Space-time, according to Einstein's theories of relativity, is a four-dimensional fabric woven together by space and time.

WSJ: Einstein Proved Right on Gravity��Again

One of his great achievements since then, together with mathematician Roger Penrose, has been to prove that Einstein's General Theory of Relativity means space and time has a beginning in the "Big Bang" and ends in black holes.

CNN: Ask Stephen Hawking a space question

Together, they developed Dr Ashtekar's idea to show that it implies that space and time are not smooth, as general relativity requires, but come in tiny, distinct chunks.

ECONOMIST: A new ��theory of everything�� is gaining ground

One is Einstein's general relativity, which deals with space, time and gravity.

ECONOMIST: The Higgs boson

"Einstein's theory of general relativity tells us that mass bends space and time, so when light comes toward us through the Universe, if it passes some dark matter, its light gets bent and the image we see gets bent and distorted, " Dr Heymans told the meeting.

BBC: Dark matter hints in widest-yet view of dark mystery

Einstein's general theory of relativity states that objects with mass cause a curvature in space-time, which we perceive as gravity.

WSJ: Einstein Proved Right on Gravity��Again

Albert Einstein published his theory of general relativity in 1916, offering a description of gravity, space and time that transformed how scientists understand the physical laws governing the known universe.

WSJ: Researchers Spent $750 million��and 52 Years��Affirming Theory of Relativity