69 pages • 2 hours read
Brian GreeneThe Elegant Universe: Superstrings, Hidden Dimensions, and the Quest for the Ultimate Theory
Nonfiction | Book | Adult | Published in 1999A modern alternative to SparkNotes and CliffsNotes, SuperSummary offers high-quality Study Guides with detailed chapter summaries and analysis of major themes, characters, and more.
Preface-Part 1Chapter Summaries & Analyses
Part 1: “The Edge of Knowledge”
Preface Summary
For decades, physicists have searched for a unifying theory that would encompass all the laws of physics in one coherent explanation of the workings of the universe. Albert Einstein spent the last years of his life searching without success. Now, theoretical physicist Brian Greene and other scientists propose one seamless theory capable of describing all of physics: superstring theory.
In The Elegant Universe, Greene argues that superstring, or string, theory is the answer and attempts to make this esoteric realm of theoretical physics more accessible to a general audience. As a public lecturer, he observes that the public “yearn[s] to understand what current research says about the fundamental laws of the universe” (x). He offers an overview of physics, from the Newtonian laws of motion through quantum mechanics, to show how those discoveries paved the way for current work in string theory.
Greene notes his hope that The Elegant Universe will interest those who have scientific backgrounds as well as a more general readership. He also hopes that his book gives an “honest and balanced sense of why string theorists are so enthusiastic about the progress being made in the search for the ultimate theory of nature” (x). Despite the complex subject, Greene avoids “technical language and equations” (xv) as often as possible. However, he forewarns readers that the concepts he explores are abstract, explaining that even physicists have difficulty with these concepts.
Part 1, Chapter 1 Summary: “Tied Up with String”
Greene opens with the central problem of modern physics: the two primary theories “underlying the tremendous progress of physics during the last hundred years” are actually “mutually incompatible” (3). These two incompatible theories are general relativity, discovered by Einstein, and quantum mechanics, founded on principles proposed by Max Planck. However, Greene states that this clash is not the first but third conflict in physics in the last 100 years.
The first conflict, which arose in the late 1800s, concerned the “puzzling properties of the motion of light” (5). Isaac Newton proposed in his laws of motion that, given enough speed, one could catch up to a moving beam of light. However, James Clerk Maxwell’s laws of electromagnetism disagreed. This first conflict was resolved by Einstein’s theory of special relativity in 1905. This development led to the second conflict in physics. According to special relativity, no object (or influence) can travel faster than light; however, Newton’s long-accepted theory of gravitation requires the transmission of gravitation forces over enormous distances of space instantaneously. Einstein resolved this second conflict via his theory of general relativity in 1915.
However, this theory led to the third (and current) conflict. As Einstein was developing relativity theory, another group of physicists was working on quantum mechanics theory. While general relativity works perfectly for large masses and large distances, and quantum mechanics works for miniscule masses (subatomic particles) and small distances, certain scenarios in which exceptionally large masses are compressed into tiny distances (such as black holes or the moment of the big bang) require the use of both theories. When combined, the incompatibility of these two theories causes the math to fail.
Greene proposes that string theory resolves this conflict. To explain, he first outlines the basics of particle physics. Scientists long believed that the atom was the smallest “uncuttable bit” (7) that makes up the universe. However, by the 1930s science had proven that the atom was not the smallest unit because it can be divided into even smaller pieces like protons, neutrons, and electrons. These can be divided into still smaller particles such as quarks, neutrinos, muons, and taus, each of which has a different mass and charge. Additionally, scientists found other particles that they named the muon-neutrino and tau-neutrino, as well as antiparticles for each that possess the same mass but the opposite charge of their partner. Physicists recognized patterns among these particles and placed them into three families, each containing two quarks, an electron or “cousin” (muon or tau), and the corresponding neutrino. While these three families have proven helpful in understanding the patterns and similarities between particles, physicists continue to wonder why: for example, why so many different particles exist, why there are three families, and why these patterns exist?
In addition to the three families, four forces are at work in physics: the gravitational, electromagnetic, weak, and strong forces. Gravity is the most recognizable, as it is the force of attraction between objects with mass and is what keeps one’s feet firmly on the ground. Electromagnetism is the force responsible for electricity, magnetism, and light. The weak force is “best known as the force responsible for the radioactive decay of substances such as uranium and cobalt” (11), while the strong force is what keeps various particles “glued” together, such as quarks inside protons and neutrons, and protons and neutrons inside an atom’s nucleus. These facts again led physicists to ask why, or as Greene ponders, “the universe is the way it is because the matter and force particles have the properties they do. But is there a scientific explanation for why they have those properties?” (13).
According to Greene, string theory answers these questions. Theorists propose that if one could look at these particles with far greater precision than current technology allows, one would see that each particle is not a zero-dimensional point but a one-dimensional loop of string that vibrates at specific frequencies. These vibrating loops make up every bit of the universe, and their vibrations dictate every feature, such as mass, charge, and force. For this reason, “string theory is sometimes described as possibly being the ‘theory of everything’” (16) that physicists have been in search of for decades.
Preface-Part 1 Analysis
The Preface opens by mentioning the most recognizable name in physics, for both scientists and general readers: Albert Einstein. By invoking Einstein at the outset, Greene instantly connects those who do not have scientific backgrounds to a familiar name and idea, bridging the gap into unfamiliar (and often confusing) territory. By opening with Einstein’s unsuccessful search, in his final year, for a unifying theory of physics, Greene introduces the central goal of physics (and his book) and positions string theory as the answer to Einstein’s search. This central problem of physics (and its answer) becomes the organizing principle around which all the following chapters pivot, even when Greene strays from string theory for portions of the book. To understand the central problem, and why Greene (and other string theorists) believe that string theory holds the key to resolving it, Greene first examines fundamental accepted science in modern physics. To this end, Chapter 1 explains the basics of particle physics—the three families and the four forces—and offers a brief overview of the major conflicts within physics that have so far prevented physicists from devising a unifying theory. The third and most recent conflict, between general relativity and quantum mechanics, constitutes the major problem that string theory resolves. Although Greene introduces this idea in Chapter 1, he addresses it in more detail in Part 2.
In addition, the Preface and Part 1 set up two of the three major themes of the work. The first and most prevalent theme is the drive for The Unification of Physics, which the very first paragraph of Part 1 introduces, thus highlighting this as a vital aspect of the book. As Greene states, Einstein became obsessed with the idea that a unifying theory must exist that is “capable of describing nature’s forces within a single, all-encompassing, coherent framework” (ix). He believed that if scientists could reach their deepest understanding, they would find that the entire universe could be encapsulated within a single simple principle that covered all aspects of space and time. The physicists who came after him continued this relentless pursuit.
The second major theme is The Human Need to Understand, best represented by the question “why?” that echoes throughout the book. It repeats many times in the first chapter alone, as when Greene asks why particles of matter should be organized into three families, or why the four forces have such vastly different strengths. This need to understand underlies Greene’s inspiration for writing The Elegant Universe for a general audience. As he states in the Preface, over the course of his career he has seen “a widespread yearning to understand” (x), not only from scientists but from the public as a whole. The question “why?” and the deep, unending need to understand every aspect of experience are the driving force of many of the discoveries and revelations discussed in the book (and throughout all of science).
