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Author Topic: An anti gravity machine for real!?  (Read 21113 times)

Offline Soul Surfer

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Re: An anti gravity machine for real!?
« Reply #25 on: 13/09/2006 09:56:56 »
Sorry Brain  I expressed myself badly there I was not suggesting any violation of the equivalence principle if the thing could be powerful enough to lift a body of the surface of the earth (which I very much doubt)  It would of course be accelerating at one g even when it is hovering  I was only thinking about the extra losses associated with moving the mass of the unit upwards.

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Offline syhprum

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Re: An anti gravity machine for real!?
« Reply #26 on: 13/09/2006 11:04:30 »
Re photon drives

I must really disagree the largest mobile power sources that we have are the nuclear power units in submarines, these are certainly less than 100 megawatts electrical probably more like ten and cannot be run for more than a year or two without major maintenance.
To drive a terawatt laser (if such a thing could be created ) they would have to be scaled up by a factor of 10^7 at the very least , made maintenance free for hundreds of years for interstellar travel with no great increase in mass.
I do not think this is just a matter of technological development I consider it impossible!.
Let me see a calculation of the probable mass of a photon drive ship travelling to the nearest known star with a planetary system and what leap in power generation technology would be required

syhprum
 

Offline lightarrow

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Re: An anti gravity machine for real!?
« Reply #27 on: 13/09/2006 15:02:36 »
quote:
Originally posted by syhprum

Re photon drives

I must really disagree the largest mobile power sources that we have are the nuclear power units in submarines, these are certainly less than 100 megawatts electrical probably more like ten and cannot be run for more than a year or two without major maintenance.
To drive a terawatt laser (if such a thing could be created ) they would have to be scaled up by a factor of 10^7 at the very least , made maintenance free for hundreds of years for interstellar travel with no great increase in mass.
I do not think this is just a matter of technological development I consider it impossible!.
Let me see a calculation of the probable mass of a photon drive ship travelling to the nearest known star with a planetary system and what leap in power generation technology would be required

syhprum

Yes, it's still not possible to make a Terawatt laser with continuous emission, as you pointed out, but what is impossible now will remain impossible in the future? I'm not talking about just some years.

Anyway, it's not even necessary to have a laser (or maser) for a photon engine: you could heat a body to high temperatures (heated with any kind of energy you want, included matter-antimatter reaction) to make it radiate light (and/or infrared radiation) and so have a thrust.
« Last Edit: 13/09/2006 15:04:39 by lightarrow »
 

Offline syhprum

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Re: An anti gravity machine for real!?
« Reply #28 on: 14/09/2006 00:32:16 »
If I place a small magnet above a superconducting sheet it remains elevated despite gravity without the expenditure of any energy.
Yet if I wish to do the same with Roger Shawyer's anti gravity machine I am told that a continuous supply of energy is required, wherein lies the difference?.


syhprum
 

Offline thebrain13

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Re: An anti gravity machine for real!?
« Reply #29 on: 14/09/2006 01:36:51 »
your magnet pushes down on the superconducter, which balances everything out. The anti-grav machine doesnt push on anything.
 

Offline syhprum

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Re: An anti gravity machine for real!?
« Reply #30 on: 14/09/2006 07:11:52 »
I deserve to have one brownie point deducted!, and I have lectured people on action and reaction on this board.

syhprum
 

Offline Soul Surfer

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Re: An anti gravity machine for real!?
« Reply #31 on: 14/09/2006 12:11:08 »
I have been doing a bit more thinking about how this machine would work (if it does work of course)  and what it would be useful for.  Here are some further thoughts and notes.

The amount of momentum ( ? static force) that you can generate depends on the Q of the cavity  a very high Q cavity can generate a lot with relatively low power input but the moment it starts to move, energy will be lost and the Q of the cavity will fall and so will the momentum that it produces.

The new scientist article suggests and tries to illustrate that this has causes a 1kw unit mounted horizontally on an air bearing causing the unit to rotate  at up to 20rpm although I note that the article did not say uambiguously that it actually did do this when the author saw it  he only said that it should spin and there was a blurred photograph of the apparatus in motion as well as a clear picture of the stationary apparatus which looked quite plausible.

The waveguide is a circular one  and is probably a TE100 very low loss overmoded waveguide to up the Q  (must look up group velocities and sizes)

I can easily accept that the momentum transfer to the wide end is greater than the narrow end but would expect that there would also be some momentum transfer to the tapered section that would balance things out and result in a zero net thrust.

We are not familiar with slow momentum transfer dynamics and think more in terms of forces and impulsive momentum transfers(like billiard balls hitting each other) and I am still trying to het my mind around how it works in a gravitational field.

Consider an object stationary and sitting on top of a balance pan that is weighing it by using a load cell that has a miniscule deviation to register. As I increase the power of the upwards momentum I would expect the object to weigh less and it appears that this has been demonstrated  with the first device producing 16 millinewtons using 1 KW of electrical power (magnetrons are quite efficient at converting electrical energy into microwaves).

If the cavity had a very high Q and there was lots of power available it might in theory be able to reduce the apparent weight to zero.  Now how does this reconcile with the equivalence principle stated above because the energy being used is apparantly much less than that required to accelerate the mass at 1g.  The only answer  I can see is that it is because we are talking about a momentum transfer and not a force  the equivalent acceleration is associated with the microwave photons that are "accelerating"  (their group velocity is increasing in the expanding waveguide as they move upwards in the cavity and strike the top face) what then happens if I try to move it upwards?  well the cavity loses efficiency and the apparant force to accelerate the object increases so the object is a bit harder to accelerate than I expect but it should still accelerate and continue to do so while I apply the force and in every way obey newtons laws of motion.  This does really seem to be like an anti gravity machine!

But what about the corresponding deceleration of the photons as they move downwards?  doesn't that counteract the acceleration?  well photons are massless and the acceleration and decelleration is only associated with the shape of their "universe"  (the cavity) and does not require any energy  (very weird!)

Again this always depends on the effect working and I am still very skeptical because it seems too much like something for nothing (or very little)

Mind you I have seen an "electromagnetic" related theory of gravitiation some years ago  (from a chap named Jennison I think from Kent university)that has some similar features to this suggesting that gravitation was just a residual "van der walls" type force resulting from the geometrical dynamics of electrical forces inside  particles atoms and of course dark matter.  If that was the case, it might be possible to produce an anti gravitational force by using energetically assymetric dynamics of electromagnetic waves.

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Offline lightarrow

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Re: An anti gravity machine for real!?
« Reply #32 on: 14/09/2006 12:32:50 »
Whatever could be the functioning, if the cavity is closed, isolated and doesn't interact with other external systems/bodies and doesn't emit particles/photons/energy, it's impossible it can receive a thrust, without violating the most basic physical laws.

When you say: "The only answer I can see is that it is because we are talking about a momentum transfer and not a force", I don't understand it, since they are the same thing: dp/dt = F.
« Last Edit: 14/09/2006 12:38:41 by lightarrow »
 

Offline alexb

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Re: An anti gravity machine for real!?
« Reply #33 on: 14/09/2006 14:11:30 »
The thing that troubles me about this is the described demonstration.

Horizontally mounted to one side of a vertical axis air bearing, the demo will provide horizontal thrust to set the equipment spinning.

But we donít need microwaves and relativity in the box to do that.  Just a vertical axis gyroscope.

Now I'm not suggesting that My Shawyer would do that.  But perhaps he should know better than to expect to demonstrate his kit in a rotational situation.

After all, we are told in the article that he used to work for Sperry Gyroscope.

Iíll not be investing my pennies just yet a while.
« Last Edit: 14/09/2006 14:22:07 by alexb »
 

Offline syhprum

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Re: An anti gravity machine for real!?
« Reply #34 on: 14/09/2006 18:34:10 »
I notice that the PSU is mounted on air bearing alongside the anti-gravity device, it is quite possible the a verticaly mounted fan in this could cause a gyroscopic effect not to mention any effect from expelled air.

syhprum
 

Offline Nieuwenhove

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Re: An anti gravity machine for real!?
« Reply #35 on: 15/09/2006 17:35:12 »
I finally was able to read this article. The explanation offered in the article is very short and very poor. Apparently, it should be related to some kind of relativistic effect which defies are intuition. Nevertheless, I do not understand sentences like "Since the microwave photons in the waveguide are travelling close to the speed of light, any attempt to resolve the forces they generate must take account of Einsteins special theory of relativity. This says that the microwaves move in their own frame of reference. In other words they move independent of the cavity - as if they are outside" And that's it ! Although I'm familiar with relativity, this really means nothing to me. Can anyone reformulate this in more scientific language ? If the machine really works (unlikely), the inescapable conclusion would be (for me) that one has demonstrated the existence of an aether and that this aether has taken up the opposite momentum.
And what would be the fate of this moving aether ?
 

Offline syhprum

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Re: An anti gravity machine for real!?
« Reply #36 on: 15/09/2006 19:14:50 »
I am begining to believe that this is just a money making scam, like cold fusion, homopathy, or the various magic water and Ice tales that we hear.

syhprum
 

Offline Nieuwenhove

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Re: An anti gravity machine for real!?
« Reply #37 on: 17/09/2006 17:00:57 »
quote:
Originally posted by syhprum

I am begining to believe that this is just a money making scam, like cold fusion, homopathy, or the various magic water and Ice tales that we hear.

syhprum


Since I'm still doubting about the feasibility of the electromagnetic drive I checked again what special relativity says about this. Acoording to special relativity, it is clear that momentum should be conserved and hence the drive can not work. On the other hand, one could also argue that one should use general relativity since the microwaves bounce of the walls (exerting pressure) and thus accelerate (changing direction). In general relativty however, momentum itself is not strictly defined (" Momentum is the Noether charge of translational invariance. As such, even fields as well as other things can have momentum, not just particles. However, in curved spacetime which is not asymptotically Minkowski, momentum isn't defined at all." ; see http://dictionary.laborlawtalk.com/Momentum [nofollow]) and thus there might be an opening here for some kind of non-conservation of momentum. Any comments ?
 

Offline bostjan

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Re: An anti gravity machine for real!?
« Reply #38 on: 18/09/2006 03:26:48 »
Oh, I can't believe that I missed the part about no energy coming out.  This is certainly impossible.  If the microwaves leave the cavity, it should be possible to generate a thrust without loss of mass, though.  I now understand the confusion over my statements.  Acceleration without expendature of energy violates more than just Newton's laws.
 

Offline Nieuwenhove

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Re: An anti gravity machine for real!?
« Reply #39 on: 17/09/2006 17:00:57 »
quote:
Originally posted by syhprum

I am begining to believe that this is just a money making scam, like cold fusion, homopathy, or the various magic water and Ice tales that we hear.

syhprum


Since I'm still doubting about the feasibility of the electromagnetic drive I checked again what special relativity says about this. Acoording to special relativity, it is clear that momentum should be conserved and hence the drive can not work. On the other hand, one could also argue that one should use general relativity since the microwaves bounce of the walls (exerting pressure) and thus accelerate (changing direction). In general relativty however, momentum itself is not strictly defined (" Momentum is the Noether charge of translational invariance. As such, even fields as well as other things can have momentum, not just particles. However, in curved spacetime which is not asymptotically Minkowski, momentum isn't defined at all." ; see http://dictionary.laborlawtalk.com/Momentum [nofollow]) and thus there might be an opening here for some kind of non-conservation of momentum. Any comments ?
 

Offline bostjan

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Re: An anti gravity machine for real!?
« Reply #40 on: 18/09/2006 03:26:48 »
Oh, I can't believe that I missed the part about no energy coming out.  This is certainly impossible.  If the microwaves leave the cavity, it should be possible to generate a thrust without loss of mass, though.  I now understand the confusion over my statements.  Acceleration without expendature of energy violates more than just Newton's laws.
 

Offline dgdavisjr

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Re: An anti gravity machine for real!?
« Reply #41 on: 22/10/2006 02:41:37 »
quote:
Originally posted by syhprum

I deserve to have one brownie point deducted!, and I have lectured people on action and reaction on this board.

syhprum


Actually you tripped over a glaring, yet continually overlooked violation of the physical laws of thermodynamics and conservation of energy. According to these laws energy cannot be created or desroyed but only converted to another form. Where does the energy that the mgnetic disk is supported by come from? Why can't it be exhausted? Like magnetic poles will oppose each other without diminishment of power level. How? The energy must (according to known law) come frome somewhere but it seems to be inexhaustable and free. Try a lecture on this.

D.G.Davis,Jr.
 

Offline lightarrow

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Re: An anti gravity machine for real!?
« Reply #42 on: 22/10/2006 10:30:30 »
quote:
Originally posted by Nieuwenhove

Acoording to special relativity, it is clear that momentum should be conserved and hence the drive can not work. On the other hand, one could also argue that one should use general relativity since the microwaves bounce of the walls (exerting pressure) and thus accelerate (changing direction). In general relativty however, momentum itself is not strictly defined (" Momentum is the Noether charge of translational invariance. As such, even fields as well as other things can have momentum, not just particles. However, in curved spacetime which is not asymptotically Minkowski, momentum isn't defined at all." ; see http://dictionary.laborlawtalk.com/Momentum) and thus there might be an opening here for some kind of non-conservation of momentum. Any comments ?
So we should have already seen momentum conservation violations every time light is reflected by a mirror, isnt'it?
 

Offline Soul Surfer

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Re: An anti gravity machine for real!?
« Reply #43 on: 22/10/2006 11:34:23 »
No, there is a force on the mirror as it reflects light.

The small magnets floating over a superconducting surface work because the surface is superconducting  and the normal eddy currents that form a a magnet approaches a conducting surface do not die away.   I have seen this happen in the lab where I worked.  as soon as the superconductor warms up a bit ans the superconductivity goes awy the magnet fall on to the surface.

I am now almost certain that this reactionless drive cannot possibly work because the designer is not taking into account the foreces on the tapered section of the waveguide.  The forces on the two ends of the cavity are clearly different but there is also a momentum transfer on the tapered section and the elements of the force in the direction of the smaller surface together with the force on the smaller surface and effective momentum change must balance out the force on the large surface.

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Offline syhprum

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Re: An anti gravity machine for real!?
« Reply #44 on: 22/10/2006 13:12:49 »
This was day one in physics when I was at school, the fact that a force exists does not immply that energy is generated or adsorbed it is only when there is movement against a force that energy comes into play ( we used to talk about it in foot pounds in the old days! )

syhprum
 

Offline lightarrow

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Re: An anti gravity machine for real!?
« Reply #45 on: 23/10/2006 13:47:24 »
quote:
Originally posted by Soul Surfer

No, there is a force on the mirror as it reflects light.
Yes, of course there is a force, and so?
quote:
...the designer is not taking into account the foreces on the tapered section of the waveguide.
It means that designer didn't even study high school physics!
 

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Re: An anti gravity machine for real!?
« Reply #45 on: 23/10/2006 13:47:24 »

 

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