e-book: The Evolution of Physics
I am currently studying this book by Einstein to get an insight into his thinking. This book was originally published in 1938 by Cambridge University Press. It was a popular success, and was featured in a Time magazine cover story.
Here is some information on this book from Wikipedia:
Background of collaboration
Einstein agreed to write the book partly as a way to help Infeld financially. Infeld collaborated briefly in Cambridge with Max Born, before moving to Princeton, where he worked with Einstein at the Institute for Advanced Study. Einstein tried to get Infeld a permanent position there, but failed. Infeld came up with a plan to write a history of physics with Einstein, which was sure to be successful, and split the royalties. When he went to Einstein to pitch the idea, Infeld became incredibly tongue-tied, but he was finally able to stammer out his proposal. “This is not at all a stupid idea,” Einstein said. “Not stupid at all. We shall do it.”
Book’s point of view
In the book, Einstein pushed his realist approach to physics in defiance of much of quantum mechanics. Belief in an “objective reality,” the book argued, had led to great scientific advances throughout the ages, thus proving that it was a useful concept even if not provable. “Without the belief that it is possible to grasp reality with our theoretical constructions, without the belief in the inner harmony of our world, there could be no science,” the book declared. “This belief is and always will remain the fundamental motive for all scientific creation.”
In addition, Einstein used the text to defend the utility of field theories amid the advances of quantum mechanics. The best way to do that was to view particles not as independent objects but as a special manifestation of the field itself: “Could we not reject the concept of matter and build a pure field physics? We could regard matter as the regions in space where the field is extremely strong. A thrown stone is, from this point of view, a changing field in which the states of the greatest field intensity travel through space with the velocity of the stone.”
Contents
I. THE RISE OF THE MECHANICAL VIEW
- The great mystery story
- The first clue
- Vectors
- The riddle of motion
- One clue remains
- Is heat a substance?
- The switchback (roller-coaster)
- The rate of exchange
- The philosophical background
- The kinetic theory of matter
II. THE DECLINE OF THE MECHANICAL VIEW
- The two electric fluids
- The magnetic fluids
- The first serious difficulty
- The velocity of light
- Light as substance
- The riddle of colour
- What is a wave?
- The wave theory of light
- Longitudinal or transverse light waves?
- Ether and the mechanical view
III. FIELD, RELATIVITY
- The field as representation
- The two pillars of the field theory
- The reality of the field
- Field and ether
- The mechanical scaffold
- Ether and motion
- Time, distance, relativity
- Relativity and mechanics
- The time-space continuum
- General relativity
- Outside and inside the lift
- Geometry and experiment
- General relativity and its verification
- Field and matter
IV. QUANTA
- Continuity—Discontinuity
- Elementary quanta of matter and electricity
- The quanta of light
- Light spectra
- The waves of matter
- Probability waves
- Physics and reality
The third chapter (Field, Relativity) examines lines of force starting with gravitational fields (i.e., a physical collection of forces), moving on to descriptions of electric and magnetic fields. The authors explain that they are attempting to “translate familiar facts from the language of fluids…into the new language of fields.” They state that the Faraday, Maxwell, and Hertz experiments led to modern physics. They describe how “The change of an electric field produced by the motion of a charge is always accompanied by a magnetic field.”
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Comments
I am with Einstein in favoring the objectivity and simplicity of the Field Theory. I don’t feel enamored by Quantum Mechanics.
I believe that underlying all reality there is a primordial field disturbed by a primordial energy. This DISTURBANCE THEORY can account for electromagnetism as well as for awareness; for matter as well as for self.
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I like the purpose of this book, “To sketch in broad outline the attempts of the human mind to find a connection between the world of ideas and the world of phenomena… “
It is interesting that Einstein recognizes MOTION to be the most fundamental mystery of nature.
From Aristotle to Galileo, the most significant progress was moving forward from an intuitive view to a mindful one of examining things in the minutest detail.
The Law of inertia is a fascinating fact of nature.
“Every body perseveres in its state of rest, or of uniform motion in a right line, unless it is compelled to change that state by forces impressed thereon.”
This law of inertia cannot be derived directly from experiment, but only by speculative thinking consistent with observation.
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In general the action of an external force changes not only the speed but also the direction of the motion. An understanding of this fact prepares us for the generalization introduced into physics by the concept of vectors.
Force seems to neutralize inertia temporarily.
When there is no inertia, what is left?
It seems that force and inertia are inverse of each other.
Not proportional?
Force is proportional to the rate of change in velocity, which is known as acceleration. The constant of proportionality is mass.
Mass represents inertia. When there is no change is velocity, then there is no force. But mass is still there. The velocity becomes uniform. And there is momentum and kinetic energy.
There seems to be more to the nature of inertia than what is known at present.
Right, so then from this, I’m not sure how to visualize force and inertia being inverse. I’m willing to but even if we don’t understand inertia, it is proportional to mass is proportional to force or else, what? Please explain more.
When there is no external force acting on the object, its motion is uniform. The motion can be perceived as zero or of any value because it is relative. The inertia is not manifested.
The inertia manifests itself as resistance only when external force is applied. So, when there is force there is also inertia. When there is no force, there is no inertia.
Therefore, inertia is like a reaction to the force.
Maybe awareness is like inertia. When there is a force vector, there is a commensurate reaction to that vector. When there is a phenomena, there is a reaction of awareness to that phenomena. When there is no relative phenomena, there is no commensurate awareness. When there is too much phenomena, too much awareness ensues in the form of confusion, shutting down, etc.,.
There seems to be a “sweet-spot” of randomness for each of us — Not too little and not too much.
That is an excellent observation. 🙂
Thank you, but it is just an idea. I am looking forward to having and spending time with the math, first with the disturbance levels and see how those metrics sound to me when done. Then see if some of these other relations can be described using the poetic rhythms of math.
That’s a nice project.
I feel I should do something tangible with — learn to speak math — before I attempt to tutor others.
Sure!
Einstein says. “The initial and fundamental steps are always of a revolutionary character. Scientific imagination finds old concepts too confining, and replaces them by new ones… The continued development along any line already initiated is more in the nature of evolution, until the next turning point is reached when a still newer field must be conquered.”
Einstein says, “One of the most important characteristics of modern physics is that the conclusions drawn from initial clues are not only qualitative but also quantitative… To draw quantitative conclusions we must use the language of mathematics… Mathematics as a tool of reasoning is necessary if we wish to draw conclusions which may be compared with experiment.”
I continue to wonder about and cannot shake the idea of time-lapse regarding the speed of action-reaction that we call acceleration and as it relates to inertia. We say there is “resistance” but what do we mean by that? What is resisting an instantaneous movement from one state to another. At the microscopic, are these accelerations by quanta or continuous?
It seems Einstein loves the metaphor as much as I.
Is EMR the unleashed “force” of the universe itself?
“Continuous” is an interesting concept.
So is ‘discrete’.
I read a supposed quote from Einstein that said there is no such thing as matter, it is just another form of energy. If so no rules associated with matter do not apply. There for nothing is impossible?????
In my opinion, what is IS. We simply need to understand it better.
Sorry, that may come across as somewhat abrupt, but there is no lack of sincerity on my part.
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Mechanics seems to be an interaction between two very different disturbance levels… Solid objects belong to one disturbance level, and the space between them belongs to another disturbance level. We generally compare solid objects relative to each other against the background of space. Uniform velocity seems to be associated with inertia or the disturbance level. Gravitational force between two objects depends on the space between them.
If we visualize space as an elastic medium whose elasticity we term gravity, it gives us another model to stretch or minds.
Possibly quanta has its beginnings as a precipitate of such a medium.
Maybe space is a greatly uncoiled singularity.
Is the space between galaxies of the same substance and mechanic as the space within galaxies?
Here is a nice excerpt from the book about gravitational and inertial mass:
A body at rest gives way before the action of an external force, moving and attaining a certain velocity. It yields more or less easily, according to its inertial mass, resisting the motion more strongly if the mass is large than if it is small. We may say, without pretending to be rigorous: the readiness with which a body responds to the call of an external force depends on its inertial mass. If it were true that the earth attracts all bodies with the same force, that of greatest inertial mass would move more slowly in falling than any other. But this is not the case: all bodies fall in the same way. This means that the force by which the earth attracts different masses must be different. Now the earth attracts a stone with the force of gravity and knows nothing about its inertial mass. The “calling” force of the earth depends on the gravitational mass. The “answering” motion of the stone depends on the inertial mass. Since the ” answering ” motion is always the same all bodies dropped from the same height fall in the same way it must be deduced that gravitational mass and inertial mass are equal.
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Here is an excerpt from the book about potential and kinetic energy:
(In a rollercoaster) At its highest point the car has zero velocity and is one hundred feet from the ground. At the lowest possible point it is no distance from the ground, and has its greatest velocity. These facts may be expressed in other terms. At its highest point the car has potential energy but no kinetic energy or energy of motion. At its lowest point it has the greatest kinetic energy and no potential energy whatever. At all intermediate positions, where there is some velocity and some elevation, it has both kinetic and potential energy. The potential energy increases with the elevation, while the kinetic energy becomes greater as the velocity increases. The principles of mechanics suffice to explain the motion. Two expressions for energy occur in the mathematical description, each of which changes, although the sum does not vary. It is thus possible to introduce mathematically and rigorously the concepts of potential energy, depending on position, and kinetic energy, depending on velocity.
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Furthermore,
In the real switchback, where friction prevents the car from again reaching as high a point as that from which it started, there is still a continuous change between kinetic and potential energy. Here, however, the sum does not remain constant, but grows smaller… Something more than kinetic and potential energies is now involved, namely, the heat created by friction. Does this heat correspond to the diminution in mechanical energy, that is kinetic and potential energy? A new guess is imminent. If heat may be regarded as a form of energy, perhaps the sum of all three heat, kinetic and potential energies remains constant. Not heat alone, but heat and other forms of energy taken together are, like a substance, indestructible…
The progress of science has destroyed the older concept of heat as a substance. We try to create a new substance, energy, with heat as one of its forms.
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There is conservation of mass.
There is conservation of energy.
Mass is a form of energy.
There is conservation of “mass and energy”.
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