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Microcosmology : Atom
SECTION IV UNIFICATION OF PHYSICS AND
PHILOSOPHY
A. INHERENT UNITY OF PHYSICAL
REALITY The aspect of inherent unity and connectedness of the physical reality manifests itself in several ways in modern science. In the double-slit experiment, when both slits are open, the light-waves going through them interfere with each other to form a pattern of alternating light and dark bands on a screen. When only one slit is open, the light-waves going through it illuminate the screen in the ordinary way. The great multitude of photons, of which a single photon eventually will be a part, distributes itself in one way if both slits are open. The question is, assuming that a single photon goes through one of the two slits, how does it know whether or not the other slit is open ? Somehow it does. An interference pattern always forms when we open both slits, and it never forms when we close one of the slits.
E.P.R. EFFECT
The connectedness is even more perplexing in another experiment. In twin-particle-system of Zero spin', spin of each of the particles cancels the other. If one of the particles has a spin ‘up' the other particle has spin 'down'. If the first particle has a spin 'right', the second one has a spin 'left'. No matter how the particles are oriented, their spins are always equal and opposite. Now, if these particles are made to go off in opposite directions, i.e., if one goes to New York, and the other to Bombay or one on the earth and the other on the moon, their combined spins will still always be Zero. Suppose the particle in New York is givena a spin 'up', we do not have to make a measurement on the other particle
1.
In some sense, particle-spin is a rotation about its own axis, but this classical concept is limited. The electron can spin clockwise or counter-clockwise, and these two values are denoted by spin 'up' and spin down'.
A particle can be given a desired spin through a Stern-Gerlach device, in which electrons are made to pass through a magnetic field.