 |
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
|
 |
Will You Live To See EM Pulse Scattering By Ships Nearing Light Speed?
We are all being asked to imagine what it will be like to see electromagnetic pulse scattering by spacecraft nearing light speed. Particularly by Timothy J. Garner, Akhlesh Lakhtakia, James K. Breakall and Craig F. Bohren in their new physics paper:
Humans will launch spacecraft that travel at an appreciable fraction of the speed of light. Spacecraft traffic will be tracked by radar. Scattering of pulsed electromagnetic fields by an object in uniform translational motion at relativistic speed may be computed using the frame-hopping technique. Pulse scattering depends strongly on the velocity, shape, orientation, and composition of the object. The peak magnitude of the backscattered signal varies by many orders of magnitude depending on whether the object is advancing toward or receding away from the source of the interrogating signal. The peak magnitude of the backscattered signal goes to zero as the object recedes from the observer at a velocity very closely approaching light speed, rendering the object invisible to the observer. The energy scattered by an object in motion may increase or decrease relative to the energy scattered by the same object at rest. Both the magnitude and sign of the change depend on the velocity of the object, as well as on its shape, orientation, and composition. In some cases, the change in total scattered energy is greatest when the object is moving transversely to the propagation direction of the interrogating signal, even though the Doppler effect is strongest when the motion is parallel or antiparallel to the propagation direction.
Electromagnetic Pulse Scattering by a Spacecraft Nearing Light Speed
Arthur C. Clarke not only asked us to imagine what it looks like when a craft nears light speed, he made an effort to describe it in his 1953 classic Childhood's End - behold the Stardrive:
...half a million kilometers away, the Stardrive went on. Up from the heart of the spreading moon-glow a tiny spark began to climb towards the zenith.
At first its movement was so slow that it could hardly be perceived, but second by second it was gaining speed. As it climbed it increased in brilliance, then suddenly faded from sight. A moment later it had reappeared, gaining speed and brightness. Waxing and waning with a peculiar rhythm, it ascended ever more swiftly into the sky, drawing a fluctuating line of light across the stars. Even if one did not know its real distance, the impression of speed was breathtaking: when one knew that the departing ship was somewhere beyond the moon, the mind reeled at the speeds and energies involved.
It was an unimportant by-product of those energies, Jan knew, that he was seeing now. The ship itself was invisible, already far ahead of that ascending light. As a high-flying jet may leave a vapour trail behind it, so the outward-bound vessel of the Overlords left its own peculiar wake. The generally accepted theory-and there seemed little doubt of its truth- was that the immense accelerations of the Stardrive caused a local distortion of space. What Jan was seeing, he knew, was nothing less than the light of distant stars, collected and focused into his eye wherever conditions were favorable along the track of the ship. It was a visible proof of relativity-the bending of light in the presence of a colossal gravitational field.
Scroll down for more stories in the same category. (Story submitted 12/11/2017)
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 ( 0 )
Related News Stories -
("
Space Tech
")
Reflect Orbital Offers 'Sunlight on Demand' And Light Pollution
'I don't have to tell you about the seven two-mile-diameter orbital mirrors...'
Chrysalis Generation Ship to Alpha Centauri
'This was their world, their planet —
this swift-traveling, yet seemingly moveless vessel.' - Nat Schachner, 1934
The First Space Warship For Space Force
'Each of the electrical ships carried about twenty men...' - Garrett P. Serviss, 1898.
Is China Mining Helium-3 On The Moon's Farside?
'...for months Grantline bores had dug into the cliff.' -
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
Cybertruck Robotic Arm F10 Drone Launch!
Drone away!
Black Fungus Blocks Radiation
'You were surrounded by Astrophage most of the time'
Liuzhi Process Now In Use In China
'He was in a high-ceilinged windowless cell with walls of glittering white porcelain.'
Reflect Orbital Offers 'Sunlight on Demand' And Light Pollution
'I don't have to tell you about the seven two-mile-diameter orbital mirrors...'
Will Robots Become Family Caregivers?
'The robant and the tiny old woman entered the control room slowly...'
Chinese Tokamak Uses AI To Keep Fusion Plasma Stable
'Guy named Otto Octavius winds up with eight limbs... What are the odds?'
Time Crystals Can Now Be Seen Directly
'It is as you thought when you constructed the time crystal, my master Vaylan.'
RoboBallet The Dance Of Cooperative Robots
'...an integrated seven-unit robot team.'
Chrysalis Generation Ship to Alpha Centauri
'This was their world, their planet —
this swift-traveling, yet seemingly moveless vessel.'
Alexa+ And Its AI Brain Improvements
'What's it do?' he asked. 'It amuses.'
Does CloneRobotics Offer A True Android?
Is this What Little Girls Are Made Of?
Brain Implant Is Able To Capture Your Inner Dialogue
'So you see, you can hide nothing from me.'
Are AIs Going Rogue Like Hal 9000
'I know that you and Frank were planning to disconnect me...'
Animated Tumblebugs On Astounding Cover!
'Gaines and Harvey mounted tumblebugs, and kept abreast of the Cadet Captain...'
LingYuan Vehicle Roof Drones Now Available, ala Blade Runner 2049
Accompanied by a small selection of similar ideas from science fiction.
China Steals Strato Airship Design From Google App Engine
'...war-balloons, or, as it would be more correct to call them, navigable aerostats.'
More SF in the News Stories
More Beyond Technovelgy science news stories
|
 |