What the Bleep Do We Know!? — страница 2

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specific locations in space, and they are hard in the sense that if hurled at each other with great force, they tend to annihilate each other accompanied by dazzling displays of energy. In contrast, waves are like undulations in water. They are not localized but spread out, and they are soft in that they can interact without destroying each other. The wave-like characteristic also gives rise to the idea of quantum superposition, which means the object is in a mixture of all possible states. This indeterminate, mixed condition is radically different than the objects we are familiar with. Everyday objects exist only in definite states. Mixed states can include many objects, all coexisting, or entangled, together. How is it possible for the fabric of reality to be both waves and

particles at the same time? In the first few decades of the twentieth century, a new theory, Quantum Mechanics, was developed to account for the wave-particle nature of light and matter. This theory was not just applicable to describing elementary particles in exotic conditions, but provided a better way of describing the nature of physical reality itself. Einstein’s Theory of Relativity also altered the Newtonian view of the fabric of reality, by showing how basic concepts like mass, energy, space, and time are related. Relativity is not just applicable to cosmological domains or to objects at close to light-speeds, but refers to the basic structure of the fabric of reality. In sum, modern physics tells us that the world of common sense reveals only a special, limited portion

of a much larger and stranger fabric of reality. Electrons can behave as both particles and waves. As waves, electrons have no precise location but exist as “probability fields.” As particles, the probability field collapses into a solid object in a particular place and time. Unmeasured or unobserved electrons behave in a different manner from measured ones. When they are not measured, electrons are waves. When they are observed, they become particles. The world is ultimately constructed out of elementary particles that behave in this curious way. In classical physics, all of an object’s attributes are in principle accessible to measurement. Not so in quantum physics. You can measure a single electron’s properties accurately, but not without producing imprecision in some

other quantum attribute. Quantum properties always come in “conjugate” pairs. When two properties have this special relationship, it is impossible to know about both of them at the same time with complete precision. Heisenberg’s Uncertainty (also know as the Indeterminacy) Principle says that if you measure a particle’s position accurately, you must sacrifice an accurate knowledge of its momentum, and vice versa. A relationship of the Heisenberg kind holds for all dynamic properties of elementary particles and it guarantees that any experiment (involving the microscopic world) will contain some unknowns. What does the phrase “we know” mean? It means that theoretical predictions were made, based on mathematical models, and then repeatedly demonstrated in experiments.

If the universe behaves according to the theories, then we are justified in believing that common sense is indeed a special, limited perspective of a much grander universe. The portrait of reality painted by relativity and quantum mechanics is so far from common sense that it raises problems of interpretation. The mathematics of the theories are precise, and the predictions work fantastically well. But translating mathematics into human terms, especially for quantum mechanics, has remained exceedingly difficult. The perplexing implications of quantum mechanics were greeted with shock and awe by the developing scientists. Many physicists today believe that a proper explanation of reality in light of quantum mechanics and reliability requires radical revisions of one or more

common-sense assumptions: reality, locality, causality or continuity. Given the continuing confusions in interpreting quantum mechanics, some physicists refuse to accept the idea that reality can possibly be so perplexing, convoluted, or improbable - compared to common sense, that is. And so they continue to believe, as did Einstein, that quantum mechanics must be incomplete and that once “fixed” it will be found that the classical assumptions are correct after all, and then all the quantum weirdness will go away. Outside of quantum physics, there are a few scientists and the occasional philosopher who focus on such things, but most of us do not spend much time thinking about quantum mechanics at all. If we do, we assume it has no relevance to our particular interests. This