Fake Physics

by | Apr 3, 2017

Page 552; my sophomore physics class textbook reads: “By means of the statistical definition of entropy, Eq. 25-13, we can give meaning to the entropy of a system in a non-equilibrium state. A non-equilibrium state has a definite entropy because it has a definite degree of disorder. Therefore, the second law can be put on a statistical basis, for the direction in which natural processes take place (toward higher entropy) is determined by the laws of probability (toward a more probable state). From this point of view a violation of the second law, strictly speaking, is not an impossibility. If we waited long enough, for example, we might find water in a pond suddenly freeze over on a hot summer day. Such an occurrence is possible, but the probability of it happening, when computed, turns out to be incredibly small; for this to happen once would take on the average a time of the order of 1010 times the age of the universe. Hence, the second law of thermodynamics shows us the most probable course of events, not the only possible ones. But its area of application is so broad and the chance of nature’s contradicting it is so small that it occupies the distinction of being one of the most useful and general laws in all science.”

That was almost 60 years ago, and I remember thinking at the time that this was false – it didn’t make common sense. But more significant, equation 25-14, discussed the statistical variation of the velocity (think momentum) of the molecules.  The molecules of water in a lake are exchanging momentum by the collisions with each other. By the first law of thermodynamics (conservation of energy), this momentum (temperature of the water) had to be conserved. Therefore the average temperature of the lake would be constant except for the slow heating/cooling due to energy exchange with its environment.  In other words, this statistical improbability is true, looking at just a few molecules but is not valid for the average of all the molecules as a function of time.  So’ the probability is zero, not some crazy low number.

Even if the probability curve represented the instantaneous temperature of the macro object (pond), the changes in temperature would be happening so fast that one would be unaware of them. The lake would still have the same average temperature.  In other words, the freezing events would be so fleeting that one would be unaware of them, and this would be true at both the micro and macro levels.

While in college, common sense told me that this could not be true, and the first law of thermodynamics rational answered the question for me.  Later, I heard of the thought experiment of reversing time looking at just a few molecules; one would not be able to tell if time was going forward or backward.  If you watched a video of a tornado ripping a house apart, then ran it backward, you would know which direction the video was running.  But if you had a video of just a few molecules of some piece of wood in the house, you would not know which direction the video was playing – it would just be some molecules bouncing around.  The point is that at the micro-level, all energy is conserved as far as the observer can tell.  It is at the macro-scale that potential energy waists away.  In other words, one cannot always tell what is happening at the macro-level by looking at the micro-level.  The physics textbook made a statement that is not even true at the micro level, because even if a system of a few molecules instantaneously “froze”, they would be “unfrozen instantaneously as well.

The first and second laws of thermodynamics, taken together provide, at least in this case, a theoretical reason that the macro-reality we experience is not problematic. And that the direction of time (video running backward) is an excellent way to visualize why natural causes reduce specified complexity (increase entropy) as well.

Think about how we experience a pond freezing.  The freezing process starts as heat exchange between the water and its boundaries due to the temperature gradients.  This conduction process occurs at different rates depending upon the details of temperature gradients and the conductivity at various positions at the edges of the lake, eventually causing the first water molecules to freeze.  More molecules freezing to these will occur.  Other freeze points will appear at the borders.  The freezing will expand, meeting other expanding froze areas, eventually freezing the whole surface of the lake, assuming enough time and cold weather.  In all cases, thermal equilibrium dictates when the process stops or reverses.  Bottom line: lake freezing is a natural process that takes time; it is not an event.  If one looks at tiny volumes in the pond that consist of just a few molecules (like 2-10), then yes, there is a probability at some instance in time, one will find the average momentum equivalent to frozen water.  But the boundaries of these tiny volumes are tiny volumes at a higher temperature.  Make the volume bigger and there is a smaller instantaneous ΔT.  Make the volumes the size of a teaspoon, and the instantaneous ΔTs would be probably so small that it would not be measurable for two reasons:

  1. The variation would occur faster than measurement means, probably impossible due to Heisenberg’s uncertainty principle.
  2. It would be a violation of the First Law of thermodynamics – that heat energy is conserved.

Such an event would require the immediate release of a massive amount of energy, like an explosion.  By my calculation, if the pond was the size of Walton’s pond, and the ambient temperature 70 degrees Fahrenheit, the blast would be about ¼ the size of the atomic bomb detonated over Hiroshima.

Treating creations as being the result of an event causes a belief that there is a finite probability of the event occurring.  The truth is different. All-natural macro processes must move toward a reduction of free energy.  To achieve a deterministic raising of free energy requires the use of machines performing specified, deterministic work or mechanisms created by machines that convert energy forms to raise local free energy.

Machines, as I define them, will not function without matter/energy held in an away-from-equilibrium condition.  Therefore they cannot be created by natural causes.  This claim includes machines in life and is falsifiable.  This thought process is the basis for the “Fake Biology” post.

Calling my physics book “fake physics” is going overboard.  I’ve always had high regard for this textbook (two books, Part I & Part II).  I never parted with them because they have been valuable references for my engineering career. I believe this to be an error of completeness of thought, which can result in false conclusions.  There is another possibility – I may be wrong.  If I am, I hope someone will explain why.

© 2016 Mike Van Schoiack

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