The first reactionless thruster?

2330ADUSA1 said:
I would like to see it actually tested for real and see if it can work as they think.


+It's been done before. http://www.springerlink.com/content/m8q0j45487613347/?MUD=MP
 
F33D said:
2330ADUSA1 said:
I would like to see it actually tested for real and see if it can work as they think.


+It's been done before. http://www.springerlink.com/content/m8q0j45487613347/?MUD=MP

I can't actually read the article with out paying (or did I miss that link?), but the use of "gedanken", assuming German here, implies to me that it is conceptual, and not "for real". The abstract implies this as well...
 
You are quite correct... anyone can post anything as if factual - always consider the source. :wink:

Note, academic and publicly funded material is very often available free of charge, even if included in costly journals, conference proceedings, etc. - the site linked above, like others, provides a location and distribution 'service' that is fee based. For such, authors and institutions typically retain full rights to original drafts and final material. Quick Google of paper title, authors, institutions, etc. will generally result in free material...

http://arxiv.org/abs/physics/0303108

You may also be interested in http://www.grc.nasa.gov/WWW/bpp/ (and its disclaimers).
 
allanimal said:
I can't actually read the article with out paying (or did I miss that link?), but the use of "gedanken", assuming German here, implies to me that it is conceptual, and not "for real". The abstract implies this as well...

It is real. Thrust has been measured.
 
F33D said:
allanimal said:
I can't actually read the article with out paying (or did I miss that link?), but the use of "gedanken", assuming German here, implies to me that it is conceptual, and not "for real". The abstract implies this as well...

It is real. Thrust has been measured.

Really? I haven't yet seen an article that states that something was actually built, tested and measured vs. just theoretical / conceptual exploring of possibilities.

From the abstract:
In this paper we consider another suggestion from science fiction and explore how the quantum vacuum might be utilized in the creation of a novel spacecraft. The spacecraft is based on the dynamic Casimir effect, ... We also show that, in principle, one could obtain the power to operate the accelerated mirror in such a spacecraft using energy extracted from the quantum vacuum using the standard Casimir effect with a parallel plate geometry. Unfortunately the method as currently conceived generates a miniscule thrust, and is no more practical than a spacewarp, yet it does provide an interesting demonstration of our current understanding of the physics of the quantized electromagnetic field in vacuum.
 
allanimal said:
Really? I haven't yet seen an article that states that something was actually built, tested and measured vs. just theoretical / conceptual exploring of possibilities.

Yes, really. They've accelerated a "mirror" in vacuum and measured it. Sorry but not everything is on the interweb tubes for you to read. Most material isn't published for free or even, for the general public at all.
 
There have been many experiments where the power of the
Casimir Effect has been measured, but as far as I know the-
re has never been such an experiment in space. The reason
is probably that the force generated by the Casimir Effect is
so small that there is currently no meaningful application of
a Casimir Effect propulsion system, because none of the spa-
cefaring nations is preparing a mission beyond our solar sys-
tem with a timeframe of thousands of years. And for the va-
rious missions within our solar system we have far more ef-
ficient propulsion methods, up to and including solar sails,
which also do not require fuel. Frankly, for all of our in-sys-
tem purposes even a good kick by an astronaut would acce-
lerate a space probe more efficiently than a Casimir Effect
drive.
 
rust said:
There have been many experiments where the power of the
Casimir Effect has been measured, but as far as I know the-
re has never been such an experiment in space. The reason
is probably that the force generated by the Casimir Effect is
so small that there is currently no meaningful application of
a Casimir Effect propulsion system, because none of the spa-
cefaring nations is preparing a mission beyond our solar sys-
tem with a timeframe of thousands of years. And for the va-
rious missions within our solar system we have far more ef-
ficient propulsion methods, up to and including solar sails,
which also do not require fuel. Frankly, for all of our in-sys-
tem purposes even a good kick by an astronaut would acce-
lerate a space probe more efficiently than a Casimir Effect
drive.

Yes, as tested, it isn't practical due to the small force generated. As to space testing, any such tests would have been done by orgs such as SPAWAR and wouldn't be published... ;)
 
The Casmir Effect has been theorized and experimentally confirmed since the late 1940's/50's. It has been observed in many experiments - and directly measured at the turn of the century. It is also accounted for in some superconductor/MEMS technologies.

As to the 'Dynamical Casmir Effect', no experiments involving actually moving mirrors have been published, but a layman magazine, Scientific American (IIRC), did have an article about an experiment done last year involving a SQUID, which could equate, theoretically, to moving an electromagnetic mirror. Haven't come across this experiment having been replicated, and the original paper (as quoted) hadn't been peer reviewed (search on Cornell University e-print service = http://arxiv.org/abs/1105.4714). This is not unlike some pre-2000 experiments involving superconducting MEMS.

As to the amount of 'force' - it isn't necessarily small, but only 'large' at small distances - at sub-molecular scales, atoms can experience fairly significant 'pressure'. Multiplied billion fold, that could become significant.

The observations are real and have been substantively verified in repeatable experiments - but the theories behind them have not. The Casmir Effect may turn out to have nothing to do with Quantum Vacuum, for instance (one theory a few years back accounts for it via relativistic van der Waals interactions, IIRC).

[Of course, any military R&D would be classified - and anyone with access to such knows the potential consequences and what rights they have given up for access to such. :roll: ]
 
BP said:
[Of course, any military R&D would be classified - and anyone with access to such knows the potential consequences and what rights they have given up for access to such. :roll: ]

Which is why one won't find details published in the web tubes... :shock:
 
Which is why no one with actual knowledge would even allude to there being any details to publish :roll:
 
BP said:
Which is why no one with actual knowledge would even allude to there being any details to publish :roll:


Wrong Kemosabi. Ya just can't disclose what has been classified to a certain level. But, one would have to have gone through the "process" to know that...
 
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