Subatomic particle physics

Of course, we recognize that progress in health is utterly dependent upon science and that ultimately all science, at least all natural science, springs from a common base. No research is so fundamental that we can say that it does not have and never will have relevance to health. Nevertheless, we must recognize a level sufficiently remote from biomedical research that its present contributions can have little if any import for the foreseeable future. For example, current work in subatomic particle physics is unlikely to have an early influence, despite the tremendous importance in biomedical research of the atomic physics of a generation ago. Few people would expect the NIH to support work in present-day atomic physics. 

Rutherford, Ernest (1st Baron Rutherford of Nelson) (1871-1937) New Zealand-born British pioneer of subatomic particle physics who proposed the nuclear structure of the atom. He studied the radioactive disintegration of elements and correctly predicted the existence of the neutron. Rutherford won the Nobel Prize in chemistry in 1908. 

The fifth was a molecular biologist, who smiled sweetly and pointed out that all the others had missed the point. The frog jumps because of the biochemical properties of its muscles. The muscles are largely composed of two interdigitated filamentous proteins, actin and myosin, and they contract because the protein filaments slide past each other. This property of the actin and myosin is dependent on the amino acid composition of the two proteins, and hence on chemical, and thus on physical properties. In the last analysis, the molecular biologist insisted, following James Watson, we are all nothing but subatomic particles. 

But if new instmments such as the spectroscope, cloud chamber, ionization chamber, and the Dolezalek electrometer allowed Thomson, Rutherford, and others to infer the existence of subatomic particles, the limitations of those instmments were obvious. Of course, they could never allow scientists to perceive an atom, much less an electron, directly the relationship between the body and mind of the observer and the object of observation was always essentially secondhand. Moreover, the relatively primitive nature of the instmments only allowed theories to progress so far. The advent of the cyclotron, the bubble chamber, and other instmments of high-energy physics were still years away. 

The science of particle physics continues to study electrons, protons, and neutrons, which are considered subatomic particles. The quest continues for even smaller subatomic, or rather subnuclear, particles. Most subnuclear particles are fleeting in time of existence, are practically weightless, and are thus very difficult to detect and measure. 

Bom coined the term "Quantum mechanics and in 1925 devised a system called matrix mechanics, which accounted mathematically for the posidon and momentum of the electron in the atom. He devised a technique called the Born approximation in scattering theory for computing the behavior of subatomic particles which is used in high-energy physics. Also, interpretation of the wave function for Schrodinger s wave mechanics was solved by Born who suggested that the square of the wave function could be understood as the probability of finding a particle at some point in space, For this work in quantum mechanics. Max Bom received the Nobel Prize in Physics in 1954,... 

Muons can easily penetrate many meters of iron and can sometimes cause problems in particle physics research. For example, the upsilon experiment at Fermilab in 1977, conducted by L M. Uederman and olhers, required building a simple magnetic system that would remeasure each muon s energy after it emerged from the main detector. See also Upsilon Particle and Particles (Subatomic). 

Neutrons and Protons. By 1932, it had been established Uiat atomic nuclei are made of comparatively small numbers of neutrons and protons. Even prior to the use of particle accelerators and the birth of high-energy physics, other expenments continued to hint at the need of additional subatomic particles to satisfy any theory that would unify scientists understanding of the atom s infrastructure,... 

PSI PARTICLE. Discovery of this subatomic particle in 1974 was announced independently by Ting (Brookhaven National Laboratory) who named it the J particle and by B.D. Richter (Stanford) who named it the psi particle. The discovery of this particle resolved a number of important problems in particle physics. Intensive research on the psi particle was carried out by Richter and the Stanford group during 1975 and 1976 and is reported firsthand by Richter (Science, 196, 1286-1297.1977). As pointed out by Richter, the four-quark theoretical model became much more compelling with the discovery of the psi particles, The long life of the psi is explained by the fact that the decay of the psi into ordinary hadrons requires the conversion of both c and c into other quarks and antiquarks. See also Particles (Subatomic). 

A frequently asked question is What are the differences between nuclear physics and nuclear chemistry Clearly, the two endeavors overlap to a large extent, and in recognition of this overlap, they are collectively referred to by the catchall phrase nuclear science. But we believe that there are fundamental, important distinctions between these two fields. Besides the continuing close ties to traditional chemistry cited above, nuclear chemists tend to study nuclear problems in different ways than nuclear physicists. Much of nuclear physics is focused on detailed studies of the fundamental interactions operating between subatomic particles and the basic symmetries governing their behavior. Nuclear chemists, by contrast, have tended to focus on studies of more complex phenomena where statistical behavior is important. Nuclear chemists are more likely to be involved in applications of nuclear phenomena than nuclear physicists, although there is clearly a considerable overlap in their efforts. Some problems, such as the study of the nuclear fuel cycle in reactors or the migration of nuclides in the environment, are so inherently chemical that they involve chemists almost exclusively. 

Frauenfelder, H. and E. M. Henley. Subatomic Physics, 2nd ed., Prentice-Hall, Englewood Cliffs, NJ, 1991. A treatment of both nuclear and elementary particle physics. 

Like all other scientific concepts, that of an element has changed its meaning many times and in many ways during the development of science. Thus wrote Wilhelm Ostwald (the father of physical chemistry and a positivist philosopher) in the 1911 edition of the Encyclopaedia Britannica. This was a time of dramatic developments in physics and chemistry within a few years, even the most entrenched positivists were beginning to believe in the real existence of atoms and subatomic particles. 

The three primary components of atoms are protons, neutrons, and electrons. The following chart summarizes the physical properties of these subatomic particles ... 

Things got steadily worse over the years. With the discovery of fossils it became apparent that the familiar animals of field and forest had not always been on earth the world had once been inhabited by huge, alien creatures who were now gone. Sometime later Darwin shook the world by arguing that the familiar biota was derived from the bizarre, vanished life over lengths of time incomprehensible to human minds. Einstein told us that space is curved and time is relative. Modern physics says that solid objects are mostly space, that subatomic particles have no definite position, that the universe had a beginning. 

Since this time, a number of discoveries have been made regarding additional subatomic particles however, these are related to the domain of nuclear physics. The basic components of the atom that relate to its chemical behavior are the proton, neutron, and electron. It is to these that we now turn our attention. 

Not all chemists believed that Dalton s atoms existed. In 1877, one skeptical scientist called Dalton s atoms "stupid hallucinations." Other scientists considered atoms to be a valuable idea for understanding matter and its behaviour. They did not, however, believe that atoms had any physical reality. The discovery of electrons (and, later, the other subatomic particles) finally convinced scientists that atoms are more than simply an idea. Atoms, they realized, must be matter. 

In Chapter 3, we learned that atoms owe their characteristics to their subatomic particles— protons, neutrons, and electrons. Electrons occur in regions of space outside the nucleus, and the electronic structure is responsible for all of the atom s chemical properties and many of its physical properties. The number of electrons in a neutral atom is equal to the number of protons in the nucleus. That simple description enables us to deduce much about atoms, especially concerning their interactions with one another (Chapter 5). However, a more detailed model of the atom enables even fuller explanations, including the reason for the differences between main group elements and elements of the ttansition and inner transition series. 

Subatomic particle tracks in a bubble chamber at CERN, the European particle physics laboratory in Geneva, Switzerland. 

To the majority of pharmaceutical and biological scientists, the neutron is simply part of the subatomic makeup of the molecules they study every day. In recent years, however, advances in particle physics have allowed the spectrum of people using neutron facilities, such as those at the Rutherford Appleton Laboratories (RAL), U.K., to broaden considerably. The application of neutron spectroscopy to the field of percutaneous penetration is not yet well established, but it has already produced some interesting results, and it is hoped that these will prompt further utilization of this powerful technique in this and other pharmaceutically oriented areas of research. 

Newton s three laws of motion revolutionized physics. For the first time the same simple set of laws explained a wide variety of apparently unrelated types of motion both on Earth and in the heavens. Not until the twentieth century were these laws surpassed by quantum mechanics and relativity for the special cases of subatomic particles, motion near the speed of light and strong gravitational fields. 

Figure 18-1 depicts the world-view of philosophical physicalism. The ultimate structures or components of reality (top) are subatomic particles. When I was a high school student, only a few such particles were known and many scientists thought that electrons, protons, and neutrons were the basics whose arrangement in patterns accounted for the way the world was. Now literally hundreds of subatomic particles have been "discovered."... 

This is the conservative or orthodox view of the mind discussed briefly at the beginning of this book. It does not really explain what consciousness is, but, citing good evidence that physically affecting the brain alters consciousness, asks not further questions and simply believes that consciousness itself is a product of brain functioning. The consequence of this view is that for an ultimate explanation of consciousness, the phenomena of consciousness must be reduced to those of brain functioning brain functioning must be reduced to basic properties of nervous systems, which must be reduced to basic properties of live molecules, which in turn must be reduced to basic properties of molecules per se, which must be reduced to properties of atoms, which must finally be reduced to properties of subatomic particles. 

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