China claims successful test of microwave relativity engine
Credit: Elvis Popovic
Researchers in China say that they've successfully managed to test an engine that runs on electricity, requires no propellant and produces no exhaust. It's called the EmDrive, and it's able to convert microwave energy directly into thrust inside a sealed chamber. Oh, it's totally silent and highly efficient, too. If it seems too good to be true, well, you're not the only one who feels that way. But the researchers have a prototype that apparently works, and they've just published a paper detailing it.
Before we get into the mechanics of the EmDrive, let's give it some context. An engine is something that converts energy into motion. There are lots and lots of different ways of doing this, but let's take a look at a very simple one: a rocket engine. With a rocket engine, you've got a big tube with some explosive stuff (propellant) in it. When you launch the rocket and the propellant combusts, it tries to expand in all directions at once, but because it's stuck in a tube, it can only make it out the back. This means that the force that explosion exerts on the tube is symmetrical in every direction except for the back and the front, and as the propellant escapes out the back, the rocket gets pushed forward.
The basic principl
is that there's a reaction going on: stuff you don't care about (the exhaust) going one way pushes something that you do care about (the rocket) the other way. The reason that this works is a fundamental law of physics: Newton's Third Law, to be exact, which says that all forces exist in pairs. It also works because of the Law of Conservation of Momentum, which says that in a closed system, total momentum (which is the product of both mass and velocity) is constant. In other words, you can't have a rocket that moves forward without something moving backwards, and you also can't have a rocket that moves forward if you seal up the back end.
According to the fundamental laws of physics, the universe should not allow it to work.This is why the engine that scientists in China are claming to have successfully tested is so crazy: According to the fundamental laws of physics, the universe should not allow it to work.
The basic operating principle of this engine was conceptualized by a British dude named Roger Shawyer several decades ago, and has been in the news over the last few years (including on DVICE) as Shawyer built prototypes. The EmDrive itself is simply a microwave resonating cavity in the form of a closed, truncated cone. You fire up a big electrically-powered microwave generator and start beaming microwaves inside this thing, and the microwaves bounce around all over the place, exerting radiation pressure on the inside of the cavity.
Here's a diagram we found on New Scientist:
http://www.dvice.com/2013-2-8/china-claims-successful-test-microwave-relativity-engine 
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Credit: Elvis Popovic
Researchers in China say that they've successfully managed to test an engine that runs on electricity, requires no propellant and produces no exhaust. It's called the EmDrive, and it's able to convert microwave energy directly into thrust inside a sealed chamber. Oh, it's totally silent and highly efficient, too. If it seems too good to be true, well, you're not the only one who feels that way. But the researchers have a prototype that apparently works, and they've just published a paper detailing it.
Before we get into the mechanics of the EmDrive, let's give it some context. An engine is something that converts energy into motion. There are lots and lots of different ways of doing this, but let's take a look at a very simple one: a rocket engine. With a rocket engine, you've got a big tube with some explosive stuff (propellant) in it. When you launch the rocket and the propellant combusts, it tries to expand in all directions at once, but because it's stuck in a tube, it can only make it out the back. This means that the force that explosion exerts on the tube is symmetrical in every direction except for the back and the front, and as the propellant escapes out the back, the rocket gets pushed forward.
The basic principl
According to the fundamental laws of physics, the universe should not allow it to work.This is why the engine that scientists in China are claming to have successfully tested is so crazy: According to the fundamental laws of physics, the universe should not allow it to work.
The basic operating principle of this engine was conceptualized by a British dude named Roger Shawyer several decades ago, and has been in the news over the last few years (including on DVICE) as Shawyer built prototypes. The EmDrive itself is simply a microwave resonating cavity in the form of a closed, truncated cone. You fire up a big electrically-powered microwave generator and start beaming microwaves inside this thing, and the microwaves bounce around all over the place, exerting radiation pressure on the inside of the cavity.
Here's a diagram we found on New Scientist:
http://www.dvice.com/2013-2-8/china-claims-successful-test-microwave-relativity-engine