If this EmDrive thruster is real, it's really cool. I love when things are found through empiricism that current theories can't explain. It either points to an error, or to a new realm of knowledge that we don't yet understand.
Ok... so... God decides to kick off early one day and go to the beach, so he rounds this one miniscule calculation up. "Psh. That's too small for anyone to notice or care..." Then he grabs his towel and surfboard, and heads off to the beach. The world will still be there tomorrow, after all! It's not like anybody else is working on this project! Self employment rocks! Then billions of years later, some eggheads notice an anomaly... and suddenly we have interstellar spaceflight. Psh. "All knowing, all powerful being" my ass! Even he took shortcuts. Apparently.
The Unruh effect is fascinating. I'm still under the impression that this theorist, McCulloch, is mistakenly using an alternative interpretation of physics (Unruh phenomena) as a generating function that then couples back into known physics. Two for him, one for me, he broke the rules. A Forbes article seems to represent the conventional interpretation of all of this. Edit: you have to click the link twice to get past the "welcome" page. C'mon, Forbes, get your shit together.
I can't say I understood many of the details, but my main takeaways from this article are: a) the EmDrive is for real, b) it's possibly even better than we thought it could be and c) this has the potential to upset our understanding of physics / roil some people's blood.
A) the EmDrive is for real The article posits a theoretical framework that explains the thrust seen in experiments. That framework basically says that for super-small accelerations, inertia comes in discrete increments. It would follow that the EmDrive will, therefore, never scale up, but that may or may not be a limitation depending on design. I don't understand the framework well enough to have any confidence in opining. B) It's possibly even better than we thought it could be Well, again, it seems to me as if the theory put forth basically says "this only works for super-tiny minuscule effects": They do put forth the idea that (1) the thruster can be tuned and reversed (2) efficiency can be increased with a dielectric (TBD) which is interesting. I understand this thing well enough that I know I couldn't build one and I know I wouldn't know what I was looking at if I saw one but I think you could have a whole bunch of them strung together which might defeat some of the limitations. But right now, we're at a tenth of a newton of thrust with 17W of power input and the discussion at hand is "let's explain this anomalous thrust" rather than "whoopee we created an impulse drive." C) this has the potential to upset our understanding of physics / roil some people's blood So... I dove into the actual paper and this part is troubling: but here this is assumed. It is not clear what the size of this mass is, but it is clear for example that light inside a mirrored box produces a kind of inertial mass for the box. I dunno. I'm not a theoretical physics genius (I'm not even a theoretical physics lunkhead) but the phrasing of that particular condition is troubling. The whole "do photons have inertia" appears, to my lay read, to be very much a semantic discussion that's wholly dependent on how you're doing the math and I'm not near clever enough to argue this one, but this looks like some supreme hand-waving.At very small accelerations, the wavelengths become so large they can no longer fit in the observable universe. When this happens, inertia can take only certain whole-wavelength values and so jumps from one value to the next. In other words, inertia must quantized at small accelerations.
McCulloch’s theory could help to change that, although it is hardly a mainstream idea. It makes two challenging assumptions. The first is that photons have inertial mass. The second is that the speed of light must change within the cavity. That won’t be easy for many theorists to stomach.
Normally, of course, photons are not supposed to have inertial mass in this way,
Did physics in college. Not genius, but hopefully not lunkhead. Photons definitely have momentum, that's not controversial. They shouldn't have mass, but that doesn't seem to be the point of the article. Speed of light should not change in a vacuum, though.