Witnessing The Past
It is possible to witness events in the past.
It is happening all the time all around us. When you go outside on a sunny day you can look up and see the light from the sun. This light is in fact at least 8 minutes old as this is the time taken for it to travel the 93 million miles across space from the Sun to the Earth. If the light from the Sun suddenly stopped when you see this occur on Earth it would actually have happened 8 minutes earlier.
The further away stars are from the Earth the longer it takes for the light from them to reach this planet. The nearest star after the Sun is Alpha Proxima and light takes a little over 4 years to reach us. So when you gaze up at the night sky all the light from the stars has taken varying lengths of time to reach us, some of it several millions of years. Many of the stars you will see will now no longer exist. The Hubble Space Telescope is able to look more closely at areas of space and see back into time to see the birth of stars. Take a look at some of the amazing photos that this telescope has taken recently - (see the Links Page).
Just as someone standing now on Earth can look up at the light from Alpha Proxima that is 4 years old so someone standing now on Alpha Proxima could look at the light from the Earth that is 4 years old. Clearly then the time taken for light to travel from one place to another is related to the distance between the two places since the speed of light is constant. The light that left the Earth in 1066 is now some 931 light years away. So positioning oneself at a point in space 931 light years away and looking back at the Earth one would see the light from 1066. By focussing on Kent one would see the Battle of Hastings. Of course you would need a pretty good telescope many, many times more powerful than the Hubble Space Telescope and able to see the light from Earth without it being flooded out by the light from the Sun but it is theoretically possible.
There are unfortunately a couple of problems with this type of Time Travel.
Firstly the Time Traveller is at a considerably distance from the event.
Secondly there is no interaction - you can look but not touch.
The second point does however help with all the problems associated with interfering with the Space-Time Continum because there arn't any! There is no interference as the Time Traveller is effectively still in the Present. The Time Traveller's World Line is still in sync with the Cosmic World Line.
Getting to this position in space is the main problem. Obviously all light is leaving the planet at the speed of light so light at a position 1 light year from Earth has taken 1 year to reach this position. If a Time Traveller from Earth wished to reach this position the Time Traveller would have to travel faster than the speed of light to get there! According to Einstein is not possible to accelerate an object beyond the speed of light. It seems that this form of Time Travel although theoretically possible cannot be achieved. To travel across vast stretches of space then requires some other medium rather than simply travelling fast in the 3 spacial dimensions. Perhaps moving into Hyperspace is the answer. Leave the Earth, step into Hyperspace, and step out somewhere else in the Universe. To be useful this would also have to happen instantly.
Now there is an interesting paradox. By moving from one position in the Universe to another without taken any time the Time Traveller has appeared to have traveled back in time!
The following takes this idea further with a full example.....
A Future Past Trip -
DISCLAIMER: All remarks at this site are strictly my own and have not been written deliberately to offend. Neither is it my intention to misinform. If you have any comments or remarks to make on any of the pages at this site whether they are regarding mistakes, inaccuraces, out-of-date links or anything else then please e-mail email@example.com
Anthony Edwards - December 1996