04 May 2015

Sorry to Harsh Your Warp Drive Buzz ………*

The reports of the EM Drive appear to be greatly exaggerated:

Perhaps we should take a long cool drink at this point. Let’s start with the “NASA validates” part. NASA is a huge agency, with more than 18,000 employees. The testing was done by five NASA employees in a lab devoted to exploring unorthodox propulsion ideas. The team leader is a researcher named Harold “Sonny” White, himself a proponent of ideas about faster-than-light warp drives that most of his colleagues have classified as physically impossible. The lead author is one of White’s Eagleworks teammates, David A. Brady. Calling this group “NASA”—as almost every popular news story has done—is a gross oversimplification.
till, science is science: What matters are data, not motivations or semantics. Did White et al actually validate Fetta’s version of the EmDrive? The abstract of their paper, which was presented at a propulsion conference in Cleveland, is freely available online. Reading it raises a number of red flags. The methodology description makes it unclear how much of the testing took place in a vacuum—essential for measuring a subtle thrust effect. The total amount of energy consumed seems to have been far more than the amount of measured thrust, meaning there was plenty of extra energy bouncing around that could have been a source of error.

Worst of all is this statement from the paper: “Thrust was observed on both test articles, even though one of the test articles was designed with the expectation that it would not produce thrust.” In other words, the Cannae Drive worked when it was set up correctly—but it worked just as well when it was intentionally
disabledset up incorrectly. Somehow the NASA researchers report this as a validation, rather than invalidation, of the device.

Did I say that was worst of all? I may have  take that back. In the paper by White et al, they also write that the Cannae Drive “is producing a force that is not attributable to any classical electromagnetic phenomenon and therefore is potentially demonstrating an interaction with the quantum vacuum virtual plasma.” That last bit stopped me. What’s a quantum vacuum virtual plasma? I’d never heard the term, so I dropped a note to Sean Carroll, a Caltech physicist whose work dives deeply into speculative realms of cosmology and quantum theory.

Carroll wrote back immediately, with a pointed message: “There is no such thing as a ‘quantum vacuum virtual plasma,’ so that should be a tip-off right there. There is a quantum vacuum, but it is nothing like a plasma. In particular, it does not have a rest frame, so there is nothing to push against, so you can’t use it for propulsion. The whole thing is just nonsense. They claim to measure an incredibly tiny effect that could very easily be just noise.” There is no theory to support the result, and there is no verified result to begin with.


That’s part of why this space-drive story bothers me so much. Abandoning known science when it feels good to do so is a dangerous proposition. As Carroll later tweeted, “The eagerness with which folks embrace sketchy claims about impossible space drives would make astrology fans blush.” I am personally a huge space enthusiast; I would love to see a new type of propulsion that would make it easier to explore the universe. But having your heart in the right place is no excuse to walk away from normal critical thinking. It is not materially different than the approach of people who reject science when they don’t like what it says about climate change, vaccines, or genetically modified organisms.
(Emphasis Mine)

Let's be clear here:  The tests are dubious, the detected "thrust" being, "Between 30-and-50 microNewtons, where the limit of the measuring device is 10-to-15 microNewtons," which makes the setup vulnerable to subtle errors and confirmation bias.

I am not saying that it's true, but I am saying that we don't have even the vaguest model to describe this phenomenon, and the scientific method requires skepticism, and this sounds like the Pons and  Fleischmann cold fusion fiasco of the late 1980s.

There needs to be a lot more testing, and some theories that could actually reliably predict the results, before we should start buying Star Trek uniforms.

*Actually, I do want to harsh your buzz. Seriously. This appears to be complete bullsh%$, or at least irresponsibly immature, and I can feel virtuous by shooting it down.
On my part, I will not be buying a Star Trek uniform. As an engineer, I would be wearing a red shirt. I do not like those odds.


Alain Coetmeur said...

Just for your information
F&P are confirmed since long by competent chemist .
this is a good review to start

there is industrial application in developement (field test)

it is time to change the example of bad science...

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