Free The Amazing Story of Quantum Mechanics by James Kakalios Page A

acts like a negative charge.

SECTION 2
    CHALLENGERS OF THE UNKNOWN

CHAPTER FIVE
    Wave Functions All the Way Down
    In 1958, Jonathan Osterman (Ph.D. in atomic physics, Princeton University) began his postdoctoral research position at the Gila Flats Research Facility in the Arizona desert. There he participated in experiments probing the nature of the “intrinsic field.” This is the collection of forces responsible for holding all matter together, aside from gravity. This would include electromagnetism, to account for the negatively charged electrons attracted to the positively charged protons in the atom’s nucleus. Electricity is much stronger than gravity, so much stronger, in fact, that the electrostatic attraction between the electrons and the protons in an atom’s nucleus is more than one hundred trillion trillion trillion times stronger than their gravitational attraction to one another. Consequently we can indeed neglect gravity’s contribution to the intrinsic field holding matter together.
    In addition to electromagnetism, the intrinsic field must be comprised of additional forces that act on the protons and neutrons within each atom’s nucleus. While opposite electrical charges are attracted to each other, similar electrical charges are pushed away. The nucleus contains positively charged protons that are electrostatically repelled from one another and electrically uncharged neutrons that are immune to the electrostatic force. The closer two charges are, the greater the electrical force between them. Given that the protons within a nucleus are less than ten trillionths of a centimeter from each other, the electrical repulsion between protons is very powerful, and any force capable of overcoming this must be very strong—so strong, in fact, that physicists named it the strong force, 19 and it is also therefore a component of the intrinsic field binding matter together. The strong force was originally believed to operate between protons and neutrons within the nucleus, holding them together. With theoretical and experimental investigations indicating that each of these nuclear particles is composed of quarks (which are in turn electrically charged), the strong force is now identified as the force that holds the quarks together and bleeds outs to neighboring particles within the nucleus. The experimental evidence for this force is indirect, as it turns out to be very difficult to slice protons and neutrons open and probe the quarks directly. But clearly there must be an attractive force operating within the nucleus that is able to overcome the electrostatic repulsion between protons at very close quarters.
    In addition, physicists were unable to explain why certain elements’ nuclei decay and emit high-energy electrons despite the binding glue of the strong force. The neutron, discovered in 1932 by James Chadwick, was found to be unstable. A neutron out in free space has a half-life of roughly fifteen minutes. That is, in a quarter of an hour, a neutron outside of a nucleus has a 50 percent chance of decaying into a proton, an electron, and a neutrino (technically an antineutrino). As the neutron is uncharged, this has nothing to do with electromagnetism, and as it is outside of a nucleus, the strong force does not apply. This decay is also found to occur for neutrons inside certain nuclei.
    There must be some other type of force that can turn a neutron into a proton. This additional force can’t be stronger than the strong force (or else nuclei would not hold together at all), but it appears to be not simply electromagnetism. This somewhat weaker force is termed, creatively enough, the weak force, and it is the third component of the intrinsic field. The strong force within the nucleus is roughly a hundred times stronger than electromagnetism (which is why nuclei with 90 to 100 protons, such as uranium and plutonium, are stable), while the weak force is one hundred billion times weaker than