Sounds like this would make good radiation sheilding for a trip to mars.
Chinese scientists have stunned the world of boffinry by fashioning an artificial "black hole" generator out of copper-coated circuit boards. Disappointingly this is not a black hole in the normal sense of a universe-wrackingly dense lump of hypercompressed matter, exerting a gravitational pull so fearsome that not even light …
Another big danger in space is the cosmic rays, charged particles that can do a hell of a lot more damage to tissue than microwaves. It sounds like the EM this would stop could also be blocked by cheaper/lighter shielding.
I'm sure this stuff will have many interesting applications but whether any will be practical is unknown. Still cool
"Possible visual-spectrum successors would appear as a black blob to the human eye rather than being invisible."
I believe a coating with similar properties used to be popular for manufacturing wall-mounted writing surfaces once used in school classrooms. Its stealth properties could be modified by the application of calcium carbonate pressed into stick form.
except black paint would absorb the light across it's entire surface which means the heat at any given point isn't going to be that much higher than ambient temperature.
This device would take all the light hitting the surface, and delivery to a small point in the center where it is converted to heat. It's the same amount energy as the black paint object, but the temperature gradient with the ambient temperature would be higher and so useful for doing work , such as with a Stirling Engine.
«except black paint would absorb the light across it's entire surface which means the heat at any given point isn't going to be that much higher than ambient temperature.»
On a sunny days you can boil water using only black paint and insulation. Very simple really. Take a clear glass bottle, paint half of it in black (along the height), lay it in a box of sand, half-burried, black half at the bottom. Cover with a glass plate, place in the sun a 3 pm, your water will be ready for the proverbial 5 o'clock.
I tried it back in the days of my innocent youth. Naver made any tea that way though, for 2 reasons. I was too young to drink tea, and I never found a bottle that didn't burst open under the pressure. Even the cider bottle caps popped, and these can take a lot of pressure. Back then sandy tea was not desirable. Nowadays, given the carbon-conscious fashion, you could maybe get people to actually drink it if you emphasize the "green" side enough.
Unless, of course, the vehicle used some of that energy for propulsion, internal power (to compensate for smaller batteries), stored chemically for weapons systems, etc.
If you have a high enough differential, there's all sorts of uses for excess heat energy. ;)
Paris, because she knows all about generating focused heat to an internal core.
This would, in fact, most likely be worse than nothing for radiation shielding against solar and cosmic radiation.
Why? Because most of that is not in the form of photons, but in the form of really fast moving charged particles. Which have the highly annoying tendency of producing hard X-rays when they impact on anything metal.
The best way to stop them is something with lots of hydrogen in it, like water, certain plastics and ceramics.
The worst way to stop them is anything metallic.
So fast-moving charged particles strike a metal surface (which is tuned to absorb the EM range associated with hard X-rays), and produce hard X-rays, all the incident ones of which are absorbed by the surface and converted to heat, which is then likely to be emitted as IR.
Don't see the issue myself, you could use one as interplanetary shielding without too much faffing about, as long as the sizing for X-ray absorbers doesn't cause it's own problems :)
in a terrifying yet unambiguously newsworthy apocalypse incident
in a terrifying yet unambiguously newsworthy apocalyptic incident
This won't happen anyway as everyone who has an education will be privy to the fact that the world will end in December 2012. Which is also the reason I don't understand everyone getting so upset and over excited about the cost of the Olympics. The world will not be around so the cost won't matter.
"Another fiction becoming reality?" ... Anonymous Coward Posted Thursday 3rd June 2010 13:36 GMT
That got me thinking further, AC.
If there were no words printed, would reality be totally different, ..... ergo is reality scripted for thoughts to follow and create/reverse engineer what is in essence and physicality/actuality, Virtual Reality, ....... for take away everything artificial/man-made/machine built, and one is as naked as a JBird in a Natural Paradise ..... Perfumed Garden of Eden, and one can then build everything again with Beta Imaginanation Shared in Words.
For a Second Chance ..... Knowing what's Coming.
I'm a little concerned that any radar-guided shed-seeking missiles might have a heat-seeker backup. Now the thermal signature of my kettle should be quite hard to lock onto, but once the targetting radar has started heating up my shed's copper coating - then I'm going to stand out like a sore thumb on infra-red...
Can a bonfire be used as some sort of missile decoy?
Visual camouflage is the least of one's worries. All you have to do is not mow the lawn for a few years, and the shed will magically disappear.
Obviously an underground volcano would be better, but a grass-covered stealth-shed is surely the next best thing.
Surely with all this heat generated (including from ambient microwave radiation we are bombarded with all the time) this heat might be stored for just such an occasion?
Most missile systems (the missile itself, usually) don't do well when bombarded with concentrated IR radiation, and at a certain point and beyond you burn out the detector. ;)
Microwave-absorbing materials may do wonders against active radar installations (since they lose their return signals, but isn't there increasing research into the realm of multistatic passive radars that work by tracking occlusion (and thus would cause radar-absorbing craft like stealth planes to stick out on the imagers like...like black holes)?
the darkest optical thing I ever saw was the batch hydrising furnace for surface modification , pre-final sharpening of about a billion razor blades. The blades were vertically & horizontally stacked sharp edge pointing outwards and had a very low albedo. This system was being built in Hope in the wilds of Derbyshire.
This is obviously a perfect, cheap, all weather conditions heating element. Even in the worst weather (cloudy, rainy, etc.) infrared radiation still exists in abundance and so one of these absorbing energy and then pumping it into a house could be a very cheap way to heat the house with no reliance on fossil fuels.
Obviously depends on size, heat output, scalability, etc, but why go all complex with radar invisbility when theres a simple problem that this could be the solution too. Plus being a "green" technology, its sure to get billions in government funds to pursue...
when I was young and the world was new, we used microwave lenses as parts of antenna systems. Some of these used large chunks of dielectric material (perspex was a good one at the time) shaped like a lens to focus a plane wave onto a point (usually a small horn). Others used a number of anular metal plates of different lengths to focus a plane wave to a point. Antennas like this could also be used as passive repeaters. It is always a good idea with things like this to ensure a good match between the system and free space so as to capture the max amount of energy. Used at 2GHz, these things stood out like a sore thumb at light frequencies but, at 2GHz, would look like a black hole.
There is nothing new about the basic idea here. The main change is that as the frequency increases, things get a bit smaller. Bandwidth of things like this is a bit of a problem, but then, designing anything to work from DC to light is not simple.
Can't we simply cover aircraft with frozen chickens to make them invisible?
Every time I stick a frozen chicken in my microwave oven it absorbs the microwaves which then get converted into heat and the chicken cooks from the inside. Sounds similar to this metamaterial stuff
Seems to me that frozen chickens would be an alternative to all this hi-tech malarky of creating black holes.
Sticking frozen chickens on the outside of bombers will also have the added benefit of having a meal ready for the pilots when they get back from their mission. In fact I think we could go the whole way and have a complete 3 course meal attached to the outside.
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