Reading Dr. White's paper, that IS the second generation's thrust - he had optimized the frequency for the device, and that varied by input power and operating temp.
EM-drive fizzle
- Thread starter Adam Dray
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Reading Dr. White's paper, that IS the second generation's thrust - he had optimized the frequency for the device, and that varied by input power and operating temp.
Well, after a brief refresher on the whole concept, I don't see anything wrong with the science. I see lots of issues with trying to upscale the concept. I think this is one of those "quirks" of physics that allows a EM radiation to resonate along one vector to create a force, but that it's more of a curiosity than a real concept that can be capitalized on.
*edit*
I do not claim to understand quantum mechanics, but what little I do know of it tells me that the reason this whole thing works is because the device is working at extremely low energy levels, the kind which quantum mechanics operates, again making it a kind of physic's oddity, but not much else. Just my arm chair opinion.
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I saw a mention of an EmDrive in Clement Sector's latest ship guide, but it got one thing very wrong. It says that the EmDrive is useful only in vacuum. I believe that the EmDrive, as understood today, will be fantastic for surface-to-orbit missions because there's not much requirement for high velocity, just constant 11 m/s thrust to escape the Earth's gravity well.
QFT. Science is often driven by accidental findings.
With a T:W of under 0.01, it's not going to be useful on worlds of size 1+. Just like Ion drives.
Have you read the "Applications" section (for the 1st-gen drive) on the EmDrive page (link)?
"For a typical 3 tonne geostationary communications satellite, with a 6kW solar power capacity, replacing the conventional apogee engine, attitude thrusters and propellant with a microwave propulsion system would result in a reduction of the launch mass to 1.3 tonnes. The satellite would be launched to LEO, where solar arrays and antennas would be deployed. The microwave propulsion system would then propel the satellite in a spiral trajectory up to GEO in 36 days."
That's a VERY slow lift-off, but it's cheaper than rockets.
Or their Future page, with the terrestrial applications of the 2nd-gen drive (link):
"Typically 3 tonnes of lift could be obtained from 1kW of microwave power."
I'm not clear if that means that 3000 tonnes of lift could be obtained by 1MW of microwave power. Does it scale that way? I think it scales linearly with power, but sigmoidally with velocity.
"For a typical 3 tonne geostationary communications satellite, with a 6kW solar power capacity, replacing the conventional apogee engine, attitude thrusters and propellant with a microwave propulsion system would result in a reduction of the launch mass to 1.3 tonnes. The satellite would be launched to LEO, where solar arrays and antennas would be deployed. The microwave propulsion system would then propel the satellite in a spiral trajectory up to GEO in 36 days."
That's a VERY slow lift-off, but it's cheaper than rockets.
Or their Future page, with the terrestrial applications of the 2nd-gen drive (link):
"Typically 3 tonnes of lift could be obtained from 1kW of microwave power."
I'm not clear if that means that 3000 tonnes of lift could be obtained by 1MW of microwave power. Does it scale that way? I think it scales linearly with power, but sigmoidally with velocity.
Timerover51
SOC-14 5K
Greetings Robject. I must apologize for not being sure what "QFT" is short for.
Beware of Shawyer's claiims - they're unrealistic and the math doesn't work. Which is why it took so long for anyone with a shred of credibility to take a look at it.
NASA, China, and the BA tests all came in at Megawatts per killogram thrust (1 KGT accelerates 1 KG at 1G).
Wrong. We have multiple replications of the same outputs ±50%, none of which match Shawyers claims, plus one group noted for absolutely no intent of actual replication failing to replicate in exactly the way they expected it to non-replicate, with questionable methods and thus questionable null results.
Real physics says, "The effect is as yet unexplained" and "the current data
makes it uninteresting to pursue"
Had they used the same construction methodology, same materials, and gotten those results, it would be more meaningful. All it proves is that THEY failed to build and/or operate the device in the same way that the successful replications (NASA/White, BA, China) did. (Which, based upon their available data, they apparently didn't do the frequency tuning that China and White both noted was required for measurable thrust.)
TLDR: Failed Replication ≠ disproval
Timerover51
SOC-14 5K
If you have a repeatable demonstrated effect that current physics does not explain, you do not say "Physics says it doesn't work". If it works, then you start looking at the understanding of physics to determine why it works when it should not. I doubt if we have a total, complete, 100% knowledge of the totality of physics.
Many years ago I was reading a book and they quoted Einstein, who may or may not have said this, as saying:
"Imagine that all possible knowledge is contained within a cube a light year, by a light year, by a light year. Then take the smallest straight pin made, and make a tiny scratch on one side of that cube. All of human knowledge would fit in that tiny scratch." The book I read was printed around 1955-1960.
