Hawking - It is wrong to take the Big Bang literally

Stephen Hawking
The Grand Design (2010)
pages 128-129

Stephen Hawking
The Grand Design (2010)
pg. 128-129

Measurements of helium abundance and the CMBR [Cosmic Microwave Background Radiation] provided convincing evidence in favor of the Big Bang picture of the very early Universe, but although one can think of the Big Bang picture as a valid description of early times, it is wrong to take the big bang literally, that is, to think of Einstein's theory as providing a true picture of the origin of the Universe. That is because General Relativity predicts there to be a point in time at which the temperature, density, and curvature of the Universe are all infinite, a situation mathematicians call a singularity. To a physicist this means that Einstein's theory breaks down at that point and therefore cannot be used to predict how the Universe began, only how it evolved afterwards. So although we can employ the equations of general relativity and our observations of the heavens to learn about the Universe at a very young age, it is not correct to carry the Big Bang picture all the way back to the beginning.