A real reactionless drive?
- Thread starter Andrew Boulton
- Start date
mike wightman
SOC-14 10K
Is this for real?
Andrew Boulton
The Adminator
AFAIK, yes.
M
Malenfant
Guest
Even if it is real, doesn't sound like it'll be any more powerful than a NEP or ion drive. Though it would save on fuel mass.
http://www.eureka.findlay.co.uk/eureka_editorial/news_reference/F-Emdrive.htm
I'm a bit suspicious of vague references to 'resonating electromagnetic bottles' though, sounds rather wishy-washy.
http://www.eureka.findlay.co.uk/eureka_editorial/news_reference/F-Emdrive.htm
I'm a bit suspicious of vague references to 'resonating electromagnetic bottles' though, sounds rather wishy-washy.
Andrew Boulton
The Adminator
No, it is reactionless (or exhaustless, anyway) - the microwaves never leave the bottle. AIUI power requirements are quite low.
Andrew Boulton
The Adminator
It's not powerful enough to reach orbit, but once you're there it'll move you around. Early versions are expected to be about as powerful as ion drives.
Replacing jet engines has been suggested for more advanced versions.
If it actually works, obviously...
Replacing jet engines has been suggested for more advanced versions.
If it actually works, obviously...
Having read a more detailed description, it's nonsense, based on arguments about phase velocity vs group velocity which make no sense.
First of all, group velocity is mostly a function of passing through a transparent medium.
Secondly, hitting a medium which results in a group velocity which is not c will result in transfer of momentum to that medium, and thus the total momentum is still conserved.
I suspect this device works by some form of measurement error. If properly set up and isolated in a vacuum, it is unlikely to do anything at all, like most such devices.
First of all, group velocity is mostly a function of passing through a transparent medium.
Secondly, hitting a medium which results in a group velocity which is not c will result in transfer of momentum to that medium, and thus the total momentum is still conserved.
I suspect this device works by some form of measurement error. If properly set up and isolated in a vacuum, it is unlikely to do anything at all, like most such devices.
Still the definitive paper on the subject
http://www.lerc.nasa.gov/WWW/bpp/TM-107289.htm
And some notes on Woodward's Machs principle drive.
http://www.npl.washington.edu/AV/altvw83.html
NASA's BPPP office gave Cramer a contract to study Woodwards drive but the office shut down before they moved on to hardware.
http://www.lerc.nasa.gov/WWW/bpp/TM-107289.htm
And some notes on Woodward's Machs principle drive.
http://www.npl.washington.edu/AV/altvw83.html
NASA's BPPP office gave Cramer a contract to study Woodwards drive but the office shut down before they moved on to hardware.
Sifu Blackirish
SOC-14 1K
It's good to see people thinking about this.
IMTU humans do not have reactionless drives, instead using a high efficiency ion system. Having maximum acceleration at .6 gee eliminates problems associated with lack of artificial gravity.
Haven't really had time to read the references thoroughly, but does it sound like 'phlogiston physics' to anyone else out there?
IMTU humans do not have reactionless drives, instead using a high efficiency ion system. Having maximum acceleration at .6 gee eliminates problems associated with lack of artificial gravity.
Haven't really had time to read the references thoroughly, but does it sound like 'phlogiston physics' to anyone else out there?
mike wightman
SOC-14 10K
I get worried when a physics article gives the unit of weight in kg...
mike wightman
SOC-14 10K
Dr. Cramer's article was written for a popular audience. But he is one of the Names in gravity. A cut behind Hawking, but close.
This stuff might not work, but some of it might. Most of it makes more sense than HePLAR. My own guess is that if the Mach's Principle drive works it will require a lot more energy than seems reasonable.
This stuff might not work, but some of it might. Most of it makes more sense than HePLAR. My own guess is that if the Mach's Principle drive works it will require a lot more energy than seems reasonable.
He's getting two grams of force per 15 KG of total apparatus, using some 1200+ watts of input. shielding included, according to the eureka article.
Not terribly efficient, unless a true nuclear reactor is in use. (as opposed to RTG's) He's about one order of magnitude less efficient on thrust than current in-use RTG powered Ion Drives for DS1.
It sounds psuedo-science to me; grams of force as opposed to newtons is, well, unusual. Not inappropriate, especially in the context given where he's measuring the "effective mass" in to different orientations and deriving a net 4g different measurement of weight.
I'm leery, though, since the mass is not evenly distributed, if his scale is being effected by the possible change in Center of gravity.
Not terribly efficient, unless a true nuclear reactor is in use. (as opposed to RTG's) He's about one order of magnitude less efficient on thrust than current in-use RTG powered Ion Drives for DS1.
It sounds psuedo-science to me; grams of force as opposed to newtons is, well, unusual. Not inappropriate, especially in the context given where he's measuring the "effective mass" in to different orientations and deriving a net 4g different measurement of weight.
I'm leery, though, since the mass is not evenly distributed, if his scale is being effected by the possible change in Center of gravity.
