📖 Summary & Notes

• What science teaches us, very significantly, is the correlation between factual evidence and general theories, something well illustrated in Einstein’s life.

• An appreciation for the glories of science is a joyful trait for a good society. It helps us remain in touch with that childlike capacity for wonder, about such ordinary things as falling apples and elevators.

• A society’s competitive advantage will come not from how well its schools teach the multiplication and periodic tables, but from how well they stimulate imagination and creativity.

• Einstein’s success came from questioning conventional wisdom, challenging authority, and marveling at mysteries that struck others as mundane. This led him to embrace a morality and politics based on respect for free minds, free spirits, and free individuals.

• He had a slow development combined with a cheeky rebelliousness toward authority.

• The young Einstein’s ability to systemize was far greater than his ability to empathize, which has led some to ask if he might have exhibited mild symptoms of some developmental disorder.

• Field theories use mathematical quantities, such as numbers or vectors or tensors, to describe how the conditions at any point in space will affect matter or another field.

• Einstein never failed mathematics in high school and was actually at the top of his class.

• He was a supporter of world federalism, internationalism, pacifism, and democratic socialism, with a strong devotion to individual liberty and freedom of expression.

• The second law of thermodynamics says that heat flows naturally from hot to cold, but not the reverse. Another way to describe it is in terms of entropy, the degree of disorder and randomness in a system. Any spontaneous process tends to increase the entropy of a system.

• The English experimenter Michael Faraday (1791-1867) discovered the properties of electrical and magnetic fields. He showed that an electric current produced magnetism, and then he showed that a changing magnetic field could produce and electric current. When a magnet is moved near a wire loop, or vice versa, and electric current is produced.

• A strength of Einstein’s mind was that it could juggle a variety of ideas simultaneously. Even as he was pondering dancing particles in a liquid, he had been wrestling with a different theory that involved moving bodies and the speed of light.

• Relativity is a simple concept. It asserts that the fundamental laws of physics are the same whatever your state of motion.

• It took Einstein more than a decade to come up with what he called a general theory of relativity, which incorporated accelerated motion into a theory of gravity and attempted to apply the concept of relativity to it.

• A person “at rest” in an armchair is actually spinning with the earth’s rotation at 1,040 miles per hour and orbiting with the earth around the sun at 67,000 miles per hour.

• Sound waves and water waves are easily explained by classical mechanics. They are simply a traveling disturbance in some medium. That is why sound cannot travel through a vacuum. But it can travel through such things as air or water or metal.

• There is no absolute time. Instead, all moving reference frames have their own relative time.

• As an object approaches the speed of light, its apparent mass also increases.

• The theory of relativity means that measurements of time, including duration and simultaneity, can be relative, depending on the motion of the observer. So can the measurements of space, such as distance and length.

• Energy equals mass times the square of the speed of light. The speed of light is huge. Squared it is almost inconceivably bigger. That is why a tiny amount of matter if converted completely into energy, has an enormous punch.

• Clocks run more slowly in a more intense gravitational field. Gravity can also bend light.

• Einstein tended to avoid painful personal emotions by immersing himself in his work.

• After Einstein formulated his special theory of relativity in 1905, he realized that it was incomplete in at least two ways. First, it held that no physical interaction can propagate faster than the speed of light; that conflicted with Newton’s theory of gravity, which conceived of gravity as a force that acted instantly between distinct objects. Second, it applied only to constant-velocity motion.

• A person in a closed windowless chamber who feels his feet pressed to the floor will not be able to tell whether it’s because the camber is in outer space being accelerated upward or because it is at rest in a gravitational field.

• Gravity was thought to be a force that masses exerted on one another rather mysteriously across empty space.

• With his special theory of relativity, Einstein had shown that space and time did not have independent existences but instead formed a fabric of spacetime.

• Just as the fabric of a trampoline will curve and ripple as a bowling ball and some billiard balls roll across it, and in turn the dynamic curving and rippling of the trampoline fabric will determine the path of the rolling balls and cause the billiard balls to move toward the bowling ball.

• If all the mass of a star were compressed into a tiny enough space, then at the center, spacetime would infinitely curve in on itself. Nothing would be able to escape the gravitational pull. Time would also be dilated to zero. In other words, a traveler nearing the Schwarzschild radius would appear, to someone on the outside, to freeze to a halt.

• Black holes have been discovered all over the universe, including one at the center of our galaxy that is a few million times more massive than our sun.

• Einstein stepped into his role as an icon and a genius. He performed, playing to the crowd, and enjoyed public acclaim. He gave interviews readily and knew exactly what made for a good story.

• Einstein never won a Nobel for his work on relativity and gravitation nor for anything other than the photoelectric effect.

• He resisted quantum mechanics because it abandoned strict causality and instead defined reality in terms of indeterminacy, uncertainty, and probability.

• Einstein did not believe in a person God who interacted with man. But believed that a divine design was reflected in the elegant laws that govern the way the universe works.

• Einstein was asked if he believed in God, and his response was, “I’m not an atheist. The problem involved is too vast for our limited minds. We are in the position of a little child entering a huge library filled with books in many languages. The child knows someone must have written those books. It does not know how. It does not understand the languages in which they are written. The child dimly suspects a mysterious order in the arrangement of the books but doesn’t know what it is. That, it seems to me, is the attitude of even the most intelligent human being toward God. We see the universe marvelously arranged and obeying certain laws but only dimly understand these laws.”

• Science without religion is lame, religion without science is blind.

• The term entanglement is used to describe the correlations that exist between two particles that have interacted but are now distant from each other.

• In the quantum realm, there is no definite location of a particle, such as an electron, at any given moment. Instead, a mathematical function, known as a wave function, describes the probability of finding the particle in some particular place.

• Quantum mechanics asserts that particles do not have a definite state except when observed, and two particles can be in an entangled state so that the observation of one determines a property of the other instantly. As soon as any observation is made, the system goes into a fixed state.

• The world has seen a lot of impudent geniuses. What made Einstein special was that his mind and soul were tempered by humility.