Most knowledgeable people acknowledge that theoretically, on paper at least, it is possible to travel back in time; back into the past. Some however say that this presents a logical contradiction. Then too there are all of those possible paradoxes that could theoretically arise. What follows arises out of my point of view in a debate I had with an “accidental meta-physician” which I’ve edited for, hopefully, sake of clarity.
Is Time Travel Possible or not Possible?
# If travel back in time is theoretically possible then travel back in time is theoretically possible – that’s logically self-evident. Time travel cannot both be theoretically possible and theoretically not possible with the same stroke of the pen. In any event, I’d even maintain that even meta-physicians see an actual example of time travel in the delayed double-slit experiment.
# If something CAN happen, then that something more likely as not WILL happen, sooner or later. Now travel in time back into the past might be in our too hard basket for thousands of years yet to come, maybe indefinitely if there are no benefits to be gained for the costs involved. But why restrict the scenario to humans? Perhaps an extraterrestrial civilization(s) millions, even billions of years in advance of ours has achieved this and turned time travel possibility into probability into actuality. Unless anyone can absolutely prove that time travel to the past is impossible, I wouldn’t bet against it having being achieved somewhere by someone at some time.
In the case of the delayed double-slit experiment, there is no alternative explanation to time travel other than that of Panpsychism. Interested readers can read up on what physicist John A. Wheeler thinks about it. The experiment was his doing.
# Time travel to the past is not logically contradictory if one can avoid the contradictory paradoxes that have been raised. There are ways and means of avoiding those paradoxes. Science fiction has paved the way by illustrating how that is possible in numerous novels and short stories. Now, can anyone prove that travel to the past is impossible in terms of the actual physics involved? If not, then time travel to the past is apparently theoretically possible: difficult, yes; but theoretically possible.
# Those who fail to learn from history are doomed to repeat it. Have readers failed to learn their history lessons?
Less than a century ago…
It was just theoretically possible to scale the highest mountain, but humans made it so.
It was only theoretically possible to build an atomic/hydrogen bomb, but humans made it so.
It was just theoretically possible to break the sound barrier, but humans made it so.
It was only theoretically possible to create antimatter, but humans made it so.
It was just theoretically possible to fly to the Moon, but humans made it so.
It was only theoretically possible to fly non-stop across the Atlantic, but humans made it so.
It was just theoretically possible to send an unmanned probe all the way out to the environs of Pluto, but humans made it so.
It was only theoretically possible to perform a heart transplant, but humans made it so.
It was just theoretically possible to pitch a perfect game in the World Series, but one human made it so.
It was only theoretically possible for humans to play God – but that too has come about.
Further theoretical ponderings that are now reality:
You can now fly around the world using just solar energy.
Humans wanted to turn lead into gold. Now it can be done.
Humans wanted to build the Pyramids, Stonehenge, the Great Wall of China, Petra, Machu Picchu and similar ancient engineering feats, and it came to pass.
The lesson to be learned here is not to ever, ever try to tell humans what they can or cannot do. Don’t sell humans short. If it theoretically can be done, and you have admitted that time travel is theoretically possible, and humans want to do it, it will be done. Or, in the words of Captain Jean-Luc Picard, “Make it so”.
# If time travel to the past (the future being another matter entirely) is a “logical self-contradiction” then travelling through time and into the past is not physically possible. Yet most acknowledge that time travel to the past is permitted in theoretical physics. Now that’s a contradiction! Something cannot both be possible and not be possible.
So here’s my FINAL word on the subject. If it (i.e. – time travel to the past) CAN be done and if humans WANT to do it badly enough regardless of the costs (social, political, economic, etc.) then sooner or later it WILL be done. End of story.