By Basil Gala, Ph.D.
In Search of Meaning
As every preschooler knows, Energy equals mass times the square of the speed of light, or E = mc², that from Einstein. The relationship of matter and energy has been settled by physicists to nearly everybody’s satisfaction. So why do I want to discuss it? Because the issue is not settled as far as I am concerned. I want to know why energy, which scatters in all directions at the speed of light, remains bound up in matter, outside of radio-active materials, a nuclear reactor, a bomb, or a sun. So here I go, until the physics police pick me up and put me away.
Let me start with matter. Four centuries before the birth of Christ, Democritus said matter was made up of indivisible pieces he called atoms, because if you take an apple and keep slicing it into finer and finer bits with a very sharp knife, you will eventually get to atoms. Modern scientists agree and go further. Atoms are divisible, with some difficulty, into protons and neutrons bound together in the nucleus, with waves of electrons around it. As to sizes, the nucleus is like a football in a stadium with electrons like flies in waves whirring around the stadium; what you have in an atom is mostly empty space, not the solid matter we sense.
The protons and neutrons in the nucleus are made up of quarks, say ‘kworks.’ Nobel-prize winner Murray Gell-Mann of Caltech gave us the word and pronunciation. Quarks are particles held together by the strong nuclear force, mediated by gluons, to form combinations known as hadrons. A hadron of two quarks is a meson and one of three quarks is a barion. Quarks have the properties of mass, spin and parity, which we cannot measure directly, but we have to infer from their behavior. Why? The answer stated by Frank Wilczek (another Nobel winner) is that quarks make it impossible to separate them from their hadrons setting them free as particles. As physicists apply more and more energy to pull quarks apart, the force of gluons holding them together becomes greater still; quarks are not found free in nature.
Tougher still, quarks may have a substructure: they may be made up of other things, but we have no evidence to suggest to us what parts make up quarks. I want to know if quark parts exist, or quarks are the boxes holding nuclear energy from flying away in all directions. Clearly, quarks are bundles of energy that are held together somehow by means of the weak nuclear force, which also binds leptons (including electrons) into bundles. The weak force is mediated by massive bosons designated by W±, and Zº. What do we mean by weak and strong forces? Using the electromagnetic force as a base of 1 for two massless mediating photons in a nucleus, the strong nuclear force is 20 times weaker; and the weak nuclear force 10,000 times weaker. Holding planets, solar systems and galaxies together, the gravitational force is 10 followed by 36 zeros weaker than electromagnetism. Weak indeed at the particle level, but without gravitation, mediated by the massless graviton, there would be no universe as we know it. The graviton remains elusive, not yet detected by any instrument devised to date.
What do physicists mean when they say a force is mediated by particles like the graviton or photon? Some authors give the analogy of two people on wheeled stools who are throwing a series of balls to each other. Each ball thrown and caught causes the two throwers to move apart with a somewhat greater velocity. This is not a satisfactory analogy, because it does not explain an attractive force such as gravity; and the graviton is without mass to cause a push. The photon is also without mass, but the electromagnetic force it carries also has large effects, such as in the electric motor or in the supercollider which speeds up protons at CERN.
The theory of force carriers, called bosons, such as the graviton, photon, gluon, etc. derive from the Standard Model, which accounts for all the particles appearing in the supercollider experiments. The data suggest theoretical models to explain them, and the models stimulate more experiments to test for the existence of particles which theory predicts. One such hypothesized particle is the Higgs boson, a very heavy boson, requiring energies to produce. Physicists will be looking in 2008 for this boson with the new Large Hadron Collider (LHC) at CERN and with the Tevatron at Fermilab in Batavia, Illinois. If it exists, the Higgs boson has a huge effect on the universe and its forces, which prompted Leon Lederer (Nobel Laureate) to name it the “God Particle” in his popular science book.
All these bosons also derive from quantum mechanics and field theory. Field theory is a better explanation for the action of force particles than the analogy of stools. According to field theory, gravitons create a field of force around a massive object which distorts space like a sloping well with the object in the center. Another object with mass coming close to the field rolls down the gravity well, or is attracted by the first object, as Newton would say. The result is gravitation. If the centrifugal force of the captured object exactly matches the force of gravity, the object circles around the gravity hole without falling in.
The same phenomena occur with antimatter. Each particle I have mentioned, including quarks, has a corresponding antiparticle, with the opposite properties. For example, the anti-electron, or positron, has a positive electric charge, while the electron has a negative one. When a particle and antiparticle collide, they annihilate each other and producing photons of energy. Such collisions are used at CERN and Fermilab by speeding up protons and anti-protons in opposite directions, and then smashing them together. The scattering of energy and sub-particles are recorded. Physicists study these recordings and develop new models of the subatomic world to further enlarge our knowledge of how the universe is put together.
Physicists tell us that a particle is a wave in accordance with quantum mechanics. The Z particle mediating the weak force is also a wave, which establishes a field of attraction among the quarks, like a web of energy. When antimatter collides with matter, the anti-Z particle and field neutralizes the field of the Z particle and vice versa. Thus energy in both matter and anti-matter is released to scatter in all directions.
I conclude that mass exists when energy packets or quanta are in a stable configuration, balancing expansive forces with centrifugal forces in an electromagnetic field. When this stability is broken, quanta become ordinary radiation moving at the speed of light.