Entropy Part III – The Arrow of Time – 2

Past Vs. Future II:

Concerning the future, we can make predictions, but those predictions have nowhere near the reliability of our memories of the past.

Ultimately, the reason we can form a reliable memory of the past is that the entropy was lower then. In a complicated system like the universe, there are many ways for the underlying the building boxes to arrange themselves into the form of what essentially is “you” with a certain memory of the past, plus the rest with an addition of the rest of the universe.
imagine all you know that you exist right now, with a memory of going skiing in the just in the midst of the snowing winter before seventh and eight grade, then you simply don’t have enough information to reliably conclude that you really did go skiing that winter. Weird as it might sound It turns out to be overwhelmingly more likely that your memory is just a random fluctuation, like the air in a room spontaneously congregating over on one side. Here lies the BIG issue: To make sense of your memories, you need to assume as well that the universe is ordered such that the entropy was lower in the past.

I f we imagine we are walking down the street and notice a broken crystal like glass glass shuddered into pieces near the edge of the park. We certainly shall not find it probable that it will suddenly reconnect by itself into a beautiful cristal looking glass, albeit, strictly speaking, this is a possibility that should be taken into account.
That shuddered crystal like glass is a perfect analogy to our brain in the sense that it’s a record of a prior event, but only if we assume a low-entropy boundary condition in the past. Our expectation for a low entropy past leaves us to believe with an extremely high degree of confidence that not long ago there must have been a crystal glass which someone dropped. nonetheless, as far as the future is concerned, we have no reason to suspect that entropy will decrease, there’s not much we can say about the future of the crystal glass shuddered on the edge of the park with its pieces close together. Why? simply because there are too many possibilities that could happen. Maybe it will stay there and grow dirty, maybe someone will clean it up, maybe a stormy wind will come by and spread the shatters of the crystal glass through the entire park… That crystal alss is somewhat like the memory in our head. A record of a prior event, but only if we inherently assume a state of low entropy condition in the past.

Another way to distinguish between past from future eveand simply spread the nts is cause and effect. causes comes first, and the effect follows. We wouldn’t expect to jump in the water and expect a splash before touching it. Nevertheless, according to the microscopic laws of physics, as reminded to us by Ludwig Boltzmann, it is certainly a possibility to arrange the water molecules and the air in the water such that we shall precisely be ejected from the pool and the air molecules to be set so orderly without us even leaving the pedestal to jump. As far as probability for such an event to occur it is such a very much negligible occurrence but by all means it is not unphysical.

Putting it in different yet to some of us outrages or at the very least mind boggling: The distinction between the fixedness of the past and the malleability of the future is nowhere to be found in the known laws of physics.
The deep microscopic the rules dictates that nature run forward and backward in time from any given situation of nature to run forward or backward in time from any given situation quite equally.

If we knew the exact state of the universe combined with a fully understanding of all the laws of physics, then the future and the past were determined on an equal ground well above Lord John Calvin dreams of predestination and the end of what shall be ever needed to further know physically.

know the exact state of the universe, and all of the laws of physics, the future as well as the past is rigidly determined beyond John Calvin’s wildest dreams of predestination.



The way to reconcile these beliefs, is to act as (and it is…) the past is once and-for-all fixed, while the future can be changed, but the fundamental laws of physics are ultimately reversible, which tied in a Gordian knot to entropy.


Because we live in a universe with an intuitive sense of the arrow of time, we treat the past and future not just as different from a practical perspective, yet they are certainly are. The past has already happened, while the future is still up for as much possibilities as ine nay imgine. in some sense—we can sketch out alternative possibilities, but we don’t know which one is real. when it comes to the past, we have a weird connection to memories and records of what happened. Our records may have varying degrees of
reliability, but they fix the actuality of the past in a way that isn’t available when we imagine a prices future.

If we knew the precise state of every particle in the universe, we could deduce the future as well as the
past. But we don’t; we know something about the universe’s macroscopic characteristics, plus a few bits of what would be described as not so organized data. With that information, we can predict some certain broad-scale phenomena (like the fact that there an extremely high probability that the sun just might
rise tomorrow), but our knowledge seems also to be compatible with a wide spectrum of specific future occurrences. When it comes to the past, however, we actually hold in the palm of our hands knowledge of the current macroscopic state of the universe, plus the fact that the early universe began in a low-entropy state (this is actually an assumption, yet a good one at that).

I would have to finish with this scientific yet one that might sting some of you readers whilist without changing the words or diving into their deepest meaning it will elevate others to the highest levels of hope (or none of the above 😉)


This one concerns what in my last sentence I’ve hinted for, but which is formally called “The Past Hypothessis”. That one extra bit of information, gives us enormous self confidence when it comes to reconstructing the past from the present. Actually, our notion of free will – the ability to change the future by making choices in a way that is not available to us as far as the past is concerned, is only possible because the past has a low entropy and the future has a high entropy.
The future seems open to us, while the past doors seemed to be locked forever, even though the laws of
physics actually treat them on an equal footing.
The major lesson to e undertaken about this specific Part about entropy and the arrow of time should be clear:

the existence of the arrow of time is both a profound feature of the physical universe, and a pervasive ingredient of our everyday lives. the existence of the arrow of time is both a profound feature of the physical universe, and a pervasive ingredient of our everyday lives. Should be attributed to Ludwig Boltzmann

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