How can we look back in time through the Hubble telescope?
You are struggling with a fairly common misunderstanding of how a telescope works. There are lots of folks who think that a telescope “reaches out” to grab the light as it departs from some distant location between the target and your eye. But a telescope cannot do that. A telescope simply takes the light that enters it, amplifies it by funneling more of it into your eye, and magnifies it by passing it through curved optical surfaces. If you place a piece of cardboard in front of the scope, the reason you can no longer see the target is that you have stopped the light before it reached the scope, not that you have prevented the scope from stretching out to grasp photons already underway. Having said that, we have to be cautious about how we describe time and space. It is true that as you look out into space, you are also looking back in time – in a sense. You are seeing light that left that galaxy – perhaps 2 million years ago – as measured in our own reference frame. But there is abso
