Is time an illusion? And can we prove it? If we pause to ask what physics has to say about why time flows at all, we find it struggles. Albert Einstein’s ideas warped time, quantum theory barely considers it, and no other facet of modern physics can satisfactorily explain it. Now, though, one of the most audacious proposals for how time really works is getting a second look. Back in the 1980s, physicists sketched out the hypothesis that time is an illusion, conjured from an essentially timeless