Perceptions of Reality: Transformations of Thought About the Nature of the Universe
~ Reggie Bain, Class of 2012, Physics and Mathematics
Throughout history, revolutionary ideas in physics have molded and shaped our perception of the world around us. Great scientific minds such as Galileo Galilee, Isaac Newton, James Clerk Maxwell, and Albert Einstein each made discoveries that transformed humanity’s vision of the nature of the universe. Today, physicists continue the search for a deeper understanding of the physical world. Building upon the monumental discoveries of the aforementioned scientific pioneers, physicists strive to better grasp the underlying workings of nature. With radical new ideas like extra dimensions of space and Superstring theory, we may soon experience a new and exciting scientific revolution in which our view of the universe at the most fundamental level may be completely overturned.
Born in 1564 in Pisa, Italy, Galileo Galilee is often regarded as the father of modern science. Galileo discovered Jupiter’s four largest moons, developed mathematical laws of motion and perhaps most importantly, observed the complete motion of the planet Venus (its orbital “phases”) around the sun. This helped to solidify Nicolas Copernicus’ theory that the Earth revolves around the sun, which represented a huge transformation in thought about the nature of the solar system. The Earth was now just a single player in a larger field of numerous planetary bodies orbiting the sun, rather than the center of everything. His ideas about the Earth’s place in the cosmos were in fact so radical at the time that Galileo was put under house arrest for the last 9 years of his life.[1]
Isaac Newton is perhaps the most influential individual in the history of physics. With the publication of his Philosophiæ Naturalis Principia Mathematica Newton invented a quantitative way of studying the motion of objects that changed the fields of physics and mathematics forever. He used his “Calculus” to devise mathematical rules for moving objects on earth and in space. Supposedly inspired by the falling of apples, Newton’s laws of gravitation were also quite profound. They declared that the same inherent force of nature that caused apples to fall to the ground was also responsible for the motion of the planets around the sun. Newton thus, in a sense, unified the laws governing motion on earth and in the heavens with one physical theory that explained both accurately.
Scottish physicist James Clerk Maxwell also theorized a unification of physical forces. Whereas Newton unified the laws governing motion on earth and in space with his theory of gravity, Maxwell stitched together the forces of electricity and magnetism into one simple and elegant framework called the “electromagnetic” force. With just 4 equations, Maxwell successfully devised a method for describing all of the seemingly very different phenomena of electricity and magnetism. Ultimately, this brilliant theory allowed for a plethora of electromagnetic inventions that we use today. Radio, television, computers, and telephones, are just a few items that utilize the electromagnetic force. Perhaps an even more profound consequence of Maxwell’s theory however, is how it changed our view of the world. Physicists now saw a deeper symmetry to the forces of nature than had ever before been understood. Physics could now describe phenomena such as light as a type of electromagnetic wave. Maxwell’s theory was in fact so groundbreaking and comprehensive that many physicists of the era believed that there was little left to discover in field of theoretical physics.
The next major revolution of thought in physics came in 1905 with the publication of Albert Einstein’s “Special Theory of Relativity.” A third class clerk in the Swiss patent office, Einstein’s brilliantly imaginative idea completely transformed our understanding of space and time. Perhaps Einstein’s most profound realization was the constancy of the speed of light. He theorized that no matter how fast or in what direction you are traveling, light will always move past you at the same speed. Upon realizing this fact, he was able to devise ideas about the universe that had never before been considered. Einstein claimed that as one approaches the speed of light (which he considered a cosmic speed limit) the “classical” laws of physics break down resulting in bizarre effects. Consider the following: two identical twins conduct an experiment where one remains on earth and the other travels in a spaceship at close to the speed of light to the other side of the galaxy, and back again. Einstein’s Special Theory of Relativity says that the traveling twin will return younger than the earthbound twin![2] As crazy as this may sound, it can be experimentally proved using atomic clocks sent into orbit around the earth. Ten years later, in 1915, Einstein proposed his “General Theory of Relativity.” Yet another work of pure genius, the theory proposed that gravity propagates through space at exactly the speed of light! It also said that gravity is actually warps and curves in a fabric of interwoven space and time. Thus, our orbit around the sun can be seen as the Earth simply following the grooves in space-time caused by the sun’s large mass.[3]
After Einstein there came the “Quantum Revolution” in physics. Neils Bohr, Werner Heinsenberg, Max Plank, and Paul Dirac are just a few of the great minds that led this expedition into the subatomic realm. What they uncovered was a reality in which the laws of physics are no longer definite; a world governed not by strict physical principals like but by chance. In this world gravity seemed to play no role and two additional physical forces (the first two being gravity and electromagnetism), called the Strong and Weak nuclear forces dominated. The Strong force is responsible for bonding together atomic nuclei as well as particles like protons (which consist of three smaller particles called quarks) and the Weak force is what causes radioactive decay. Heisenberg’s “Uncertainty Principal” further distanced the new laws of the microscopic realm from that of ordinary objects. The principal basically states that you can’t know exactly the position and velocity of a particle and the more you know about one, the less you can know about the other. This idea of the world of the small being unpredictable was such a paradigm shift in thought that even Albert Einstein refused to accept it as a reliable physical theory.[4] However, since its conception in the mid 20th century, “Quantum Mechanics” has grown to be universally accepted as the method by which to study the most elementary constituents of matter.
Today, physics is once again entering an extremely transformative era. Later this year, the European Center for Nuclear Research (CERN) in Switzerland plans to power up the Large Hadron Collider (LHC), the most powerful particle accelerator ever built. The LHC will put to the test a number of recent breakthroughs in theoretical physics. New experiments such as ATLAS (A Toroidal LHC ApparatuS) and CMS (Compact Muon Solenoid) at CERN will adamantly search for answers to both new and age-old questions in physics. One such quest is for a theorized elementary particle called the “Higgs” boson. This particle, named for British physicist Peter Higgs, is thought to be responsible for giving mass to the elementary constituents of matter. Another search is for extra dimensions of space beyond the three that we are familiar with. A third is called “Supersymmetry” which calls for the existence of “sparticles,” (Supersymmetric-particles) which are heavier partners of all of the particles currently known. Just as for every matter particle there is an anti-matter anti-particle, in Supersymmetry, every matter particle (such as the electron) has a force carrying sparticle partner and every force carrier particle (such as the photon) has a matter sparticle partner.[5] The numerous theorized sparticles of Supersymmetry will likely include “sleptons,” “gluinos,” and “squarks.”
Delving into these new ideas in physics brings scientists ever closer to developing theories of “Grand Unification” and eventually a “Theory of Everything.” Just as Newton and Maxwell combined seemingly different physical phenomena into unified theories of gravitation and electromagnetism, many physicists today are searching for a new theory that brings together electromagnetism and the strong and weak nuclear forces, thus achieving what physicists “Grand Unification.” Ultimately, the “holy grail” of physics would be a so-called “Theory of Everything.” In such a theory, all four of the fundamental physical forces—gravity, electromagnetism, and the strong and weak nuclear forces—could be weaved together into one theoretical tapestry, perhaps even one ultimate equation, by which all of the laws of nature could be defined. The most popular candidate for a theory that encompasses all of the forces is called “Superstring theory” or “string theory” for short. String theory is a fascinating concept that proposes that everything in the universe is, at the most fundamental level, composed of tiny, vibrating strands of energy called strings. The theory also requires extra-dimensions of space (eleven actually) and the existence of Supersymmetric particles. If proved correct, string theory may very well be the long sought after theory that would achieve the ultimate symmetry in the laws of physics, a unification of all physical forces.
Isaac Newton once said “If I have seen further, it is by standing on the shoulder of giants.” Today, physicists build upon the foundations set down by scientific giants like Newton and Einstein to expand our understanding of the world around us. In this time of rapid progress in physics, we may very well be witness to a new revolution in physics, where our understanding of the laws of nature and our perception of reality is transformed like never before.
[1] “The Galileo Project | Chronology | Galileo Timeline.” The Galileo Project. http://galileo.rice.edu/chron/galileo.html (accessed August 10, 2009).
[2] French, A. P.. Special Relativity: (M.I.T. Introductory Physics Series). New York: W.W. Norton & Co., 1968.
[3] Greene, Brian. The Elegant Universe: Superstrings, Hidden Dimensions, and the Quest for the Ultimate Theory. New York: Vintage, 2000.
[4] Isaacson, Walter. Einstein: His Life and Universe. New York: Simon & Schuster, 2007.
[5] Greene, Brian. The Fabric of the Cosmos: Space, Time, and the Texture of Reality. New York: Vintage, 2005.
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