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Why can't we remember the future?

When pondering this question you might think it's a silly question, but do ponder further as this question is actually a good question believe it or not.

It's not like we try and remember. In a way, it just comes to us. When we think about it, though, it seems quite strange that our psychological “arrow of time” moves with the same force as that dictated by our entropic universe: which in a nutshell says things get more messed up over time. There are more ways a system can be disordered rather than ordered, hence why glass breaks into multiple pieces.

The laws of physics are all symmetrical in time. Classical mechanics, in which particles and objects obey Newton's laws, and General Relativity, which describes gravitation by describing how mass warps space-time, suggest that time is symmetric. According to these theories, the past and future are equally knowable: both can be calculated from the knowledge of the positions and velocities of particles at a given moment.

Here, we'll be summoning an old philosophy of time called Eternilsm but instead of philosophy nowadays it is known as four dimensionlism and the block universe theory. This uses General Relativity which has been proven time and time, so this radical view of time should be pondered seriously.

The arrow of time is usually explained in terms of the Universal Second Law of Thermodynamics, where entropy is a measure of the disorder or randomness in an isolated system, i.e., a physical system in isolation from external influences doesn’t have entropy because there are no interactions between elements. So if you want to figure out why you'd have to consider more than just broken glass, for example; it's about better understanding that entropy arises from energy not flowing into usable work in an isolated system. Making it harder for you to predict what will happen next - something that's needed for reasoning within the context of time. So, the psychological arrow of time aligns with the thermodynamic one.

But Leonard Mlodinow of the California Institute of Technology in Pasadena and Todd Brun of the University of Southern California say that this statement is not entirely accurate. In theory, you can remove any need for erasure or initialization since you could remember everything—which means that recording information in the memory would be reversible entirely in time. However, even in that case, the arrows of time must align because there is a broader principle at work.

The researchers argue that this extra ingredient is something they call generality. They illustrate the argument with a rotating turnstile that records the passage of gas molecules from one chamber to another. The system starts with most of the molecules in the left-hand chamber, and at any instant, the rotor reveals the net number that has passed from left to right since some earlier reference time.

However, since the laws of thermodynamics follow predictable and irreversible Newtonian principles, the readout could also be interpreted as showing the number of molecules that will pass between the time of the reading and some future reference time. One can