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Faster-than-light (superluminal or supercausal) travel and communication are the conjectural propagation of matter or information faster than the speed of light (c). The special theory of relativity implies that only particles with zero rest mass (i.e., photons ) may travel at the speed of light, and that nothing may travel faster.
The theory of relativity says information cannot be transmitted faster than light. This experiment does not actually transmit a signal from object 1 to object 2. The time when the light beam strikes object 2 is controlled by the person at the lighthouse, not anyone on object 1, so no one on object 1 can transmit a message to object 2 by this ...
The former distance is about 4 billion light-years, much smaller than ct, whereas the latter distance (shown by the orange line) is about 28 billion light-years, much larger than ct. In other words, if space were not expanding today, it would take 28 billion years for light to travel between Earth and the quasar, while if the expansion had ...
In science fiction, hyperspace (also known as nulspace, subspace, overspace, jumpspace and similar terms) is a concept relating to higher dimensions as well as parallel universes and a faster-than-light (FTL) method of interstellar travel. In its original meaning, the term hyperspace was simply a synonym for higher-dimensional space.
In some cases, objects or waves may appear to travel faster than light (e.g., phase velocities of waves, the appearance of certain high-speed astronomical objects, and particular quantum effects). The expansion of the universe is understood to exceed the speed of light beyond a certain boundary.
In special relativity, a faster-than-light particle would have spacelike four-momentum, [3] unlike ordinary particles that have time-like four-momentum. While some theories suggest the mass of tachyons is imaginary , modern formulations often consider their mass to be real, [ 14 ] [ 15 ] [ 16 ] with redefined formulas for momentum and energy.
The speed of gravitational waves in the general theory of relativity is equal to the speed of light in vacuum, c. [3] Within the theory of special relativity, the constant c is not only about light; instead it is the highest possible speed for any interaction in nature.
This phenomenon is caused because the jets are traveling very near the speed of light and at a very small angle towards the observer. Because at every point of their path the high-velocity jets are emitting light, the light they emit does not approach the observer much more quickly than the jet itself.