Physics is Simple and Over

Professor Eli Rabett has analyzed a lifetime of study and concluded, interestingly, physics is simple.

Here's his post verbatim:

Physics is Simple

Physics is the simplest science, a hard won truth that Eli has reached after many years in many fields. A bunny can do a lot of physics with pencil and paper, maybe even without those if enough homework has been passed in and marked.

This may seem, perhaps, a bit simplistic to some and mistaken to your average physicist, but consider, science is done through a mix of observation and computation. Physicists in the 17th century didn’t have to observe very much before they could start generating computational theories using pen and paper and testing them against observation. Physics is simple enough that one only need observe a few things before starting to build theories and compute results that could be compared to observations.

Other areas, not so simple. Lavoisier put it well, you cannot have a science without an agreed nomenclature because without you cannot talk about anything. 

“The impossibility of separating the nomenclature of a science from the science itself, is owing to this, that every branch of physical science must consist of three things; the series of facts which are the objects of the science, the ideas which represent these facts, and the words by which these ideas are expressed. Like three impressions of the same seal, the word ought to produce the idea, and the idea to be a picture of the fact. And, as ideas are preserved and communicated by means of words, it necessarily follows that we cannot improve the language of any science without at the same time improving the science itself; neither can we, on the other hand, improve a science, without improving the language or nomenclature which belongs to it. However certain the facts of any science may be, and, however just the ideas we may have formed of these facts, we can only communicate false impressions to others, while we want words by which these may be properly expressed”

A useful working definition of science, a well liquored and tasty combination of observation, ideas and discussio. 

Just to pick the next simplest science chemistry, the nomenclature is voluminous, systematic though it might be, to occupy a huge database and committees of learned souls called together by the International Union of Pure and Applied Chemistry to deal with new discoveries. Biology is worse. A lagomorph might argue that biology began with Linnaeus’ nomenclature for living organisms and for quite some time stayed there. And then we have geology and the rest of the alphabet soup of the geosciences each with their own dictionary that has to be mastered. 

Eli conceptualizes this as the cladistic dimension. The physics dictionary is pretty thin by comparison except where physics meets materials and the other sciences bring their descriptive overload in. 

Computationally a lot of physics can indeed be done with pen(cil) or paper depending on how many mistakes are to be made. You can do damn near no chemistry with pencil and paper beyond simple physics applications such as thermo or stat mech.

When Eli moved over to chemistry in the 1970s, theory was an object of derision and, as general chemistry today, required a series of rules, sequentially setting forth any number of simple models for chemical bonding and reaction following the historical development of the science. As each model was stacked on the next to extend them and handle myriad exceptions to each, students struggle. Why each of these simplifications works and their limits of applicability was not obvious, or at least not so until reaching the quantum basis of atomic and molecular structure. At that point, perhaps, when it became obvious how each of the historical models is an expression of quantum mechanics everyone, hopefully nods their heads and says "Oh yeah".

By the 1970s computational chemistry was a hungry beast posed to devour computer cycles. The formalism was prepared and a few brave souls had seen the future, working out relatively simple cases on several reams of paper, or with mainframe heat pumps filled with vacuum tubes.  

The driving force is interesting. About twenty years ago it became clear that observation could never be complete enough to describe all the chemistry that was wanted. One could never measure any chemical process for all of the conditions possible and even if one could and could do a statistical parameterization of the results it would be flying blind because there would be no understanding of the underlying chemistry. It would all be handwaving, perhaps statistically valid handwaving but handwaving none the less, and worse, it would not be clear under what conditions the handwaving would fail. 

Computational chemistry, validated against observational chemistry is today’s gold standard. 

Eli would posit that atmospheric science has passed through this same progression enabled by computational forcing, but more so. Not only can we not make all the observations that would be needed to fully describe the Earth’s atmosphere, but absent a time machine and a large ensemble of Earth, or at least Earth like planets, we could never do so. 

Thus Earth System Models, if you like Global Climate Models grown up. 

(Stay tuned for part two)

[20180623]

Special addendum: The End of Physics.

Science is maybe only three times as old as Eli (Eli is very old, has he mentioned that recently) maybe 5 if you count back to Newton.  About a month and a half ago, the Bunny pointed out that physics was the simplest science, the one where you could most easily combine and contrast observations with theoretical descriptions in useful models.  It is also the science where humans have gone the farthest.  That raises the interesting question as to whether we have reached the end of physics or if a lagomorph prefers, the end of physics that a bunny can understand or do or use for other ends.  Comes to the same thing

There is little doubt that progress on foundations of physics finds itself in a traffic jam of a multitude of unprovable theories.  String theory, the multiverse, and other attempts to break out have not been very successful, one could say not at all for more than a few decades.  Astronomy, confronted with the issues of dark matter or modified gravity may not be far behind.

Attempts to go beyond the current paradigms for gravity and quantum behavior have become increasingly fanciful.  Peter Woit, on his blog, Not Even Wrong, has chronicled the search.  Sabine Hossenfelder, on her blog Backreactionand book Lost in Math: How Beauty Leads Physics Astray grapples with these issues.  Both are optimists in that they think that further progress is possible.  Eli maybe not so much.

John Horgan, in 2012, wrote about an interview he had with Thomas Kuhn.  There is much of what Kuhn says that Eli disagrees with but perhaps more on that later.  For example, Kuhn appears to miss much of the interplay between observations and theory and models.  He also appears to fall into the philosophers trap of what does a thermometer measure, however there is a disturbing for us thread in the interview.

Kuhn described normal science as the working out of puzzles within an accepted framework or paradigm.  IEHO, for some areas it is almost certain that humans have approached the point where no further changes are likely.  Paradigm shifts in those areas are jogs not car crashes, and most often the new is simply an extension of the old to more extreme, smaller, or larger conditions.  Extension rather than revolution is something that the follow on to physics sciences are now experiencing.

In that sense it is to be expected, that for example in chemistry, many new, exciting and useful puzzles will be solved in new ways but don't expect the hydrino revolution.  Ain't happening folks.

New foundational science can end.  It might have already done so in physics