The problem of time is one of the greatest puzzles of modern physics. The first bit of the conundrum is cosmological. To understand time, scientists talk about finding a ‘First Cause' or ‘initial condition' – a description of the Universe at the very beginning (or at ‘time equals zero'). But to determine a system's initial condition, we need to know the total system. We need to make measurements of the positions and velocities of its constituent parts, such as particles, atoms, fields and so forth. This problem hits a hard wall when we deal with the origin of the Universe itself, because we have no view from the outside. We can't step outside the box in order to look within, because the box is all there is. A First Cause is not only unknowable, but also scientifically unintelligible.
