Emdrive (electromagnetic microwave reactionless drive) ? / General Chatting / Forums

Forums

4hv.org :: Forums :: General Chatting

« Previous topic | Next topic »

Emdrive (electromagnetic microwave reactionless drive) ?

1 2 3 4 next

Move Thread

LAN_403

Conundrum

Sun Sept 10 2006, 12:06PM

Registered Member #96 Joined: Thu Feb 09 2006, 05:37PM
Location: CI, Earth
Posts: 4059

I also saw this in "New Scientist". For a change it is actually consistent with the laws of physics, however the force generated is fairly low, comparable with an ion drive.

One interesting note though, the research seems to indicate that a superconducting Q-chamber would be many times more efficient, as has been seen in particle accelerators.

-A

Marko

Sun Sept 10 2006, 12:15PM

Registered Member #89 Joined: Thu Feb 09 2006, 02:40PM
Location: Zadar, Croatia
Posts: 3145

It is nothing new actually. You still have 'reaction' from radiation emmited. It has no mass but can still carry momentum.

It can even be parasitic in some cases; one theory behind pioneer anomaly

is that it is getting slowed down by IR radiation emmited from his RTG and reflected from his hull.

Recently launched 'new horizons' probe will try to investigate that more throughly.

Monstrous lasers are known to be able to 'push' small objects, and already known solar-sail drive uses solar radiation (and wind in some cases) to weakly propel ship forward.
Generated force is minor but presistent and can go practically forever.
Anyway gravitational slingshot and chemical drives still seem to be favourites.

Bjørn

Sun Sept 10 2006, 09:17PM

Registered Member #27 Joined: Fri Feb 03 2006, 02:20AM
Location: Hyperborea
Posts: 2058

The prototype is at least 4 years old, why has no one I know reproduced this fairly simple experiment?
Why is this company and great inventor using an AOL mail address?

Marko

Sun Sept 10 2006, 09:25PM

Registered Member #89 Joined: Thu Feb 09 2006, 02:40PM
Location: Zadar, Croatia
Posts: 3145

I didn't actually bother reading that article fully as it loked BSssy.

Electromagnetic radiation can produce thrust and it still isn't 'reactionless' at all.

Problem is that force (either from artifical EM source or solar sail) is incredibly weak and probably not of much real use.

Bjørn

Sun Sept 10 2006, 09:44PM

Registered Member #27 Joined: Fri Feb 03 2006, 02:20AM
Location: Hyperborea
Posts: 2058

The claim is that the force is determined by the Q factor of the cavity. So if you manage get the wave to reflect a million times the force will be a million times larger. Then we use it to drive a generator and we have free energy for everyone. Sounds almost too good to be true.

HV Enthusiast

Sun Sept 10 2006, 10:20PM

Registered Member #15 Joined: Thu Feb 02 2006, 01:11PM
Location:
Posts: 3068

What a BUNCH of CRAPOLA!

Firstly, look at the website . . .
http://www.emdrive.com

I would think someone that is the brainchild of the next evolution of spaceflight, backed by academics and governments (as stated in the article), would be able to afford an AD-free web provider. Also, the AOL address is pretty lame as well.

Plus, his company, SPR Ltd - if you do a search on it via the UK company register, it states it is bankrupt. Hardly something i would expect from the scientific invention of the millenium.

Reaching

Sun Sept 10 2006, 10:56PM

Registered Member #76 Joined: Thu Feb 09 2006, 10:04AM
Location: Hemer, Germany
Posts: 458

its nothing new actually, its just a source of electromagnetic radiation reflected by this huge conical thing and voila you have some thrust, very weak but it works. search for this laser experiments where a conical shaped metal lifts off just with the power of a few watts laser, by reflection on the inside of the conical flyer. i think there is some truth behind this story, not to mention that you need power and that its no free energy source or whatever, just a microwave oven with a funny case

Carbon_Rod

Mon Sept 11 2006, 12:58AM

Registered Member #65 Joined: Thu Feb 09 2006, 06:43AM
Location:
Posts: 1155

EVR makes a good point

Perhaps with a purely diamagnetic interstellar medium this thing would still likely not work.

=] lol

Bjørn

Mon Sept 11 2006, 01:41AM

Registered Member #27 Joined: Fri Feb 03 2006, 02:20AM
Location: Hyperborea
Posts: 2058

It seems like SPR Ltd lives here

and that whoever made

did not know the proper name of the company.

its nothing new actually, its just a source of electromagnetic radiation reflected by this huge conical thing and voila you have some thrust, very weak but it works.

It helps if you read the claims before you comment on them. The prototype is a closed system where no radiation escapes except waste heat.

search for this laser experiments where a conical shaped metal lifts off just with the power of a few watts laser

You can't lift anything with a few watts of laser. You need a very powerful pulsed laser that superheats air to generate trust. The conical shape is not to reflect the light but to concentrate it. In vacuum it will do absolutely nothing except fall to the ground.

AndrewM

Mon Sept 11 2006, 02:07AM

Registered Member #49 Joined: Thu Feb 09 2006, 04:05AM
Location: Bigass Pile of Penguins
Posts: 362

BjÃ¸rn BÃ¦verfjord wrote ...

You can't lift anything with a few watts of laser. You need a very powerful pulsed laser that superheats air to generate trust. The conical shape is not to reflect the light but to concentrate it. In vacuum it will do absolutely nothing except fall to the ground.

So you don't believe in solar sails either? Or that photons carry momentum?

I believed in the microwave doodle until the Q factor bit; gotta have some exhaust.

1 2 3 4 next

Moderator(s): Chris Russell, Noelle, Alex, Tesladownunder, Dave Marshall, Dave Billington, Bjørn, Steve Conner, Wolfram, Kizmo, Mads Barnkob