What do you think?
Rate this book
Relativity for the Layman
Relativity for the Layman
144 pages, Paperback
First published January 1, 1954
3 people are currently reading
73 people want to read
Ratings & Reviews
Friends & Following
Create a free account to discover what your friends think of this book!
Community Reviews
Displaying 1 - 19 of 19 reviews
August 27, 2022
I pulled the following out of this book for the (lay) thoughts they provoked:
Regarding the dramatically different character of the light spectrum (it’s not only fast….): “The velocity of light will always be constant at 186,000 miles a second relative to the observer. Just think of it. This means that a light wave leaving a star will have a velocity of 186,000 miles a second relative to an observer, regardless of whether he and the star are approaching or separating at a relative velocity of 185,999 miles a second or one mile a second!”
Regarding an object moving at the speed of light: “Does the object disappear? This is precisely what the formula says does happen, for it is easily seen that as v approaches the velocity of light, c, the length of the object approaches zero. And at v equal to c, the length is zero, which means that the object has disappeared….if we let v increase to the point where it is equal to the velocity of light, c, the denominator becomes zero, which means that the mass becomes infinite.” There’s something about speed - is it added energy from the outside that increases speed -- that converts an object to energy, with (mathematically?) infinite mass?
“The vibrating atom is similar to the vibrating string. A particular string will vibrate at a set frequency depending on its length, tension, etc., which does not change unless the length, tension, etc., change. Similarly, every atom vibrates at its own particular frequency, which should not change. But if it does change, it means that the time processes in the atom have changed. In particular, if the frequency decreases, we have seen this means that the time per vibration has increased, or that time itself has slowed down in the particular atom.”
Regarding unified field theory: gravitational attraction, i.e., every object in the universe attracts every other object,” is similar to “other types of forces (unlike electric charges will also attract each other)…And we also have a similar formula giving the force of attraction between two unlike magnetic poles (a north magnetic pole and a south magnetic pole)….the three equations which mathematically express different and entirely unrelated phenomena are identical in form….Gravitational forces are forces of attraction only, but electric and magnetic forces can be of attraction or repulsion….the similarity between the three types of forces (gravitational, electric, and magnetic) is so striking that it seems as if all three must be branches of a more fundamental or basic phenomenon of nature….When two gravitational masses or electric charges or magnetic poles) attract each other, the interaction takes place in the region, or field between the masses….It may very well be that there exists such a thing as nuclear fields….Is it not possible that a gravitational force of repulsion can exist in our universe and that this missing link awaits our discovery of the general laws of fields before we can create such a repulsive gravitational force?” Is gravitational attraction also repulsion (resistance); if more energy (relative mass) attracts, does it more strongly resist the attraction of a lesser mass?
August 26, 2022 Addition to Review:
Isn’t gravitational “attraction” an outdated legacy from Newton’s “action at a distance” for three reasons. First, per Einstein, a large gravitational mass, itself, does not pull/attract a lesser gravitational mass. Rather, the former depresses/warps spacetime and the latter follows spacetime pathways toward the gravitational center. Second, per the inverse square law, this movement increases the movement (strength, speed) toward the gravitational center and such movement is commonly described as an attractive force. Third, to say that gravitation is an attractive force neglects, per Einstein, that it is also an inertial force that (a) persists in its straight-line motion, and (b) resists the deviating, accelerating effects of other gravitational bodies, including its “state of rest” (equilibrium/balanced state vis-à-vis those bodies?).*
Is it possible that all mass-energy exhibits toward (“attractive”) and against (“resisting”) qualities? But the new curve ball is that, per Einstein, gravitational mass is only indirectly an attractive force, and that it is primarily an inertial force that, like all energy-mass, wants to move. And that movement has accelerating effects on other bodies in a spacetime field** consisting of interacting matter-energy that, in turn creates via inertia a resisting force that, in the end, results in a new equilibrium state?
Seen this way, is it possible that a unified field theory unites electro, magnetic, and gravitational movement in the following way: The pattern of movement is toward equilibrium, a stable energy state where there are no energetic differentials. This movement is a “pulling” toward the center, toward zero. Was Aristotle sort of right after all – a state of rest (equilibrium, understood as a continuum between no-movement and movement) governs and resistance is a pushing away to maintain an equilibrium state?
Under the General Theory of Relativity, all motion is relative to something else. There is no absolute motion. But under the big bang scenario, isn’t this an absolute reference point for both time and space (distance, as measured by light years)?
Coleman writes of mass and energy as separate entities. In the conversion of mass to energy, for example, it’s the lost mass that has been converted to energy. Written this way, it suggests that mass is something other than energy, as opposed to being concentrated energy in the form of matter, that becomes “dissipated” as pure energy (void of matter).
With its expansion, matter and energy dissipate so that gravitational effects are zero and therefore spacetime curvature is zero. If this is so, how then can straight-line motion (say, radiation of light) return back to its origin by following spacetime curvature? *** If matter and energy is dissipated, does this mean that the universe has no curvature?
*Also, is there a connection of inertial to “a repulsive gravitational force?” Coleman asks: “Is it not possible that a gravitational force of repulsion can exist in our universe and that this missing link only awaits our discovery of the general laws of fields before we can create such a repulsive gravitational force?”
**But is a gravitational field merely the pathways of spacetime, or does it consist of gravitons (actual particles of mass-energy)?
***“If the Einstein conception of the universe is correct, a ‘spacetrian’ who leaves the earth and continually travels in a space line will always end up again at the earth, regardless of what his original direction is away from the earth.” “There is no outside edge to the universe, for we have seen that continual travel in a space line brings you back to the starting point. Our universe closes on itself.” “An astronomer might someday build a super-duper telescope and we can imagine what will happen when he looks through it. He may see a shiny luminous object which looks like the moon but with a very peculiar-looking curved three growing out of it. Only after many hours of quiet and careful scrutiny will it dawn on him that he is looking at his own gleaming bald pate, the light from which has gone completely around the universe and returned!”
Regarding the dramatically different character of the light spectrum (it’s not only fast….): “The velocity of light will always be constant at 186,000 miles a second relative to the observer. Just think of it. This means that a light wave leaving a star will have a velocity of 186,000 miles a second relative to an observer, regardless of whether he and the star are approaching or separating at a relative velocity of 185,999 miles a second or one mile a second!”
Regarding an object moving at the speed of light: “Does the object disappear? This is precisely what the formula says does happen, for it is easily seen that as v approaches the velocity of light, c, the length of the object approaches zero. And at v equal to c, the length is zero, which means that the object has disappeared….if we let v increase to the point where it is equal to the velocity of light, c, the denominator becomes zero, which means that the mass becomes infinite.” There’s something about speed - is it added energy from the outside that increases speed -- that converts an object to energy, with (mathematically?) infinite mass?
“The vibrating atom is similar to the vibrating string. A particular string will vibrate at a set frequency depending on its length, tension, etc., which does not change unless the length, tension, etc., change. Similarly, every atom vibrates at its own particular frequency, which should not change. But if it does change, it means that the time processes in the atom have changed. In particular, if the frequency decreases, we have seen this means that the time per vibration has increased, or that time itself has slowed down in the particular atom.”
Regarding unified field theory: gravitational attraction, i.e., every object in the universe attracts every other object,” is similar to “other types of forces (unlike electric charges will also attract each other)…And we also have a similar formula giving the force of attraction between two unlike magnetic poles (a north magnetic pole and a south magnetic pole)….the three equations which mathematically express different and entirely unrelated phenomena are identical in form….Gravitational forces are forces of attraction only, but electric and magnetic forces can be of attraction or repulsion….the similarity between the three types of forces (gravitational, electric, and magnetic) is so striking that it seems as if all three must be branches of a more fundamental or basic phenomenon of nature….When two gravitational masses or electric charges or magnetic poles) attract each other, the interaction takes place in the region, or field between the masses….It may very well be that there exists such a thing as nuclear fields….Is it not possible that a gravitational force of repulsion can exist in our universe and that this missing link awaits our discovery of the general laws of fields before we can create such a repulsive gravitational force?” Is gravitational attraction also repulsion (resistance); if more energy (relative mass) attracts, does it more strongly resist the attraction of a lesser mass?
August 26, 2022 Addition to Review:
Isn’t gravitational “attraction” an outdated legacy from Newton’s “action at a distance” for three reasons. First, per Einstein, a large gravitational mass, itself, does not pull/attract a lesser gravitational mass. Rather, the former depresses/warps spacetime and the latter follows spacetime pathways toward the gravitational center. Second, per the inverse square law, this movement increases the movement (strength, speed) toward the gravitational center and such movement is commonly described as an attractive force. Third, to say that gravitation is an attractive force neglects, per Einstein, that it is also an inertial force that (a) persists in its straight-line motion, and (b) resists the deviating, accelerating effects of other gravitational bodies, including its “state of rest” (equilibrium/balanced state vis-à-vis those bodies?).*
Is it possible that all mass-energy exhibits toward (“attractive”) and against (“resisting”) qualities? But the new curve ball is that, per Einstein, gravitational mass is only indirectly an attractive force, and that it is primarily an inertial force that, like all energy-mass, wants to move. And that movement has accelerating effects on other bodies in a spacetime field** consisting of interacting matter-energy that, in turn creates via inertia a resisting force that, in the end, results in a new equilibrium state?
Seen this way, is it possible that a unified field theory unites electro, magnetic, and gravitational movement in the following way: The pattern of movement is toward equilibrium, a stable energy state where there are no energetic differentials. This movement is a “pulling” toward the center, toward zero. Was Aristotle sort of right after all – a state of rest (equilibrium, understood as a continuum between no-movement and movement) governs and resistance is a pushing away to maintain an equilibrium state?
Under the General Theory of Relativity, all motion is relative to something else. There is no absolute motion. But under the big bang scenario, isn’t this an absolute reference point for both time and space (distance, as measured by light years)?
Coleman writes of mass and energy as separate entities. In the conversion of mass to energy, for example, it’s the lost mass that has been converted to energy. Written this way, it suggests that mass is something other than energy, as opposed to being concentrated energy in the form of matter, that becomes “dissipated” as pure energy (void of matter).
With its expansion, matter and energy dissipate so that gravitational effects are zero and therefore spacetime curvature is zero. If this is so, how then can straight-line motion (say, radiation of light) return back to its origin by following spacetime curvature? *** If matter and energy is dissipated, does this mean that the universe has no curvature?
*Also, is there a connection of inertial to “a repulsive gravitational force?” Coleman asks: “Is it not possible that a gravitational force of repulsion can exist in our universe and that this missing link only awaits our discovery of the general laws of fields before we can create such a repulsive gravitational force?”
**But is a gravitational field merely the pathways of spacetime, or does it consist of gravitons (actual particles of mass-energy)?
***“If the Einstein conception of the universe is correct, a ‘spacetrian’ who leaves the earth and continually travels in a space line will always end up again at the earth, regardless of what his original direction is away from the earth.” “There is no outside edge to the universe, for we have seen that continual travel in a space line brings you back to the starting point. Our universe closes on itself.” “An astronomer might someday build a super-duper telescope and we can imagine what will happen when he looks through it. He may see a shiny luminous object which looks like the moon but with a very peculiar-looking curved three growing out of it. Only after many hours of quiet and careful scrutiny will it dawn on him that he is looking at his own gleaming bald pate, the light from which has gone completely around the universe and returned!”
April 13, 2024
I was awarded this book as part of a school maths prize back in 1975! I decided to re-read it. I don't know what happened to the other 3 books that comprised the prize and which had the relevant stickers in.
Anyway, this book was written in the 1950s and revised in 1969 so I was interested to see what the 'current state of play' back then was.
Most interestingly, though there is mention of super-massive stars which are so massive, light cannot escape, the term "black holes" was not used despite this being what was described. So I looked up the terminology of when the term was first used and it wasn't until 1967 (coined by John Wheeler) so had probably not really filtered through at the time this book was revised.
It may be that subsequent editions of the book have updated this but as this edition was revised in 1969, I don't know.
Anyway, the book itself is a relatively (haha) light introduction to the topic and I don't think the basics have changed much in the last 50 years.
Why only 4 stars? Because it is of course quite old now which is not a fault of the book.
Anyway, this book was written in the 1950s and revised in 1969 so I was interested to see what the 'current state of play' back then was.
Most interestingly, though there is mention of super-massive stars which are so massive, light cannot escape, the term "black holes" was not used despite this being what was described. So I looked up the terminology of when the term was first used and it wasn't until 1967 (coined by John Wheeler) so had probably not really filtered through at the time this book was revised.
It may be that subsequent editions of the book have updated this but as this edition was revised in 1969, I don't know.
Anyway, the book itself is a relatively (haha) light introduction to the topic and I don't think the basics have changed much in the last 50 years.
Why only 4 stars? Because it is of course quite old now which is not a fault of the book.
August 23, 2017
i did enjoy the book as it did as stated and somewhat explained Einstein's theories in layman's terms. However, being the nerd that I am, I would now like to find out how these, seemingly, outlandish experiments were conducted way back in the early twentieth and late nineteenth centuries.
Examples measurement of mass of atoms, the drag effect on their movement. even earlier in the 1600s, how did Kepler figure out the orbits of planets and stars?
Very interesting.
Examples measurement of mass of atoms, the drag effect on their movement. even earlier in the 1600s, how did Kepler figure out the orbits of planets and stars?
Very interesting.
February 10, 2020
This book is easily digested for those who is not even has a science background. The explanation mostly using a common sense. I feel enlightened why time is called as fourth dimension.
I really like the poem too.
I really like the poem too.
August 28, 2020
This is a book I read just before I tackle Stephen Hawking's "A Brief History of Time". I have read it two or three times and find it gives a good description of relativity.
October 12, 2020
อธิบายภาพสังเขปของทฤษฎีสัมพัทภาพ ไม่เจาะลึกในตัวสมการมากนัก แต่ขอหักคะแนนในส่วนที่ไม่บอกว่ามันเป็นเช่นนี้ได้เพราะอะไร พิสูจน์หรือทดลองกันมายังไง เป็นต้น
November 17, 2021
Very good and simplifief
This entire review has been hidden because of spoilers.
August 14, 2023
A perfect intro to relativity
June 6, 2011
An interesting read as much for the historical context as it is an explanation of Einstein's theories of relativity. I thought Einstein's own explanation was easy enough to understand in Relativity, though as Coleman explains, it isn't that relativity is a difficult concept to understand; it's the consequences of it that are difficult to believe. What makes the book an interesting read in its historical context is that it was written only shortly after the end of WWII (and the dropping of the atom bombs and the subsequent development of the hydrogen bomb) and several years before Gagarin became the first man in space. Coleman writes of men riding in "rocketships", but at the time he was writing it, the concept of man in space was purely theoretical.
Coleman does include both the evolution of ideas leading up to Einstein's Special and General Theories of Relativity, as well as the subsequent experiments that confirmed those theories. Nowadays there is no end to the number of programs about Einstein and his theories on the History Channel or Science Channel, which do a better job, and probably more accurate job of explaining relativity to the layperson (even our vocabulary has changed in the past fifty years), but they can't offer the same flavor for the wonder of the birth of the Atomic Age that this book does.
Coleman does include both the evolution of ideas leading up to Einstein's Special and General Theories of Relativity, as well as the subsequent experiments that confirmed those theories. Nowadays there is no end to the number of programs about Einstein and his theories on the History Channel or Science Channel, which do a better job, and probably more accurate job of explaining relativity to the layperson (even our vocabulary has changed in the past fifty years), but they can't offer the same flavor for the wonder of the birth of the Atomic Age that this book does.
July 25, 2012
Clear introduction to the theory of relativity. As the author writes in his introduction, it's not necessary the theory itself that is mind-boggling, but the consequences and results. To me these consequences could have been explained more carefully, since the author skips quite a few steps to come to his conclusion. This makes the book easier to read, but also less clear.
Read
July 11, 2016If you really want to know the truth, this simple to read book is a MUST read. It takes you back to the basics, the fork in the road. Along with further reading of other books it shows where our theoretical physics derailed and has now ended up with strings, bubbles, parallel universes and other esoteric magical constructs.
April 29, 2015
Very easy to read & follow intro to Einstein's theories. The material is obviously a bit dated now, but serves its stated purpose of laying down a complicated subject with as little dense mathematics as possible. Fun, quick read.
May 24, 2015
Nice, simple beginning introduction to relativity. This book and The Universe and Dr. Einstein were my introductions to the subject, and got me hooked.
February 1, 2008
Read and enjoyed this -- probably back when I was in junior high. I'm sure there are better and more current books on relativity, but this one fueled my interest in science.
March 27, 2009
great overview of the theory of relativity and what discoveries lead to it
Want to read
October 22, 2009The book I own is a signet library edition (1958 US printing).
December 13, 2010
Explains relativity concepts in simple English with tons of good examples. Learnt more than from Uni course in special relativity.
September 3, 2012
Still didn't understand it! Got lost on page 3.
Displaying 1 - 19 of 19 reviews