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
From The Evolution of Physics:
In every event in nature one form of energy is being converted into another, always at some well-defined rate of exchange.
From The Evolution of Physics:
If we regard the whole universe as a closed system, we can proudly announce with the physicists of the nineteenth century that the energy of the universe is invariant, that no part of it can ever be created or destroyed.
“If . . . “
That’s correct. I have been thinking that awareness is a form of energy too, or it is something that should be included in the conservation postulate along with mass and energy.
From The Evolution of Physics:
Our two concepts of substance are, then, matter and energy. Both obey conservation laws: An isolated system cannot change either in mass or in total energy. Matter has weight but energy is weightless. We have therefore two different concepts and two conservation laws. Are these ideas still to be taken seriously? Or has this apparently well-founded picture been changed in the light of newer developments? It has! Further changes in the two concepts are connected with the theory of relativity. We shall return to this point later.
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“Matter has weight but energy is weightless.”
What can be attracted to another has weight just as it can have inertia. Space is attracted to mass, does it therefore have weight? We don’t seem to be clear about what energy is other than “a disturbance in or of space.”
Space is attracted to mass?
Doesn’t mass attract space and time?
By attract you mean warp? These are two different concepts.
How so?
at·tract to draw by a physical force causing or tending to cause to approach, adhere, or unite; pull (opposed to repel ): The gravitational force of the earth attracts smaller bodies to it.
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warp to bend or twist out of shape, especially from a straight or flat form, as timbers or flooring.
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Repeating that which we’ve already said does not show the inconsistency in what I wrote. Aye, here are two separate words with separate definitions. Again, we are looking at a tautology for clarity.
The inconsistency lies in the thinking that these two words mean the same thing, when they don’t.
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I’m not trying to discuss the two words. I am asking whether the force at work in each word is the same force or a different force? If gravity attracts, then is space time warped by a different force?
I am really sorry, I am unable to follow your thinking.
Mass is thought to warp space and time; but your supposition that mass attracts space and time is not evident from that article, which you linked.
Vin: Mass is thought to warp space and time; but your supposition that mass attracts space and time is not evident from that article, which you linked.
Chris: “The sun is so incredibly massive it essentially bends the space around it, pulling into orbit lesser objects (like planets) nearby. Similarly, with enough mass an object can even cause an otherwise straight beam of light to curve. In astronomy, that’s called gravitational lensing.”
Vin: Mass is thought to warp space and time; but your supposition that mass attracts space and time is not evident from that article, which you linked.
Chris: “Time is not immune to the effects of gravity either. It passes more quickly the less gravity there is, a phenomenon known as gravitational time dilation. On most days you might not credit gravity with anything more than keeping your feet on the ground, but a gravitational field can also warp time. That’s gravitational time dilation in a nutshell, and for an example of time dilation in action, we need look no further than the nearest geosynchronous satellite. Even with ultra-precise atomic clocks, these satellites would inevitably wind up a few microseconds fast without correctional programming.”
Vin: Mass is thought to warp space and time; but your supposition that mass attracts space and time is not evident from that article, which you linked.
Chris: But undercutting this immediate discussion is what I consider an inadequate or short look at gravity as it relates to massive objects. What I currently believe is that locally space-time is condensing. I write locally to mean within our galaxy because my model doesn’t yet account for galaxies flying apart if that is what they are truly doing. Locally might also include Andromeda, into which we seem to be crashing. I believe that gravity is an innate property of space-time. I believe it may be the elastic force or quality of space-time to gather itself together.
But is the force which warps and the force which attracts a different force? Is the space-time which is warped around a massive object not attracted by that massive object? How have I misunderstood the forces at work? Beyond the event horizon of a black hole, is space-time being bent? Is space-time being attracted? For me, massive objects contain condensed space and time. Is this not correct? And how? Possibly you are not comfortable with the definition or else the use of the word attract?
To me warping doesn’t mean the same thing as attracting. It doesn’t communicate the same way.
I understand, therefore are the force of gravity and the force of warping different forces? Or does our understanding of the source of these forces need to evolve?
Vin: To me warping doesn’t mean the same thing as attracting. It doesn’t communicate the same way.
Chris: This can be resolved by stating the vector of attraction force compared to the vector of warping force. If these vectors are the same direction and force, then they are the same force and we see that we are in an argument of semantics. If they are not the same, then I will be feeling very lost on the subject and have to go back and restudy the materials that I’ve already covered.
To me, energy and mass are aspects of space-time.
I am not feeling comfortable with our exchange. When you change or remove my comments or yours to alter the meanings of the comments in the discussion, I feel that you are arguing with me rather than discussion the topic.
As you did here:
“vinaire commented on Evolution of Physics by Einstein. in response to vinaire: Space is attracted to mass?
To me, energy and mass are aspects of space.”
I am afraid I am not following you.
What did I change or remove?
Vin: I am afraid I am not following you. What did I change or remove?
Chris: Well above you wrote “. . . aspects of space.” Then I wrote “Time too.” Then you revised your comment from space to space time which makes my comment look dull as though I am not paying attention to what you are writing.
Sorry about that. I didn’t realize that you are responding from your email, and not from the blog.
I clarified my post right after I wrote it, but the earlier version went to you over the email. Do you want me to delete your response as it no longer applies?
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I guess so, for clarity.
Done.
Scientists have been looking at the conservation of physical elements only.
Is there a broader law pertaining to the conservation of “physical and metaphysical” elements?
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From The Evolution of Physics:
The results of scientific research very often force a change in the philosophical view of problems which extend far beyond the restricted domain of science itself. What is the aim of science? What is demanded of a theory which attempts to describe nature? These questions, although exceeding the bounds of physics, are intimately related to it, since science forms the material from which they arise. Philosophical generalizations must be founded on scientific results. Once formed and widely accepted, however, they very often influence the further development of scientific thought by indicating one of the many possible lines of procedure. Successful revolt against the accepted view results in unexpected and completely different developments, becoming a source of new philosophical aspects. These remarks necessarily sound vague and pointless until illustrated by examples quoted from the history of physics.
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MOTION
INERTIA
VELOCITY
CHANGE IN VELOCITY (magnitude and direction – vector)
FORCE (proportional to change in velocity)
ACCELERATION AND MASS
FORCE AND DISTANCE
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EXPERIMENTS
CONSISTENCY OF CONCEPTS
SIMPLICITY IN THE UNDERSTANDING OF REALITY
OBJECTIVE TRUTH AS THE IDEAL LIMIT OF A CONCEPT
CONCEPT OF MASS: INERTIAL AND GRAVITATIONAL
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MOTION – FRICTION – HEAT
MECHANICAL ENERGY: POTENTIAL & KINETIC
MECHANICAL EQUIVALENT OF HEAT AS ENERGY
CONCEPT OF ENERGY: MECHANICAL, HEAT
ENERGY IS ANYTHING THAT CAN BE CONVERTED TO MECHANICAL ENERGY AND HEAT
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> matter demonstrates its existence as a source of force by its action on other matter.
> The easiest matter to imagine are spherical particles.
> The easiest forces to imagine are those of attraction and repulsion.
> The force vectors lie on a line connecting the material points.
> Simple postulate: the force between any two given particles depends only on the distance between them,
> But is it possible to describe all physical phenomena by forces of this kind alone?
PS: This is a slammin’ good book. No one understands Einstein’s Relativity better than he. The language is very easy to read. Thanks for turning me on to it.
You are welcome.
Looking at space as having properties and quantities such as weight and mass takes everyday physics in a fresh direction. Referring to space as being elastic and gathering itself is a different look at gravity than “massive objects attract.”
> Success of mechanics has contributed to the belief that it is possible to describe all natural phenomena in terms of simple forces between unalterable objects. Is this belief correct?
THE MECHANICAL VIEW
THE KINETIC THEORY OF MATTER
AVAGADRO’S NUMBER –> WEIGHT OF ATOMS
> In the kinetic theory of matter and in all its important achievements we see the realization of the general philosophical programme: to reduce the explanation of all phenomena to the interaction between particles of matter.
> Heat must be mechanical energy if every problem is a mechanical one.
> More heat in the vessel [containing gas molecules] means a greater average kinetic energy.
> Heat is just the kinetic energy of molecular motion.
> To any definite temperature there corresponds a definite average kinetic energy per molecule.
> Kinetic theory predicts that pressure would increase as gas is compressed.
> Kinetic theory predicts that at the same presure, volume and temperature, the number of molecules would be the same.
> It explains quantitatively as well as qualitatively the laws of gases as determined by experiment.
> A fall in the temperature of matter means a decrease in the average kinetic energy of its particles.
> It is therefore clear that the average kinetic energy of a liquid particle is smaller than that of a corresponding gas particle.
> Kinetic theory of matter also explains the mysterious Brownian Motion.
> Thus, the bombarding particles (molecules) have mass and velocity.
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From The Evolution of Physics:
In mechanics the future path of a moving body can be predicted and its past disclosed if its present condition and the forces acting upon it are known. Thus, for example, the future paths of all planets can be foreseen. The active forces are Newton’s gravitational forces depending on the distance alone. The great results of classical mechanics suggest that the mechanical view can be consistently applied to all branches of physics, that all phenomena can be explained by the action of forces representing either attraction or repulsion, depending only upon distance and acting between unchangeable particles.
In the kinetic theory of matter we see how this view, arising from mechanical problems, embraces the phenomena of heat and how it leads to a successful picture of the structure of matter.
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II. THE DECLINE OF THE MECHANICAL VIEW
The two electric fluids
The magnetic fluids
The first serious difficulty
The velocity of light
Light as a substance
The riddle of color
What is a wave?
The wave theory of light
Longitudinal or transverse light waves?
Ether and the mechanical view
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Example of a theory:
There exist two electric fluids, one called positive ( + ) and the other negative ( – )… Two electric fluids of the same kind repel each other, while two of the opposite kind attract… There are two kinds of bodies, those in which the fluids can move freely, called conductors, and those in which they cannot, called insulators.
The aim of every theory is to guide us to new facts, suggest new experiments, and lead to the discovery of new phenomena and new laws… There are no eternal theories in science… Every theory has its period of gradual development and triumph, after which it may experience a rapid decline… Nearly every great advance in science arises from a crisis in the old theory.
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A hundred years after Newton discovered the law ofgravitation, Coulomb found a similar dependence of electrical force on distance… But gravitational attraction is always present, while electric forces exist only if the bodies possess electric charges… In the gravitational case there is only attraction, but electric forces may either attract or repel… Like heat the electric fluids are also members of the family of weightless substances.
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> Analogy: Electric charge is like Heat
> Analogy: Electric potential is like Temperature
> The tendency of charge to escape from a conductor is a direct measure of its potentials.
> ARBITRARY CONVENTION: The electric fluid flows from the conductor having the higher (+) potential to that having the lower (-).
From The Evolution of Physics:
Although we can consistently carry out the mechanical view in the domain of electric and magnetic phenomena introduced here, there is no reason to be particularly proud or pleased about it. Some features of the theory are certainly unsatisfactory if not discouraging. New kinds of substances had to be invented: two electric fluids and the elementary magnetic dipoles. The wealth of substances begins to be overwhelming!
The forces are simple. They are expressible in a similar way for gravitational, electric, and magnetic forces. But the price paid for this simplicity is high: the introduction of new weightless substances. These are rather artificial concepts, and quite unrelated to the fundamental substance, mass.
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