Brian David Josephson

views updated

Brian David Josephson

1940-

English Physicist

Brian Josephson is as well known for his contributions to physics as he is for his beliefs that physics must also explain extrasensory perception and paranormal phenomena.

Josephson first came to the attention of the scientific community when he was still an under-graduate at Cambridge University. At the age of 20 and in his third year of undergraduate studies he developed a new, improved way of calculating how the Doppler shift, which is a change in the frequency of radiation emitted by objects moving near light speed, is affected by gravity.

Shortly thereafter in 1962 Josephson, then a graduate student at Cambridge, made several predictions concerning the behavior of super-conducting circuits. When certain metals and alloys are cooled to extremely low temperatures they lose all resistance to the flow of electrons and become perfect electrical conductors, called superconductors. Josephson predicted that when two parallel superconducting wires were separated by a thin layer of a non-superconducting material (an insulator), an electric current would begin to flow between the two superconductors. This is due to an effect of quantum mechanics called tunneling. Electrons can sometimes tunnel through a material even when they don't seem to possess enough energy. Josephson predicted correctly that electrons in both super-conductors could pair up. This would lower their energy state and allow them to tunnel across the barrier. As well, these electrons would be flowing simultaneously in both directions.

When these predictions were confirmed by Bell Laboratory scientists the scientific community was quick to praise him. In 1973 he was awarded the Nobel Prize for his discovery. In his honor, this physical process is now called the Josephson effect, and these types of electrical circuits are called Josephson junctions.

Josephson junctions initially showed great promise to the computer industry. Many engineers looked for ways of applying them to computer circuits. IBM reportedly spent over $100 million before abandoning their efforts at finding broad-reaching uses for these circuits.

The single workable application to come out of these efforts are SQUIDs, or superconducting quantum interference devices. When an electrical current is traveling steadily across the insulating layer between the two superconductors, the current, called a standing wave, becomes extremely sensitive to any changes in the surrounding magnetic fields. Since electricity and magnetism are inseparably linked, small changes in electrical voltages can also be detected. SQUIDs can sense changes of picovolts (one trillionth of a volt), and are almost 1,000 times more sensitive than traditional voltmeters.

SQUID detectors have been used to study voltage changes in the brain and the heart. Detectors that analyze magnetic fields are used by geologists to monitor changes in rocks and by the U.S. Navy to detect submarines.

Since winning the Nobel Prize Josephson has turned toward more esoteric studies. He is currently a physics professor at Cambridge University's Cavendish Laboratory. There he directs the Mind-Matter Unification Project of the Theory of Condensed Matter Group. His current research interests include human consciousness, psychic phenomena, and paranormal events. He believes that some facet of quantum mechanics may be able to explain these happenings.

As well, Josephson has also been investigating the link between the mind and music. He believes that music may affect the minds of different people in the same way. Music, according to Josephson and his collaborator Tethys Carpenter, may have some sort of universal structure or pattern that gives it meaning, while cultural and individual influences play a smaller role than that attributed by other psychologists and musicologists.

PHILIP DOWNEY