Emdrive Electromagnetic Drive For Chinese Space Ships?
Tired of those conventional space drives that require some sort of reaction mass? Chinese researchers claim to have confirmed the basic principles behind the Emdrive - an electromagnetic drive concept that converts electrical energy into thrust using microwaves.
The Chinese are currently building a demonstration model to see if it works.
('Emdrive' Electromagnetic Space Drive)
Take a look at the explanation offered on Roger Shawyer's Emdrive website:
The principle of operation is based on the well-known phenomenon of radiation pressure. This relies on Newton’s Second Law where force is defined as the rate of change of momentum. Thus an electromagnetic (EM) wave, travelling at the speed of light has a certain momentum which it will transfer to a reflector, resulting in a tiny force.
If the same EM wave is travelling at a fraction of the speed of light, the rate of change of momentum, and hence force, is reduced by that fraction. The propagation velocity of an EM wave, and the resulting force it exerts, can be varied depending on the geometry of a waveguide within which it travels. This was demonstrated by work carried out in the 1950’s. (CULLEN, A.L. ‘Absolute Power Measurements at Microwave Frequencies’ IEE Proceedings Vol 99 Part 1V 1952 P.100)
Thus if the EM wave travelling in a tapered waveguide is bounced between two reflectors, with a large velocity difference at the reflector surfaces, the force difference will give a resultant thrust to the waveguide linking the two reflectors. If the reflectors are separated by a multiple of half the effective wavelength of the EM wave, this thrust will be multiplied by the Q of the resulting resonant cavity.
The inevitable objection raised, is that the apparently closed system produced by this arrangement cannot result in an output force, but will merely produce strain within the waveguide walls. However, this ignores Einstein’s Special Law of Relativity in which separate frames of reference have to be applied at velocities approaching the speed of light. Thus the system of EM wave and waveguide can be regarded as an open system, with the EM wave and the waveguide having separate frames of reference.
The beauty of engineering is that you can actually build something to test it; we'll find out soon enough if Emdrives will power space craft.
In the meantime, you might want to compare the Emdrive explanation with other famous pseudo-scientific science-fictional space drives. See the entries for the spindizzy from James Blish's Cities in Flight and of course the elegant infinite improbability drive from Douglas Adam's Hitchhiker's Guide to the Galaxy .
Via Wired; see also the Emdrive website.
Scroll down for more stories in the same category. (Story submitted 9/29/2008)
Follow this kind of news @Technovelgy.
| Email | RSS | Blog It | Stumble | del.icio.us | Digg | Reddit |
you like to contribute a story tip?
Get the URL of the story, and the related sf author, and add
Comment/Join discussion ( 5 )
Related News Stories -
Elon Musk Tweets Versions Of Clarke's Operation Cleanup
'Fortunately, the old orbital forts were superbly equipped for this task.' - Arthur C. Clarke, 1978.
Espresso Telescope Searches For Exoplanets
'These instruments were the wonderful ones our astronomers had perfected.' - Edmond Hamilton, 1936.
Manned Maneuvering Unit From 1984
'The glittering little rocket bolted to the black iron behind him.' - Jack Williamson, 1933.
Astronaut Gets Younger In Space
'So what we're looking for now is not an antibiotic - an anti-life drug - but an anti-agathic, an anti-death drug...' - James Blish, 1957.
Technovelgy (that's tech-novel-gee!)
is devoted to the creative science inventions and ideas of sf authors. Look for
the Invention Category that interests
you, the Glossary, the Invention
Timeline, or see what's New.
Swarm Of Mindless Robots Works Together
'Very tiny pseudo insects that... can unite to form a superordinate system.'
SpotMini Robot Dog, Autonomous And On Sale In 2019
Great, an autonomous slamhound. It is cute, though.
RoboFly Is Laser-Powered, Adorable
Don't swat this fly!
MSG Sphere Las Vegas, ala Star Wars
'The smoky globe, hung in the vault, was shot with colored light...'
Tetraplegics Dominate Avatar Races
Well, just speaking brain-to-computer...
MIT Ampli Blocks Build Biomedical Devices
Damn it Spock, I'm a doctor not an engineer!
UberAIR Asks For Skytaxi Landing Prototypes
You know you want to ride in one.
Boring Tunnel Almost Ready
Your underground future is calling!
Handheld Human Skin Printer
It outputs a thin wad of uniflesh.
Healthy Fast Food Courtesy Of Robot Chefs
'The electric cook was stirring empty nothing in a pan, with a zeal worthy a dozen eggs.'
Mass Production Of In Vitro Meat From One Sample
They're Assimilating Our Culture, That's What They're Doing
Amazing 'Hybrid' Solar-Powered Sea Slug Does Photosynthesis
Thank goodness for Star Trek.
Retinal Prosthesis Uses Organic Printing Inks
We can rebuild you - well, your eyes, maybe.
Should You Submit Your DNA To A Database?
Consumer DNA services are often inaccurate.
Squid-Like Robots Soon To Be 3D Printable
'It was a chemotactic artificial jellyfish designed to slither...'
Humans Evolve Deep Diving Abilities
Sounds like '60s sci-fi to me.
More SF in the News Stories
More Beyond Technovelgy science news stories