Fragments of the book, Einstein. His Life and Universe, written by Walter Isaacson.
About Authority
“A foolish faith in authority is the worst enemy of truth”. His early suspicion about authority, which never wholly left him, was to prove of decisive importance. Without it he would not have been able to develop the powerful independence of mind that gave him the courage to challenge established scientific beliefs and thereby revolutionize physics.
About Observation
The essence of Mach’s philosophy was this, in Einstein words: “Concepts have meaning only if we can point to objects to which they refer and to the rules by which they are assigned to these objects”. In other words, for a concept to make sense you need an operational definition of it, one that describes how would observe the concept in the operation. This would bear fruit for Einstein when, a few years later, he and Besso would talk about what observation would give meaning to the apparently simple concept that two events happened “simultaneously”.
About Absolutes
Near the end of Einstein’s first year at the Polytechnic, in the spring of 1897, there was a mathematics conference in Zurich where the great Poincaré was due to speak. At the last minute he was unable to appear, but a paper of his was read there that contained what would become a famous proclamation: “Absolute space, absolute time, even Euclid geometry, are not conditions to be imposed to mechanics”, he wrote.
The most influential thing that Mach did for Einstein was to apply this approach to Newton’s concepts of “absolute time” and “absolute space”. It was impossible to define these concepts, Mach asserted, in terms of observations you could make. Therefore they were meaningless.
About Unifying Concepts
HE had an urge – indeed, a compulsion – to unify concepts from different branches of physics. “It is a glorious feeling to discover the unity of a set of phenomena that seem at first to be completely separate”, he wrote to his friend Grossmann as he embarked that spring on an attempt to tie his work on capillarity to Bolzmann’s theory of gases.
About Established Academia
Originality and creativity were not prime assets for climbing academic ladders, especially in thee German-speaking world, and he would have felt pressure to conform to the prejudices or prevailing wisdom of his patrons. “An academic career in which a person is forced to produce scientific writings in great amounts creates a danger of intellectual superficiality”, he said.
About Special Relativity
Theory of Relativity is a theory of spacetime invariance and was the initial name idea from Einstein (later discarded and finally called Theory of Relativity). See wormhole about Invariance Testing.
The special theory about relativity that Einstein developed in 1905 applies only to a special case (hence the name): a situation in which the observers are moving at a constant velocity relative to one another — uniformly in a straight line at a steady speed – referred to as an inertial reference system.
“Two events which, viewed from a system of coordinates, are simultaneous, can no longer be looked upon as simultaneous events when envisaged from a system which is in motion relative to that system”. In other words, there is no such things as absolute simultaneity,
E = mc^2Energy equals mass times the square of the speed of light. The speed of light, of course, is huge. Squared it is almost inconceivable bigger. That is why a tiny amount of matter, if converted completely into energy, has an enormous punch.
About the Road of Knowledge
“A new idea comes suddenly and in a rather intuitive way”, Einstein once said. “But”, he hastened to add, “intuition is nothing but the outcome of earlier intellectual experience”.
Einstein’s discovery of special relativity involved an intuition based on a decade of intellectual as well as personal experiences. The most important and obvious, I think, was his deep understanding and knowledge of theoretical physics. He was also helped by his ability to visualize thought experiments, which had been encouraged by his education in Arau. Also, there was his grounding in philosophy: from Hume and Mach he had developed a skepticism about things that could not be observed. And this skepticism was enhanced by his innate rebellious tendency to question authority.
“All knowledge of reality starts from experience and ends in it”. But he immediately proceeded to emphasize the role that “pure reason” and logical deductions play. He conceded, without apology, that his success using tensor calculus to come up with the equations of general relativity had converted him to a faith in mathematical approach, one that emphasized the simplicity and elegance of equations more than the role of experience. “Nature is pleased with simplicity”.
About Gravitation
If we imagine that the enclosed elevator is being accelerated upward in a region of outer space where there is no gravity, then the downward force felt by the man inside (or the force that tugs downward an object hanging from the ceiling by a string) is due to inertial mass.
If we imagine that the enclosed elevator is at rest in a gravitational field, then the downward force felt by the man inside (or the force that tugs downward on an object hanging from the ceiling by a string) is due to gravitational mass. But inertial mass always equals gravitational mass. “From this correspondence”, said Einstein, “it follows that it is impossible to discover by experiment whether a given system of coordinates is accelerated, or whether… the observed effects are due to a gravitational field”.
Einstein called this the equivalence principle. “We shall therefore assume the complete physical equivalence of a gravitational field and a corresponding acceleration of reference system”. If his notions were correct, clocks would run more slowly in a more intense gravitational field.
About General Relativity
Einstein’s goal was to find the mathematical equations describing two complementary processes:
- How a gravitational field acts on matter, telling it how to move
- And in turn, how matter generates gravitational fields in space-time, telling it how to curve.
The general laws of nature are to be expressed by equations that hold true for all systems of coordinates, that is they are covariant with respect to any substitutions whatever.
Rμν - 1/2 gμνR = 8πTμνThe left side compresses together all of the information about how the geometry of spacetime is warped and curved by objects (now known as the Einstein tensor). The right side describes the movement of matter in the gravitational field.
“The suggestion of a finite but unbounded space is one of the greatest ideas about the nature of the world which has ever been conceived”, the physicist Max Born has declared.
Einstein accepted that his gravitational field theory implied that empty space has physical qualities. The mechanical behavior of an object hovering in empty space, “depends not only on relative velocities but also on its state of rotation”. And that meant, “space is endowed with physical qualities”.
About a Unified Field Theory
His new passion, finding a unified field theory that would reconcile general relativity with electromagnetic theory and, if possible, with quantum mechanics.
Over the ensuing years, researchers would discover new forces in nature, besides electromagnetism and gravity, and also new particles. These would make Einstein’s attempts at unification all the more complex.
About Moral Views and World Government
Freedom and individualism are necessarily for creativity and imagination to flourish. “I believe that the most important mission of the state is to protect the individual and to make it possible for him to develop into a creative personality”, he said.
“If the idea of the world government is not realistic,” he said in 1948, “then there is only one realistic view of our future: wholesale destruction of man by man”.
“I do not know how the Third World War will be fought,” he answered, “but I can tell you what they will use in the Fourth – rocks”.
Throughout his life, Einstein was consistent in the fundamental premises of his politics. Ever since his student days in Switzerland, he had supported socialist economic policies tempered by a strong instinct for individual freedom, personal autonomy, democratic institutions, and protection of liberties.