A Note on Quantum Mechanics

According to Classical Physics and Relativistic physics, the past and future positions & velocities of an object can be determined from its present position and velocity. Without equivocation, classical physics declares that the past and future are etched into the present. This feature is also shared by both special and general relativity. Although the relativistic concepts of past and future are subtler than their familiar classical counterparts, the equations of relativity, together with a complete assessment of the present, determine them just as completely.

Quantum Mechanics is based on a variety of data newly acquired from the atomic and subatomic realm. But according to the quantum laws, even if you make the most perfect measurements possible of how things are today, the best you can ever hope to do is predict the probability that things will be one way or another at some chosen time in future, or that things were one way or another at some chosen time in the past. The universe, according to quantum mechanics, is not etched into the present; the universe, according to quantum mechanics, participates in a game of chance.

Although there is still controversy over precisely how these developments should be interpreted, most physicists agree that probability is deeply woven into the fabric of quantum reality. Whereas human intuition, and its embodiment in classical physics, envision a reality in which things are always definitely one way or another, quantum mechanics describes a reality in which things sometimes hover in a haze of being partly one way and partly another. Things sometimes hover in a haze of being partly one way and partly another. Things become definite only when a suitable observation forces them to relinquish quantum possibilities and settle on a specific outcome. The outcome that's realized, though, cannot be predicted - we can predict only the odds that things will turn out one way or another.

This, plainly speaking, is weird. We are unused to a reality that remains ambiguous until perceived. But the oddity of quantum mechanics does not stop here. At least as astounding is a feature that goes back to a paper Einstein wrote in 1935 with two younger colleagues, Nathan Rosen and Boris Podolsky, that was intended as an attack on quantum theory. With the ensuing twist of scientific progress, Einstein's paper can now be viewed as among the first to point out that quantum mechanics - if taken at face value - implies that something you do over here can be instantaneously linked to somethings happening over there, regardless of distance. Einstein considered such instantaneous connections ludicrous and interpreted their emergence from the mathematics of quantum theory as evidence that the theory was in need of much development before it would attain an acceptable form. But by the 1980s, when both theoretical and technological developments brought experimental scrutiny to bear on these purported quantum absurdities, researchers confirmed that there can be an instantaneous bond between what happens at widely seperated locations. Under pristine laboratory conditions, what Einstein thought absurd really happens.