I came across the EMdrive recently. It appears to be pseudoscience. It cannot work without violating conservation of momentum.
But then I found it was independently verified by three teams. How is this possible?
>note that those 3 teams arent billionaires right now rigorously using this technology to advance jack crap
the results are so small, people are waving their hands off as merely normal interference
"There are other examples of observation conflicting with the 'laws of nature', such as galaxies rotating at speeds different from that predicted by the 'laws of nature'. In this case, rather than modifying the 'laws' to conform to the new observations, the theorists simply revised the universe to confirm to the laws by 'deducing' existence of dark matter and dark energy from the fact that the galaxy rotation would be 'violating a law of nature' unless the universe consisted predominately of dark matter and dark energy with properties and distribution as required to make observations conform to said laws." -- Hoo Nose
>SPR is actually trying to market it
Shawyer works with the NWPU, they do ion drives as well.
2.88e-04 N/W means 86486 times the 'legal limit' of 3.33e-9 N/W
Get your quality drive at alibaba.com and a cheap toy version for your kids at aliexpress.com
Increasing the Q factor of the cavity.
The NWPU model of 2010 (details published in 2012) that ran on 2.5kW apparently had a Q factor of about 1530 (calculated from specified resonant frequency of 2.45GHz and 3dB bandwidth of 1.6MHz).
Experimental results from a newer model testet in late 2013 (published in early 2014) show that the resonant frequency and quality factor of the resonator system are 2.44895 GHz and 117495.08 respectively. Diagram looks like active tuning during operation, similar to what NASA now does. Note the sensor signal leading from the cavity to the controller.
If this scales linearly (it may not) that would mean 23mN/W or almost 7 million times the 'legal limit'. Let's wait and see..
Source: http://wulixb.iphy.ac.cn/CN/10.7498/aps.63.154103 (in Chinese)
>It appears to be pseudoscience
Because it is. If it works then it violates conservation of momentum and conservation of energy. The only way around that is to listen to Shawyer's "theory", which is embarrassingly incompetent (for example he thinks that there's an absolute reference frame, moreover he thinks that the earth is at rest with respect to it). The effects are almost certainly something else other than actual thrust. For me this all seems like the so-called "Pioneer anomaly" all over again, the tldr of it is:
>Pioneer was drifting off course for no discernible reason
>Cooks claimed all sorts of modifications to physics to explain it
>Turns out it can be explained by thermal force recoil
>I have literally no understanding of either dark matter nor dark energy.
>Shawyer's "theory", which is embarrassingly incompetent
i agree, but that doesn't mean the device does not work
>If it works then it violates conservation of momentum
it only violates it if you expect the device to work by radiation pressure. but it might take advantake of some wierd quantum effect we did not discover yet
> and conservation of energy.
how so? you don't get more work out of it than you put in
was already observed indirectly
>how so? you don't get more work out of it than you put in
Simple thought experiment:
Assuming the effect is velocity independent, you could put a drive on the edge of a wheel, and turn it on. The wheel would accelerate to the point where the power produced was greater than the power required to operate the drive.
The conclusion is that either the drive doesn't work at all, the effect is velocity dependent, or physics is seriously hosed. Which is more likely?
Let me try. According to Shawyer his device use energy when its accelerating but produces energy when decelerating. The problem is a deceleration is just an acceleration in a certain direction, so we have an infinite energy device.
No it would not. Given a constant power input, it would flatline at an angular velocity that is also dependant upon on the characteristics of the wheel and the load it is driving. To generate more power, you'd have to put more power in.
How is deceleration producing energy a problem? My Prius does this everyday.
If he said it could translate electrical energy into linear motion and back again WITHOUT the usual sacrifice to Lord Carnot, God of Entropy, that would be a problem.
the difderence is, your prius is mechanically coupled with earth. EMdrive is not.
an EMdrive laying on a table is accelerating towards the center of earth at 9.8g.
if you flip it over, it's decelerating by the same amount. thus it's making free energy.
Your Prius is on land. The friction between the wheels and the ground keeps the wheels spinning, which effectively uses your car's kinetic energy to generate electric potential with a DC generator (at least I assume they use a DC generator).
We do not have this luxury of friction in space.
Anyway, no it's not. The EM drive never claimed to generate free energy. You made that up. In fact, right now it wastes A LOT of energy (possibly all of it). All it does is create propellent -less energy, so that we don't have to physically carry fuel up into space to generate thrust. It would always use more energy than it would create, no one ever said otherwise.