Radio-wavelength, electro-magnetic radiation is a form of energy. When it is absorbed, it raises the kinetic energy of the substance absorbing it. This translates as heat energy.
Aluminum and iron oxide are two main components to thermite. Powdered magnesium is the third component. How many paints contain magnesium compounds? Since most rooms usually have multiple layers of paint after a few years, the odds of having all three ingredients in close proximity get pretty high. Theoretically, you could blast a room painted in that fashion with enough radio energy to ignite it with, interesting, results.
Maybe we should suggest the experiment to MythBusters?
University of Tokyo researchers have developed special paint that can block wireless signals.
By mixing aluminum-iron oxide particles into paint, the researchers have invented paint that blocks radio frequency in higher spectra where Wi-Fi and other higher-bandwidth communications occur.
Though most Wi-Fi technologies operate at 2.4GHz and 5GHz, the special paint can block frequencies all the way up to 100GHz, the researchers said.
A 200GHz-blocking paint is under development.
Here’s how it works: the metal particles within the paint resonate at the same frequency as Wi-Fi and other radio waves, so signals can’t pass through the thin layer of pigment. Voilà: a secure wall that stops signals from entering the house and yours from breaching walls coated with the special paint.
The use for such a novel product is already present. Movie theaters have been interested for quite some time in finding a legal way to silence cell phones during screenings. (Electronic jammers that actively block wireless signals are illegal.)
But that’s not all. One of the researchers, project lead Shin-ichi Ohkoshi, spoke to the BBC:
“In a medical setting, you could transmit large volumes of data from a medical device, such as an endoscope, to a computer. You could block phone signals from outside and stop people’s phones ringing during the movie. By painting a solution containing our magnetic particles on the walls, you would quickly, and effectively, shield the room from stray electromagnetic radiation from outside.”
The debate would then be how dangerous such a system would be during a disaster in which emergency communication would be necessary.
Security’s also a concern, too. After all, what do you do when you have to open the door?
UPDATE: SmartPlanet’s Dana Blankenhorn makes the case for what he thinks is the real value in anti-Wi-Fi paint.
