Invisibility cloak made from simple mirrors

[Still Waters]

Researchers at Northwestern University have designed an invisibility cloak that can temporally hide objects for an indefinite period of time.

Objects covered by this invisibility cloak wouldn’t disappear from sight, but rather it would appear that time has completely stopped for the cloaked object. A clock, for example, would continue to tick — but to the human observer, the hands would never move.

http://www.extremete...me-indefinitely

[pallidin]

The title extension is misleading, not by the OP here, but by the article writer.

The "can stop time indefinetly" is not true at all.

In fact, this appears to be a very complex process that, not only is just theorectical(though likely) but has significant limitations.

For example, the article states:

The duration of the temporal cloak is twice the time it takes light to travel between A and B — and so if you place B a very, very long way away — such as on another planet — you could theoretically cloak an object for minutes, or hours… or light years. I guess you could even do it here on Earth, if you created a massive (and I mean millions of miles massive) network of mirrors capable of bouncing light around for a few seconds or minutes.

In other words, this technique at short distances(a few feet or even several miles) will simply not work to any useful degree.

And, of course, time can not be stopped. What is happening here, though clever, is "delayed perception" However, given the speed of light, it takes an enormous amount of distance/mirrors to create this effect to any perceptable degree, and a considerable amount of loss in light intensity would result.

Edited August 19, 2013 by pallidin

[wyelander]

I built an invisibility cloak a couple of years ago. Trouble is I've not been able to find it since...

[Mac E]

This is another invisibility cloak with major limitations making it relatively useless for practical applications.

[ash68]

Many great inventions we take for granted today started out pretty useless with limitations so I think you have to appreciate this as a first step towards something great

[paperdyer]

Even in Star Trek, if you looked hard, you could see the spacial distortions from a Romulan or Klingon cloak.

[StarMountainKid]

I witnessed a real invisibility cloak in Chicago years ago. I was at a St. Patrick's Day parade. What it was was a garbage truck covered with mirrors. It was really a strange sight...or not a sight. The truck couldn't be seen at all, all there was to see were the reflections of the buildings around the truck.

The truck was invisible. If you had seen it in person, it was weird.

Another kind of invisibility cloak was tried in WW2 to hide war ships at sea. The U.S. Navy Dept. asked some scientist how to do this. His reply was to put bright lights on the ship in daytime. The Admirals thought this was a crazy idea, but when they tried it, bright lights a ship near the horizon made it impossible to see.

I don't have a link for this, though.

[shrooma]

Another kind of invisibility cloak was tried in WW2 to hide war ships at sea. The U.S. Navy Dept. asked some scientist how to do this. His reply was to put bright lights on the ship in daytime. The Admirals thought this was a crazy idea, but when they tried it, bright lights a ship near the horizon made it impossible to see.

.

sounds more plausable than the 'Philidelphia Experiment' SMK!

[brlesq1]

Hey, this is pretty cool. Don't know what you'd use it for, but it's still pretty cool.