What is truth? - continued.

One of my abiding memories is of a family meal years ago at a pub up in the Malvern Hills somewhere. It was one of those perfect days - the weather was perfect, the food was perfect, the company was perfect - which is why it has stuck in my memory. And when we'd finished eating, we took the rest of our drinks out onto the patio at the rear of the pub. Like I say we were up in the Malverns, and from the patio you could look down on the countryside below, and see for miles. And there in the distance was a man hammering in a fence-post - I could see him swing his sledgehammer onto the post, and then maybe a couple of seconds later, I would hear a faint "thwack". It's a well-known phenomenon - compared with the speed of light, sound travels slowly, so you see the man hit the post well before you hear it happen. So I'd had a good meal and a couple of beers and it was a warm afternoon, and you can guess what happened - my eyes started to close. So now I was sitting there listening to the "thwacks" as the man continued with his work. At the time I was just enjoying the moment, but later it occurred to me that there were two different realities going on here - with my eyes open, the man hit the post when I saw him do it, but with my eyes closed, he didn't hit the post until I heard it. So, what's the truth? When does he hit the post? More to come, I'm afraid!