Time may flow backwards

[Kaleva]

Was reading an article in a science magazine in the Doctor's lounge while waiting to get a shot in my very hurting knees. The article was about the possibility that time flowed backwards. Everything we do or have done is dictated by events in what we call the future. There really is no free will or chance because everything we do or have done must lead to a conclusion that has already happened or taken place. The jogger running on the beach who was killed by a landing plane could have done nothing to avoid that fate because his death had already occured and everything the man did must lead to that result.

Supposing God doesn't give prophets a glimpse of the future: He is giving them a history lesson. In His time frame, the end of the world and Judgment Day have already happened. One might argue then that there is free will and God gives people visions so as to afford them the opportunity to modify events, that in God's view, have already taken place.

[ZombieHorde]

1. Did the article mention how the backward time conclusion came about?

Sounds like some high school students dropped some acid and started talking philosophy; next thing you know you are reading about it in your doctor's office.

[Kaleva]

6. It was an observation of the decay rate of two atoms.

The atoms were similar in all respects but one decayed much faster then the other. The scientists conducting the experiment could find no reason why the past or anything at the time of the experiment could have caused the difference so they thought that maybe that something in the future created the difference.

[ZombieHorde]

25. That is not enough to outweigh the counter evidence, for example...

child birth comes after conception, things fall after you let go of them, a message is written before it is posted, etc.

[darkstar3]

2. And they say Merlin aged backwards.

It's an interesting thought, and it makes for good sci-fi/fantasy, but that's all it is.

[saltpoint]

3. Does that mean I get a do-over on my first driver license test?

[Ozymanithrax]

4. Because time moves back wards, and we remember the, the we remember things...

that have not happened yet. Our entire live a along process of forgetting the future.

[yodoobo]

5. who are we to say that its backwards or forwards?

Backward or forward relative to WHAT?

Time flows. Whether we call it backward is forward has no meaning other than the choice of letters we string together to write that description.

Its like discussing which way is up when you are in outer space.

[John Q. Citizen]

7. Counter-Clock World

Counter-Clock World is a 1967 science fiction novel by author Philip K. Dick. It was expanded from his short story Your Appointment Will Be Yesterday, first published in the August 1966 edition of Amazing Stories.

Plot introduction

The novel describes a future in which time has started to move in reverse, resulting in the dead reviving in their own graves ("old-birth"), living their lives in reverse, eventually ending in returning to the womb, and splitting into an egg and a sperm during copulation between a recipient woman and a man.

http://en.wikipedia.org/wiki/Counter-Clock_World

[FarrenH]

8. As I understand it

time is just a direction in physics. Which is why we talk about the space-time continuum. Its one of the dimensions of our universe. Thats why Einsteins theories predict it will bend when space bends.

IOW, in a purely mathematical descriptions of physical interactions, we can't find "times arrow", or the sensation we have of moving in one direction in time, in the math. Its also why Hawking says in "A brief history of time" that the universe doesn't really have a "beginning" and an "end", just two boundaries in space-time.

Feynman came up with a neat way of describing particle interactions in 2D form called Feynman diagrams, where you collapse all of the spacial dimensions into one axis and have time as another. In this view movement along the Y axis is movement in time and along the X axis movement in any of the spatial dimensions. When we picture an electron and a positron colliding using this format, it looks something like this

time
^
|  photons
|    \  /
|     \/
|     /\
|    /  \
|   e- e+
----------------> space


IOW, the electron and positron move forward in time and at the point in which they converge in space, they mutually annihilate, and photons are emitted from the event. But the same event can be seen as a electron moving forward in time, emitting photons (which are quanta of energy) and the resulting "kick" causing it to reverse direction and move backwards in time as a positron (a positron is mathematically indifferentiable from an electron travelling backwards in time). Neither perspective can be shown to be the "true" perspective, so where do we get our biased perspective of time?

My physics is a little rusty but AFAIK the perception of time (the sense that we are moving forward) is resolved in a number of ways. Times arrow is accounted for by universal entropy (which results in matter getting more disorganised in one direction, and more organised approaching the big bang) and, curiously enough, its reverse as a local phenomenon. Even though the universe as a whole is getting more disorganised, locally in time and space we organise matter into what we call memories in only one direction*. Again this is simply a consequence of physical laws, but our memories increase in one direction along the temporal axis.

IOW, its because we can remember the past but not the future that we experience time. As I said my physics is a little rusty, and I think other reasons are given too, but the above would motivate against the idea that we perceive "echoes" of the future, an idea that has been suggested by, amongst others, Frank Tipler in "the physics of immortality" and biologist/mystic Terence McKenna. IOW, you can't really talk about "perceiving" something that you don't remember, even for a fleeting second.

*btw, when I say locally we organise matter into memories, it appears to be a violation of the second law of thermodynamics, but its strictly local. The biological processes that organise matter to form organisms and memories rely on an external energy source (the sun) and give off large amounts of disorganised energy in the form of heat, so over time there is a net loss of organisation. Because of this, the appearance of energy becoming more organised is still only a local phenomenon, and the universe as a whole continues to become more disorganised in the direction of the Big Crunch, in keeping with the second law of thermodynamics.

[tama]

10. Thanks, well explained

Some questions and comments to keep the discussion going:

Psychological unidirectional time (special case of geometric time) can well be described as entropic, in fact both thermodynamically and Shannon entropically as loss of information.

Now, is it really necessary to assume that univiverse "as whole" is a limited system where second law applies but not "negentropy"? E.g. how does "dark matter" and quantum mechanical Bose-Einstein condensate figure in relation with second law?

Quantum superposition of classical universe(s) is a Big Thought but let's give it a thought. As far as I understand decoherence into observable classical physics is entropic process that does not mean collapse of (universal) wave function but just entropic loss of order/information in the entropic direction to the observation events / quantum measurements that this classical observable universe is all about. Classical Aristotelian philosophical concepts of potentiality and actuality are quite usefull in this respect - sea of potentiality or superposition of all possible worlds contains all possible information and order and actualizing classical worlds just entropic fractions of all the infinite potentiality.

Infinite potentiality sounds like another way of saying "negentropy".

[tama]

11. Just found this:

New evidence hinting that universe is not a closed system (which is peculiar presumption in the first place):
http://news.nationalgeographic.com/news/2010/03/100322-dark-flow-matter-outside-universe-multiverse/

[FarrenH]

14. The jargon is dense in this post, young skywalker

I'm a middle aged analyst/developer, not a physicist, who hasn't picked up a book on physics in about ten years, so the compact use of jargon above is more than a little confusing. I only understand parts of it. Will do a little Wiki'ing later to update my terms then get back to you :)

Are you describing a many-worlds type situation where no wave function collapse is "actually" taking place but each possible world is being experienced, and each individual experience is constrained by entropy's arrow (which only exists within the boundaries of each particular history) to recalling only events in that lead up to that world, thus creating the perception of a collapse?

[tama]

18. Everet's many-world

is one interpretation of no-collapse, but not the only one. Bohmian interpretation of no collapse is more pleasing to me aesthetically and ethically (the concept of decoherence goes back to Bohm).

But if no actual collapse of superposition of all possible worlds takes place but is only perceived as such, then I see no reason to presume that some no-collapse interpretation would be more correct than some other - or even collapse-interpretations. Both Everet's many worlds and Bohm's holistic universe can decohere or actualize as perceived and so can collapse-interpretations.

Starts to sound like "each observer to the hell or heaven of his chosen interpretation..." :)

[westerebus]

16. Briefly.

As our mind observes, it does so in the present tense, it "fixes" a point in time to reference the "observation of the event". It is a means to catalog that reference.

That reference in time becomes historical. It happened. Past tense.

This allows an other mind that had not observed the event to establish a fixed point in time by referencing what was observed along a time line of observed events.

Events that are not observable in the present tense that are cataloged as future events, a point in time in which to establish a reference point.

Past, present, and future appear to the observer as fixed. Which helps explain our bias toward linearity as to how we established a time line.

What is fixed as a requirement to communicate what's observed in a manner that establishes coherence is a "time line".

One of the limitations of language.

It is a built in bias. You can say it is a scientific fact that time exists. It does if you want the math to work. Remove time from the equation and then what?


How would you repeat an experiment? If you don't have a time line.

We can make this more complicated and complex, but do we need to?

[tama]

19. One more question, if I may

What math might make me want the math to work? How does intentionality (topological vector arrow?) emerge from number theory, mathematically?

"God Given" number theory complexities not cast aside but preserved because I have no intention to argue against Gödel's platonism.

[westerebus]

26. I didn't know that was going to be on the test.

As for question number 1 : Euclid's geometry. Building codes come to mind.

As for question number 2 : One of mankind's great innovations, calenders are progressive in time.

As for question number 3 ( implied ): What lies out side our knowledge is not provable.

The proposition that it requires proof is illogical.

The universe contains both knowledge and illogic.

The universe contains probability.


You do grade on a curve don't you?

[tama]

27. More or less

Pirahã speakers don't know any numbers and cannot be teached to count. How primitive of them to not care about quantity, but only about quality!

http://www.spiegel.de/international/spiegel/0,1518,414291,00.html
http://en.wikipedia.org/wiki/Pirah%C3%A3_language

[westerebus]

29. I hear their herbalist mixes a mean cocktail.

The proportions are never quite the same. Innkeeper, more. Simplicity itself.

Thanks for the link.

[charlie]

9. So when you play heavy metal backwards

they really are singing odes to Satan?

[Silent3]

12. The only way it makes sense to talk about "backward" time...

...would be if you found examples of localized phenomena which did things like decrease in entropy without creating a corresponding increase in entropy in the surrounding environment.

Otherwise the use of the words "backward" and "forward" are merely conventions, and it would be as silly to talk about "discovering" that time goes backward as to say you've discovered that Antarctica is "really" at the north pole, not the south. (Geographic, not magnetic, north/south, since the magnetic pole can, and almost certainly eventually will, shift.)

If the point being made is about causality and determinism, especially if the point to suggest a completely deterministic universe, then the whole of history and time would simply be an intricate but fixed pattern, with it being an arbitrary decision to call one direction through that pattern "forward" and the reverse "backward".

[tama]

13. Gardening examples

Producing more exergy or "decreasing entropy" by reforesting desert or using compost heat to lengthen growth period by planting veggies on the compost instead of keeping it covered, etc.

As hard as I think, I don't see how these examples create corresponding increase in entropy in the surrounding environment. Maybe I just can't think hard enough?

[Silent3]

15. Thermodynamics

The primary way that biological activity increases entropy is the conversion of "high quality" energy, such as visible sunlight and concentrated chemical energy, to lower quality quality energy, such as infrared radiation.

You have to realize that the "surrounding environment" extends into outer space. In fact, the cold of space surrounding the Earth is the heat sink we rely on to be able to take in energy (primarily from the sun, but we also use energy stored during the formation of the planet), locally increasing complexity/decreasing entropy in the form of well-ordered systems such as zebras and shopping malls, while still obeying the rules of thermodynamics by dumping waste heat from all of these processes into space as infrared radiation, making the universe, overall, a more disordered place.

[tama]

17. OK

Now I understand better that Earth has been often described as thermodynamically closed system, but of course it's just relatively closed system and absolutely closed systems exist only as abstract idealizations. Also to my understanding there is no a priori reason to presume that universe as whole is thermodynamically closed system, could be, could be not.

The way a gardener thinks and acts is biological activity. When a gardener finds a way to use lower quality energy from compost heat to capture more higher quality chemical energy from sunlight ("exergy") by lengthening the growth period, why not call gardener's biological cognitive ability 'negentropic' at least in relativistic terms, in relation to relatively closed system of Earth?

[struggle4progress]

20. IIRC, Kurt Godel wrote a paper on general relativity showing that

there were solutions of Einstein's field equations in which one could find space-like paths through space-time from a first event to a second event in the first event's past

I should expect that such space-like paths could be very long, so that if I were to launch a particle from here-and-now into my past, it might take quite a long time to get there-and-then, and it might undergo many scattering events which I would have no way of predicting. So it's not at all clear to me how one could prove or disprove such a matter experimentally, our experiments being rather local; and if such things occur then their background effects presumably already contribute to the world as we experience it

Perhaps the real question is not whether such a description is true -- "true" being (after all) a word that science does not really know -- but whether the description is really useful for any purpose

[tama]

21. Gödel is Göd

According to one theory, each quantum jump rewrites both past and future, but there is infinite size scale of quantum jumps inside and outside surrounding other quantum jumps and all of them getting engangled into a bloody mess.

[Jim__]

22. Gödel is dead!

Sorry, couldn't resist.

[RagAss]

23. So that divorce ended up in my first marriage?

HAHAHHAHAHHAHAAA

[RagAss]

24. More likely....

Time
The Past is a memory, i.e. an idea, an object of consciousness. The Future is an image, another idea, another object of consciousness. The Present, which we never know until it is Past, is therefore also an idea, a notion, an object of consciousness. None of them is real, each is imaginary. Time does not exist.

The eternal present, the now-moment, the interval between thoughts, which we normally never perceive, alone is real.


-Wei Wu Wei 1960

[Laura902]

28. Really smart idea......

.......if your high. :rofl: