Superluminal in a sentence

However, it is not the group velocity but the signal velocity that determines the communication speed, and superluminal group velocity does not imply superluminal signal velocity.

Superluminal motion occurs when objects are traveling close to the speed of light along a direction that is close to our line of sight.

According to Asher Peres citation and David Kaiser, citation the publication of the no-cloning theorem was prompted by a proposal of Nick Herbert citation for a superluminal communication device using quantum entanglement.

All forms of energy are believed to interact at least gravitationally, and many authors state that superluminal propagation in Lorentz invariant theories always leads to causal paradoxes.

Because the group velocity for such a field is superluminal, naively it appears that its excitations propagate faster than light.

By contrast, tachyonic fields - quantum fields with imaginary mass - certainly do exist, and exhibit superluminal group velocity under some circumstances.

For a hidden variable theory, if Bell's conditions are correct, the results that agree with quantum mechanical theory appear to indicate superluminal effects, in contradiction to the principle of locality.

For example, travelling to Vega (which is 25 light-years from Earth) requires arranging everything so that the bubble moving toward Vega with a superluminal velocity would appear; such arrangements will always take more than 25 years.

For large gaps between the prisms the tunnelling time approaches a constant and thus the photons appear to have crossed with a superluminal speed.

However, it was quickly understood that the superluminal group velocity does not correspond to the speed of propagation of any localized excitation (like a particle).

However, such fields have luminal signal velocity and do not allow superluminal communication.

In other words, a comet at such a distance is superluminal in a geostatic, and therefore non-inertial, frame.

Quantum nonlocality (and in particular the phenomenon of quantum entanglement ) is often proposed as another mechanism for superluminal communication.

So we cannot say for sure that quantum entanglement will never be used for superluminal communication, nor can we say it will for sure.

Technically, the microscopic causality postulate of axiomatic quantum field theory implies the impossibility of superluminal communication using any phenomena whose behavior can be described by orthodox quantum field theory.

There are real systems with superluminal group velocity, some of which have been experimentally realized and studied in the lab.

Therefore, this does not imply the possibility of superluminal information transmission.

These are one of the few methods of superluminal travel which may be possible under current physics.

The term " tachyon " was coined by Gerald Feinberg in a 1967 paper, but it was soon realized that Feinberg's model in fact did not allow for superluminal speeds.

This double image effect is most prominent for an observer located directly in the path of a superluminal object (in this example a sphere, shown in grey).