Author Topic: Quantum vacuum plasma thruster  (Read 1344 times)

Offline Lynx Cat

  • Miocene Terror Bird
  • *******
  • Posts: 211
  • Karma: +0/-0
    • View Profile
    • Worldline Collapse
Quantum vacuum plasma thruster
« on: August 06, 2014, 08:29:13 AM »
XKCD drew my attention to something that's been making the rounds of pop-sci publications: some folks at NASA are testing something called a "quantum vacuum virtual plasma thruster". In short, it bounces microwaves back and forth in a tube whose width is equal to the wavelength and somehow get thrust out of it, without propelling anything, which of course violates conservation of momentum. Or they don't, and it's just some measurement error, as in the case of the infamous faster-than-light neutrinos.

There have been actually two recent experiments of the sort. The first, called "EmDrive", purports to work as described above. The second one (which is the one made by NASA folks) has been nicknamed the Cannae Drive (after McCoy's "ye cannae change the laws of physics!" quote from Star Trek), and I don't know how exactly is this experiment different from the first (if at all), but this time they're touting the "quantum vacuum virtual plasma" explanation. Which basically says that they get thrust from pushing agains the quantum vacuum's virtual particles.

Now, I know that virtual particles becoming "real" is apparently a real thing, as observed in the Casimir effect and Hawking radiation. So I guess that, in principle, you might get thrust by artificially creating Hawking radiation, so to speak (which is how I understand their explanation) and shooting it out the other end, thus maintaining conservation of momentum. So what's the big fuss then? Am I getting it wrong? Or is it more about getting the energy to do that for "free", since it apparently comes from a standing wave?
Did I do, O CROM, did I as I said Id do? Good! I did.