Science Friday: Trompe-l'œil | Old Laptop Into A Touchscreen Tablet Conversion | Your Microwave is an EMP Protector
Trompe-l'œil (deception of the eye)
- If you only watch one optical illusion today in which a stream of water appears to have droplets freeze in mid-air or inch their way backwards back into the tube from whence they came, make it this one.
The effect is caused by syncing up a camera with the vibrations of the water. The speaker behind the stream of water is generating a 24 hz sine wave, and the camera is filming at 24 fps, which causes the water to appear frozen. Or, you can adjust the hz rating of the wave and move the stream very slowly forwards (at 25 hz) or, much crazier for our purposes, very slowly backwards, at 23 hz.
This might be a rolling shutter, but I think it's the same principle
- Tablets are taking over the portable-computing market, but that doesn’t mean the netbooks that they’ve replaced are useless. It’s possible to jam the processing power and battery life of most netbook models into a smaller, touchscreen-equipped package. The project is very straightforward: Remove a few parts, add a touchscreen overlay (about $80; MyDigitalDiscount), reseal the device in its new tablet form, install a driver, and calibrate the screen. And if you use an old netbook you have lying around (or buy a used one), it costs a fraction of the price of a new tablet.
Steps 1-5 at the link
- You sleep with your iPhone beside you, waking up in the middle of the night to check your e-mail? Feel anxious when separated from your smartphone?
An electromagnetic pulse (EMP) is a wave of energy that follows nuclear detonations and threatens to fry your personal electronics. Could something already in your abode save your electronics from an early demise? Let's answer this question as we look at the nature of electromagnetic pulses and if your microwave could prevent damage from an energy attack.
Electromagnetic pulses and Faraday cages
If a nuclear bomb is detonated high in Earth's atmosphere, the damage from the blast would not be in the form of vaporized buildings, but in the form of a wide-scale electromagnetic pulse. With the EMP would come a voltage spike that would likely fry most electronics.
Ideally, a Faraday cage would divert the energy from an electromagnetic pulse and prevent damage to the electronics within. Faraday cages are containers made of a conducting material, typically copper or aluminum sheets or mesh, with the conducting material altering the alignment of electrical charges inside to counteract the incoming energy pulse.
Faraday cages are simple to make - the first consisted of a small room covered in metal foil, with the foil successfully countering high-voltage discharges from an electrostatic generator and preventing changes in the electrostatic environment inside. You can create your own Faraday cage easily, but you likely have one - your microwave oven.