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The discrete-time physics hiding inside our continuous-time world
phys.org ^ | 04/15/2019 | Santa Fe Institute

Posted on 04/15/2019 6:26:23 AM PDT by BenLurkin

Scientists believe that time is continuous, not discrete—roughly speaking, they believe that it does not progress in "chunks," but rather "flows," smoothly and continuously. So they often model the dynamics of physical systems as continuous-time "Markov processes," named after mathematician Andrey Markov. Indeed, scientists have used these processes to investigate a range of real-world processes from folding proteins, to evolving ecosystems, to shifting financial markets, with astonishing success.

In a pair of papers, one appearing in this week's Nature Communications and one appearing recently in the New Journal of Physics, physicists at the Santa Fe Institute and MIT have shown that in order for such two-time dynamics over a set of "visible states" to arise from a continuous-time Markov process, that Markov process must actually unfold over a larger space, one that includes hidden states in addition to the visible ones. They further prove that the evolution between such a pair of times must proceed in a finite number of "hidden timesteps", subdividing the interval between those two times...

The authors stumbled on the necessity of hidden states and hidden timesteps while searching for the most energy-efficient way to flip a bit of information in a computer. In that investigation, part of a larger effort to understand the thermodynamics of computation, they discovered that there is no direct way to implement a map that both sends 1 to 0 and also sends 0 to 1. Rather, in order to flip a bit of information, the bit must proceed through at least one hidden state, and involve at least three hidden time steps.

It turns out any biological or physical system that "computes" outputs from inputs, like a cell processing energy, or an ecosystem evolving, would conceal the same hidden variables as in the bit flip example.

(Excerpt) Read more at phys.org ...


TOPICS: Science
KEYWORDS: discretetime; stringtheory
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1 posted on 04/15/2019 6:26:23 AM PDT by BenLurkin
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To: SunkenCiv

2 posted on 04/15/2019 6:26:39 AM PDT by BenLurkin (The above is not a statement of fact. It is either satire or opinion. Or both.)
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To: BenLurkin

Nonsense. There is no shorter time than the Planck time. Therefore time is quantized not continuous.


3 posted on 04/15/2019 6:37:09 AM PDT by backwoods-engineer (Enjoy the decline of the American empire.)
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To: Pride in the USA

ping for a later read.


4 posted on 04/15/2019 6:39:45 AM PDT by Pride in the USA
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To: backwoods-engineer

5 posted on 04/15/2019 6:41:50 AM PDT by BenLurkin (The above is not a statement of fact. It is either satire or opinion. Or both.)
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To: BenLurkin

Nice post!


6 posted on 04/15/2019 6:41:53 AM PDT by <1/1,000,000th%
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To: BenLurkin

Don’t know why but it reminds me about an article I read about multi-tasking. It has been proven impossible for a human to do several things simultaneously. They may think they can do several things at once but, in fact, they are constantly switching from one task to another, and efficiency in completing any one of the tasks is diminished..


7 posted on 04/15/2019 6:42:33 AM PDT by be-baw
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To: backwoods-engineer

It seems to me that this paper is in agreement:

In a pair of papers, one appearing in this week’s Nature Communications and one appearing recently in the New Journal of Physics, physicists at the Santa Fe Institute and MIT have shown that in order for such two-time dynamics over a set of “visible states” to arise from a continuous-time Markov process, that Markov process must actually unfold over a larger space, one that includes hidden states in addition to the visible ones. They further prove that the evolution between such a pair of times must proceed in a finite number of “hidden timesteps”, subdividing the interval between those two times...


8 posted on 04/15/2019 6:43:56 AM PDT by Moonman62 (Facts are racist.)
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To: BenLurkin

Time is the passage of events...I sometimes wonder what came first....time or events...then I realize they happened simultaneously when God spoke the universe into being.
If we can ever truly grasp “a time before time” we may be on to something.


9 posted on 04/15/2019 6:46:35 AM PDT by trebb (Don't howl about illegal leeches while not donating to FR - it's hypocritical.)
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To: BenLurkin

Time is like a movie film strip - each frame has notches on the sides which the camera uses to grab the film and pass to the next frame to be projected. Our eyes project the light which passes through the frame illuminating it (a Greek concept - which prevailed for hundreds of years and may not have been unique to them).

Some time the ‘film’ breaks and is ‘spliced’ back together seamlessly - but some frames are left on the cutting room floor, so to speak, which causes people and things to just vanish never to be seen again.

This actually happened to me 60 years ago while waiting for a traffic light to change - one moment the light as there and the next gone, only to reappear a few intervals later ...


10 posted on 04/15/2019 6:48:00 AM PDT by PIF (They camTo think the choice came down to Gorka/Bannon oe for me and mine ... now it is your turn ...)
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To: trebb

“Time before Time” Sister Bernadette wasn’t successful in explaining that to me sixty years ago.


11 posted on 04/15/2019 6:53:55 AM PDT by Dr. Ursus
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To: BenLurkin
This just seems to be an example of the limits of observation. If you sample at a rate of N, then you only understand something unfolding at a rate of N/2, i.e. you have to sample twice as fast as the phenomenon you are looking at is changing.

These "hidden" states may just be the observations the scientists would have liked to have been able to make to better catch the fluctuations of the observables.

12 posted on 04/15/2019 6:54:19 AM PDT by who_would_fardels_bear
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To: BenLurkin
I'm not impressed, Santa Fe Institute and MIT guys. Because I proved all that 25 years ago while waiting for a bus outside of Goobertown, Arkansas. Only modesty prevented me from publishing at that time. Here's my simple proof:


13 posted on 04/15/2019 6:56:52 AM PDT by Leaning Right (I have already previewed or do not wish to preview this composition.)
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To: BenLurkin
Just because nature seems to employ step functions does not prove that time itself is discrete.

14 posted on 04/15/2019 7:01:22 AM PDT by BitWielder1 (I'd rather have Unequal Wealth than Equal Poverty.)
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To: BenLurkin

Conclusion?

The world is a lot more complex than any computer program. And computer simulations are never tied to reality.

Theoretical physics might be more accurate than the computer models.

Remember, we put a man on the moon and brought him back with cedar pencils and slide rules. (mostly 3 significant digits computation)

And remember, men still do a better (safer) job of piloting aircraft and cars than computers do. (except possibly the SR71, which I am told could not be controlled without the computer)


15 posted on 04/15/2019 7:08:44 AM PDT by Texas Fossil ((Texas is not where you were born, but a Free State of Heart, Mind & Attitude!))
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To: Texas Fossil

“..except possibly the SR71, which I am told could not be controlled without the computer..”

And that computer in its time was probably no more sophisticated then a Commodore 64! ...like much less! .... mid-1960s technology.


16 posted on 04/15/2019 7:15:55 AM PDT by Reily
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To: BenLurkin
If you start with a protein in state 'a,' and over an hour it usually turns to state 'b,' and then after another hour it usually turns back to 'a,' there must be at least one other state 'c'—a hidden state—that is influencing the protein's dynamics.

The law of causality is an axiom. It states that entities cause the actions of entities, and an entity must act in accordance with its nature. If the nature of an entity contains a hidden state, then that state must be discovered and understood.

17 posted on 04/15/2019 7:17:20 AM PDT by mjp ((pro-{God, reality, reason, egoism, individualism, natural rights, limited government, capitalism}))
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To: BenLurkin

Time and form are the greatest delusions sustained by human kind (in my opinion).


18 posted on 04/15/2019 7:19:18 AM PDT by Mr Ramsbotham ("God is a spirit, and man His means of walking on the earth.")
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To: BitWielder1

Hidden states refers to spatial displacement ... there is only present time for our three variable spatial and one variable temporal. The spatial position yields the illusion of time passing. We sensors are tesseracts feeding input data to our brain which is interfaces with the mind of the soul. The mind of the soul exists in a different set of coordinates than the physical brain and sensors.


19 posted on 04/15/2019 7:21:12 AM PDT by MHGinTN (A dispensation perspective is a powerful tool for discernment)
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To: Reily

Yes indeed. Suited for managing multiple related tasks.

In my opinion, the more complex the computer application the less tied to reality it can be.

Some programmers say that there is nothing a computer cannot solve by “simply adding” a couple of more layers of abstraction.

My experience is that the more layers of abstraction the program has the more totally out of attachment to the real world it actually is.

I’m 71, built my first PC in 1982. I love good applied technology, but to me that does not mean complex technology.

Einstein understood that when he said “Everything Should Be Made as Simple as Possible, But Not Simpler”.


20 posted on 04/15/2019 7:26:23 AM PDT by Texas Fossil ((Texas is not where you were born, but a Free State of Heart, Mind & Attitude!))
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