Did the big bang originate from singularity?

A ‘singularity’ means that things become zero and infinite. As we go back to the big bang, we end up in regimes of ever higher temperature, pressure, density,… And in the big bang itself all that becomes infinite. We have no knowledge of physics where everything is infinite, so in the big bang our ignorance is also infinite in a sense.

The Big Bang as the point where time begins provides another way of speaking of it in terms of a singularity. It’s kind of like the North Pole in a latitude and longitude coordinate system. If you start from the equator, you can always end up at greater latitudes, until you are at 90 degrees, at the pole. There is no more northerly than the North Pole. Similarly, there is no ‘earlier than the big bang’ in our time.

What is a bit flawed in the previous lines of reasoning is that we regard time as an axis that goes on continuously. This is difficult to reconcile with quantum physics, which sees all physical quantities – including time – as built up from discrete pieces. That way we already have problems before we get to the singularity ‘time zero’: we have to keep silent about everything that is earlier than ten-to-the-minus-43rd second.

Quantum physics is the physics of the ‘infinitely small’. Rather, the universe is about the ‘infinitely great’. But in the big bang both come together. And that’s what cosmologists are working on today. The man you are referring to is undoubtedly Allan Guth, who first came up with the ‘inflationary scenario’ for the early universe. Strictly speaking, this is not so much about that singularity. One of those who has been and still is deeply involved in the latter is Stephen Hawking.