You Have Never Seen Now

Look at the Moon: you see it as it was over a second ago. The Sun: eight minutes in the past. If it simply blinked out, you would carry on in full daylight for eight whole minutes before the sky went dark — never seeing the moment it happened. Light is fast, but it is not instant, so everything you see is a report from the past: near things barely delayed, distant things ancient.

There is no way around it. There is no view of the universe "as it is now"; across distance, "now" isn't even something physics can define. You only ever see where things were when their light left them.

And it is not only the sky. The very same lag, in miniature, happens inside your own skull — your brain, too, shows you a world a beat behind.

And if even your own eyes serve you the past — have you ever once seen the present?