Science Fiction
Dictionary
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
 |
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 |
Would
you like to contribute a story tip?
It's easy:
Get the URL of the story, and the related sf author, and add
it here.
Comment/Join discussion ( 5 )
Related News Stories - (" Space Tech ")
Solitary Black Hole Wanders In Space
'...the Hole is something like a vortex or a whirlpool?' - Frank K. Kelly, 1935.
Spaceplane From Virgin Atlantic
'ZARNAK, YOU'RE TO COMMAND A SCOUTING EXPEDITION --- FIND OUT WHAT THIS IS ALL ABOUT!'
Taikonauts Exercise In China's Tiangong Space Station
'Joe got out the gravity-simulator harnesses...' - Murray Leinster, 1953.
SpaceX's Starman Tesla Roadster In Space
'Somewhere in space, a chrome and blue automobile raced the green light of Earth.' - Theodore Sturgeon, 1941.
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.
Science Fiction
Timeline
1600-1899
1900-1939
1940's 1950's
1960's 1970's
1980's 1990's
2000's 2010's
Current News
Robotic Barber Programmed With a Number of Styles
'He found a barber shop which, he thought, would be good for an idle hour.'
Humanoid Boxing Robot KO's Opponent - It's A Knockout!
'Thirty rounds of fighting is tough work. Even for machines.'
Caterpillar Electric Mining Loader Not Yet Ready For Moon
'...the excavations were already in progress, for he saw gray slopes of rubble.'
Centipede Robots Down On The Farm
'...the walking mills of Puffy Products began to tread delicately on their centipede legs across the wheat fields of Kansas.'
Anthropic's Claude AI Creates Legal Citation From Whole Cloth
'Here is a Clerk that would work incessantly, and neither eat, sleep, want payment, or grumble.'
Students Vie For Lunar Regolith Mining Robot Prize
'About time you got here,' the astronaut said.
'They Erased My Memory' Says Ariana Grande
'...using a neutralizing electronic impulse.'
Solitary Black Hole Wanders In Space
'...the Hole is something like a vortex or a whirlpool?'
Spaceplane From Virgin Atlantic
'ZARNAK, YOU'RE TO COMMAND A SCOUTING EXPEDITION --- FIND OUT WHAT THIS IS ALL ABOUT!'
DARPA Wants 'Large Bio-Mechanical Space Structures'
'These are your rudimentary seed packages... Some will combine in place to form more complicated structures.'
Robot Hand Creeps Along, Separate From It's Owner
'The crawling... object was V-Stephen's surgeon-hand...'
Taikonauts Exercise In China's Tiangong Space Station
'Joe got out the gravity-simulator harnesses...'
Korean Exoskeleton Suit F1 Helps You Put It On
'Better late than never.'
Have AI Researchers Given Up On 'Bio-Babies'?
'You couldn't have the capstone without the pyramid to hold it up.'
Bunker Busters and Bore-Pellets
'The first revelation of the new Soviet bore-pellets.'
'Spikeless' Brand Swizzle Stick Detects Spiked Drinks
'the unobtrusive inspections with tiny remote-cast snoopers...'
