Brian Greene
Brian Greene, a Harvard and Oxford graduate and Rhodes Scholar, and professor of physics and math at Cornell and now Columbia University, is widely regarded for a number of discoveries in superstring theory. He has gift for declarative statements that enliven and decipher the arcane subjects of quantum mechanics, Einstein’s (1879-1955) theories of relativity and the incipiently unifying concepts of string theory. In masterfully simple prose, his Elegant Universe (EU), first published in 1999, helps the layman see through layers of esoteric science to principles that scientists now believe underlie the workings of the universe and life itself, and he accomplishes without the use of mathematical equations or too heady physics. It is manifestly more informative and easier to grasp than the shorter Einstein’s Universe by Nigel Calder or the totally incomprehensible Quantum Theory of Fields by Weinburg (2000). EU makes a fine companion to such books as Hawkings’ Brief History of Time, Bryson’s History of Almost Everything, Gould’s Wonderful Life, and Conway-Morris’ Crucible of Creation – the latter-two focusing on the paleontologist’s view of the evolution of life forms on our planet. EU’s abiding purpose is to explain the workings and the implications of the String Theory on space and time. If you have an appetite for atoms, electrons, quarks, neutrinos, muons, taus and other subatomic particles, and the inner workings of gravitational and electromagnetic forces, and the new string theories that may soon unite the disparate positions of quantum mechanics and relativity theories – or if you simply want to secure a better feel for the universe in general — this is the book for you. (You can always speed-read any too esoteric data.) It’s worth the effort.
EU’s complex tapestry describes Newton’s laws of gravity, which explains why our solar system and galaxy look so ordered. Greene then leaps into Einstein’s “Special Theory of Relativity” as unveiled in 1905 (STR), which shows that space and time are malleable constructs whose form and appearance depend upon one’s state of motion; that is, time passes differently and distance varies depending upon the position and speed at which the observer is traveling. In Einstein’s General Theory of Relativity as published in 1915 (GTOR) predicted an ever-expanding universe (open) but Einstein didn’t accept that and adopted, for a time, his “cosmological constant” (or flat universe). In the ensuing 100 years since Einstein shook the world with these papers, scientists have expanded upon Einstein’s theories and validated them. Hubble and others later established that the universe is expanding and space with it. (The universe and its 100 billion galaxies likely began the size of a grain of sand or a “point” some 15 billion years ago (BYA). GTOR shows, among many things, that gravity bends both space and time and that space and time warp and curve in response to matter or energy and that matter is a form of energy (E=MC squared — energy = mass times the speed of light squared) and that gravity is the natural result of the bending of space and time (“spacetime”) and that masses change the shape of spacetime. Spacetime has four dimensions: height, width, depth and time. Under String Theory (ST), there are many more dimensions. Time is eternal. “All moments [past, present and future] already exist in the fullness of time and are fixed forever.” We only see/experience the present, as that is our viewpoint at any given point in time. Matter changes its form, but its elements remain, eternally. Rebirth is the law of the universe, but the atoms of things past will likely reappear in very different forms. Similarly, energy can not be created or destroyed; everything is made of energy, which comes in specific packets or quantities (quantums); atoms are quanta.
GTOR, however, conflicts with quantum mechanics (i.e., where the actions of atoms are observed under massive microscopes), and this conflict has been called the central problem of modern physics. The String Theory (ST) many scientists believe offers a resolution; ST asserts that there are more than three dimensions. The Greeks presciently guessed that atoms were the smallest component of matter – atom, in Greek, means indivisible — a belief that held until atoms were seen to be comprised of electrons, protons and neutrons; now scientists believe that matter is comprised of five things: electrons, up quarks and down quarks, neutrinos and muons (heavy electrons). Scientists seem to be discovering more and more subatomic particles by slamming bits of matter together at enormous speeds. Each particle has an “antiparticle” (a particle with identical mass but with the opposite electrical charge). There are now held to be four fundamental forces: gravitational, electromagnetic, strong and weak force. Mass determines an objects amount of gravitational force (E=mc squared), which formula tells us that energy can be converted into mass and vice versa and reveals the malleability of mass (matter), energy and motion.
Electromagnet force drives lights, computers, TV’s, phones, lightening and the soft touch of a human hand. The electric charge of a particle plays the same role for electromagnetic force as does mass for gravity. An electromagnetic ray gun fires a stream of photons (light particles). Light itself is an electromagnetic wave. Electromagnetic force is 10 to the 12th power times stronger than gravitational force. That is, to 10 to the 12th power, which means that, if your left bicep represents gravitational force and your right bicep represented electromagnetic force, the right would need to extend to the edge of the universe. So, what maintains the balance between these two disparate forces? The antiparticles within each do so; thus, being “anti” isn’t always bad.
String Theory (ST) maintains that all particles of matter (atoms, electrons, quarks and their derivatives) are actually tiny, super thin “loops” of string. Strings, rather than atoms, become the smallest component of matter. Like a piano string, the dominant physical characteristic of all matter is an infinite pattern of vibrations called “resonances” which make music of a sort, from its endless loops by the “notes” that its strings “play”. ST is said to be the Theory of Everything (TOE). Each “string” (or loop of string) is 100 billion billion times smaller than an atom (10 to the 20th power). (500 million atoms can hide behind a single human hair; so, imagine the miniscule size of a “string”.) This miniscule size is sometimes called “Planck’s Length”, named after the scientist who first measured it.
The speed that objects move is relative to the speed and position of other objects around them. This is the essence of relativity. Light is the exception. No matter what we or other objects do, the speed of light is always 186Kmps or 670Mmph (SoL). This fact spelled the downfall of Newtonian physics.
Motion affects the passage of time. There is no passage of time at the SoL. If the clock is moving and we aren’t, the clock ticks more slowly (to cover the added distance it must travel between ticks). The faster we go, the slower our clock ticks. Moving clocks record time at different rates. The faster a clock or we move, the more slowly it and we record time. Time passes more slowly for anything in motion. If we traveled at 99.5% the speed of light (SoL), we would live 10 x as long, but everything that we did would take 10 x as long; we would live in slow motion. Motion has an equally dramatic effect on space. Accelerated motion warps both space and time. Einstein showed the space-warping through various experiments; e.g., using three circles on flat, round and curved surfaces (simulating the changes that motion effects); even though the radii of all circles were identical, the circumferences were different in each. The author’s diagrams make this evident.
Objects also have effects on space. Space is not a passive arena. It responds to the objects within it. Objects, by their presence alone, bend or warp space; the larger object warps it more and thus pulls on the smaller objects around it. Thus, mass tells space how much to curve; space tells mass how much it can move.
Einstein concluded, “Gravity is the warping of space and time.” The greater the gravitational pull, the slower the clock runs; so, gravity distorts time as well as space. Thus, Newton explained gravity’s effects on us and on the universe, while Einstein explained how gravity works.
Quantum mechanics (QM) studies the microscopic properties of the universe and has been called “the physics of our universe”. In QR, the objects (electrons) defy logic and seem to travel “infinite paths” or the “sum-of-paths” as one physicist (Feynman) called it. QM describes Nature as She is: absurd. When viewed in smaller and smaller scales, the universe is a frenetic place. In quantum field theory, a particle and its antiparticle can collide and momentarily annihilate one another, producing a photon. Subsequently, a photo can give rise to another particle and antiparticle traveling along different trajectories.
The brilliant Greene continues ad infinitum, and despite his gift for lucid layman-driven explanations, at last, he leaves most readers in a series of explanations and drawings that demand some training in geometry, physics and mathematics. Still, on balance, the layman can grasp the fundamentals and ascertain a much better understanding of the universe, the way that it was born (the Big Bang about 15 BYA), its ongoing expansion, the hundreds of billions of galaxies, each containing billions of stars and countless black holes, the emergence of our solar system about 5BYA likely via a supernova (an exploding star), and the fact that, barring a mathematically perfect balance, someday the momentum of the expansion could reverse, returning the entire universe into a massive black hole that leads to a Big Crunch, wherein all matter is reduced to “the point” or posture of it preceding the Big Bang. Some speculate that there may be multiple universes; others maintain that black holes themselves may be the source of future universes. The “Theory of Everything” remains undiscovered, but the knowledge obtained, since Einstein showed the way almost 100 years ago, has been astonishing.
All of this, of course, is mind boggling to wee mortals. The subject of a Creator is never mentioned. Believers, of course, will see a Creator causing all of this, begging the question of the source of the Creator. Most scientists attribute it to Mother Nature, but, either way, its complexity, infinite rhythms, the “music” of resonating “strings”, comprise an “Elegant Universe” in the author’s words. Due to the violent upheavals at every level, especially in the world of quantum mechanics, I might liken it more to an Elegant Symphony, albeit one with cacophonic as well as harmonic sounds. No matter, because Brian Greene is brilliant physicist and, among scientists, a marvelous and lucid writer. For those with a quest for knowledge of what makes the universe work, this book is another “Must Read”.