New scientist if you're willing to buy it:
http://www.newscientist.com/channel/fundamentals/mg19125681.400-relativity-d
rive-the-end-of-wings-and-wheels.html
Or a free and essentially available copy:
http://www.shelleys.demon.co.uk/fdec02em.htm
end than the other. Microwaves are pumped in and 'push' more against the
wide end than the narrow. This normally tiny effect is magnified somehow by
some complex relativity mathematics, and you get measurably thrust.
Yes I know it sounds daft, and yes I remember how cold fusion didn't work
out, but this one seems to have been pier reviewed 8
*before* being announced. More over, a similar effect is known about in
particle accelerators like CERN, where is it considdered most annoying as
the movements throws off their measurements.
Provisos:
1) Curently it only generates low thrust, in the same range of ion
thrusters.
2) Even more complex physics states the thrust will drop off as it moves
along its axis. So it will hover, but not push upwards.
3) To lift a car (which might be possible) the chamber would need to be
super conducting, requiring liquid hydrogen or something to cool the
delicate and fragile materials, which conveniently can then be fed into a
turbine to generate the power for the magnatron.
4) Large magnatrons are current an area of active research for weapons use,
and much of the reasearrch about true upper limits is clasified, making it
hard to evaluate the true potential of such technology.
John
I googled the timeline of this and a year ago the EMdrive was
generally scourned in forums of physics, with the occasional moderate
asking for independent reproduction.
works, but somehow I am so deluded with "antigravity" machines that I
think that I will believe on this when I see EMdrives being used in
commercial satellites and the such. ;-)
Gosh... if this thing is true, Solar System colonization could be just
around the corner and relativistic interstellar travel a few decades
away. Oh, well, I should take care to not get drugged on optimism.
On 9/8/06, ANTIcarrot wrote:
> From: Lucio de Souza Coelho
> I googled the timeline of this and a year ago the EMdrive was
> generally scourned in forums of physics, with the occasional moderate
> asking for independent reproduction.
understand how rockets can work in a vacuum. ;) Did you come across more
professional sources of criticism?
> Now that you mentioned the 8 peer-reviews, though...
Odd thing. I didn't put that 8 in there. Don't know what happened, as it
didn't turn up in a CC post sent to another group. Quotingf from the
article:
*A working prototype has been produced and can produce a measurable thrust
of 16mN.
*The UK government hired an indipendent space engineer called John Spiller
to review the work, who was impressed.
*The US airforce is reported to be at least interested. (which makes sense
since thier expensive spy sats keep running out of fuel)
*The chinese tried to buy it. Not exactly the best mark of repubility I
know...
*Published in more detail in 'The development of a microwave engine for
spacecraft propulsion' in the Space Cronicle Journal of the British
Interplanetary Society. Dont' know if that counts as pier reviewed or not.
*New Scientist often publishes *potential* theories for FTL, antigravity,
theory of everything etc, but this is the first one in a long time that they
have said is real and actually works.
And again, as a STRONG PROVISO, there seem to be real problems with thrust
reducing/power requirements increasing rapidly with speed/acceleration. So
the engine could support a 1000ton train a meter off the ground, but
couldn't easily lift up that high. Speed of course is relative though, and
the NS article does not discuss space application beyond station keeping.
John
On 08/09/06, ANTIcarrot wrote:
> New scientist if you're willing to buy it:
> http://www.newscientist.com/channel/fundamentals/mg19125681.400-relativity-d
> rive-the-end-of-wings-and-wheels.html
> Or a free and essentially available copy:
> http://www.shelleys.demon.co.uk/fdec02em.htm
>
> Basically it's a tube (preferably superconducting) that's narrower at one
> end than the other. Microwaves are pumped in and 'push' more against the
> wide end than the narrow. This normally tiny effect is magnified somehow by
> some complex relativity mathematics, and you get measurably thrust.
momentum, and this thing is based on Maxwell's equations. Relativity
is derived *from* Maxwell's equations (plus one additional assumption,
which does not violate conservation of linear momentum).
A closed device cannot start moving without an external force, not via
electromagnetic forces in a closed shape, which is what he is
claiming.
Therefore he's screwed up his maths, and the small effect he is
experimentally measuring is extremely likely to be an experimental
artfact.
Additionally, I read the article and then was able to show that if the
thruster were to be able to be placed in space and gain speed when
they put energy into it; it violates conservation of energy as well as
linear momentum. So it would be possible to build a perpetual motion
machine.
> Yes I know it sounds daft, and yes I remember how cold fusion didn't work
> out, but this one seems to have been pier reviewed 8
> *before* being announced. More over, a similar effect is known about in
> particle accelerators like CERN, where is it considdered most annoying as
> the movements throws off their measurements.
Nobody is saying that electromagnetism can't create huge forces
*between* things. What it can't do is make unbalanced forces (except
where beams are allowed to escape- there is a photon rocket effect-
but this device doesn't do that.)
> Provisos:
> 1) Curently it only generates low thrust, in the same range of ion
> thrusters.
That's one of the signs of pseudo science by the way- the effect is
small, and stays small even as the experiment improves.
> 2) Even more complex physics states the thrust will drop off as it moves
> along its axis. So it will hover, but not push upwards.
That makes no sense from relativity theory.
> John
--
-Ian Woollard
"Victory can be perceived but not created."
For your own security, the Department of Homeland Security is watching you.
> From: Ian Woollard
> Additionally, I read the article and then was able to show that if the
> thruster were to be able to be placed in space and gain speed when
> they put energy into it; it violates conservation of energy as well as
> linear momentum. So it would be possible to build a perpetual motion
> machine.
about conservation of energy. There's a comparison with ESA's Smart-1
engine. Using those numbers (700W, 88mN, 9kg system weight) you get 4.3*10-4
joules of kenetic energy out for every 700J of electrical energy you put
into the system. To my understanding, that does not violate the conservation
of energy principle, since you are not outputting more energy than you are
inputting. If on the other hand you're wondering where the energy is comming
from in the first place, solar panels (for example) would stop it from being
a closed system, and hence CoE would not even be applicable.
> That makes no sense from relativity theory.
It sounds odd too, but relativity is not mentioned in that part of the
article. Besides, turbo jet engine thrust also falls off quickly with
increased speed. This is one of the bigger reasons why no one has ever built
one that works at mach 16.
> Therefore he's screwed up his maths, and the small effect he is
> experimentally measuring is extremely likely to be an experimental
> artfact.
Direct measurements of time dialation also produce small results, but that
doesn't mean it's not real. I admit, if I had come across this myself on the
internet, I would have assumed it's bogus as well, and my defence of the
idea comes mostly from the reputation of New Scientist, who I trust not to
publish outright lies.
John
On 09/09/06, ANTIcarrot wrote:
> > From: Ian Woollard
> > Additionally, I read the article and then was able to show that if the
> > thruster were to be able to be placed in space and gain speed when
> > they put energy into it; it violates conservation of energy as well as
> > linear momentum. So it would be possible to build a perpetual motion
> > machine.
>
> Unfortunately, whether it works or not, I do not believe you're correct
> about conservation of energy. There's a comparison with ESA's Smart-1
> engine. Using those numbers (700W, 88mN, 9kg system weight) you get 4.3*10-4
> joules of kenetic energy out for every 700J of electrical energy you put
> into the system. To my understanding, that does not violate the conservation
> of energy principle, since you are not outputting more energy than you are
> inputting. If on the other hand you're wondering where the energy is comming
> from in the first place, solar panels (for example) would stop it from being
> a closed system, and hence CoE would not even be applicable.
a bit counterintuitive. What happens is that the propellant gains
kinetic energy as the vehicle accelerates and the vehicle gains back
some of that kinetic energy when the propellant is emitted; and that's
why an ion drive vehicle can accelerate with constant acceleration
with a constant energy source. And the external source of energy makes
no difference to the result.
With a reactionless thruster that doesn't happen, because there's no
propellant. So you would have to put more energy in as you accelerate
to keep 0.5 m v^2 true.
But for the reactionless thruster to work in the same way, I believe
it would need a prefered reference frame since it has nowhere to store
the energy (no propellant) that it has gained from accelerating. That
violates the relativity principle, and hence also violates Maxwell's
equations.
> John
--
-Ian Woollard
"Victory can be perceived but not created."
For your own security, the Department of Homeland Security is watching you.
On 9/10/06, Ian Woollard wrote:
(...)
> But for the reactionless thruster to work in the same way, I believe
> it would need a prefered reference frame since it has nowhere to store
> the energy (no propellant) that it has gained from accelerating. That
> violates the relativity principle, and hence also violates Maxwell's
> equations.
(...)
and confirmed by several independent sources, and apparently it is
violating conservation of momentum, action and reaction, etc. Could it
be that in fact the machine *is* transferring momentum to something,
but through indirect and difficult to detect means?
For instance, suppose a thought-experiment involving an engine able to
be repelled instead of attracted by gravity. This thing would move
upwards in a seemingly "reactionless" way. In reality, though, it
would balance momentum with Earth in the same way that a falling
object does (though with opposite signs). As for energy, one could
postulate that the energy needed for this engine to produce this
negative weight would equals the potential energy of this negative
weight relatively to infinity.
What I am trying to say is that if this "reactionless" thing works
then the conservation laws are probably not being thrown away; they
are just being obeyed in subtler ways. Think of how the neutrino was
discovered based on an apparent violation of energy conservation.
On 11/09/06, Lucio de Souza Coelho wrote:
> Lets suppose that the effect being measured in that machine is real
> and confirmed by several independent sources,
small; and all he needs is more money to make the effect big. Honest!
> and apparently it is
> violating conservation of momentum, action and reaction, etc. Could it
> be that in fact the machine *is* transferring momentum to something,
> but through indirect and difficult to detect means?
There's nothing in his machine that could do that. It's basically just
an oddly shaped microwave oven that he claims he has calculations that
show it will rise into the air; and he has an experimental apparatus
that he claims gives a few milli-Newtons of lift. I claim he has just
messed up his calculation and the experiment.
> What I am trying to say is that if this "reactionless" thing works
That's not the way to bet.
> then the conservation laws are probably not being thrown away; they
> are just being obeyed in subtler ways. Think of how the neutrino was
> discovered based on an apparent violation of energy conservation.
The idea that everybody would have missed something like this in well
over 100 years of Maxwell's equations is so unbelievably remote. He's
just claiming to have solved Maxwell's equations and gained lift from
nowhere.
--
-Ian Woollard
"Victory can be perceived but not created."
For your own security, the Department of Homeland Security is watching you.
> From: Ian Woollard
> It isn't though. Only one guy has done it, and the measured effect is
> small; and all he needs is more money to make the effect big. Honest!
great for science, but bad for engineering and intelectual property rights.
Intel didn't turn to their rivals at the time and say, "We think we've got a
nifty little invention here that could make us billions. Here are the
blueprints and all the theory you need to make your own. Can you test to see
if we're right about it working?" This kind of thing is a big problem for
small inventors, even after they demonstrate their inventions work and are
publically aknowledged as the inventor.
Guess how much money the USMC paid the inventor of the hovercraft for use of
his idea. Or how much the Bell Aircraft Corporation paid the Miles Aircraft
Company for the latter's all-moving tailplane idea and supersonic
aerodynamics data. I'll give you a clue: It's less than the average worth
people give their thoughts in internet forums.
John
perhaps rather than sell an invention, inventors should ask for a
percentage of profits over time. If it really works, they can make
millions, while the companies dont pay anything for it untill it does.
wrote:
>
> > From: Ian Woollard
> > It isn't though. Only one guy has done it, and the measured
effect is
> > small; and all he needs is more money to make the effect big.
Honest!
>
> A significant problem here is asking others to replicate your
experiments is
> great for science, but bad for engineering and intelectual property
rights.
> Intel didn't turn to their rivals at the time and say, "We think
we've got a
> nifty little invention here that could make us billions. Here are
the
> blueprints and all the theory you need to make your own. Can you
test to see
> if we're right about it working?" This kind of thing is a big
problem for
> small inventors, even after they demonstrate their inventions work
and are
> publically aknowledged as the inventor.
>
> Guess how much money the USMC paid the inventor of the hovercraft
for use of
> his idea. Or how much the Bell Aircraft Corporation paid the Miles
Aircraft
> Company for the latter's all-moving tailplane idea and supersonic
> aerodynamics data. I'll give you a clue: It's less than the average
worth
On 12/09/06, ANTIcarrot wrote:
> Guess how much money the USMC paid the inventor of the hovercraft for use of
> his idea. Or how much the Bell Aircraft Corporation paid the Miles Aircraft
> Company for the latter's all-moving tailplane idea and supersonic
> aerodynamics data.
> John
--
-Ian Woollard
"Victory can be perceived but not created."
For your own security, the Department of Homeland Security is watching you.