Close Look at Recent EmDrive Paper
centauri-dreams.org
centauri-dreams.org
But they're only testing at relatively low power levels like 40W, 60W, 80W. There are lots of commercially available sources for Klystron and TWT type amplifiers rated up to 3000W (used for C, Ku and Ka-band satellite earth station Tx applications). If the question is whether it's real, would it not make sense to build a HUGE FUCKING HIGH POWERED test rig with >1500W input?
If we're measuring possible "thurst" in micronewtons, and the claim of the original research is that the thrust will scale somewhat proportionally with the power level applied, does it not make sense to develop an unambiguous result by building a very high powered test rig?
In a theoretical scenario where a high powered test rig produces real measurable thrust that is far too great to be a measurement error, it would be an amount in millinewtons that is far too great to be explained by a non-thrust variable such as thermal expansion/contraction in the power cables, etc.
If the claim is 260 micronewtons at 60W, use COTS klystron and/or TWTA technology to build a 3000W test rig. Question answered.
here are some examples of high powered units for satcom purposes: http://www.cpii.com/product.cfm/4/13
edit: The thing is described as a "resonant cavity" and operates at 1.9 GHz: http://arc.aiaa.org/doi/10.2514/1.B36120
Looks damn near identical to a weird feed horn to me. The test article looks like a cone or horn antenna with a feed horn stuck onto the back of it. High power capable waveguides and feed horns for big-ass satellite telecom things (like an 11 meter sized C-band Tx/Rx earth station) are a well known science. You can buy them from a myriad of COTS sources.
Space operations also might cause new types of artifacts. One such might be forces from induced currents due to spacecraft motion relative to the Earth's magnetic field.
I think it's just expensive to do a really definitive physical demo in this domain, given that the effect (if there is one) is so small and sources of artifacts so numerous.
The paper says the thrust is somewhat non-linear with respect to drive. It does nothing, then comes on quickly.
https://news.ycombinator.com/item?id=13249730
One of the comments in this threads story, was to place the apparatus is a faraday cage. That does not shield against static magnetic fields. For that you need chambers of multiple layers of high permeability materials, separated by air.
My take - the people pushing this are charlatans and should be ignored completely.
"We don't understand it and the explanation is likely boring, so let's ignore it" might be a decent engineering tradeoff, but it comes from a goal of cost savings, not from a goal of improving our knowledge of physics. Science is about improving our knowledge and understanding.
1) Were looking for the error in their method, not trying to get press and/or budget using a claim of FTL particles.
2) Had already done their darnest to not be fooled by their experimental setup. And this was a huge lot of phycisists having looked.
Neither 1 nor 2 hold here; and so these people are wasting other people's time.
The likely explanation is "it's really hard to isolate this setup so that we can measure it effectively".
Or well-respected scientists investigated and debunked the anomalous results. Because that's how science works.
In the case of the emdrive, we've got plenty of theoretical reasons to assume it's wrong. It's really on the proponents to come up with more convincing evidence. Occam's razor and all that. If you feel bored, check it out, but there's probably nothing there.
I feel differently about EmDrive than you, I guess. Digging into anomalies seems like good science to me. I'm glad it's happening if just to provide a counterpoint to the sensational reporting.
It's expected that the people working on this for 15 years would claim to find an effect, since they clearly have an agenda that they want to be seen as right. It's explained by this very article how there are many reasons other than "propulsion-less thrust" that would cause the reported results.
Jelly beans cause acne. But if you investigate further, only green ones. Unless you keep pouring money down the drain with it, in which case it's only the green ones of a certain weight.
This sort of experiment requires a very expensive, delicate laboratory. No one is going to run a replication of this and then not publish in some form, even on a blog or a conference poster.
If it crashes to earth after a year, then it clearly doesn't work.
If it steadily starts to escape earth's orbit, then it DOES work.
As of right now the claimed effect is smaller than the thermal effects even in the lab. You put it in space and it'd be impossible to untangle the tiny real effect, if it exists, from all the other forces superimposed upon it that are much larger and literally impossible to predict the time variation of.