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Why the "NASA Tested Space Drive" Is Bad Science
StartsWithABang writes Just over a century ago, N rays were detected by over a hundred researchers and discussed in some three hundred publications, yet there were serious experimental flaws and experimenter biases that were exposed over time. Fast forward to last week, and NASA Tests Microwave Space Drive is front page news. But a quick analysis shows that it isn't theorists who'll need to struggle to explain this phenomenon, but rather the shoddy experimentalists who are making the exact same "bad science" mistakes all over again.
The NASA science is just fine: http://www.wired.co.uk/news/archive/2014-08/07/10-qs-about-nasa-impossible-drive
Wait, is this guy talking about space drives or global warming skeptics?
FTA:
1. The magnitude of these effects varied tremendously from experiment to experiment. //endtroll
2. The threshold of measurement—the difference between a detection and a non-detection—was always extremely close to the actual claimed detection.
3. Many attempts at confirming the experiments by some of the leading scientists of the day, including Lord Kelvin, Heinrich Rubens and Robert Wood, all produced null results.
4. And finally, even if you restricted your data sets to the positive the experimental results, their claims were inconsistent with one another.
FTFY
He made three key points:
-The thrust from all 3 experiments varied by 500%. -Duh, the Chinese used kilowatts and Nasa used watts of energy.
-The thrust measured 30-50n was too close to the min tolerance 10-15n of the instrument. -3x-5x the min is "too close"?
-OMG the control showed the same thrust as the actual drive! -Not true. But hardly surprising given the wording of the abstract. You would think he would read the paper before tearing holes in it.
Don't get me wrong. I think the drive probably doesn't work. But this article is written by someone who is gleefully uninformed.
Except none of your points applies to climate change.
The effect is robust: there was a whole independent project to determine if the thermodynamically meaningless "global average temperature" is increasing. It is: http://www.bbc.com/news/scienc...
The threshold of measurement is around 0.5 C for a single station, and we have an effect that is about 1 C over the past 100 years. Not as big a margin as one would like, but difficult to ignore. And growing.
No one has produced any results that show the instrumental temperature record in the past century is not real. There are debates about causes, but the reality of the phenomenon is not in doubt.
Everyone who has looked at the question agrees that there is about a 1.6 W/m**2 addition to the Earth's heat budget from anthropogenic CO2, so clearly when taking the "positive cases" there is still good agreement.
There are large and legitimate areas of disagreement with regard to climate change (far more than the moron, anti-science, "the science is settled crowd" would have you believe) but the basic phenomenon, unlike the EMDrive, is not just consistent with but actually required by the laws of physics.
Finally: the summary is terrible, even by /. standards. The article does not point out any errors in the experiments. Rather it points out that reporters have been lying about the experiments, pure and simple. That is not the fault of the scientists, who honestly reported their null results.
Blasphemy is a human right. Blasphemophobia kills.
* they did pretty much all of the things you would like to see (such as reversing the direction and making sure the thrust reverses).
* they seem to have done a thoughtful and careful job, including testing in vacuum.
So, I still think they are likely wrong, but this ups the ante. In my opinion, you can't just say "this is obviously wrong."
Sure I can. Was the apparatus temperature controlled during the vacuum test? Was it tested in all orientations (not just backwards) to remove any gyroscopic weirdness from the rotation of the earth (think Michelson-Morley experiment). Was there EM coupling between the cavity, the torsion balance, and the chamber that could manifest as an anomalous torque, not thrust (that is, did they just make a big brushless motor)? Does the instrument register a thrust when the cavity is radiating but is bolted to the chamber floor and not the balance? Is there no thrust when it's oriented orthogonally? Does it still work if the power supply is electrically isolated from the vacuum chamber without a common return (ie did they build an electron gun)?
It's sad how pathetic the pretenders on Slashdot are sometimes. So full of themselves and sure that they are smarter than the next guy.
I know it's appeal to authority, but NASA doesn't employ idiots. And if you had bothered to do even a simply Google search you would have found this which sheds some more light on the situation.
Just to save you the effort, the abstract sucks (most likely written by a public relations flunky), they were very careful in setting up the experiment, it WAS done in a vacuum, there is something there. Note that they didn't explain it, they just report their observations.
But you go ahead and stick with your second year physics student attitude.
Bigger stupid one: the "null" device wasn't even supposed to be an EmDrive. It was supposed to be a Cannae Drive, which has a similar design but was invented by a completely different person and (supposedly) operates on different principles. The inventor of the Cannae Drive claimed that the difference between the null and actual test devices would mean there were different results. He was wrong, as shown experimentally.
The actual inventor of the EmDrive (whose device was also tested by NASA, months ago, and was produced twice the thrust on 60% as much power) says that the Cannae Drive is just an inefficient EmDrive in either null or "real" configuration. http://en.wikipedia.org/wiki/E...
There's no place I could be, since I've found Serenity...