There is an ongoing PBS TV series (also several books and also a website) called “Closer To Truth”. It is hosted by neuroscientist travelresourcesonline Kuhn. He’s featured in one-on-one interviews and panel discussions with the cream of the cream of today’s cosmologists, physicists, philosophers, theologians, psychologists, etc. on all of the Big Questions surrounding a trilogy of broad topics – Cosmos; Consciousness; God. The trilogy collectively dealt with reality, space and time, mind and consciousness, aliens, theology and on and on and on. Here are a few of my comments on one of the general topics covered – Is time travel possible?
# Is time travel possible? Actually I personally don’t believe time exists. Change exists, and time is just our measurement of rate of change. IMHO time is just a concept. Time is a mental construct that helps us come to terms with change. Some cosmologists say that time was created at the Big Bang, as if time were a thing with substance and structure, but I challenge them to actually create some time in front of their peers or maybe a TV audience or at least produce a theoretical equation or two that would create time. In the meantime, here’s a trilogy of points.
First, the concept of time travel is one of those fun parts of physics. Whether true or not, it is entertaining to play the ‘what if’ game. If nothing else, the concept makes or forces one to think about the nature of reality.
Secondly, Einstein and others have postulated that time travel is a theoretical reality and I’m not in their sort of league that I can dispute the theories. I’ll leave that to others who know the field inside and out.
But thirdly, and most importantly, you can never actually be in the future or the past, only in the future or the past compared to where and when you are now. In other words, no matter how you slice and dice things, you exist in the where-ever and in the whenever in that where-ever’s or whenever’s NOW or in other words in the present. You cannot literally be in any future or in any past since you only experience the NOW which is the present. If you should somehow travel back one hour, you would still experience things as belonging to NOW. If you sleep for one hour then wake up, you are in the future relative to when you went to sleep, but you still find yourself in the NOW.
# Is time travel possible? The answer is both yes and no. Yes, we can travel into the future at one second per second, we do that anyway whether we like it or not. Yes we can travel into the future at a slightly quicker rate by going to sleep or otherwise having our sense of consciousness, our awareness of rate of change (which is what time really is or measures) incapacitated. You get drunk and pass out and the next thing you know you are 12 hours into the future. Yes we can travel into the future as outlined by Einstein’s twin ‘paradox’ where one twin travels at a very high rate of speed outward bound, stops and returns to home base, while the stay at home twin, well, stays home. Upon their reunion the travelling twin finds their stay at home twin to be far older, so the travelling twin has travelled into the future more rapidly than would otherwise have been the case.
Yes, you can travel back in time, in theory, according to the apparent theoretical properties that wormholes or black holes can have. No, you can’t travel to the past because of all of those nasty paradoxes. I like the variation on the grandfather paradox whereby you travel back just one hour into the past and shoot yourself dead. That’s a novel way of committing suicide! The other paradox I like is when you go back in time to have Shakespeare autograph your copy of “Hamlet”. Shakespeare isn’t home but the maid promises to have him autograph your book when he returns. Alas, your timing is slightly off and Shakespeare hasn’t yet written “Hamlet”, so when he receives your copy from his maid to autograph, he reads it, and after you return to Shakespeare’s home and receive back your now autographed copy and return home to your own time,