Search results
Results from the WOW.Com Content Network
Relativistic rocket means any spacecraft that travels close enough to light speed for relativistic effects to become significant. The meaning of "significant" is a matter of context, but often a threshold velocity of 30% to 50% of the speed of light (0.3c to 0.5c) is used.
Later studies indicate that the top cruise velocity that can theoretically be achieved by a Teller-Ulam thermonuclear unit powered Orion starship, assuming no fuel is saved for slowing back down, is about 8% to 10% of the speed of light (0.08-0.1c). [44] An atomic (fission) Orion can achieve perhaps 3%-5% of the speed of light.
From the planetary frame of reference, the ship's speed will appear to be limited by the speed of light — it can approach the speed of light, but never reach it. If a ship is using 1 g constant acceleration, it will appear to get near the speed of light in about a year, and have traveled about half a light year in distance. For the middle of ...
This constancy of the speed of light means that, counter to intuition, the speeds of material objects and light are not additive. It is not possible to make the speed of light appear greater by moving towards or away from the light source. [14] [15] [16] [17]
Lorentz factor, γ, as a function of speed, v. Its initial value is 1 when speed is zero and increases without bound as speed approaches light speed, c. Inverse of Lorentz factor as a function of speed, v, as a proportion of light speed, c - a circular arc.
Einstein [H 7] analyzed a uniformly accelerated reference frame and obtained formulas for coordinate dependent time dilation and speed of light, analogous to those given by Kottler-Møller-Rindler coordinates. 1907: Hermann Minkowski [H 9] defined the relation between the four-force (which he called the moving force) and the four acceleration
The Hubble length or Hubble distance is a unit of distance in cosmology, defined as cH −1 — the speed of light multiplied by the Hubble time. It is equivalent to 4,420 million parsecs or 14.4 billion light years. (The numerical value of the Hubble length in light years is, by definition, equal to that of the Hubble time in years.)
The speed of light in vacuum is defined to be exactly 299 792 458 m/s (approximately 186,282 miles per second). The fixed value of the speed of light in SI units results from the fact that the metre is now defined in terms of the speed of light. All forms of electromagnetic radiation move at exactly this same speed in vacuum.