General relativity

The speed of light is sacrosanct

Nothing can travel through space faster than the speed of light, yet entangled particles appear to defy this rule. As of yet there is no agreed explanation for this phenomenon.

Space and time are space-time

The three dimensions of space and one of time that we experience are really wrapped up together in a four-dimensional fabric called space-time. This fabric is smooth and continuous.

Gravity is geometry

Newton was wrong – gravity isn’t a pull from a massive object. Instead it is the effect we see of bodies following a curved path through spacetime as the result of a massive object, like a star, warping it.

Acceleration and gravity

The equivalence principle says you cannot distinguish between a gravitational pull and an acceleration. Accelerate through space and you’ll experience the same ‘gravity’ as on Earth.