[cornelis]

"the problem of explaining the ‘beginning of time’ remains,"

What kind of time? Theoretically, one kind of infinity consists in a cycle or series of beginnings and endings. In that sense, the "problem of explaining the beginning" hints at a misunderstanding that LogicWings pointed out.

[Alamo-Girl]

What kind of time?

Indeed, in the view of Hawking and Hartle we ought to consider imaginary time as unbounded and real time as having a beginning.

One's concept of time has much to do with his other understandings, including his theology. This discussion on the religion forum is particularly engaging: TIME: What is time and when did time start?