A few days back I wrote a post on how we experience ‘time travelling’ to the past by means of observational astronomy(link in the end). Now, theoretically, relativity and string theory, allow for ways to actually travelling back in time, and the difficulty we are facing is the construction of an experiment to realize these ways because they require stuff like going inside a black hole, or infinite energy, or creating a ‘wormhole’, or negative energy or ‘strings’ the size of the Universe. Nevertheless, it’s an intriguing topic, to being able to go back in past, but after much thought, I am of the view that no matter how advance we get, forgetting all engineering restrictions, we can never travel to the future, and here is why.
Let’s remove the restriction that we cannot build the required machine, or energy source to travel in time, assuming that we can have all we need to build and power a time machine to travel, if its possible. Even then, the best we have is that we can go to any point of time we desire, but here is the only theoretical restriction, we can only travel backwards in time and not a bit in the future direction. Why? Because Quantum ‘Weird’ Mechanics. Quantum Mechanics is the physics of the atomic/nuclear world. Just like relativity controls, or predicts the behaviour of the vast Universe like stars, galaxies and space-time, quantum mechanics is responsible for the world of atoms, the miniscule world of particles like electrons, quarks and bosons. Unlike our regular world were everything obeys our intuition, the world of nuclear physics which obeys the rules set by quantum mechanics is WEIRD, and it gets weirder the more you know about it. We need to leave behind all our held ideas, expectations and intuitions when we transit from the area of relativity to quantum area. Quantum mechanics rests on the foundations of probability, that is chance of an event happening in comparison to others. Some of the crazy, and ‘tested’ results of this theory includes the fact that electrons can exist at two places at once, quantum tunneling, entanglement and many other un-intuitive things. Now, one of the consequences of this probability-based nature of quantum mechanics is that the future is un-determined. Let me explain you. When you decide something, you might have certain number of options, say two. Now, until and unless you make a choice and act on it, it is unknown which of the two options will be selected after all. It can be A and it can be B as well, with exactly the same chances of being picked as A (considering A and B are independent). This means unless you have made a decision to that question and went on with it, your future is unknown. You don’t have a definite future!
This has far-reaching consequences. Suppose you were to decide after the end of the next month, which places out of Paris and Japan you want to visit for vacations. Now, until you decide it after the end of next month, there is a chance that in the future you will be visiting Paris, and simultaneously there is a chance, with equal odds, of you visiting Japan. If we are a bit more realistic, even this decision depends on the decisions you make till the end on next month, like if you decide tomorrow to not go anywhere this year, or go to a completely different location, even this would affect your future decision and its result, which makes the future as of this moment more unpredictable. So, basically at every point of your present, you have many, many possible futures, and which one will you finally live depends on your decisions that you will make when the respective time comes. Consequently, until and unless that future finally becomes your ‘present’ and you have experienced it you cannot say with 100% confidence what it will be.
Thus, if you could in theory build a time machine to travel to the future, and lets say you fed the data to travel to the beginning of the second month from now, you would have no control whatsoever, to which of the numerous possible futures you might end up in. Frankly, this would be useless, and a waste of science! You might end up seeing your vacation in Paris, but what if when time comes you decide Japan? All your time travelling to the future in which you went to Paris becomes inconsistent with your decision that you make, and also a kind of paradox, because you travelled the a future that ‘did not happen’. Science hates paradoxes.
Your complete future depends on what decisions you make. If it were not so, and you had a definite future that would simply mean that all your efforts, decisions and hard work is in vain. No matter how much hard you study for that exam if you are ‘destined’ to fail you will, and so logically, exams are useless, there is no thing as ‘crime’, because nothing happens for a fault of your own. This also bring a lot of divine indulgence which is unnecessary and ugly for a science situation. Experiments like electrons existing in two places at once, or double-slit interference show that the theory of probability that ‘which of the possible events will occur’ is accurate no matter how counter-intuitive it is. This is the beauty of quantum mechanics. This also proves my point, why you cannot travel to future. One way I think my paradox above is solved, is that when you have travelled to one of the possible futures, you have destructed all the other ones (exactly like measuring which slit the electron passed through destroys the interference pattern in the double-slit experiment), which means you have already made the decision which you were to make in the future, and thus ‘destroying free will’ (because you had no control to which of the futures you might end up in). This is a consequence of quantum mechanics, that ‘observation’ erases the probabilities of other events and only one that is observed is the ‘new’ and only existent event, this process is also called as ‘quantum eraser’.
Some of you might say that we are actually travelling towards the future as every second passes, but to be clear what I meant was travelling at a faster speed. So this is what I think about time travel to the future, and why it can never be possible and if it is, it will create paradoxes, or will mean that free will isn’t real, and just an illusion. Got any views or ideas of your own on it? Do share them below by commenting below with any of your social accounts. Like and share with your pals. And when you travel in time, certainly in the past, travel responsibly. Happy reading!
-The Cosmogasmic Person.