Shawyer's EMdrive: Lift a Car Against Gravity?

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In summary, the conversation is discussing a controversial claim about using a superconducting cavity to lift a car using 30,000 Newtons per kilowatt. While some question the science behind it and its practical applications, others point out flaws in the theory and the lack of peer-reviewed evidence. The conversation also touches on the role of Lorentz Force in the machine and the questionable validity of the claim.
  • #1
Kosta
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http://www.shelleys.demon.co.uk/fdec02em.htm"
And check out new scientist's issue last week if you have subscription, http://www.newscientist.com/data/images/archive/2568/25681401.jpg"

What do you guys think of the science behind this? He says with a superconducting cavity he could get 30,000 Newtons per kilowatt - enough to lift(hover) a large car.

He says it wouldn't be useful for propulsion but if it can lift a car againts gravity for a long period of time.. remove that gravity (such as in space) would it not go flying? And would it not be able to achieve at least 1g acceleration? (ie eath-to mars(median 280mil km) in just under 4 days including turnaround)

Thanks, (whats my nick again?):confused:

P.S btw sry if this has been posted before, I searched.. nothing .. I am new..
 
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  • #2
It seems to violate conservation of momentum, but I'm a bit rusty as to taking into account the momentum contained in the EM field. Also, I don't think the radiation pressure on one side of the cavity would be smaller than the other since the effective areas are the same once you take into account the sloped inner surface.
 
  • #3
From the diagram, it is pretty simple to understand why it doesn't work: radiation pressure is what he's talking about and pressure is force over area. The pressure on one side would be higher than the other, but the net force is the same in both directions.

In the photo of his demonstration device, I notice there is something sitting under the side of the balance that his device is sitting on...
 
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  • #4
What does Lorentz Force have to do with this machine? In his paper, he uses a shortened version for the force which neglects the cross-product between velocity and the magnetic field. In Shawyer's formulation the force is just placed there without regard for the direction.
 
  • #5
By all appearances, this is a crank claim and not worth discussing. The paper has never been published in a peer-reviewed journal.

This thread should have been locked long ago.
 

1. What is Shawyer's EMdrive?

Shawyer's EMdrive is a proposed propulsion system that claims to be able to generate thrust without the use of any propellant.

2. How does Shawyer's EMdrive work?

The EMdrive works by converting electrical energy into microwaves, which bounce back and forth inside a specially shaped chamber. The asymmetrical shape of the chamber causes a net force to be exerted, resulting in thrust.

3. Is there any scientific evidence to support Shawyer's claims?

There have been several tests conducted on the EMdrive, but so far, no conclusive evidence has been found to support Shawyer's claims. Many scientists remain skeptical due to the lack of a plausible explanation for how the drive could produce thrust without violating the laws of physics.

4. Can Shawyer's EMdrive really lift a car against gravity?

No, there is currently no evidence to suggest that the EMdrive is capable of lifting a car against gravity. While it has shown very small amounts of thrust in laboratory tests, this is not nearly enough to lift a car.

5. Is Shawyer's EMdrive a viable technology for space travel?

At this point, it is unlikely that the EMdrive will be a viable technology for space travel. The lack of scientific evidence and the many unanswered questions about how it works make it a highly controversial and unproven concept in the scientific community.

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