The EmDrive Doesn't Generate Thrust

You can add the EmDrive to the long list of too good be true scientific ideas: The Dean Drive, cold fusion, and the OPERA experiment that found faster-than-light neutrinos.

In June I posted that a team of German physicists was attempting a definitive test of the EmDrive. They've published their results and found that the observed thrust could be accounted for by magnetic fields generated in the wires feeding power to the device. When the device was properly isolated, there was no thrust.

Tajmar’s results are exactly what you’d expect for the systematic error explanation: with a properly shielded apparatus, with no additional electromagnetic fields induced by the wires, there is no observed thrust at any power. They conclude that these induced fields by the electrical wires, visibly present in the other setups, are the likely culprit for the observed, unexplained thrust:

"Our results show that the magnetic interaction from not sufficiently shielded cables or thrusters are a major factor that needs to be taken into account for proper µN thrust measurements for these type of devices.

To the best of our knowledge, then, rockets will still require propellant. The EmDrive isn’t a reactionless drive at all, and all the laws of physics should still work. In short, we fooled ourselves."

So you can now add the EmDrive to the long list of too-good-to-be-true scientific ideas: The Dean Drive, cold fusion, and the OPERA experiment that found faster-than-light neutrinos.

Update: Wired has more details on the experiment, which did measure a small amount of thrust, which the experimenters believe is due to thermal expansion of the copper cylinder. Experiments are still ongoing.