Relativity by Albert Einstein

This is not a super fact post but another kind of fact-oriented post. It is a book review for a book that I find interesting, Relativity: The Special and the General Theory by Albert Einstein. Yes, the book was written by Albert Einstein in 1916 and translated into English in 1920. It is written for laymen, average readers, and despite being more than 100 years old (well this reprint is from 1995) it does not feel outdated.

I should say that I wrote my review decades ago and Amazon has hidden about 900 of the oldest reviews including mine. So, you can no longer find it. Luckily, I still had it, but I cannot provide a link to it. The book comes in formats, hardcover (2024), paperback (1995), Kindle (2014), Audio (2009). I bought the paperback version.

  • Publisher : Independently published (July 29, 2024), ASIN : B0DBQVVJVQ, ISBN-13 : 979-8334454118, 109 pages, item weight : 7.8 ounces, dimensions : ‎ 6 x 0.47 x 9 inches, Translator : Robert W. Lawson, it costs $12.33 on US Amazon. Click here to order it from Amazon.com.
  • Paperback –  Publisher : Crown (June 6, 1995), ASIN : 0517884410, ISBN-13 :  978-0517884416, 208 pages, item weight : 8 ounces, dimensions : ‎ 5.2 x 0.5 x 8 inches, it costs $7.89 on US Amazon. Click here to order it from Amazon.com.
  • Kindle –  Publisher : Amazon Kindle Direct Publishing (February 23, 2014), ASIN : B004M8S53U, 126 pages, it costs $0.99 on US Amazon. Click here to order it from Amazon.com.
  • Audiobook –  Publisher : HighBridge, a division of Recorded Books (November 14, 2009), ASIN : B002XGLDAA, Listening Length : 2 hours and 14 minutes, it costs $12.09 on US Amazon. Click here to order it from Amazon.com.
The front cover of the paperback version feature Albert Einstein in front of a black board full of equations, title “Relativity: The Special and the General Theory” and author – Albert Einstein | Relativity by Albert Einstein
Front cover of Relativity: The Special and the General Theory by Albert Einstein. Click on the image to go to the Amazon page for the paperback version of the book.

Amazon’s Description of Relativity by Albert Einstein

This book was originally written in German by Albert Einstein in 1916 and later translated to English by Robert W. Lawson in 1920. In Einstein’s own words, “The present book is intended, as far as possible, to give an exact insight into the theory of Relativity to those readers who, from a general scientific and philosophical point of view, are interested in the theory, but who are not conversant with the mathematical apparatus of theoretical physics. It is an easy-to-understand collection of the ideas of one of the greatest scientists of the twentieth century including the idea he is most known for, the theory of relativity.

Redesigned inside and out to have a fresh, appealing look, this new edition of a classic Crown Trade Paperback is a collection of Einstein’s own popular writings on his work and describes the meaning of his main theories in a way virtually everyone can understand.

Below is my review for Relativity: The Special and the General Theory by Albert Einstein. First, I should mention that the book is divided into two sections, one for the Special Theory of Relativity and another for the General Theory of Relativity. In addition, there are five short appendices. The five appendices are not written for layman and require at least high school mathematics.

Relativity Explained by Einstein himself

I found it very interesting to read an explanation of the theories of relativity by the developer of those theories. However, it is important to remember that the inventors of science theories aren’t always the best ones to explain them. Isaac Newton is a prime example.

Another thing to remember is that today there are a lot of books and online graphics that use clever pedagogic techniques and visualizations to assist you in understanding these theories, and naturally this book does not contain any of that.

This book was originally written in 1916 and updated in 1920 and since then it has been reprinted/edited several times (as this book is an example of). I should say that the General Theory of Relativity had just been published so there weren’t much else out there for laymen at the time.

I’ve already read many good books on relativity, and I believe I understand special relativity pretty well, but my understanding of general relativity is partial. I did not buy this book to understand relativity. The reason I bought this book was to gain another perspective on the subject. If you just want to learn and understand relativity, I recommend Relativity Visualized by Lewis Carroll Epstein instead.

“Relativity: The Special and the General Theory” features no derivations of the formulas in relativity (except in the appendix) and no visualizations demonstrating relativistic effects and phenomena. The book is focused on the conceptual foundations of relativity and physics.

For example, what are Geometrical propositions, what does it mean to measure the length of a rod, or the time of an event, what do we mean by speed, what is simultaneity, what is the difference between what we observe and what we measure, etc? Einstein spends one and a half page explaining addition of velocities in classical-pre-relativistic kinematics (w = v + u) and what assumptions that are inherent with the approach. In that sense the book is quite philosophical, which is what I meant by “another perspective”. The book covers both the Special Theory of Relativity and the General Theory of Relativity. However, the sections on the General Theory of Relativity are quite short and very introductory.

There are some issues with the book. In appendix 1 Einstein (I presume) derives the Lorentz transforms. However, it is not, in my opinion, the best derivation from a pedagogical standpoint and it also had typos in it. As far as I can tell the formula on page 50 is wrong unless what Einstein means with the “m” is “additional relative mass” and not actual “mass” as stated.

The book features an addition written in 1920 where he is discussing an ad hoc modification to his theory that he had previously made but it turned out to be unnecessary (related to cosmology). The language is also very old fashioned. On the other hand, this kind of stuff makes you feel as if you travel back in time to when the theories of relativity were being churned out.

I don’t recommend the book for learning the theories of relativity but overall I liked the book. It focuses very much on basic concepts and near philosophical aspects of time, space and relativity. The book presents a valuable perspective if you already understand what the theories of relativity are about.

The back cover of the paperback features an overview of the background to relativity and to this book as well as ISBN number and publisher | Relativity by Albert Einstein
Back cover of Relativity: The Special and the General Theory by Albert Einstein. Click on the image to go to the Amazon page for the hardback version of the book.

Other Relativity Related Posts


To see the Super Facts click here

What is Time

Image above by Kevin from The Beginning at Last

Many and strange are the universes that drift like bubbles in the foam upon the River of Time—first sentence of Wall of Darkness by Arthur C. Clarke, 1949.

What is Time? What is the arrow of time? Does entropy define an arrow of time? Is there a past and a future? Has time always existed as, for example, in the eternal inflation cosmological model in which universes continuously pop into existence via Big Bangs like the bubbles on the River of Time in the Arthur C. Clarke quote above. Does time have a beginning as a recent Big Bang model by Stephen Hawking imply. If time came into existence with the universe itself then there is no place for creation, just as in an infinitely existing universe. There cannot be anything north of the north pole, and there cannot be anything before time itself.

In the theories of relativity time is relative. The speed of clocks as well as the order of events differ from observer to observer. The presence of energy or mass will bend time. There is no universal flow of time. There is no universal time.

The goal of this blog is to create a list of what I call super facts. Important facts that we know to be true and yet they are surprising, shocking or disputed among non-experts. It is a type of myth busting. However, I also create posts that are not super facts but that feature other interesting information, such as this book review and book recommendation.

In the picture there are objects from the past as well as futuristic elements and several clocks | What is Time
This picture reminded me of the mysteries of time. This is a submission for Kevin’s No Theme Thursday

About Time: Einstein’s Unfinished Revolution by Paul Davies

The book I am about to present focuses a lot on relativity. This is not strange since the theories of relativity shed a lot of light on time. Yes, pun intended. I’ve come across a lot of people who make various claims about time, and even consider themselves philosophers of time, and yet they do not even understand the special theory of relativity.

Because of this they say a lot of profound sounding things about time that ultimately are nonsensical. There is no way around it. If you want to say profound things about time and expand human knowledge on this topic you need to first have some understanding of relativity as well as other related physics such as thermodynamics and entropy. This book will provide that.

I should say that the book is somewhat outdated, being written in 1995 and 1996. However, most of it is still relevant and I know of no other book that approaches the topic in such an honest and rigorous way. The book comes in two formats hardcover and paperback. I bought the paperback version.

  • Hardcover –  Publisher – Simon & Schuster; First Edition (March 13, 1995), ISBN-10 : 0671799649, ISBN-13 : 978-0671799649, 316 pages, item weight : 1.3 pounds, dimensions : ‎ 6.25 x 1.25 x 9.5 inches, it costs $18.09 on US Amazon. Click here to order it from Amazon.com.
  • Paperback –  Publisher – Simon & Schuster; First Edition (April 9, 1996), ISBN-10 : 0684818221, ISBN-13 : 978-0684818221, 316 pages, item weight : 0.704 ounces according to Amazon but I think that should be 0.704 pounds, dimensions : ‎ 9.21 x 6.14 x 0.8 inches, it costs $12.28 on US Amazon. Click here to order it from Amazon.com.
Front cover of hardback version of the book About Time: Einstein's Unfinished Revolution by Paul Davies
Front cover of hardback version of the book About Time: Einstein’s Unfinished Revolution by Paul Davies. Click on the image to go to the Amazon page for the hardcover version of the book.

Amazon’s Description of About Time: Einstein’s Unfinished Revolution

An elegant, witty, and engaging exploration of the riddle of time, which examines the consequences of Einstein’s theory of relativity and offers startling suggestions about what recent research may reveal.

The eternal questions of science and religion were profoundly recast by Einstein’s theory of relativity and its implications that time can be warped by motion and gravitation, and that it cannot be meaningfully divided into past, present, and future.

In About Time, Paul Davies discusses the big bang theory, chaos theory, and the recent discovery that the universe appears to be younger than some of the objects in it, concluding that Einstein’s theory provides only an incomplete understanding of the nature of time. Davies explores unanswered questions such as:

* Does the universe have a beginning and an end?

* Is the passage of time merely an illusion?

* Is it possible to travel backward — or forward — in time?

About Time weaves physics and metaphysics in a provocative contemplation of time and the universe.

My four-star review for About Time: Einstein’s Unfinished Revolution

The link above will take you to my original review for About Time: Einstein’s Unfinished Revolution. Below is a slightly modified version of the review.

Our Evolving Concept of Time

Science, particularly physics, has revealed to us some profound insights about time, and yet it remains a mysterious topic. In the first chapter of the book “A Very Brief History of Time” the author describes how the concept of time has evolved throughout human history. The ancient philosophers had a very fuzzy notion of time, and they often dismissed both motion and time as illusions. The author tells us about “cyclic time”, and the “linear time” concept from Judeo-Christian thinking, and how it was incorporated into science as a “time variable”. This made it possible to solve the paradoxes created by such Greek thinkers as Zeno, who based on apparent paradoxes concluded that motion and time cannot really exist. Those “false” paradoxes were solved with the concept of linear physical time.

Physical time also made Calculus and Physics possible, and it became clear that there was a difference between physical time, which is a measurable entity used to sequence events, and experienced time, which is the subjective human feeling of a past, present, and a future.

Most of the rest of the book is focused on the Special Theory of Relativity and the General Theory of Relativity. The theories of relativity revolutionized how we view time, and they enabled a much deeper understanding of time. Special relativity refuted the concept of universal absolute time. Not only do clocks in different systems run at different speeds, but there is no universal “Now”.

However, the theories of relativity are not all there is to know about time, and we are not even done drawing conclusions about time based on the theories of relativity. This is why the book is called “About Time Einstein’s Unfinished Revolution”. The book also discusses quantum time, the arrow of time, worm holes, neuroscience and modern psychological experiments.

The book contains a lot of information and yet it scratches only on the surface. Time is a quite complex concept when you start digging into it. Take, for example, the discussion on the arrow of time. The conclusion of the books seems to be that there really is an arrow of time. Time has direction. The author is presenting both “sides” of the issue and to really get a grasp of the issue you need to clarify and look at the physics. Time certainly seems to have a direction if you look at the concept of entropy. The Cosmos is filled with irreversible processes. Our memory, which is essential for our experience of a self, is another example.

However, time has a direction even on the most fundamental level in subatomic particles. Kaon, a type of meson, decays in a way that is not time symmetric. The same may be true for the neutron. These particles “know” the difference between the past and the future. One could easily imagine how this chapter could be turned into a several thousand pages long book by just digging deeper into the related physics.

“About Time Einstein’s Unfinished Revolution” covers a lot of interesting topics related to time and it is often quite informative. The book is also well written, well organized, it has a good pace, and it is very interesting. It strikes a good balance between depth and breadth, and it does not overwhelm its readers. However, I do have some critique of the book, which prompted me to give the book four stars instead of five stars.

To understand some of the discussions in the book you should have a decent understanding of the theories of relativity, in my opinion. The author is explaining the theories of relativity to some degree, but the explanations did not seem to be that good. I did not have a problem with understanding these explanations since I already studied these topics, but I don’t think I would have understood what I needed to understand had I encountered the theories of relativity for the first time while reading this book.

Another criticism I have of the book is that he introduces ugh Everett’s many-worlds interpretation of quantum mechanics and in my opinion promotes it. This interpretation is in my opinion both strange and implausible and is not necessary for the discussions in the book.

In short, it proposes that every quantum measurement creates new universes, each corresponding to a different possible outcome of that measurement. In essence, our Universe is just one of many, and each quantum event splits the universe into multiple versions, where each version experiences a different outcome.

The problem with this interpretation is not so much that you get multiverses, but that you an infinite number of new fully evolved universes every nanosecond, which in turn create an infinite number of universes, which in turn create an infinite number of universes, and so on infinitely, and there is no way to empirically verify their existence. It is a so-called solution to a problem that is fictitious in my opinion and is derived from an old naïve interpretation of quantum waves. It is “hip” and “cool” interpretation, but I don’t see how it is useful. I should add that I have no problem with, for example, the multiverse idea stemming from string theory.

Anyway, except for my two complaints I think this is a pretty good book that I can recommend.

Front cover of paperback version of the book About Time: Einstein's Unfinished Revolution by Paul Davies.
Front cover of paperback version of the book About Time: Einstein’s Unfinished Revolution by Paul Davies. Click on the image to go to the Amazon page for the paperback version of the book.

About Paul Davis

Paul Davies is an internationally acclaimed physicist, cosmologist, and astrobiologist at Arizona State University, where he runs the pioneering Beyond Center for Fundamental Concepts in Science. He also chairs the Search for Extraterrestrial Intelligence Post-Detection Taskgroup, so that if SETI succeeds in finding intelligent life, he will be among the first to know.

The asteroid 1992OG was officially renamed Paul Davies in his honor. In addition to his many scientific awards, Davies is the recipient of the 1995 Templeton Prize–the world’s largest annual prize–for his work on science and religion. He is the author of more than twenty books, including The Mind of God, About Time, How to Build a Time Machine, and The Goldilocks Enigma. He lives in Tempe, Arizona.

Other Relativity Related Posts

To see the Super Facts click here

Relativity Visualized by Lewis Carroll Epstein

The goal of this blog is to create a list of what I call super facts. Super facts are important and true facts that are nevertheless highly surprising to many or disputed or misunderstood by many. In a sense this is a myth busting blog regarding important information. However, I also make posts that are not super facts but feature other interesting information, such as this book review and book recommendation.

Relativity Visualized by Lewis Carroll Epstein

Lewis Carroll Epstein <<Link-1>> is a physicist, teacher and author who has written a number of physics books for layman. He is somewhat famous for coming up with ingenious ways of using diagrams, pictures and puzzles to explain complex matters without using mathematics. His approach is unorthodox but, in my opinion, quite successful. You still have to invest time in reading this 200-page long book and solving most of the puzzles to understand what is going on. The book features some math, notably regarding the derivation of the formula for energy-mass equivalency E = mc2. However, it is in a special section for “teachers only”.

It is an old book and the only version currently available on Amazon is the paperback version. The publisher of the paperback is Insight Press; First Edition (January 1, 1985), ASIN : 093521805X, ISBN-13 : 978-0935218053, 206 pages, item weight : 12.8 ounces, dimensions : 6.25 x 0.75 x 9 inches. It costs $48.99 on US Amazon. Click here to order it from Amazon.com.

The front cover features the title “Relativity Visualized” and the author’s name and in the background is the night sky with the milky way. At the bottom of the front cover is a train with a head lamp and a light beam | Relativity Visualized by Lewis Carroll Epstein
Front cover of the paperback version of Relativity Visualized by Lewis Carroll Epstein. Click on the image to go to the Amazon page for the paperback version of the book.

Amazon’s Description of the Relativity Visualized By Lewis Carroll Epstein

Perfect for those interested in physics but who are not physicists or mathematicians, this book makes relativity so simple that a child can understand it. By replacing equations with diagrams, the book allows non-specialist readers to fully understand the concepts in relativity without the slow, painful progress so often associated with a complicated scientific subject. It allows readers not only to know how relativity works, but also to intuitively understand it.

This is my five-star review for Relativity Visualized

Note, I wrote this review in 2016, so it is relatively old, pun intended. In my original Amazon review I used very large paragraphs. I have changed that by breaking up the paragraphs a bit but without changing the content in any way.

Relatively Intuitive

In my opinion the theories of relativity are among the most interesting intellectual achievements in human history. They revolutionized physics and changed the way we think about physics, space, time, mass, energy, electromagnetism and essentially everything in nature. Despite that fact, the theories of relativity are deterministic and possible to visualize, and unlike Quantum Physics they are not statistical in nature and they don’t have a big issue with interpretation.

I’ve been interested in this topic ever since I came across it as a high school student. Therefore, I did not learn a lot about relativity from this book. I was more interested in the approach to explaining it, and I think his approach is a very good one.

I’ve found that an explanation for relativity that lacks rigor and quantitative reasoning creates misconceptions. The reader may end up thinking he understands it when he doesn’t. I’ve also found that books that focus on deriving complex equations were not only unattainable to the layman but sometimes left the mathematically inclined student with a poor understanding of relativity as well.

Lewis Carroll Epstein’s book “Relativity Visualized” seems to succeed in making relativity accessible to both the layman and those who are mathematically inclined. He explains the special theory of relativity and the general theory of relativity using graphs, visual constructs, and logical puzzles that the reader solves for himself. In a sense he allows the reader to develop the theories of relativity on his own. He avoids equations and formulas, but the reader will still discover more exactly what is going on.

One thing that really impressed me with this book is its special focus on the difference between what you see/experience and what you measure. As an example, take two lights that flash at the same time (in your reference frame). They could appear to flash at different times if the distance between them is large. So, you will see them flash at different times. However, if you time the light flashes and take the distance into account you can measure that they flashed at the same time (non-relativistic situation).

In relativity the differences you measure between frames do not only arise from the distance the light travels or from Doppler Effects but also from the relativity of time and space as well, and Epstein explains the details without confusing the reader. He focuses a lot on simultaneity/non-simultaneity right from the very beginning, and in my opinion understanding relativistic non-simultaneity is crucial to understanding what is going on.

The book also discusses the General Theory of Relativity. The General Theory of Relativity is often seen as completely off limits to the layman. It is typically explained using complex tensor calculus, differential geometry, and topology, or alternatively in a non-technical vague way that leaves the reader clueless. General Relativity was born out of an enigma. Special relativity had shown that energy and mass are the same things, so light has mass. A light beam traveling through a gravitational field must thus bend.

However, that means that the side of the light closer to the mass will travel a shorter distance. From known properties of light (always a transverse/orthogonal wave) this means that the side of the light beam closer to the mass moves slower than the outer rim which would violate the constancy of the speed of light in vacuum.

To solve this enigma Einstein had to introduce a time warp in gravitational fields. Later he discovered that this time warp would cause objects to fall towards the masses that caused the time warp and the practical effect of this turned out to be essentially identical to Newton’s theory of gravity and thus the mysterious force of gravity could be removed. Einstein also discovered that there is a warp effect on space which is negligible unless the speed of the objects is large (like magnetism for electric forces). The book helps you visualize all of this without using complex math.

Lewis Carroll Epstein’s book contains unique pedagogic approaches, novel geometric representations of relativity, as well as engaging questions and answers. For this reason, the book is fiercely protected by copyright law. On the negative side, his writing style is somewhat rigid and old fashioned, the drawings and the graphics are sometimes of low quality, and the book might be quite a bit of work for the layman reader, so it requires that you are really interested. However, overall, this is a very rigorous, detailed, correct, and yet entertaining book that I highly recommend.

Good Myths

I also would like to mention another tool that Lewis Carroll Epstein use in his book, and that is the concept of a Good Myth. A Good Myth is a description that isn’t technical and maybe not exact but that isn’t wrong either. In a loose way it captures the truth of what is going on.

An example of one of these myths is that everything, including all of us, is always traveling through time and space at exactly the speed of light in vacuum. In other words, we are all traveling at the speed of c = 299,792,458 meters per second. If we are sitting still, then we are traveling through time at the speed of light. If we are traveling through space at the speed of light then we are not traveling through time at all, like photons, for which time does not exist.

If we are traveling through space at a high speed, then if we add, in a vector way (Pythagoras theorem), our speed in space to our speed in time, they together will add up to the speed of light in vacuum. But that means that we are traveling through time at a speed that is less than the speed of light. So, our clocks will run slower.

The back cover features the title of the book, praise for the book and very brief description | Relativity Visualized by Lewis Carroll Epstein
Back cover of the paperback version of Relativity Visualized by Lewis Carroll Epstein.

Other Posts on Relativity

Below is a list of other posts I made on Relativity

  • The Speed of Light In Vacuum Is a Universal Constant : to see post click here
  • Two events may be simultaneous for some but not for others : to see post click here
  • Time Dilation Goes Both Ways : to see post click here
  • The Pole-Barn Paradox and Solution : to see post click here
  • Book-Review : The Special Theory of Relativity by David Bohm : to see post click here

Do you feel that you are traveling through time at the speed of light?

To see the Super Facts click here

The Special Theory of Relativity by David Bohm

The goal of this blog is to create a list of what I call super facts. Super facts are important and true facts that are nevertheless highly surprising to many, disputed among the public, or unnecessarily misunderstood. They are special facts that we all can learn something important from. However, I also make posts that are not super facts but feature other interesting information, such as this book review and book recommendation.

The Special Theory of Relativity by David Bohm

David Bohm a close colleague of Albert Einstein was one of the most interesting theoretical physicists of the 20th century. This book “The Special Theory of Relativity” is one of the most interesting and thorough introductory books on the Special Theory of Relativity that I have come across. It is a series of lectures on the topic. It features algebra, equations, and a little bit of differentials but not too much.

You may want to have some math, physics and some relativity under your belt before you tackle this book. In my estimate it is written for those who have taken high school AP physics and AP algebra, maybe calculus as well, or one or two college level physics classes and math classes (or more). It is probably too basic for professional physicists, but it is not written for laymen. I bought the paperback version.

  • Hardback –  Routledge; 1st edition (October 10, 1996), ISBN-10 : 0415148081, ISBN-13 : 978-0415148085, 256 pages, item weight : 13.6 ounces, dimensions : ‎ 5.75 x 0.75 x 9 inches. It is out of stock, and it costs $75.60 – $144.00 on US Amazon. Click here to order it from Amazon.com.
  • Paperback –  Publisher : Routledge; 1st edition (September 4, 2006), ASIN : 0415404258, ISBN-13 : 978-0415404259, 304 pages, item weight : 12 ounces, dimensions : 5.08 x 0.69 x 7.8 inches. It is out of stock, and it costs $12.36 – $17.21 on US Amazon. Click here to order it from Amazon.com.
  • Kindle –  Published : Routledge; 1st edition (September 29, 2015), ASIN : B009W3W6MG, 306 pages, it costs $10.10 – $13.77 on US Amazon. Click here to order it from Amazon.com.
The front cover of “The Special Theory of Relativity by David Bohm.”
Front cover of the paperback version of The Special Theory of Relativity by David Bohm. Click on the image to go to the Amazon page for the paperback version of the book.

Amazon’s Description of the Book

In these inspiring lectures David Bohm explores Albert Einstein’s celebrated Theory of Relativity that transformed forever the way we think about time and space. Yet for Bohm the implications of the theory were far more revolutionary both in scope and impact even than this. Stepping back from dense theoretical and scientific detail in this eye-opening work, Bohm describes how the notion of relativity strikes at the heart of our very conception of the universe, regardless of whether we are physicists or philosophers.

This is my five-star review for The Special Theory of Relativity

Note, I wrote this review in 2014, so it is relatively old, pun intended.

Lorentz Electrodynamics, Special Relativity, and our Perception of Reality

This book is a thorough and well written introduction to the “Special Theory of Relativity”. In addition to the basics of special relativity it covers the history of Special Relativity and it includes 60-pages of Lorentz Electrodynamics. The book also discusses Minkowski Diagrams, the Twin Paradox, relativistic Doppler effects, K-Calculus, and philosophy related to relativity. The book does not discuss General Relativity.

Bohm does not derive many formulas for electrodynamics, optics, quantum physics, thermodynamics, etc., and therefore this book does not resemble a textbook. Bohm’s focus is on a deeper understanding of the special theory of relativity itself, and on time and space.

He discusses perception of reality and includes discussions on child development, psychology and neurology related to perception, the meaning of the relational concepts in relativity, the structure of scientific revolutions (T.S. Kuhn), our perceptions of time and space, philosophy, and other related topics that cannot be classified as physics.

In K Calculus you draw the world lines of light pulses sent at constant intervals between different observers. Then you calculate what is essentially the Doppler factor K and uses it to explain what is going in relativity. In contrast the Lorentz transform is concerned with the space-time coordinates that you measure after taking into account that light have to travel a certain distance and that this takes time. Basically, the “actual time and space coordinates”.

K Calculus on the other hand is including both relativistic effects and the distance and time it takes for light to travel. K Calculus is thus not what you “measure” but what you “observe”. K Calculus makes it very easy to explain special relativity to an audience that is not strong in math and it also adds a new understanding to the special theory of relativity.

However, I see an inherent risk with K-Calculus in that it can end up fooling the student into believing that he understands relativity, for example, if a student incorrectly comes to believe that time dilation is some form of Doppler Effect.

Except for the fact that some of the mathematical derivations were unnecessarily complex I thought this book presented relativity lucidly, the philosophical discussions were insightful, and it added to my understanding of the topic. It should probably not be your first book on Special Relativity but it is a very good second book. I highly recommend it for those who want to think through the concepts of relativity a little deeper.

The back cover of "The Special Theory of Relativity by David Bohm"
Back cover of the paperback version of The Special Theory of Relativity by David Bohm. Click on the image to go to the Amazon page for the kindle version of the book.

To see the Super Facts click here

The End of Everything By Katie Mack

What will the end of everything be like? How will everything end? Will it be the Big Crunch as the Universe collapses back to a reverse Big Bang? Will it be the heat death, or what is better called the high-entropy death? Will it be the Big Rip as the Universe is ripped apart, or vacuum decay? Maybe it will be the Quantum Bubble of Death? Wouldn’t the Quantum Bubble of Death be a cool way to die?

The goal of this blog is to create a list of what I call super facts. Important facts that we know to be true and yet they are surprising, shocking or disputed among non-experts. Super facts are important facts that people get wrong. However, I sometimes create posts that are not super facts but other interesting information, such as this book review and book recommendation.

The End of Everything: (Astrophysically Speaking) by Katie Mack is a relatively easy book on cosmology. It features scientifically guided speculation on how the Universe will end. As in the previous book I reviewed the cosmic microwave background radiation (CMBR) is a major source for the information. It is amazing what it can tell you. I bought the hardback version of it. I can add that this book and my Amazon review was written in 2020, a good year for talking about the end of the world.

  • Hardcover –  Publisher : Scribner; Illustrated edition (August 4, 2020), ISBN-10 : 198210354X, ISBN-13 : 978-1982103545, 240 pages, item weight : 2.31 pounds, dimensions : ‎5.5 x 1 x 8.38 inches, it costs $19.14 on US Amazon. Click here to order it from Amazon.com.
  • Paperback –  Publisher : Scribner (May 4, 2021), ISBN-10 : 1982103558, ISBN-13 : 978-1982103552, 256 pages, item weight : 2.31 pounds, dimensions : ‎ ‏ : ‎5.5 x 0.6 x 8.38 inches, it costs $10.99 on Amazon. Click here to order it from Amazon.com.
  • Kindle –  Published : August 04, 2020, ASIN : B07Z41TTNK, 237 pages, it costs $14.89 on US Amazon. Click here to order it from Amazon.com.
  • Audiobook –  Publisher : Scribner (August 4, 2020), ASIN : B07Z8B5NZ8, it costs $13.12 on US Amazon. Click here to order it from Amazon.com.
Front cover of The End of Everything By Katie Mack | The End of Everything
Front cover of The End of Everything? Click on the image to go to the Amazon page for the hardcover version of the book.

Amazon’s description of The End of Everything By Katie Mack

A NEW YORK TIMES NOTABLE BOOK OF 2020

NAMED A BEST BOOK OF THE YEAR BY * THE WASHINGTON POST * THE ECONOMIST * NEW SCIENTIST * PUBLISHERS WEEKLY * THE GUARDIAN

From one of the most dynamic rising stars in astrophysics, an “engrossing, elegant” (The New York Times) look at five ways the universe could end, and the mind-blowing lessons each scenario reveals about the most important concepts in cosmology.

We know the universe had a beginning. With the Big Bang, it expanded from a state of unimaginable density to an all-encompassing cosmic fireball to a simmering fluid of matter and energy, laying down the seeds for everything from black holes to one rocky planet orbiting a star near the edge of a spiral galaxy that happened to develop life as we know it. But what happens to the universe at the end of the story? And what does it mean for us now?

Dr. Katie Mack has been contemplating these questions since she was a young student, when her astronomy professor informed her the universe could end at any moment, in an instant. This revelation set her on the path toward theoretical astrophysics.

Now, with lively wit and humor, she takes us on a mind-bending tour through five of the cosmos’s possible finales: the Big Crunch, Heat Death, the Big Rip, Vacuum Decay (the one that could happen at any moment!), and the Bounce. Guiding us through cutting-edge science and major concepts in quantum mechanics, cosmology, string theory, and much more, The End of Everything is a wildly fun, surprisingly upbeat ride to the farthest reaches of all that we know.

This is my five-star review for The End of Everything

The End of the Universe can be a lot of fun

Katie Mack’s timely (it’s 2020 after all) survey of the various ways the Universe might end, based on current physics, was a delightful read. It is an interesting and fun book. We learn about the Big Crunch (the Universe shrinking back), the Heat Death, or rather the high-entropy death, the Big Rip, Vacuum decay, or the “quantum bubble of death” if you want to call it that, and the “bounce”. 

To understand where the various ideas regarding the end of the Universe come from, you need to understand some of the physics and the cosmology. We learn something about CMB, or the Cosmic Microwave Background, Big Bang, cosmic inflation, Planck Time, GUTs, Nucleosynthesis, the standard model, de Sitter Space, black holes, electroweak symmetry breaking, the Higgs Boson and the Higgs field, multiverses, and much more.

Perhaps most importantly, we learn about dark matter and dark energy, which are important concepts that have greatly changed cosmology over the last few years. Chapter 2 on the Big Bang reminded me a lot about an old book by Stephen Weinberg, the first 3 minutes. However, Katie Mack puts a modern spin on it and goes much further beyond our Universe. I was intrigued to hear that it might be possible to communicate between different Universes in a multiverse using gravity, or gravity waves.

The book is written for laymen, and I found it to be between Neil De Grasse Tyson / Carl Sagan and Stephen Hawking in difficulty level. The book covers a lot of concepts and theories but does so concisely, simply and not in a mathematical way. Not so simply though that it is misleading.

I am an Engineer with an undergrad degree in physics so I may not be the best person to judge whether this is an easy read for laymen, but I believe it is. I am very interested in these kinds of topics, and I read all popularized books on cosmology, modern physics, the standard model, that I can find. This was one of the most fun books that I’ve ever read.

The back cover of The End of Everything by Katie Mack
Back cover of The End of Everything? Click on the image to go to the Amazon page for the hardcover version of the book.

Would you like to travel in time into the future to see the end of the Universe?


To see the Super Facts click here