Neither matter, nor energy, nor anything capable of being used as a signal can travel faster than the speed of light. This limitation of the speed signalling to 299,796 kilometres a second seems a rather arbitrary decree of Nature.

Nothing travels faster than the speed of light, with the possible exception of bad news, which obeys its own special laws.

Nothing travels faster than the speed of light with the possible exception of bad news, which obeys its own special laws.

We sometimes hear of things that can travel faster than light. Something called 'the speed of thought' is occasionally proffered. This is an exceptionally silly notion especially since the speed of impulses through the neutrons in our brain is about the same as the speed of a donkey cart.

Light thinks it travels faster than anything but it is wrong. No matter how fast light travels it finds the darkness has always got there first, and is waiting for it. <small>(p.230, in the edition published in 1991 by Victor Gollancz, ISBN 0-575-04979-0)</small>

Light thinks it travels faster than anything but it is wrong. No matter how fast light travels, it finds the darkness has always got there first, and is waiting for it.

[T]hus... any intelligent species would develop at least the rocket technology capable of... a travel velocity v_es of 3 x 10^-4c. At this velocity the travel time to the nearest stars would be between 10⁴ and 10⁵ years. This... would necessitate... self-repair capacity... Nuclear power-souces would supply the power... If power utilization during the free-fall period was... low, even chemical reactions could supply the power.

to travel faster than a speeding bullet is not much help if you and it are heading straight towards each other

El mundo es totalmente diferente si la máxima velocidad de un mensaje es la que pueden alcanzar un caballo o una carabea, o bien la de la luz. La velocidad de la luz significa que podemos hablar - prácticamente a tiempo real- con cualquier persona de la Tierra o incluso de la Luna. Pensemos en la medicina. Hace unos siglos, la mayoría de los niños nacidos en las grandes familias de Europa morían en la infancia, a pesar de contar con la mejor asistencia médica de su época. Hoy en día, incluso los pobres de algunas naciones tienen una mortalidad infantil asombrosamente inferior a la de las cabezas coronadas del siglo XVII. O pensemos en la disponibilidad de medios seguros y baratos de control de la natalidad, que implica una revolución en las relaciones humanas y, sobre todo, en la condición de las mujeres.

Let us suppose that an explosion occurs on Mars, which is observed by an astronomer on earth, who records the instant when he sees the flash. If light travelled instantaneously with an infinite velocity, this instant would coincide with the time... recorded by the... observer on Mars. In this way a meaning could be attached automatically to absolute time and the simultaneity of events at different places; indeed, the classical theory is now regarded as the limiting form of Einstein's theory when the velocity of light becomes infinite. But as there is a mass of experimental evidence supporting the view that light takes a finite time to travel... the terrestrial observer must correct the time recorded on his watch. This correction... will depend on assumptions concerning the velocity of light and the measurement of distance. Thus the concept of a world-wide simultaneity ceases to be a primitive idea.

Imagine we could accelerate continuously at 1 g — what we're comfortable with on good old terra firma — to the midpoint of our voyage, and decelerate continuously at 1 g until we arrive at our destination. It would take a day to get to Mars, a week and a half to Pluto, a year to the Oort Cloud, and a few years to the nearest stars.

I travel light. But not at the same speed.

Twenty kilometers. At an average speed of 120 klicks per hour, we should cover the distance in ten minutes. Ten freezing, adrenaline-pumping, gorge-rising, terror-beating-against-the-ribs, react-in-a-microsecond-or-die seconds.

Special relativity says nothing can travel through space faster than the speed of light. But space itself can do whatever the heck it wants, at least in general relativity. And as space expands, it can carry distant objects, which are at rest in the space where they are sitting,