Chapter One

Newton’s Dilemma

Gravity

Let us travel back in time to that semi-apocryphal story of Sir Isaac Newton under the apple tree.  The apple falls and bops him on the head.  Eureka!  Newton suddenly grasps that what makes the apple fall is the same force that makes the moon orbit the earth.  The modern theory of gravity is born.

In short time, armed with his newly invented mathematics later to be named “calculus” it becomes possible to predict the motions of all heavenly bodies as well as all projectiles hurled on earth. Prediction is not the same as understanding, however. 

On the subject of what actually causes the force of gravity, Newton had only this to say. “I have not yet been able to discover the cause of these properties of gravity from phenomena and I feign no hypotheses… It is enough that gravity does really exist and acts according to the laws I have explained, and that it abundantly serves to account for all the motions of celestial bodies.”

Albert Einstein changed our view of gravity as a “force” to a warping of space time.   The classic two dimensional metaphor used to describe this four dimensional effect is that of a bowling ball placed in the center of a trampoline.  If one tries to roll a golf ball past it, the golf ball will instead circle around it until it slows enough to spiral down.

As for why matter/energy curves spacetime, that’s just considered a fundamental law, and like all fundamental laws it doesn’t have any explanation.

Inertia

Aside from the gravity that kept the moon from flying away from the earth, there was also another force that kept it from falling and crashing into it.  That force is commonly known as “centrifugal force” and is one of the first forces a child learns about when he twirls a toy on a string around his head.  The faster he twirls it, the higher it rises until it is parallel to his hand.  Further speed increases the force exerted on his hand until either the string breaks or his hand gives out.

What causes this centrifugal force?   

Actually it is the force of inertia, also known as Newton’s First Law of Motion. This law, expressed simply, says that an object that is not subject to any net external force moves at a constant velocity. In even simpler terms, inertia means that an object will always continue moving at its current speed and in its current direction until some force causes its speed or direction to change.

In the case of centrifugal force that “changing” force can be the string tied to the toy or the force of gravity attracting the moon to the earth.  The faster an object is moving, the more force is required to deflect it from continuing in its current direction.  Therefore the faster the object spins, the harder it is for the child to hang on to it.

There is no single accepted theory that explains the source of Inertia. Various efforts by notable physicists such as Ernst Mach and Albert Einstein have all run into significant criticisms from more recent theorists. The source of Einstein’s inspiration for his theory of General Relativity, (Newton’s apple so to speak)  which  produced Einstein’s “Eureka!” was his realization that the force of acceleration against inertia was completely equivalent in its effects to the force of gravity.  This became known as the “equivalence principle,” and it was on the basis of this that Einstein was able to understand that gravity was not a force but rather a result. 

Just as the pressure one feels when one floors a sports car is not a force but a result of acceleration, so gravity is not a force but a result of the curvature of spacetime.

The dilemma

From Brian Greene’s Fabric of the Cosmos:

It’s not often that a bucket of water is the central character in a three hundred- year-long debate. But a bucket that belonged to Sir Isaac Newton is no ordinary bucket, and a little experiment he described in 1689 has deeply influenced some of the world’s greatest physicists ever since. The experiment is this: Take a bucket filled with water, hang it by a rope, twist the rope tightly so that it’s ready to unwind, and let it go. At first, the bucket starts to spin but the water inside remains fairly stationary; the surface of the stationary water stays nice and flat. As the bucket picks up speed, little by little its motion is communicated to the water by friction, and the water starts to spin too. As it does, the water’s surface takes on a concave shape, higher at the rim and lower in the center…

That’s the experiment – not quite something that gets the heart racing. But a little thought will show that this bucket of spinning water is extremely puzzling. And coming to grips with it, as we have not yet done in over three centuries, ranks among the most important steps toward grasping the structure of the universe.

So what’s so strange about the bucket?  Doesn’t centrifugal force explain it the same as the spinning toy?

Unfortunately, it doesn’t.  When the child spins his toy, he spins it relative to himself.  We can then say that the toy spins relative to the child… But does it spin relative to say, the sun?

This was what concerned Newton about the bucket.  Relative to what is the water spinning that causes it to become concave?  What is the meaning of “spin” unless it is relative to something else?

It can’t be relative to the bucket that it spins.  It only reaches its maximum concavity when it is rotating at the same speed as the bucket.  Yet, if we suddenly stop the bucket from rotating, the water will maintain its concave surface as it continues to spin inside the stationary bucket.  It only becomes completely flat again when it again achieves the same speed as the bucket, e.i. motionless.

Newton’s solution

Newton explained that the water inside the bucket was spinning relative to “absolute space.”   Newton believed that all phenomena in the universe took place against a constant background – identical everywhere – of absolute space and absolute time.

Think of it as a presidium stage upon which the drama of the universe is acted out.  It is relative to this presidium that the water is spinning and thereby acquiring its concave shape.

While Newton believed strongly in his theory of “absolute space,” he indicated discomfort with having to rely on a idea for which there was absolutely no way to test if it actually existed.  Furthermore, it challenged his 3^rd law of motion that for every action there is an equal and opposite reaction.  What was the effect of the spinning bucket on space?  Finally, and most difficultly, why should constant motion through absolute space cause no effect while accelerated motion did?

Newton’s answer, though challenged by Ernst Mack, essentially stood for two centuries until the young patent clerk in Bern, Switzerland removed forever our ability to believe in either absolute space or absolute time.

Relativity

A story is told about the great American philosopher and psychologist William James.  One day while taking a walk through the park with a number of his colleagues they came upon a squirrel that quickly scampered onto the trunk of a great Oak tree.  One of James’ friends wanted to get a closer look at it and approached the tree. 

As is the nature of squirrels, the little creature immediately scurried to the other side of the Oak for protection.  As his friend circled the tree to try to see the rodent, the squirrel carefully maneuvered around the tree so as to always be on the far side of the Oak from the threatening human.

As they continued their walk, James raised the question, “Did you manage to go around the squirrel?”

A simple question with no simple answer.  Think about it.  From the point of view of his friend, he had definitely circled around the squirrel.  After all, the creature never left the tree trunk and his friend had circled the tree.  QED, no?

Not so fast!  The squirrel would be well within his right to claim that the intruding human never went around him at all.  After all, his own maneuvering had made sure that the man never got in back of him.  If he never was in back of him, how could he claim that he had gone around him?

This little story does more than illustrate how deep thinking our greatest American philosopher was.  It illustrates beautifully the meaning of relativity.  How it is that two objects in different locations and motions can define reality in completely different ways.

Einstein’s special theory of relativity turned our universe into squirrels, Oaks and friends.  Depending upon which one you were, your experience of reality would differ.  Not only that, but as with James’ squirrel, each experience of reality was equally as valid, i.e. as “true” as were the other experiences, even though they appeared to contradict one another.

Einstein’s special relativity destroyed forever the comforting presidium stage that Newton had constructed.  From now on, both space and time would be malleable and adjust themselves to the relative speed of the object from which the observation was being made. 

The classical seeming paradox that resulted became known as the Twins Paradox.  Assuming one of two twins got on a super fast rocket that took him at near the speed of light to Pluto and back, upon his return he would still be a young astronaut while his twin brother would be an ancient geezer.  Not only that, but the distance the astronaut would have travelled would have been far shorter than the distance his aging brother would had watched him traverse.

 Most people think that relativity theory implies that everything in the universe is relative.  This is untrue.  In fact, for this reason Einstein himself never liked calling his theory “relativity.”  He wanted to call it the “theory of invariance”.  What remains identical for all observers regardless of their relative motions was the speed of light and their motion through the four dimensional “spacetime” that Einstein introduced in his theory.

So, given the new reality of relativity, relative to what is the water in Newton’s bucket spinning?  Furthermore, why should constant motion create no effect while accelerated motion did?

Ernst Mach

At the end of the 19^th century, the great physicist Ernst Mach, (after whom is named the speed of sound i.e. The Concorde flew at Mach 2) took up the question of Newton’s bucket and created a theory to explain it that did not rely on Newton’s presidium “absolute space.”

Mach theorized that in a completely empty universe, the water in the bucket would remain flat when spun.  Building on the great German philosopher Gottfried Wilhelm von Leibniz, a contemporary of Newton’s, he believed in a relationist view of space.  According to Leibniz, space had no meaning beyond providing the natural language for discussing the relationship between one object’s location and another.

For example, if the only thing contained in all of space was a single ball, is there any meaning to the notion of the ball having motion?  How would one possibly measure it?

In much the same way, a spinning bucket in an empty universe cannot be said to be spinning either.  According to Mach, such a bucket’s water would remain flat if spun.

How then could Mach explain Newton’s bucket?  He explained it by claiming that since the universe was not empty in the least, the bucket could be viewed as spinning relative to all the mass contained in the universe including all the stars and galaxies no matter how distant they may be.  The sum of the effect of all the gravity created by all the matter in the universe could be the “force” that caused the water to become concave when rotated relative to it.

Einstein was intrigued and attracted to Mach’s theory at first and tried hard to fit it into his general theory of relativity as he developed it.  Ultimately however, Einstein realized that the bucket could be said to spin and would cause the water to become concave even in an otherwise utterly empty universe.  According to relativity or the theory of invariance, the buckets spins relative to an absolute “spacetime” of which the entire universe in constructed.

While this answers the question of what the bucket is spinning relative to, it leaves unanswered what the force is that acts upon the water to make it concave.  In empty space there’s no gravity to act on it.  Why then should it be affected by spinning even relative to spacetime?

The Mass of Nows

The Mass of Nows theory answers this question as well as just about every other “open” question that remains today in the New Physics which incorporates the theories of relativity and quantum mechanics.  Along the way it also eliminates the seeming conflict between the theory of General Relativity and Quantum Mechanics while providing the first explanation for quantum “weirdness” that is actually accessible to common sense as well as to the complex mathematics from which quantum theory is built.

The central question it answers is why accelerated motion is different from constant motion. The most modern theory of the source of mass, the “Higgs” field still leaves this question unanswered.

This book will explain the theory in straight forward language that any non-scientist reader should be able to understand even if the reader was formerly unfamiliar with the ideas about which it speaks. 

In order to grasp the concepts involved, it is necessary for me to review the history of how we arrived at our modern conceptions of space-time and quantum physics.  For many of my readers this may be an unnecessary review, and I invite them to skip directly to the chapter entitled The Mass of Nows.  For most people, even those like myself well versed in the two fields, the review provided will bring into sharp focus the issues that all need to be kept in mind at once in order to appreciate this new theory.

While it’s a mind bending journey to a certain extent, it’s also an E-ticket ride at the end of which the reader will hopefully emerge with a new sense of confidence that he/she has a handle on the wondrous ways that the universe employs itself, and furthermore, how there’s simply no other way it could exist.