Category Archives: Physics

William Gilbert: On the Lodestone

I recently read William Gilbert’s renaissance masterpiece “On the Lodestone”, and found his work to be extremely intriguing.  Gilbert lived at the dawn of the scientific era, from 1544-1603, predating Francis Bacon – originator of the modern scientific method – by about 20 years.  He is considered by some to be the father of electromagnetism, and indeed is the first to use the term “electricity” in describing what we now know as static electricity (the primary source of static electricity in Gilbert’s experience was amber; the Greek word for amber is elektron). 

Gilbert is a staunch defender of the experimental basis for Truth – at least most of the time.  He attacks earlier writings concerning magnetism as simple repetitions of prior writings which generally are based in nonsensical assertions, which could be easily discounted if anyone bothered to acquire a magnet and observe its behavior.  In the sixteenth century, the primary source of magnetism was the naturally occuring mineral magnetite (ferrous-ferric oxide), or lodestone.  It should be understood that the best (purest) lodestones are barely capable of lifting iron objects of their own weight – very unlike modern “magnets” which generally can lift objects much heavier than themselves, particularly in the case of rare earth magnets which can lift several thousand times their own weight.

Gilbert attacks many myths about the magnet – that coating a lodestone with garlic oil removes the magnetism; that a diamond placed near a lodestone similarly destroys its power; that electrical attraction and magnetism are the same force.  In each case he makes strong derogatory statements about earlier authors who never even saw, let alone tested, a lodestone.  Gilbert proceeds to build a set of facts and observations of his own, each supported by experiment.  Many of his observations I had never considered before (as a trained physicist).  For example:

  • To determine the north and south poles of a magnet, allow the magnet to rotate freely in Earth’s magnetic field.  Mark the end that points to geologic north as the south pole, and the end that points south the north pole.  Which of course makes perfect sense, since opposing poles attract.
  • Apply a magnet’s pole to the center an iron bar, thereby magnetizing the bar.  If you use the north pole of the magnet, this will create north poles at both ends of the bar.   If the bar is curved into a C shape, there will be a repelling force between the cusps of the C.
  • Cut a magnet in half, holding one piece firmly. The cut ends will immediately repel each other, causing the free magnet to rotate rapidly to bring the opposite end to face the cut end.  This implies a continual stress present in  the material near the poles of any magnet.

Gilbert uses spherical lodestones, which he calls “terrellas” for “little Earths” for many of his demonstrations.  Using a device of his invention, the “versorium” – basically a compass needle mounted on a very free-turning point – he maps out the magnetic field lines of the terrella, and demonstrates their equivalence to the directions in which a compass points as it travels over the Earth.  Furthermore, he demonstrates the equivalence of the “dip” of the versorium at high “latitudes” on the terrella with the corresponding subtle dip of an accurate three-dimensional compass observed by navigators as they sail in higher latitudes.  The dip is caused again by the attraction of the pole, which is both north and “under” the compass increasingly as we reach higher latitudes.

There is a wealth of additional experimental and empirical information Gilbert conveys in this work, about not only magnetism, but static electricity as well – I am only remembering the highlights as I write this, some 3 months after finishing it.  And so Gilbert would appear to be a solid hero of scientific reasoning, living at the very end of the middle ages, and opening the door to the coming scientific revolution.  And, as far as the material above, this is certainly the case.

The first inkling we have that Gilbert may not be consistent in his scientific thinking is when he begins describing the relationship between the lodestone and the Earth.  He accurately shows that iron ore and lodestone are related – the one is attracted to the other; the iron can take on weak magnetic properties after exposure to lodestone.  But then he makes a large leap – which just happens to be true – in asserting that the Earth is mostly made from magnetic materials (iron and lodestone), and that what we experience on the surface – bodies of water, various soils, mountains and canyons – are but aberrations of the Earth that exist only on the relatively small surface in comparison to the bulk of the planet.  He, of course, has no experimental evidence for this claim (our experimental evidence came hundreds of years later in mapping how earthquake tremors penetrate the planet).

However, his entire thesis for the work is to explain magnetism, not merely describe its effects and laws.  And this is where he turns shockingly away from reason.  The magnet is aligning itself to the Soul of the Earth – so he asserts without demonstration.  Further, the Earth is a living Being, and this Soul is not a literary euphemism – it is asserted to be real.   After building up a large assortment of truly impressive scientifically-verified facts, and teasing the reader along the way, indicating that his studies have lead to a determination of the true Nature of the lodestone, he quite suddenly moves from demonstration to dogmatic assertion.  In addition to the Earth as a living entity, he goes on to assert that all celestial bodies are alive, each with its own Soul, and that each will exert a force on the material from which it is made, just as the Earth exerts a force on lodestone and iron.  He winds up this strange path through the irrational with an appeal to astrology – that these same forces affect the development of humans born under the various stars and constellations.  If it weren’t so tragic, it would almost be comical.

Gilbert is a fascinating example of an intellectual genius caught between two radically different philosophical worlds, with one foot planted in each.

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Heinz Pagels Interpretation of Quantum Mechanics

Quantum mechanics is viewed by Objectivism with disdain and discredit for lacking an objective philosophical basis.  The standard “Copenhagen Interpretation” of quantum mechanics states that the uncertainty principle is an absolute feature of reality.  The uncertainty principle states that one cannot simultaneously determine the momentum and position of an existant (usually referencing a particle, but it need not be a particle).  The Copenhagen Interpretation goes further to state that an existant does not have a specific position or momentum  – or in general a specific “state” – until the existant is observed.  Rather, what the existant has is a probability (amplitude) wavefunction that extends throughout space whose intensity describes a probability distribution for the properties of the existant.

Somehow, that just doesn’t sit well with Objectivists.  (Other interpretations are much worse, however – we can discuss those later).  Among the consequences of the Copenhagen Interpretation is a choice between a failure of local causality, or instantaneous action over indefinite distances (Einstein’s “spooky action at a distance”).  That would be another nauseating choice for Objectivists to accept.  And so, they don’t accept the validity of the theory.

Recently, I fell upon the book “The Cosmic Code” by Heinz Pagels.  Pagels was a physicist, and this book was an attempt to bring modern physics issues to a public audience.  Such attempts are generally extraordinarily difficult, and all too frequently result in pushing misconceptions into the minds of the unprepared reader.  Pagels’ book is no exception, and a good part of it is not safe reading for someone who truly wants to understand modern physics.  (It is my opinion, as a partially-educated physicist, that someone who truly wants this understanding had better start by educating themselves in the appropriate math to handle the actual theories directly.  I believe that I have about 70% of what it may take to gain this understanding, which means I’m tortured by recognizing bad discussions of the theories in popularizations, but am not able to understand the actual theories in their full form).

Pagel’s book is separately into two significant parts.  In the first, he builds up the history and basic structure of the theory of quantum mechanics.  In this discussion, he does a fairly decent job with reducing the subject to terms for the layman without leading him too far off into the possibilities for misconception.  The second half is devoted to an understanding of particle physics and cosmology – and here I believe he moves beyond what he is able to describe carefully to an untrained mind.  Nonetheless, my interest is in the first part of the book. 

The crux of Pagels’ work lies in his development of a new position between the standard Copenhagen interpretation of Quantum mechanics, and the macroscopic world.  Pagels believes that the lack of objectivity in the microscopic world need not mean that there is a corresponding lack of objectivity in the macroscopic world.  His argument for this is based on thermodynamics, and in particular, in the second law of thermodynamics.  Pagels states that quantum mechanics is insensitive to the direction of time.  Specifically, that the governing equations and associated laws of the theory work equally well whether time moves forward or backward.  In fact, the renowned physicist Richard Feynman caused quite a stir among particle physicists when he proved that the behavior antimatter (existing as positrons and antiprotons, as well as many more exotic particles) can be alternatively described as normal matter moving backward in time. 

However, says Pagels, as one “zooms out” from a microscopic viewpoint, there comes a scale at which larger structures are seen to behave very differently dependent on the direction of time.  He gives the example of viewing the smoke from a pipe.  At a microscopic level, we see a random-looking motion of individual molecules.  At the critical scale, we begin to see the smoke leaving the pipe and dispersing irreversibly through the surrounding air.  Time has now taken on a permanent direction – the smoke is going to continue to disperse with time, not suddenly reverse and travel back into the pipe.  Pagels invokes the second law of thermodynamics – that entropy of a closed system will increase over long time averages – to explain his observation. 

To tie this observation to a statement about macroscopic objectivity, he then states that the flow of entropy is inherently related to the flow of information.  Humans acquire information only through massive averages of microscopic phenomena – we acquire only macroscopic information.  Since at the macroscopic scale the direction of time is fixed, information, once acquired, cannot be lost in principle.  Because of this fact, objective truth and causality are inherent in the macroscopic world.

Unfortunately, the presentation of this huge conclusion is all done within a page or two in The Cosmic Code, and I find it very difficult to fill in some of the gaps that have been left – both because of the brevity, and because the presentation is targeting a non-scientific audience.  Having thought over this interpretation for several weeks now, there are some significant problems that need to be investigated further for this to satisfy my own disillusionment with the quantum theory.  A key area of concern is the intersection between Pagels’ view of information, human epistemology, and the second law of thermodynamics.  A second concern is over the statement that humans only acquire information through massively averaged phenomena.  Beyond this, there are a few splinter questions that he has raised within the book, each deserving a separate discussion.

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The Present

I run an astronomy course for homeschooled children of elementary and middle school ages.Last night’s session wasmy lecture entitled “Distance and Time”, dealing with the rather fascinating fact that in astronomy we are always observing events in the past. Although most educated adults “understand” this fact superficially, spending a couple hours talking about the ramifications of this fact as I expand the range that we’re discussing from the Moon (at about 1.25 light seconds from Earth) to the most distant objects observed by the Hubble Space Telescope (at about 13,000,000,000 light years from Earth) creates a lot of discussion in the class.

Last night, near the very end of the lecture, the youngest member of this class – age 8 I think – asked a very, very profound question. I had driven home the point repeatedly that everything we see happened in the past – even watching me across the room, the light they were seeing had left me a few nanoseconds before they “saw” it. His question (slightly paraphrased):

If everything we see and experience happened in the past, does the Present exist?

This question amazed me on several levels. In his actual phrasing of the question, it was clear to me that this was not an accidental stumbling upon a deep question – he really did have an inkling of what he was asking. The amount of experience he attempted to integrate in that instant was a huge surprise. I am still trying to follow how his mind could have created that question at such an early age.

I had no real hope of answering him in a manner he could understand, but that didn’t stop me from trying. Here is an expansion of what I told the class, in which I tried to explore the issue of observing very short time intervals. Although this was a somewhat technical answer (that no one in the room understood, perhaps including myself at the time), it has lead me further to consider just what the concept “Present” may actually represent.

Similar to how a computer functions, the human mind has a “clock rate”. Unlike a computer, which can perform billions of elementary calculations per second, the human brain’s neurons can fire at most 500 times a second.To receive and recognize visual information may require the firing of dozens of neurons, which brings our visual “frame rate” to maybe 10-50 frames per second. (This makes some sense, since a movie shot at 15 frames a second will appear visually “jerky”, while one shot at 30 or 60 frames per second generally looks smooth). For concreteness, let’s say the mind can receive one frame in 1/50th of a second. That means that anything happening in less than 1/50th of a second will be experienced as simultaneous.

Light travels at 186,000 miles per second. So, using our 1/50th second frame rate, anything that we observe within a range of about 3720 miles at a given instant in “global time” will appear to happen simultaneously. In some psychological sense then, our experience of “Now” has a range of 3720 miles.

As I said, this argument confused us all. And what I’ve written here is much clearer than what I said in the class last night – yet I’m still musing over what it means epistemologically, and what it means for our concept of Time.

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Experience of the Rate of Time

How quickly time appears to pass depends on the “clock” against which change in the perceived world is compared. By a clock is meant a separate stream of change appearing simultaneously with the perceptions being timed. There are what I’ll term “objective clocks”, whichconsist of aperiodic motion with a nearly-constant period. These occur overa vast range of scale – the ticks of a clock, beats of a heart, length of a “day”, of a “week”, and of seasons, the extent of a lifetime. We develop a concept for the time intervals of these clocks through our repeated exposure to them. Against an objective clock, one can obtain an objective measurement of elapsed time – one whose scale is independent of subjective interpretation. When I say this, however, it must still be recalled that all time experience requires an entity with memory – to retain the perceptions of the clock “ticks” and the phenomenon being timed – and consciousness, so that a concept of time interval can form.

However, we also experience a more psychologically-based time measurement, which lacks the uniformity provided by a clock. Let me express this first through some examples.

Let’s start with “anxious waiting”. When we are waiting, time appears to pass very slowly. Waiting in a line, sitting through an uninteresting meeting or class, getting delayed while travelling, all of these cases can be catagorized as time dialation caused by anxious waiting. Time also appears dialated during emergencies, which would appear to be the complete opposite experience. However, I suggest that these two experiences – of anxious waiting, and of severe fearful excitement, have a common feature. When I am anxiously waiting, my mind wanders over a long list of items that I could – or should – be doing, instead of passivelyfacing the wait that I am currently compelled to experience. I consider with increasing emotional concern the impact of my lack of activity on meeting my day’s schedule, achieving my short term goals. My mind is occupied with a continual stream of various thoughts, andnegative emotions are engaged. In an emergency, I experience a similar mixture of heightened mental activity – in a desparate search for actions to relieve the emergency – combined with intense negative emotion. Under both of these circumstances, time is subjectively slowed.

Time passes quickly when our mind is focussed narrowly on a single stream of thought. If I spend an afternoon working on a single mathematics problem with no other distractions, the hours will pass by rapidly. The more narrow the field of consideration, the more rapidly time appears to pass. In the extreme, when we sleep peacefully, time passage appears instantaneous. Notably, if we sleep poorly, or are disturbed by dreams, negative emotion stirs, and we have a “long night”. Not to be trite, but time does indeed pass quickly when we are “having fun” – positive emotion, coupled with a narrow mental focus, or a lack of focus, speeds the subjective passage of time.

Attempting to generalize from these observations, I suggest that the subjective rate of time is a function of the level of mental activity. The more “mental states” we experience in a fixed interval of (objectively measured) time, the longer that interval appears to last. I further conjecture (based again on self observation) that the rate of change of mental state is in general higher when we areexperiencing negative emotion, than when we experience positive emotion. The link to our experience of time durationcan be explained if we are comparing the rate of change in our external world to the rate of change in our mental state – that is, if our mind’s actions are the “clock” against which we are measuring time.

I fully recognize that this hypothesis is very incomplete. Note that I have not defined “mental state”, nor can I explain the conjecture that rapid change of mental states generally give rise to negative emotion. I will next attempt to sketch – still realizing this is only a suggestive sketch – of what I mean by mental state.

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The Plenum

The Universe is a continuous plenum of Existence, containing no voids. A void would constitute an area of nothingness, a non-existent within the realm of Existence. Such a concept is an inherent contradiction. Indeed logically, “a non-existent” is what I’ll term an improper noun – it has no referent. [I run the risk here that there is a prior definition of “improper noun”, but for this post I’ll take that risk].

The difficulty in integrating the statement that the Universe is a plenum often lies in a confusion between a void and a vacuum. A vacuum is an area of space containing no matter, while a void contains nothing with an identity – this is a far greater restriction than a lack of matter. Vacuums can and do exist in the Universe, while a void cannot.

Bringing this to a concrete example, consider two spheres not in contact with one another. By “not in contact” is meant there exists a distance between them. A distance is a difference in position. To have a difference in position there must be “space” between them. This space may be occupied, with matter, or not occupied, as is the case in a vacuum. In either case, the space itself is a non-void, and existent.

A description of the structure and behaviour of space is in the realm of Physics, and beyond the context of Philosophy. Nonetheless, a consideration of some of the attempts to represent the Plenum in physics can serve as illustrative examples that can help the process of integrating the concept of a vacuum as an existing entity, and therefore completely different in principle from the non-existent void.

Here I will mention only briefly four representations of the Plenum. In pre-Relativistic physics, we have the Ether described as a “fluid” through which electromagnetic waves propagate, permeating – consisting – of all of space. In “modern” “accepted” physics the concept of the Ether is replaced by the quantum field. This field is the substrate for not only electromagnetic propagation, but all energy and matter in the Universe. There are severe philosophical issues with the quantum field (it itself relies upon false concepts of the non-existent), but it is again identified with all of “space”. Lastly, I’ll list two alternatives to the accepted theories. The elementary wave theory of Lewis Little presents an approach to modern physics which rests upon firmer philosophical grounds, and has been accepted by many Objectivists as an alternative to quantum mechanics. Finally, there is the view of the Universe as computation. In this framework, the Universe consists of a vast array of computational cells, plus a “program” of evolutionary rules which determine the content of these cells through time. This alternative framework has been pursued by Edward Fredkin, Steven Wolfram, and others.

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