Relativity Drive

[hagbard_celine]

This was in David's headlines:

http://technology.newscientist.com/article/mg19125681.400

Click the picture to see here an enlarghement of the diagram.

I saw something like this demonstrated at the Probe conference a couple of years ago and the designer explained it to me. The thing about it is that it needs a power source, in this case a 1.1 KW magnetron. The engine itself may be zero emission, but the power it needs to run has mto be generated from somewhere.

It's not a free lunch, and therefore however efficient it is there are better things out there. There are devices that can produce that kind of power without any energy imput!:eek::cool:

[tabea_blumenschein]

From the linked article:

Hang on a minute, though. If the cavity is to move, it must be pushed by something. A rocket engine, for example, is propelled by hot exhaust gases pushing on the rear of the rocket. How can photons confined inside a cavity make the cavity move? This is where relativity and the strange nature of light come in. 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 Einstein's special theory of relativity. This says that the microwaves move in their own frame of reference. In other words they move independently of the cavity - as if they are outside it. As a result, the microwaves themselves exert a push on the cavity.

Excuse me for a moment ...

* Tabea repeatedly bangs head against keyboard *

Okay, I'm back.

Good god.

Visible light is just one small part of the much larger electromagnetic spectrum, which includes gamma rays, x-rays, ultraviolet light, visible light, infrared radiation, microwaves, and finally tv and radio waves, with the only difference being the frequency (wavelength). All em radiation propagates through space at exactly the same velocity as visible light, not "close to the speed of light."

Microwaves don't have "their own frames of reference" either - relativity is based entirely on the idea that the speed of light (and all em radiation) is invariant and will be the same for all frames of reference.

Let me know if someone actually builds a working em drive. A demonstration of such a device would in one fell swoop disprove numerous laws of physics, and we'd need to get a hell of a bonfire going to dispose of all our newly-outdated physics textbooks ...

[the seeker]

Yes, but what about the Infinite Improbability Drive? I hear that one is damned impressive.

[abaddon]

* Tabea repeatedly bangs head against keyboard *


Microwaves don't have "their own frames of reference" either - relativity is based entirely on the idea that the speed of light (and all em radiation) is invariant and will be the same for all frames of reference.

"This says that the microwaves move in their own frame of reference. In other words they move independently of the cavity - as if they are outside it. As a result, the microwaves themselves exert a push on the cavity."


Both quotes are right in their own respect? :) Just so the picture is crystal.

Funnily enough, I was reading this article a few days ago, and after, found my way to this link:
Spacecraft propulsion - Wikipedia, the free encyclopedia

[tabea_blumenschein]

I've just been reading some comments on that New Scientist article posted at one or two other sites. Apparently I'm not the only one having a bit of trouble figuring out what the article is trying to say (example (http://forums.randi.org/showpost.php?p=4074471&postcount=13)).

Abbadon, you might be interested in reading http://en.wikipedia.org/wiki/Relativity_drive on the Relativity Drive.

[hagbard_celine]

Yes, but what about the Infinite Improbability Drive? I hear that one is damned impressive.

Greetings, fellow Hitchhiker! Have you got your towel?:D

[hagbard_celine]

Both quotes are right in their own respect? :) Just so the picture is crystal.

Funnily enough, I was reading this article a few days ago, and after, found my way to this link:
http://en.wikipedia.org/wiki/Spacecraft_propulsion


The ion thrusters are in use now on some satelites. I remember hearing about them on Tommorrow's World when I was a kid.

[strt]

greetings, fellow hitchhiker! Have you got your towel?:d

"DON'T PANIC" lol