How can you see the Past

Have you ever wished you could look into the past? It’s theoretically possible. In fact, you’re doing it right now.

The closest star you can see is the sun, which is just over 8 light minutes away from us. When see the sun, you are not seeing the present – you are seeing it as it was 8 minutes ago.

The sun could literally disappear and you would have no way of knowing about it for 8 minutes.

Some of the stars we see in the night sky are over 100 light years away. When you view them, you are literally looking 100 years into the past.

The brightest star you can see is Alpha Centauri, located 4.3 light years away (to be accurate, what you see is actually a collection of three stars). The light reaching Alpha Centauri right now is light emitted 4.3 years ago – stuff from 2010. If some entity in that region is looking at earth using a ridiculously good telescope, it is seeing earth’s past.

If you could find a way to put a giant mirror into space several light years away, you could theoretically watch your own history. The farther away you put it, the further back in time you could see. If it was 50 light years away, you’d be seeing earth 100 years into the past.

All the light you have ever emitted your entire life is still traveling across the universe somewhere – maybe not so easy to collect, but your past is theoretically obtainable.

So this is all nice sounding, except having to repeatedly say “theoretical”. What about something practical?

I once was at a high school baseball game where 2 fields sat opposite each other with concurrent games being played. I found it amusing how I could see the crack of the aluminum bat hitting the ball on the field in the distance a moment before I actually heard it. And then it occurred to me – I was hearing the past.

This is the same phenomena we experience when we see the crack of lighting only to wait a few seconds to listen to the following thunder. The reality though, is that everything we sense comes to us after it occurred. As fast as light travels, it still requires time to reach our eyes – time so small we can’t perceive it, but it is not possible to actually see the present. Thus, we are currently seeing the past.

To a lesser extent, when we record video and replay it, we are seeing the past in a form of stored light. It is not as romantic as putting a giant mirror in deep space, but it operates within the same realm of ideas.

We shouldn’t underestimate just how awesome video technology is. We have a manner of seeing the past that was not available to anyone living more than 150 years ago (and realistically much more recent than that).

I’m not that old but my parents never had a video recording device when I was young so there isn’t any video of myself as a child. I have only some photos and memories to explain what I was like to my kids. This saddens me somewhat as I’d love to reminisce, to see my parents and I when I was young, to relive some of the ordinary events that made up my childhood.

But at least I have photos. So much of human history had nothing but their own minds to relive the past. Think about that. How lucky are we? The ability to see the past though video would have been a dream to most humans in history. Yet we don’t even think twice about carrying video devices in our pockets.

Its funny, we live in a generation where people are getting apprehensive about video – a completely rational and understandable response to the ease at which we can now be filmed without permission. Yet I wonder, how much do we take this amazing technology for granted?

Do you wish you could see more of your past?