One of The Brickmuppet's Crack Team of Science Babes sends you all seasons greetings and shows off a reliable and well understood way to generate thrust applied to one's shoulder. The
uses an explosion to send a 14 gram projectile at 760 meters a second in one direction and that force minus the mass of the rifle is applied to the shooters shoulder.
Note that "minute" doesn't do justice to the infinitessimality of the thrust levels involved.
There seems to be SOMETHING going on with these devices, but the thrust is so low (at least in the NASA sponsored tests) that prctical application of them seems dubious even if they do work.
So maybe...
In any event, after this Chinese announcement, we here at Brickmuppet Blog remain deeply skeptical, but ever so slight more hopeful.
As it stands now, the thrust levels have little practical application, being orders of magnitude lower than even arc jets, However, IF, it actually works, and IF they can increase the thrust by a few orders of magnitude, then this could be a real thing. Those are a couple of pretty big and unlikely "Ifs"but they would portend a truly awesome development.
It would also be a disturbing one since it would mean that our understanding of even the most very basic rules of our universe is completely wrong.
1
I'm about a trillion percent skeptical of the EM Drive. It violates the laws of motion, the laws of thermodynamics, relativity, QM, and Noether's Theorem. I'll believe it when they fly one from LEO to Mars and back.
Maybe.
Posted by: Pixy Misa at Thu Dec 22 20:54:40 2016 (PiXy!)
2
The last time this made news, it was finally debunked publicly. Unfortunately, like an idiot, I never saved any of the links. The bottom line, if I remember correctly, is that you have to intentionally fudge the numbers in order to show thrust via the math, as it is not actually measurable.
Incidentally,
here's the "Chinese" drive featured in the article. As used in Discover Magazine in 2014. Exact same picture. A picture provided by the sales and marketing guy who's taken over trying to sell the EmDrive.
So......I call complete and utter bunk on the whole story.
Posted by: Ben at Thu Dec 22 22:43:41 2016 (S4UJw)
Posted by: Rick C at Fri Dec 23 15:53:10 2016 (ECH2/)
4
FIEND! You not only post non-deferential comments, you do so with naked URLS. What do you think this is? A free country?
As I said in the post, I'm quite skeptical. But my skepticism is not quite on Pixy's level, being just over 9000. It looks like it could be producing thrust via the same way a lightbulb does or it's the RF equivilent of a Dean Drive...stuff bouncing around and it's a tad off balance like a badly loaded washing machine...but with radio. This would make it useless or worse. Note that the thrust is in millinewtons...MILLINEWTONS.
The Chinese claim seems to imply a certain practicality that had heretefore eluded anyone, which is what inspired the post. There are three potential reasons for the Chinese press release.
1: The Chinese discovered something interesting.
2: There is a translation glitch.
3: The Chicoms are lying (as Chicoms will).
I think that the probability here is weighted towards two and three, but some interest is still warranted.
Posted by: The Brickmuppet at Fri Dec 23 19:33:49 2016 (KicmI)
5
The last "scientific explanation" of the drive I read, it basically worked like the ZPE drive originally featured in Heinlein's "The Number of the Beast". Getting into the estoterica of zero point energy and whether you can or can't interact with it is a bit beyond my comprehension of physics, so I remain skeptical but hopeful. On this article though, it was pointed out where I first read about it that the headline and content didn't match, and nothing in the source actually indicated that China was actually claiming to have results from space tests yet, they were just announcing that they had a test article on the station and were going to be running tests, and the mention of test results was referring back to their ground tests.
Posted by: David at Sat Dec 24 00:37:35 2016 (9UHFZ)
6
David, yeah, that's where it would violate Noether's Theorem. ZPE is real, and experimentally verified. But to interact with it in some surprising way would require a new subatomic particle, known as a gauge boson, like the recently discovered Higgs boson.
But because the effect is claimed in a little microwave device running at a few tens of watts, not an enormous particle collider or a supernova or something, the energy of the particle itself would also be small. Noether's Theorem lets us calculate the energy, and it's low enough that the particle would have been discovered in the first cyclotron experiments back in the 1930s. Since it wasn't, either Noether's Theorem is wrong (and it's fundamental to most of modern physics) or the EM Drive doesn't work.
So if the EM Drive works, then the computer I'm using to type this comment doesn't, and vice-versa.
Posted by: Pixy Misa at Sat Dec 24 03:21:36 2016 (PiXy!)
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One thing to think about:
The EM Drive supposedly generates force without reaction, you just need energy. Put X amount of energy in, you accelerate by Y amount.
Y is very small, but that's okay, use nuclear power (an RTG or a full fission reactor) and you can keep the thing running as long as you want.
But while the energy required to accelerate the EM Drive to a given velocity is proportional to that velocity, the kinetic energy of the object moving at that velocity is proportional to the
square of the velocity. At some point, as you keep accelerating, the EM Drive becomes a magical free-energy device.
That's why no serious physicist gives this thing the time of day. It violates every law of physics in ways that would be obvious from a million previous experiments if they were possible.
Posted by: Pixy Misa at Sat Dec 24 03:31:12 2016 (PiXy!)
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So if EM drives actually worked, we would have figured that out a long time ago, and some stage of the Cold War would have involved America and Russia pointing them at each other?
Posted by: Karl at Sat Dec 24 05:21:39 2016 (1FrBd)
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Putting it mildly. If the EM Drive actually worked, the average temperature of the Universe would be something like a trillion degrees, there'd be nothing but gamma rays and protons.
Posted by: Pixy Misa at Sat Dec 24 05:45:34 2016 (PiXy!)
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