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OT? Shawyer EMdrive Independently "Verified"

A scientist with "a long history of experimentally testing (and debunking ) breakthrough propulsion systems" has replicated the Eagleworks results- 2

0 micronewtons thrust for 700W input. He can't explain it either.

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However, his experimental setup has some of the same problems as the orig inals like poor temperature management, systematic irregularities, and ina dequate instrumentation.

"I noted in [the study's] conclusion paragraphs that [Tajmar's] apparatus w as producing hundreds of micro-Newtons of thrust when it got very hot and t hat his measuring instrumentation is not very accurate when the apparatus b ecomes hot... He also stated that he was still recording thrust signals eve n after the electrical power was turned off which is a huge key clue that h is thrust measurements are all systematic artifact false positive thrust si gnals."

"The experiment is quite detailed but no theoretical account for momentum v iolation is given by him, which will cause peer reviews and technical journ al editors to reject his paper should it be submitted to any of the peer-re view physics and aerospace journals,"

His paper is here:

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It's paywalled but the first page, with abstract, is readable.

One thing that really bothers me is that his cavity Q, like the originals , is about 50. That's a measly *fifty*, when I can solder up something with a Q in the hundreds out of cut-up coffee cans in minutes. Superconducting cavities used in particle accelerators get up into the single-digit exponen ts of ten regularly.

It's almost as if they're just not trying to optimize their systems to se e a definitive effect one way or the other.

Mark L. Fergerson

Reply to
Alien8752
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Momentum transfer accompanying heat transfer via the residual gas circulating around the box?

The paper says that it is in an evacuated chamber - but didn't say how well evacuated. It doesn't take too many gas molecules bouncing off a hot surface with a higher speed they had when they hit it to generate micro-newtons of thrust.

The thermal conductivity of a non-convecting gas doesn't change much with pressure until the mean free path of the molecules gets longer than the gap over which the conductivity is being measured.

That energy transfer depends on momentum transfer as well.

--
Bill Sloman, Sydney
Reply to
Bill Sloman

This is funny:

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How are micronewtons of thrust going to get to the moon in four hours? I'd like to see the math.

Micronewtons per kilowatt doesn't sound very promising.

--

John Larkin         Highland Technology, Inc 
lunatic fringe electronics 

jlarkin att highlandtechnology dott com 
http://www.highlandtechnology.com
Reply to
John Larkin

The Maths are not awe-inspiring, which doesn't mean Shawyer is wrong, just probably wrong. It would be interesting to test a superconducting model which is predicted to produce large unambiguous forces. I tried raising money to do the test but couldn't swing it.

Nasa Eagleworks did a test on it and measured thrust, but I think there may have been some problems with their instrumentation. They came up with a different theory that supports their current pet project called a quantum vacuum plasma thruster.

ChesterW

Reply to
ChesterW

So, toss one up into orbit and turn it on. If it stays in one spot, you've learned something. If it whizzes off, you've learned something else.

--

Tim Wescott 
Wescott Design Services 
http://www.wescottdesign.com
Reply to
Tim Wescott

However, his experimental setup has some of the same problems as the originals like poor temperature management, systematic irregularities, and inadequate instrumentation.

Even radiation pressure will get you almost to that sort of number.

F = dp/dt = P_laser/c = 3.3 micronewtons per kW.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
ElectroOptical Innovations LLC 
Optics, Electro-optics, Photonics, Analog Electronics 

160 North State Road #203 
Briarcliff Manor NY 10510 

hobbs at electrooptical dot net 
http://electrooptical.net
Reply to
Phil Hobbs

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