Albert Einstein (1879 – 1955) was a pioneer of space-time. In 1905, he published his theory of Special Relativity, in which he discovered the energy in mass (*E* = *m*.c^2) based on the constancy of the speed of light to all observers. He also introduced time dilation (time going slower at high speed), based on the Lorentz transformation in the origin of the transformed reference frame.

In 1916, he published his theory of General Relativity, giving an explanation to the perihelion precession of Mercury and the bending of starlight around the sun at an Eclipse. He also deduced the existence of gravitational waves, which were confirmed long after his death. His “relativity principle” combined with tensor analysis made a powerful field theory of gravitation. Einstein, a pioneer of space-time.

However, he changed his mind more often than is generally known, leaving paradoxes in his theory of Special Relativity when he changed from the Lorentz transformation to the differential Minkowski formula. He also ignored Noether’s theorem, leaving small errors in the Schwarzschild and Robertson-Walker Solutions. The authors see Einstein as a pioneer of space-time, but repair his relativity for his own (unpublished) changes of mind and for Noether’s theorem.