Don’t think so but the paper states
Previous thread, which also references another previous thread.
But it emits energy, doesn’t it? Energy goes in; energy comes out. Or is the thrust detected simply a directional heat emission generated by the energy going in?
No, you wind up with waves reflecting back and forth inside the cavity and so you wind up with no net force. This EmDrive apparently does experience a push in a specific direction.
Now you can argue one side of the drive is getting preferentially hotter and so emitting radiation and effectively acting like a infrared photon rocket. Apparently, that isn’t what’s happening here. I only skimmed the paper but my thoughts are it’s time for a number of groups to go forth and reproduce!
That’s what the paper looks like.
It might produce an effect that would explain what they see with shape used. What would happen if the shape were asymetrical? As pointed out before, now that there seems to be something to study we should see a flurry of research.
In the spirit of my recent prediction that the Democrat Party would sweep the Houses of Congress, let me share another about this. It is the first real world example of dark energy and it explains why the universe is accelerating outward.
Please note that something having passed peer review doesn’t mean that it’s right, nor that the referees, or even the authors, think it’s right. At best, they haven’t yet figured out any way to show how it’s wrong. (For instance, in my field, a paper was published that apparently demonstrated a device for faster-than-light communication; the referee was pretty certain that it was wrong, but at the time, nobody knew what didn’t fit. The resulting work led to the discovery of the no-cloning theorem, the fact that you can’t copy a single quantum system in an unknown state, which is nowadays one of the cornerstones of quantum information theory.)
And while I haven’t yet read the paper (and am not an expert in the field regardless), just from the quotes in this thread, I kinda have to wonder how it ever got past peer review—the supposed ‘explanation’ is basically gobbledygook; quantum fluctuations are just a handy bookkeeping tool for certain calculations, and saying that you can ‘push off’ of them is basically like saying you’re pushing off of numbers. I certainly wouldn’t have accepted a paper with such a dodgy claim.
But dodgy theory aside, if there’s an effect there, it’s certainly worth investigating. I’m reminded here of the Pioneer anomaly, which was an unexplained acceleration that the Pioneer spacecraft experienced that eventually turned out to be due to uneven thermal radiation. I don’t think this would be an effect strong enough to explain the acceleration in this case, but it’s certainly way too early to discount any mundane explanations of the effect—after all, the Pioneer anomaly also took a couple of years to resolve, and led to a lot of exotic speculation.
You can’t really ‘emit energy’. Energy is a property of stuff, or of a collection of stuffs. If you move forward from a standstill, and nothing else ends up moving the other way, you’re violating conservation of momentum.
The germ theory of disease.
There was a doctor who did sufficient science to prove that if he and his nurses washed their hands, after working with the dead and ill, there was a lower mortality rate in the infant ward. All the other doctors decided that this was nonsense, since he had no theory about what was happening.
It should also be noted that Newton had no particular theory for gravity. He simply provided the formula and said, “Who cares why, it just is.”
I seem to recall that the effectiveness of basic reaction rockets was seriously questioned before we succeeded in putting them in space. The idea was that in a vacuum they would not have anything to push against.
Obviously, that was not correct. It would be cool if something similar happened here demonstrating that the concept does work, but I’m not holding my breath.
My understanding of the workings of the EM Drive is that microwaves are generated, then bounce around in a closed chamber, which somehow produces a measurable amount of thrust. The big “problem”, as I understand it, is that it does this “without requiring a fuel source”, which defies known laws of physics.
But it seems to me that there is a “fuel source”…a craft powered by this engine either needs to carry some power source to generate the microwaves (call that “fuel”), or else it needs to obtain the power from some external source (say, the sun). In either case, we’re just ‘burning fuel’ to create thrust, just like in any other sort of engine, aren’t we?
I assume I’m missing something here…but what?
Surely you jest.
I’m pretty sure Newton’s third law was well understood by the entire scientific community before rockets made it to space. You may be recalling something that was said by non-scientists.
This.
I’m not a physics expert by any means, but both Galileo and Newton were dealing with the behavior of objects in a vacuum well before the 20th century. By that time, the models were all already making the presumption of a vacuum as the default, with air resistance, etc. being a modifier to the system.
Everything we design to move has to generate thrust. Sailboats generate thrust by deflecting the wind, cars by pushing against the ground with tires, rockets by pushing shit out behind them. With rockets, the mass and speed (momentum) of what goes out the back is approximately equivalent to the speed the rocket achieves in the other direction: conservation. Spacecraft have been tested with engines that create thrust by pushing ionized gas out the back, but conservation still applies.
So, this thing seems to produce thrust simply by consuming energy to set up radiowave interference pattern inside the chamber. Nothing is coming out the back and there is nothing thrusting against something else to explain how the force is being created.
This could be good because rockets need to haul around the matter they use to push themselves forward. This thing never pushes shit out the back, so the fuel mass would not have to be the large amount needed to complement the desired motion. If the power source were a TW nuclear reactor, the force could, theoretically, be respectable for a large craft without requiring an equivalent mass of reaction fuel.
At the moment, any ansewers would be guesses, but does this scale up or does it run into a mass wall at some point, ie like using an outboard motor to move a freighter.
Second, what would the on ramp speed be for this drive, something like the plasma drive which takes a while to get up to speed, or a Jeremy Clarkson power on demand.
Personal observation, if the drive works, it could open up the inner solar system.
Not entirely true. If I put a big hunk of steel on one side of a table and a super powerful electric magnet on the other, and hit the on switch, there will be no thrust moving the magnet toward the steel block.
I could theorize (based on nothing whatsoever) that the EM device acts on a similar principal, using attraction to move itself, but somehow is able to shield itself from the attraction on one side, so that it is able to move any desired direction it wants.
The paper that Grey linked to above presents a possible QM explanation as to what is happening,
(emphasis mine)
I greatly abbreviated the content. It is from section 10. Discussion, about 9/10[sup]th[/sup]s of the way down the page. Fascinating stuff.
I can’t remember where I read this - I’m a space history geek, so I’ve read a lot of that stuff. I’ll post it when it comes to me.
But if you put both the magnet and the block of steel on an operating air hockey table (frictionless surface), the two will be drawn together, to a barycenter (point closer to the heavier mass). To move the block all the way across the table, the electromagnet must have a counterforce (it is effecting thrust against whatever it is mounted on).