WHAT is “now”? It is an idea that physics treats as a mere illusion, yet it is something we are all familiar with. We tend to think of it as this current instant, a moment with no duration. But if now were timeless, we wouldn’t experience a succession of nows as time passing. Neither would we be able to perceive things like motion. We couldn’t operate in the world if the present had no duration. So how long is it…?
This article first appeared in New Scientist on 10 January 2015. To continue reading, click here (paywall).
THE old man shields his eyes against the fierce light of the Altiplano and considers the question. When he talks about his ancestors, does he mean the Incas? No, he replies in a sort of Spanish creole, he means his great-great-grandfather. And with his right hand he makes a rotating gesture up and forwards from his body. The Incas, he adds, came way earlier. And with the same hand he sweeps even further forward, towards the mountains on the horizon…
This article first appeared in the Guardian on 24 February 2005. To continue reading click here.