To Thermodynamics  To General Relativity and Gravity 
196 The Bible According to Einstein
The fifth book of Physics, called


The New Testament 197
Chapter III: The First Principle Now the first principle of special relativity shall say that the laws of Nature are the same for all constantmoving viewers. And what shall be a constantmoving viewer? It shall be an observer with a constant speed moving in a fixed direction. And what shall the first law mean? It shall mean that an experiment performed at rest and an experiment performed while moving at a constant speed in a fixed direction shall yield precisely same results. And suppose thou live inside a rocket far in outer space. Then, billiard balls will deflect off one another in the same manner whether thy rocket be at rest or moving. Likewise, the decay of radioactive nuclei will proceed in the same way, whether thou art at rest or moving. And this is natural, for if thou live in the black of outer space, thou know not whether thou move or not. And so the behavior of objects under Nature shall be identical when viewed from constantmoving frames of reference. Chapter IV: The Second Principle Now since the constancy of the speed of light is one of Nature’s law, it shall be, by the first principle, the same for all constantmoving viewers. Thus all such constantmoving viewers shall measure the speed of light to be the same. In thy rocket, thou shall find light’s speed to be the same, whether the light moves at thee, away from thee or by thee. And this speed shall be identical whether thy rocket be at rest or not. And since the speed of light is the same for every constantmoving viewer, it shall be a fundamental concept. And so the speed of light shall be a universal constant – a little less than threehundredthousandkilometers per second. And this speed shall be labelled "c". Thus c shall be threehundredthousandkilometers per second.
____________________ ^{190} An example of this is as follows. A man standing by a highway sees eastwardmoving cars travelling at the same speed as westwardmoving cars. But a man sitting in a speeding eastwardbound train sees eastwardmoving cars travelling slower than westwardmoving cars. In fact, if the train moves somewhat faster than the traffic, the eastwardmoving cars seem to him to travel slowly backward! 

198 The Bible According to Einstein
Chapter V: The Third Principle Now the third principle says that under no circumstances shall an object travel faster than the speed of light. Instantaneous communication shall be impossible. And this lack of instantaneous communication shall have great implications for causality, or causeeffect. And for example, actions in one part of the Universe cannot suddenly affect the actions in another part – only when such a distant action propagates and arrives at another part of the Universe can such a distant action have effect. And for example, when a supernova explodes tenthousandlight years from thee, ye initially see nothing; ye must wait for the light to come to thee; ye must wait tenthousand years to see the flash. Thus the supernova ye see today is a supernova that exploded long ago. Chapter VI: The Fourth Principle Now the fourth principle says that time shall be the fourth dimension. And how can time, which is measured in seconds, be space, which is measured in meters? Time shall be like unto gold. Gold is a metal. But it is also money. And to convert gold into money one needs to know the exchange rate, the number of dollars that an ounce of gold is worth. So time, which is the ticking of a clock, can also be a meter stick. And what is the exchange rate for time? It shall be the speed of light. And so, to convert time into distance, one multiplies time by the speed of light. Thus one second of time shall be threehundredthousand kilometers, which is also called one lightsecond. Two seconds of time shall be sixhundredthousand kilometers, or two lightseconds. And one minute of time shall be eighteenmillion kilometers, which is sixtylight seconds, or one lightminute. And one hour of time shall be a little more than onebillion kilometers, which is threethousandandsixhundred lightseconds, or sixty lightminutes, or one lighthour. And one day of time shall be twentysixbillion kilometers, which is twentyfour lighthours, or one lightday. And one year of time shall be nineandahalftrillion kilometers, which is threehundredandsixtyfive lightdays, or one lightyear. Thus a lightsecond, a lightminute, a lighthour and a lightyear shall not be measures of time but distance. And for example, the distance to the nearest star, Alpha Centuri, shall be fourandathird lightyears; the distance between Pluto and the Sun shall be almost six lighthours; and the distance between the Earth and the Sun shall be eightandathird lightminutes. And time, when it is represented as a length, shall be called ctime.
And the fourth dimension will baffle a man with a "Newtonian brain," for his visual world is threedimensional, and his brainwaves are threedimensional, and his imagination is threedimensional. But a man with an "Einsteinian brain" has a fourdimensional imagination and can picture a fourdimensional space. (And a voice spake, saying, 

The New Testament 199
Chapter VII: The Fifth Principle Now the fifth principle says that time intervals and spatial distances shall not be universal concepts but shall depend on the observer. And for example, two observers, moving with respect to one another, will not agree on whether two events occur at the same time! Nor will they agree on an object’s length! But they will agree on the properspacetime interval. And the situation shall be like that unto a triangle – the Pythagorean theorem says that, for a rightangle triangle, the length of the hypotenuse squared is the sum of the squares of the two smaller sides. And if two geometricians start with a common hypotenuse and draw two more sides to make two different rightangle triangles then the lengths of the shorter sides are not equal. But for both of them, the sum of the squares of the two smaller sides is the same. Now the hypotenuse of a righttriangle shall be like unto a properspacetime interval – it is something on which constantmoving viewers can agree. And the two shorter sides shall be like unto the time interval and the distance between two separate events.^{192} Now there shall be a relativistic hyperbolic Pythagorean theorem: The properspacetime interval squared shall be the spatialseparation squared minus the ctimeelapsed squared. And the relativistic hyperbolic Pythagorean theorem says that all constantmoving observers shall agree on the properspacetime interval between two separate events.
____________________
^{191} "Fourd space" is the phrase scientists often use for fourdimensional space. 

200 The Bible According to Einstein
Now since one subtracts ctime squared in the computation of the properspacetime interval, spacetime shall not be Euclidean; Minkowski space is what it shall be called.^{193} And so the fourdimensional manifold of spacetime shall be Minkowski space. Chapter VIII: The Sixth Principle Now the sixth principle says that E=mc^{2}. And because c squared is ninetymillionbillion meterssquared per secondsquared, c squared shall be a very large number. Hence, conversion of a small amount of mass into energy shall produce a lot of energy. And this is why nuclear bombs, which are based on the conversion of mass into energy, shall produce enormous blasts. And man will make "the bomb" And the equivalence of energy and mass will be confusing to children with "Newtonian brains." But by the time such children are adults, they will have heard of Einstein and of E=mc^{2} so many times they will believe it. Chapter IX: Albert, Isaac and a Sacred Creature He who hath an ear, Now is this the parable of Albert, Isaac and a sacred creature. Once not so long ago, Albert was camping with three physics friends, Peter, James and John. And Albert said to them, "Today I shall climb that mountain." And he pointed to the peak. "I want you three to stay here and wait for me. When I come back I shall reveal to you what I have learned. In the meantime, build tents so that we may camp here tonight."
____________________ ^{193} Euclidean spaces are the "worlds" in which Euclidean geometry and the ordinary Pythagorean theorem are valid. In nonEuclidean spaces, theorems such as "the sum of the interior angles of a triangle adds up to 180 degrees" no longer hold. 

The New Testament 201
Now on the mountain Albert spied another man and a sacred creature. And the man was quite old. His name was Isaac. And he had a Newtonian brain. Now the sacred creature had no age, no name and no brain. But it always told the truth, always obeyed instructions and always followed Nature’s laws. 

202 The Bible According to Einstein
"This is a little boring," said Albert. "Let’s speed things up." And so Albert and Isaac put on space suits and helmets. And they got in a rocket and blasted into outer space. And there, Albert asked the creature to drive a spacejet at onehundredandeightythousand kilometers per second. "By Jove," interjected Isaac, "That’s threefifths the speed of light. I’ve never seen an object go that fast." And Albert responded, "These are modern times, old fella. Technology has made great advances lately." And Albert instructed the creature to turn on a light and shine it forward when the spacejet goes by them. And Albert turned to Isaac and asked him, "When we measure the speed of the light, what will it be?" And Isaac said, "Well, the speed of the spacejet will add to the speed of the light. Onehundredandeightythousand plus threehundredthousand is fourhundredandeightythousand. Thus the light will travel at fourhundredandeightythousand kilometers per second for us." "I don’t believe you," Albert said. Annoyed Isaac replied, "Again you doubt the thinking of an experienced one like me?" And Albert said, "Well, let’s make a wager. I’ll bet you a gold coin you’re wrong." And the two men put on special space suits and got out of the spacejet. And each contributed a gold coin. And the two gold coins floated there in outer space. Then the creature fired the spacejet engine and did as he was told. And Albert and Isaac measured the speed of the light and it was threehundredthousand kilometers per second. And Isaac was astounded and upset, "The creature must not have followed your instructions correctly." But Albert replied, "Remember, this is a sacred creature and it never disobeys." And Albert snapped up the two gold coins and put them in his pocket. 

The New Testament 203
"You look a bit upset, Isaac. I’ll give you a chance to win your coins back. Light is very special. The pedantic teachers at my school even called it an electromagnetic wave. Waves behave differently from particles. Let’s repeat the experiment with particles. Here I have an electrongun which shoots electrons at threequarters of the speed of light." "That’s some gun," Isaac interjected. He seemed quite impressed. And Albert continued, "Let’s instead have the creature shoot electrons out the front of the spacejet." And Albert turned and said, "Creature, run the spacejet at threequarters of the speed of light, aim the electron gun forward, and when you pass us pull the trigger." And turning back to Isaac, Albert asked, "How fast will the electrons move?" "Well, the speed of the spacejet will add to the speed of the electrons. Threequarters plus threequarters is oneandahalf. Thus for us, the electrons will travel at oneandahalf times the speed of light or fourhundredandfiftythousand kilometers per second." "Well Isaac, my answer is different from yours. I say they’ll travel at four percent less than the speed of light, just a little less than threehundredthousand kilometers per second." 

204 The Bible According to Einstein
And floating there in outer space were eight gold coins. Now the first stick was placed in the window of the spacejet. And the creature fired the engines and sped by Albert and by Isaac. Isaac had to react quickly. Perhaps his hands shook a bit, but when he lined up the ruler with the stick in the window, the stick in the window was one meter less. And Isaac’s mouth opened with astonishment. And four coins fewer was his purse. 

The New Testament 205
"Let’s perform a simpler experiment. I have an accurate stopwatch here. The sacred creature has no brain but he does have a heart. His heart beats once a second. I bet that if the spacejet goes at onehalf of one percent less than the speed of light, or 0.995c, then his heart will beat about once every ten seconds. So if I’m right, you’ll have lots of time to make the measurement." And Isaac responded, "You talk nonsense. If there were two such creatures then the creature in the spacejet would live ten times longer than a creature sitting with us. But think of things from the point of view of the spacejet. If the creature in the spacejet looks at the creature with us, he thinks the creature in space sitting with us is moving at 0.995c in the opposite direction. Therefore, the creature with us should also live ten times longer. How can both creatures outlive each other by a factor of ten?" Isaac was getting quite worked up. His face was red as he sensed his world was falling all apart. 

206 The Bible According to Einstein
"And what is the last experiment?" asked Isaac sadly, "I have only sixteen gold coins left." And Albert took the coins and answered, "Here are two piles of Uranium235. You will hold one pile in your left hand and one pile in your right hand. Please hold your arms far apart. And you will walk off. And when you are thousands of kilometers away, you will bring your hands together. The divided substance will come together as one. And if you come back, I’ll return to you all your gold coins." And Isaac, who was thoroughly distraught and mentally destroyed, did as he was told. And those who do not believe in Nature’s Laws will be fooled. 

The New Testament 207
Chapter X: The Parable of the NonBelieving Pharaoh Hearken unto these words. And the Pharaoh was told to release the slaves, and if he did not, then his rivers would turn to blood. And the Pharaoh did not believe. And the Pharaoh did not release the slaves. And the rivers turned to blood. And the Pharaoh was told to release the slaves, and if he did not, then frogs would invade his lands. And the Pharaoh did not believe. And the Pharaoh did not release the slaves. And frogs invaded his lands. And the Pharaoh was told to release the slaves, and if he did not, then lice would attack his people. And the Pharaoh did not believe. And he did not release the slaves. And lice attacked his people. And it continued as so. The invasion of flies was followed by the disease of the oxen, horses, asses, camels, sheep and cattle. Then came the outbreak of boils on the skin of the Pharaoh’s people, the rain of hail, and the invasion of the locusts. And still the Pharaoh did not believe. And still the slaves were not released. And there were three days of darkness. And the Pharaoh was told to release the slaves, and if he did not, then the first born of each household in his kingdom would die. And the Pharaoh did not believe. And the Pharaoh did not release the slaves. And the first born of each household suddenly did die. And the Pharaoh’s people cried up in anguish, for their leader had led them astray. And reluctantly, he released the slaves. Finally they were free. And they fled the land of the Pharaoh. But the Pharaoh and his warriors pursued the slaves. And a great sea was divided and made dry so that the slaves could pass. And the slaves crossed the dry divided sea. But when the Pharaoh’s chariots and horsemen entered the divide, the sea was restored. And the horses, chariots and horsemen were engulfed in deep waters and all drowned. And this was the result of one who did not believe. The blind will lead the blind to death. And special relativity will be difficult to comprehend. But one should verily believe, for it is the truth. 

To Thermodynamics  To General Relativity and Gravity 