Time Travel Proposal: Observing Objects from the Past?

[NetMage]

Hello, so last night something occurred to me that I thought perhaps some of you might find interesting and enlighten me with validation. As I understand light travels at c in a vaccum. When light propogates through our atmosphere and through other particles it travels slower than c. Does this go to say that if we observe and object from a distance, we are experiencing it sometime in the past ( even if ever so slightly ). Due to the information we observe sent optically which still propogates at some time. . Rowland institute for science in 1999 slowed light to 38 miles per hour. That goes to say that if an object we could observe 38 miles away, we would be experiencing it an hour in the past? Please validate this and post your thoughts.

 

[chroot]

Hey NetMage,

Your deductive logic is spot-on. You are correct. Since light takes time to travel over a distance, you really see objects as they were in the past.

This effect gets really serious when you're looking at astronomical objects. It takes over 8 minutes for the light from the Sun to reach the Earth. When you look up at the Sun, you're really seeing it as it was 8 minutes ago. If you look back even further, you can see how galaxies looked when they were very young. We know of galaxies that are billions of light years away. They appear as they were billions of years ago, when they were young. They're called 'quasars,' I think they are some of the most interesting objects in the night sky.

- Warren

 

[NetMage]

Yes, that is quite something. So theoretically, if we found some materials, say a box of hypothetical gas or something that we could see right through, but light propogates through the gas at a very slow rate...and we had people in this box ( say it was a 30m x 30m box ), we would be observing their actions perhaps minutes or so ( depending on how slow the light propogates through it of course ) in the past. Say bob throws a football to alice, we might see this minutes after it happens even if we were only standing just outside the box? I am intruiged by this as you can tell. It just seems to me as seeing stars that are light years away has less significance than something observable that happens on a daily basis. Maybe not less significant, but less tangible, for if some one stepped into the box, they are now living some where in the past to outside observers.

 

[sophiecentaur]

I'm not sure that your proposal is any more 'time travel' than using a delayed Video recording of an event. You are only able to see what has already happened in either case.

Many scams have been suggested and some have worked when a 'mug' has been fooled into thinking he was getting real-time information, which was actually delayed by a few minutes / seconds and the scammers can appear to predict the future by acting on the real time info. But that's just Hollywood and Banking!

 

[Ash Small]

You are actually 'seeing' photons, not the actual event.

Photons are radiated or reflected from an object and take time to travel to the eye of the observer, where they are converted into electrical impulses and passed to the brain.

You don't actually 'observe' the event, just the photons radiated by, or reflected by, 'the event'.

The 'event' happened in the past, due to the time taken by the photons to reach your eye.

Hope this helps.

 

[chroot]

Hey NetMage, in theory you are correct. You could use one of those devices to slow the light down, and it would add a time delay between their actions and your seeing their actions. sophicentaur is right, though, you could achieve the same effect by putting someone in a jail cell and only letting them communicate through a videotape delay in both directions. You don't really need any fancy physics to do it.

- Warren