Posted on 10/01/2020 10:13:13 AM PDT by Red Badger
No one has yet managed to travel through time – at least to our knowledge – but the question of whether or not such a feat would be theoretically possible continues to fascinate scientists.
As movies such as The Terminator, Donnie Darko, Back to the Future and many others show, moving around in time creates a lot of problems for the fundamental rules of the Universe: if you go back in time and stop your parents from meeting, for instance, how can you possibly exist in order to go back in time in the first place?
It's a monumental head-scratcher known as the 'grandfather paradox', but now a physics student Germain Tobar, from the University of Queensland in Australia, says he has worked out how to "square the numbers" to make time travel viable without the paradoxes.
"Classical dynamics says if you know the state of a system at a particular time, this can tell us the entire history of the system," says Tobar.
"However, Einstein's theory of general relativity predicts the existence of time loops or time travel – where an event can be both in the past and future of itself – theoretically turning the study of dynamics on its head."
What the calculations show is that space-time can potentially adapt itself to avoid paradoxes.
To use a topical example, imagine a time traveller journeying into the past to stop a disease from spreading – if the mission was successful, the time traveller would have no disease to go back in time to defeat.
Tobar's work suggests that the disease would still escape some other way, through a different route or by a different method, removing the paradox. Whatever the time traveller did, the disease wouldn't be stopped.
Tobar's work isn't easy for non-mathematicians to dig into, but it looks at the influence of deterministic processes (without any randomness) on an arbitrary number of regions in the space-time continuum, and demonstrates how both closed timelike curves (as predicted by Einstein) can fit in with the rules of free will and classical physics.
"The maths checks out – and the results are the stuff of science fiction," says physicist Fabio Costa from the University of Queensland, who supervised the research.
The new research smooths out the problem with another hypothesis, that time travel is possible but that time travellers would be restricted in what they did, to stop them creating a paradox. In this model, time travellers have the freedom to do whatever they want, but paradoxes are not possible.
While the numbers might work out, actually bending space and time to get into the past remains elusive – the time machines that scientists have devised so far are so high-concept that for they currently only exist as calculations on a page.
We might get there one day – Stephen Hawking certainly thought it was possible – and if we do then this new research suggests we would be free to do whatever we wanted to the world in the past: it would readjust itself accordingly.
"Try as you might to create a paradox, the events will always adjust themselves, to avoid any inconsistency," says Costa. "The range of mathematical processes we discovered show that time travel with free will is logically possible in our universe without any paradox."
The research has been published in Classical and Quantum Gravity.
Allah Hu Ackbar...................
This would make a great thread to list your favorite time travel movies and TV shows.
Seven Days
The 4400
The Crossing
Manifest
Continuum
Tru Calling
Time Tunnel......................
Perhaps the rulz do not allow one to go back before time travel was invented?
Causality shifts/recrystallizes/goes through a phase change from that moment...
Have a feeling lots of people are having the same thought!
As for myself, I want to go back to Christmas Day when I was 18. Declined a once-in-a-lifetime opportunity. It haunts me to this day.
The river flows to the sea no matter what individual water molecules do, that doesn't stop some of them from watering a garden or generating power. Perhaps some molecules can choose a path that goes through a particular service, but still reache the ultimate goal by the scenic route.
BTW, if your scenario is correct, and we do have no control over any decision, the concepts of sin and virtue are meaningless.
You're assuming our earth isn't the center of the universe.
I better add /s.
Well, duh! Observing The Big Bang is the #1 destination for every curious entity in the universe. All that mass showing up in exactly the same place and time is The Big Bang!
Yeah? Prove it was murder!
I have a bunch (too many!) people I want to see again on the other side of the veil.
Bookmarking
The classical one is murdering Hitler as a baby.
Really people! All it takes is an ill timed knock on a bedroom door the night he otherwise would have been conceived!
I could make the case that without Marx, there would have been no Hitler.
So, knock on his parents’ door.
But if not Marx, there would be another author with much the same something for nothing to sell.
Remember, YOUR first life experiences were communistic.
As a baby you got everything you needed without providing any labor...
screw that
tell her to never, ever, ever listen to a snake
I’ll be able to time travel in my resurrection body. Won’t need any time machine.
I wondered about that one. If the newspaper headlines changed, couldn’t the sports almanac change also?
The act of placing the bets could possibly change the results of the game.
I think it’s easier to go foward in time than backwards. I think this because of an experience I had. I experienced the event before it happened. I was very shakened but who wouldn’t be shaken by a car accident?
Then, a week later, the actual event happened...i mean in my present time.
I knew immediately that this was the event, what was going to happen, how it was going to happen and even what the injuries were. It gave me an opportunity to correct my own responses as well as experiment with a few things. For example, in my foreview, I asked the police officer for a cifarette and he gave me 4 of them. So I tested it and asked the officer for a cigarette and low and behold..he gave me 4! I was sitting in the back seat of a police car in the preview and in the present view. I knew the head injury sustained by my husband was minor and that the police would give him a ride home from the hospital...so I asked the police to take me home. They did and they wouldn’t take me to the hospital which I already knew.
The event was in the future but changing the past occurred when the past became the future..and the present.
And no, it wasn’t dejavu. Drhavu is the “feeling” that we’ve been there before, but there are no actual memories to support the feeling.
So yes, I do believe that time travel is not only possible, but can occur naturally. And that you can change the past in the present because the present becomes the past very quickly! If you know in advance what happens, the outcomes, you can change those things only to a degree. You can only change what YOU do or what you feel.
In my preview, I reacted hysterically so when the present event happened, I was at peace and remained composed. I already knew the outcome.
Im not a mathematician but could my statement above be translated into an equation? I’m sure it could be..and the statement provides the answer. Others have experienced it as well.
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