Video Lecture on Time Travel

The Vega Science Trust video collection has a video linked here of Professor Paul Davies giving a scientific talk on wormholes and the possibility of time travel. The lecture is targeted to the general audience so you do not need to be a physicist to understand it. In fact, Davies showed only two equations and one of them is the famous “e equals m c squared”.

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There are very interesting ideas and some time travel paradoxes presented. Another article explains some paradoxes of time travel.

He made reference to singularity, anti-gravity, relativity, black hole, world line, and space time diagrams. The idea to get out of this lecture is that physics does not preclude the possibility of time travel. And in fact time travel into the future is possible and the effects can be measured. It is time travel into the past that is tougher. It is not that the laws of physics prevent it, but that to achieve it would be so great of an undertaking that practicality precludes it. There were some bits of humor in the lecture and Davies concluded with a great ending.

There was a small question and answer session at the end where Davies made a point that if in fact a time machine can be invented, it can never bring a person back to a time before the machine’s invention.

Whether time travel is possible or not is a question that physicists are still debating. They may not come up with a definitive answer until the quantum mechanics and general relativity have been unified under the grand unified theory (of which they are still working on).