documents

There's nothing mysterious about this. The problem is that if someone gets control of circuit breakers for large rotating equipment, they may be able to disconnect it, let it get out of sync, and reconnect it. This causes huge stresses on motor and generator windings and may damage larger equipment. This is a classic problem in AC electrical systems. A more technical analysis of the Aurora vulnerability is here.

The attack involves taking over control of a power breaker in the transmission system, one that isn't protected by a device that checks for an in-phase condition. Breakers that are intended to be used during synchronization (such as the ones nearest generators) have such protections, but not all breakers do.

Protective relaying in power systems is complicated, because big transient events occur now and then. A lightning strike is a normal event in transmission systems. The system can tolerate many disruptive events, and you don't want to shut everything down and go to full blackout because the fault detection is overly sensitive. A big inductive load joining the grid looks much like an Aurora attack for the first few cycle or two.

There's a problem with someone reprogramming the setpoints on protective relays. This is the classic "let's make it remotely updatable" problem. It's so much easier today to make things remotely updatable than to send someone to adjust a setting. The Aurora attack requires some of this. There's a lot to be said for hard-wired limits that can't be updated remotely, such as "reclosing beyond 20 degrees of phase error is not allowed, no matter what parameters are downloaded."

Comment: Re:Buy the book BANNED by Costco! (Score 1) 144

by DahGhostfacedFiddlah (#47417647) Attached to: Physicists Spot Potential Source of 'Oh-My-God' Particles

Okay, I've read through a number of your replies, and one question keeps coming up. Who the Hell are you? What skin do you have in this game?

Companies pull books all the time for all kinds of reasons. Why is this one worth disrupting the site over? Are you Dinesh himself, trying desperately to get more income (or mindshare, whatever). Or has he hired you to spread the word on whatever sites you can? Are you simply a Concerned Citizen for whom this one book is the final straw?

Or are you a crazy lib who hates Dinesh D'Souza, and intends to delegitimize him by being a dick on websites in his name?

Or are you just trying out a new trolling technique? In which case, full marks for creativity, full marks for getting the bites. But 0/10 for pulling at the emotions like a traditional troll does. You're stirring up more confusion than anger.

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