"All these things being considered, it seems probable to me that God in the beginning formed matter in solid, massy, hard, impenetrable, moveable particles of such sizes and figures, and with such other properties, and in such proportion to space, as most conduced to the end for which he formed them; and that these primitive particles being solids, are incomparably harder than any porous bodies compounded of them; even so very hard, as never to wear or break in pieces; no ordinary power being able to divide what God himself made in the first creation. While the particles continue entire, they may compose bodies of one and the same nature and texture in all ages: but should they wear away, or break in pieces, the nature of things depending on them would be changed. Water and earth, composed of old worn particles and fragments of particles, would not be of the same nature and texture now, with water and earth composed of entire particles in the beginning. And there, that nature may be lasting, the changes of corporal things are placed only in the various separations and new associations and motions of these permanent particles."
Isaac Newton - Optics
Nuclear and Particle Physics
Particle Physics is the discovery and measurement
of the fundamental constituents and their basic interactions.
Particle Physics is not all of physics.
Æ Complex systems require new concepts,
Particle Physicists try to ignore multibody systems.
Nuclear Physics is the study of the simplest complex
systems constructed from the fundamental constituents.
Together, nuclear and particle physics are sometimes
called Subatomic Physics.
The Particle Physics Universe
Constituent point fermions
interacting via forces mediated by vector bosons
W+, W-, Z0
as a consequence of gauge symmetries
Experimental Subatomic Physics
Thompson's discovery of the electron
was the first example of a non-accelerator particle search experiment.
Thompson showed that cathode rays were electrically charged particles
with a fixed value of e /m. Since e was roughly
known, he showed that the cathode particles were ~2000 times lighter
than a hydrogen atom. Atoms were considered to be the indivisible
fundamental constituents of matter, so nothing lighter was expected
|team||Geiger(RA),||cast of thousands|
|(Rd, ~5 MeV)||(Tevatron, 900 GeV)|
|detector||ZnS screen||10000 ton hermetic|
|(data acquisition)||+ disks, tapes, ....|
|analysis||student+pencil||~102 students + computers|