A Simple and Elegant Cloaking Device

By Anupum Pant

In the year 2011, UTD NanoTech unveiled their carbon nanotube invisibility cloak, making us move one more step closer to realizing a piece of magical cloth which fictional characters often use to turn themselves invisible. And then there was a 3D printed invisibility cloak too.

A few researchers at the University of Rochester have now created their own elegant version of an invisibility cloak. It’s, in principle, a fairly simple optical device which uses just four lenses to cloak objects behind it, keeping the image behind it still visible.

In fact, whatever it does, it does it in 3 dimensions. That means, the viewer looking through the device can actually pan to change the viewing angle and can still see the image of the background, undistorted, as if there were no lenses in between, in real-time. And it is probably the first ever cloaking device to be able to do that.

The device has a blind spot (sort of). In a way that It doesn’t cloak anything that lies in the axis of the lens system. The cloaking area is in the shape of a dough nut. Any part of the object that accidentally enters the axis area becomes visible and conceals the background. The device is simple and cheap enough to be easily scaled to cover greater area, as long as lenses of that size can be made. The video explains it better.

via [Quarks to Quasars]

A Fan With No Blades

By Anupum Pant

Fans have always had blades which chop up the air and send a turbulent gush towards you. Also, “you can’t put your head or hand through the traditional fan”. Although these things aren’t big problems that the device says it’d solve, I still like how different and innovative this thing is. Certainly worthy of sharing in my engineering section…

This one, one of the many amazing things invented by sir James Dyson, is a blade-less fan. Or as the man likes to call his invention – an air multiplier. As the name suggests, the device has no blades and yet it is capable of shooting out a steady stream of air on your face.

It’s amazing how it works. Watch Sir James Dyson himself explain it to you.

Weather Reporting Leeches

By Anupum Pant

Of all the creatures in the whole wide world, you’ll be surprised to know that leeches have played a fairly important role in the history of weather forecasting. An incredibly bizarre device invented by Dr. George merry weather, in the 19th century, called the tempest prognosticator, was basically a barometer powered by leeches.

Dr. George Merryweather, aptly named, was a surgeon by profession who was a lot into leeches. Since barometers were already being used for a long time then, to indicate approaching storms, he knew that air pressure was crucial in determining weather. However, Dr. Merryweather, an ingenious man, hell-bent on doing things the different way, had a different plan in his mind.

In his profession, he came across medicinal leeches all the time. In course of time, with a keen ability to notice details, he noticed that leeches were sensitive to electrical variations in the atmosphere.
He noticed a peculiar behaviour among these creatures. He observed that the leeches often started squirming around in a chaotic manner before a storm arrived.

Putting this practical knowledge to use, and experimenting with a number of designs, Dr. Merryweather devised a contraption. It consisted of 12 pint-sized bottles arranged in a circle. Each of which contained a leech in one-and-half-inch deep rain water. The top of every bottle had a tube into which the leech could crawl and disturb a mechanism, which in turn would activate a hammer to hit a bell – indicating that a storm is coming.

When a storm would come, the leeches were expected to crawl up the bottle, into the little pipe and activate a Heath-Robinson like mechanism which would make a hammer hit the bell. When the leech had completed its job it would fall down into the water and the hammer would go back to its place.

However, a number of times the leeches would give a false alarm. That was the reason he decided to use a jury of 12 leeches. And said,

The more of them that rang the bell, the more likely it was that a storm would be on its way.

If you ever go to Devon, you must take some time out to visit the Barometer World Museum to check out a full-scale working model of this device. Or you could go to the Whitby Museum in North Yorkshire to see the other working model.