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How To: Be Invisible

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If you have several billion dollars and
a defense department contract:

You may be able to get invisible thanks to a new technology based off the Fantastic Four. According to comic book mythology, the Invisible Woman pulls off her shtick by bending light waves around her body with a force field—so instead of seeing a blond chick in spandex, super villains see whatever happens to be behind her. So far, this skill is strictly for fictional hotties, but researchers at St. Andrews University in Scotland think that, in the near future, those of us not genetically altered by radioactive rays from space may be able to do something similar. The concept works like this: We see objects because they reflect light back to our eyes. So if an object were able to curve light around itself like water flowing around a river stone, it would be effectively invisible. We'd see all the things around and behind it that reflected the light instead. To be invisible, a person or object would have to be concealed behind a shield made of metamaterials, highly engineered manmade solids that can bend waves of energy. So far, the metamaterials are still theoretical, but scientists agree that they're coming soon. Both the researchers at St. Andrews and a different group at the Pentagon have predicted that successful metamaterials capable of hiding objects from radar or electromagnetic waves (though, sadly, not from the human eye) could debut as early as 2008.

If you have a couple million and airfare to Japan:
You can be transparent right now, though people may accuse you of cheating. Tachi Laboratories at the University of Tokyo has developed a sort of virtual invisibility cloak made of a luminescent material, similar to a movie screen or stop sign paint. Using a digital camera linked to a powerful computer, researchers can project live images and video from behind the cloak onto its front, making it blend in, chameleon style, with the background. The effect isn't all that realistic; you won't be using this cloak to walk into a bank and rob it undetected. However, the technology promises to be very useful to surgeons, who could use it to "see" through their own hands for a better view of their patient's innards.

If you're on a budget:
You can't be invisible, but your Pyrex® glassware can. Turns out, Pyrex® and Wesson oil reflect light at almost the exact same angle—so if you immerse a rod of Pyrex® in a jar of cooking oil, the submerged glass will appear to vanish.

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Watch How to Make a Compass
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Let's say the mega-earthquake comes and you're stranded with just some MacGyver-style bits and bobs. If you've got a magnet and a little knowledge, you can make a compass that reliably points north. Below, check out a vintage segment from Curiosity Show explaining how to do it—and a bit on the science of why compasses work.

In the clip below, presenter Deane Hutton shows three methods involving a mirror, cork, a pin, a drinking straw, and a circular magnet (in different combinations). There's something for everyone!

Incidentally, one of the key issues in making a compass is knowing which end of a magnet points north and which points south. One YouTuber asked how to determine this, if it's not already marked—as might be the case in a survival situation. Decades after the clip aired, Hutton chimed in via YouTube comments to answer:

Wait till the Sun is about to set. Stand with your right shoulder toward the setting Sun. You are now facing South. Suspend the magnet and let it swing freely. When the magnet stops swinging, the end pointing South is the South Pole of the magnet. Deane.

Science is cool. Anyway, enjoy:

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Watch How To Make a Self-Starting Siphon Using Bendy Straws
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In this vintage video segment from Curiosity Show, we learn about self-starting siphons. These things start a flow of water without the user having to squeeze a pump or suck on a tube, which is a distinct benefit.

In the segment, we also observe the limitations of self-starting siphons. Because the act of submersion starts the flow, we're limited to siphoning water out of very full vessels. But still, this could be useful for a home aquarium, which is one of a thousand scenarios in which you don't want to use a mouth-primed siphon.

The best part of the segment is when presenter Rob Morrison shows how to make your own self-starting siphon. File this under "Handy stuff you can do with bendy straws." Tune in and enjoy this simple physics demo:

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