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Comment: Re:Inside of cameras (Score 5, Informative) 156

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: Re:CmdrTaco would say... (Score 2) 353

by ColdWetDog (#47439915) Attached to: Slashdot Asks: Do You Want a Smart Watch?

No FM Radio. Less storage than a Nomad. Lame.

http://slashdot.org/story/01/10/23/1816257/apple-releases-ipod

This actually makes me nervous. Given the unbroken track record of Slashdot mistaking the market share for every major advance in technology since the iPod, I'm forced to believe that smart watches are going to be a hit.

And I'm not sure I want to live in that world.

Comment: Re:because drinking water is so pristine (Score 3) 229

by ColdWetDog (#47439093) Attached to: Texas Town Turns To Treated Sewage For Drinking Water

Or just plain ol activated charcoal. My sailboat has an RO system with a charcoal canister that I replace twice a year. Bigger systems have more complex pre filters. I'm sure that the system in TFA is at least cleaner than any river water or shallow well system. Possibly not as pure as a deep artesian system but if it passes EPA criteria, it's going to be pretty clean.

Really Slashdot, RO systems are old hat. You can buy them on Ebay. Soon they'll be in breakfast cereal.

Comment: Hard to tell if it's working. (Score 4, Informative) 319

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:Ted Postol very bias opinion. (Score 2) 319

by ColdWetDog (#47438711) Attached to: A Skeptical View of Israel's Iron Dome Rocket Defense System

You don't expect a critical appraisal from the vendor, do you? Take his, and everyone else's reporting with some degree of skepticism.

One notable fact that was tangentially mentioned is that one doesn't see any 'hits' in the media. I would think one would be able to see the effect of the missile intercepting the targets at least some of the time. Given the intense media coverage, one wonders. It's certainly possible that by the time the interceptor hits the target it's too small to visual, but there is one hell of a lot of energy involved. Kinetic energy often creates sparkly bits that can be seen.

It is also hard to argue that this ISN'T just one more aspect of the public relations game that is endemic to this conflict. Both sides (as is pointed out in TFA) engage in trying to get the other side to look mean and nasty. It's way more complicated than that.

If you do something right once, someone will ask you to do it again.

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