If you need assistance, please send an email to forum at 4hv dot org. To ensure your email is not marked as spam, please include the phrase "4hv help" in the subject line. You can also find assistance via IRC, at irc.shadowworld.net, room #hvcomm.
Support 4hv.org!
Donate:
4hv.org is hosted on a dedicated server. Unfortunately, this server costs and we rely on the help of site members to keep 4hv.org running. Please consider donating. We will place your name on the thanks list and you'll be helping to keep 4hv.org alive and free for everyone. Members whose names appear in red bold have donated recently. Green bold denotes those who have recently donated to keep the server carbon neutral.
Special Thanks To:
Aaron Holmes
Aaron Wheeler
Adam Horden
Alan Scrimgeour
Andre
Andrew Haynes
Anonymous000
asabase
Austin Weil
barney
Barry
Bert Hickman
Bill Kukowski
Blitzorn
Brandon Paradelas
Bruce Bowling
BubeeMike
Byong Park
Cesiumsponge
Chris F.
Chris Hooper
Corey Worthington
Derek Woodroffe
Dalus
Dan Strother
Daniel Davis
Daniel Uhrenholt
datasheetarchive
Dave Billington
Dave Marshall
David F.
Dennis Rogers
drelectrix
Dr. John Gudenas
Dr. Spark
E.TexasTesla
eastvoltresearch
Eirik Taylor
Erik Dyakov
Erlend^SE
Finn Hammer
Firebug24k
GalliumMan
Gary Peterson
George Slade
GhostNull
Gordon Mcknight
Graham Armitage
Grant
GreySoul
Henry H
IamSmooth
In memory of Leo Powning
Jacob Cash
James Howells
James Pawson
Jeff Greenfield
Jeff Thomas
Jesse Frost
Jim Mitchell
jlr134
Joe Mastroianni
John Forcina
John Oberg
John Willcutt
Jon Newcomb
klugesmith
Leslie Wright
Lutz Hoffman
Mads Barnkob
Martin King
Mats Karlsson
Matt Gibson
Matthew Guidry
mbd
Michael D'Angelo
Mikkel
mileswaldron
mister_rf
Neil Foster
Nick de Smith
Nick Soroka
nicklenorp
Nik
Norman Stanley
Patrick Coleman
Paul Brodie
Paul Jordan
Paul Montgomery
Ped
Peter Krogen
Peter Terren
PhilGood
Richard Feldman
Robert Bush
Royce Bailey
Scott Fusare
Scott Newman
smiffy
Stella
Steven Busic
Steve Conner
Steve Jones
Steve Ward
Sulaiman
Thomas Coyle
Thomas A. Wallace
Thomas W
Timo
Torch
Ulf Jonsson
vasil
Vaxian
vladi mazzilli
wastehl
Weston
William Kim
William N.
William Stehl
Wesley Venis
The aforementioned have contributed financially to the continuing triumph of 4hv.org. They are deserving of my most heartfelt thanks.
Registered Member #4266
Joined: Fri Dec 16 2011, 03:15AM
Location:
Posts: 874
Themic emmisions, normal from a hot source, acceralting electrons from metal, Nasa would like this even if its bull, as it would help ion engines, eventhought electrons are to light even acceralted close to the speed of light.
Registered Member #2529
Joined: Thu Dec 10 2009, 02:43AM
Location:
Posts: 600
Daedronus wrote ...
Antonio wrote ...
The paper ends with "The results are consistent with theor etical calculations". But the paper does not show any calculation. Just nonsense, or some parasitic effect as heating more air at the large end.
What air? it was tested in vacuum. Find some other reason why it won't work.
Who tested in a vacuum, and what results did they get????
Shawyer didn't.
The Chinese didn't.
NASA may have done, I haven't checked, but they got essential fuck-all thrust, it was right down at the limit of what they can measure at; and it was a thousand times less thrust than the Chinese got or something.
Registered Member #72
Joined: Thu Feb 09 2006, 08:29AM
Location: UK St. Albans
Posts: 1659
Andy wrote ...
Themic emmisions, normal from a hot source, acceralting electrons from metal, Nasa would like this even if its bull, as it would help ion engines, eventhought electrons are to light even acceralted close to the speed of light.
While electrons would eject more momentum than photons, unfortunately a net flow of electrons from the engine would eventually charge it up so much that you'd have to fling an equal number of +ve charges out of the back to keep it neutral, and this is where the consumable +ve ion source becomes a problem. The specific impulse of the electrons would be very low, don't forget that they prefer heavy +ve ions like Xenon. An ion thruster would get 200k times more deltaV from the Xe+ than the e- being thrown out of the back. Looks like photons, as they can be created from energy, and have momentum, are the only suitable thing for continuous propellant-less operation, it's just that they are horribly inefficient. An alternative is collecting the non-vacuum in front of the craft and accelerating it out of the back. The trouble with that is it's very thin, and a mix of species.
So if the EM drive can be wished into working, it would solve a lot of problems.
Registered Member #3414
Joined: Sun Nov 14 2010, 05:05PM
Location: UK
Posts: 4245
Ash Small wrote ...
Thermodynamics of a black body photon gas ??
Photons are all we have to work with here. Looks like it has to be 'black body radiation' and 'photon gas' if it has any chance of being 'created/explained'
EDIT: Maybe 'Photon Drive' would be a more apt name?
Registered Member #2529
Joined: Thu Dec 10 2009, 02:43AM
Location:
Posts: 600
Daedronus wrote ...
NASA did, it did not affect the thrust at all, so whatever it is it's not something as easy as a heating effect.
NASA got fuck-all thrust, and there was very little difference between the thrust they got with the normal hypothesis and the one they predicted to give 1000x higher thrust.
Look, this isn't even worthy of discussing more. Shawyer is doing pseudoscience, I mean, I read his paper and there's massive theoretical issues with it; and the thrust he got was consistent with hot air effects. The Chinese very probably fucked something up; probably there's an aerodynamic effect due to heating also.
NASA did stuff in a vacuum, and consequently got essentially no thrust (~50 micronewtons), I expect with more careful analysis the experiment will be shown to be pure experimental error.
Registered Member #2529
Joined: Thu Dec 10 2009, 02:43AM
Location:
Posts: 600
Because in Shawyer's case, it wasn't done in a vacuum, and you get significant air flow due to the hot air; the air flows past the apparatus, and it causes lift; it gets deflected by the conical shape.
Now, you might think that lift always goes upwards- WRONG!!!! With formula one cars, lift points downwards (called downforce), with aircraft in a bank, the lift points at an angle to the vertical; in Shawyer's case, the lift can point sideways; and then it will rotate on the air bearing.
This effect can be controlled for by running in a vacuum; which the NASA team did, and got one thousandth of the thrust (the remaining is doubtless experimental error- they were known to be pretty shit with the apparatus).
Registered Member #3414
Joined: Sun Nov 14 2010, 05:05PM
Location: UK
Posts: 4245
BigBad wrote ...
Because in Shawyer's case, it wasn't done in a vacuum, and you get significant air flow due to the hot air; the air flows past the apparatus, and it causes lift; it gets deflected by the conical shape.
Now, you might think that lift always goes upwards- WRONG!!!! With formula one cars, lift points downwards (called downforce), with aircraft in a bank, the lift points at an angle to the vertical; in Shawyer's case, the lift can point sideways; and then it will rotate on the air bearing.
This effect can be controlled for by running in a vacuum; which the NASA team did, and got one thousandth of the thrust (the remaining is doubtless experimental error- they were known to be pretty shit with the apparatus).
But when NASA did it in a vacuum they didn't get results ultil it 'warmed up', right?
Registered Member #2529
Joined: Thu Dec 10 2009, 02:43AM
Location:
Posts: 600
That would be a photonic drive, but photonic drives only give you 30 micronewtons per kilowatt or something, but I think the NASA team are claiming higher thrust than that.
That was how the Pioneer anomaly worked, they were emitting more photons forward than backwards; it's measurable, but usually a very small effect.
This site is powered by e107, which is released under the GNU GPL License. All work on this site, except where otherwise noted, is licensed under a Creative Commons Attribution-ShareAlike 2.5 License. By submitting any information to this site, you agree that anything submitted will be so licensed. Please read our Disclaimer and Policies page for information on your rights and responsibilities regarding this site.
EmDrive
