What the Bleep Do We Know!?
| Разделы | Иностранные языки •Физика |
| Тип | |
| Формат |
 Microsoft Word
|
| Язык | Английский |
| Загрузить архив: | |
| Файл: ref-24076.zip (10kb [zip], Скачиваний: 153) скачать |
What the Bleep Do We Know!?
“The important thing is not to stop questioning. Curiosity
has its own reason for existing. One cannot help but be in
awe when one contemplates the mysteries of eternity, of life,
of the marvelous structure of reality. Itis enough if one tries
merely to comprehend a little of this mystery every day.
Never lose a holy curiosity.” - Albert Einstein
At the core of this report are provocative questions about the way we participate in an unfolding, dynamic reality. What the Bleep Do We Know!? proposes that there is no solid, static universe, and that reality is mutable - affected by our very perception of it. At the same time, the report acknowledges that reality is not entirely relative or simply created out of thin air. Mothers do give birth to real babies. Some things are more solid and reliable than others.
In fact, according to quantum physics, things are not even “things”, they are more like possibilities. According to physicist Amit Goswami, “Even the material world around us - the chairs, the tables, the rooms, the carpet, camera included - all of these are nothing but possible movements of consciousness.” What are we to make of this? “Those who are not shocked when they first come across quantum theory cannot possibly have understood it,” notes quantum physics pioneer Niels Bohr. Before we can consider the implications of quantum mechanics, let’s make sure we understand the theory.
What is Quantum Mechanics?
What is Quantum Mechanics? Quantum mechanics, the latest development in the scientific quest to understand the nature of physical reality, is a precise mathematical description of the behavior of fundamental particles. It has remained the preeminent scientific description of physical reality for 70 years. So far all of its experimental predictions have been confirmed to astounding degrees of accuracy. To appreciate why quantum mechanics continues to astound and confound scientists, it is necessary to understand a little about the historical development of physical theories.
Keeping in mind that this brief sketch oversimplifies a very long, rich history, we may consider that physics as a science began when Isaac Newton and others discovered that mathematics could accurately describe the observed world. Today the Newtonian view of physics is referred to as classical physics; in essence, classical physics is a mathematical formalism of common sense. It makes four basic assumptions about the fabric of reality that correspond more or less to how the world appears to our senses. These assumptions are reality, locality, causality, and continuity.
Quantum reality
Reality refers to the assumption that the physical world is objectively real. That is, the world exists independently of whether anyone is observing it, and it takes as selfevident that space and time exist in a fixed, absolute way. Locality refers to the idea that the only way that objects can be influenced is through direct contact. In other words, unmediated action at a distance is prohibited. Causality assumes that the arrow of time points only in one direction, thus fixing cause-and-effect sequences to occur only in that order. Continuity assumes that there are no discontinuous jumps in nature, that space and time are smooth. Classical physics developed rapidly with these assumptions, and classical ways of regarding the world are still sufficient to explain large segments of the observable world, including chemistry, biology, and the neurosciences. Classical physics got us to the moon and back. It works for most things at the human scale. It is common sense.
But it does not describe the behavior of all observable outcomes, especially the way that light - and, in general, electromagnetism - works. Depending on how you measure it, light can display the properties of particles or waves. Particles are like billiard balls. They are separate objects with 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 is understandable and in most cases perfectly fine for practical purposes. But when it comes to understanding the nature of reality, it is useful to keep in mind that quantum mechanics describes the fundamental building blocks of nature, and the classical world is composed of those blocks too, whether we observe them or not. The competing interpretations of quantum mechanics differ principally on which of the common-sense assumptions one is comfortable in giving up.
Interpretations
Wholeness – Einstein’s protégé David Bohm maintained that quantum mechanics reveals that reality is an undivided whole in which everything is connected in a deep way, transcending the ordinary limits of space and time.
Many Worlds – Physicist Hugh Everett proposed that when a quantum measurement is performed, every possible outcome will actualize. But in the process of actualizing, the universe will split into as many versions of itself as needed to accommodate all possible measurement results. Then each of the resulting universes is actually a separate universe.
Quantum Logic – This interpretation says that perhaps quantum mechanics is puzzling because our common sense assumptions about logic break down in the quantum realm. Mathematician John von Neumann developed a “wave logic” that could account for some of the puzzles of quantum theory without completely abandoning classical concepts. Concepts in quantum logic have been vigorously pursued by philosophers.
NeoRealism – This was the position led by Einstein, who refused to accept any interpretation, including the Copenhagen Interpretation, asserting that common sense reality does not exist. The neorealists propose that reality consists of objects familiar to classical physics, and thus the paradoxes of quantum mechanics reveal the presence of flaws in the theory. This view is also known as the “hidden variable” interpretation of quantum mechanics, which assumes that once we discover all the missing factors the paradoxes will go away.
Consciousness Creates Reality – This interpretation pushes to the extreme the idea that the act of measurement, or possibly even human consciousness, is associated with the formation of reality. This provides the act of observation an especially privileged role of collapsing the possible into the actual. Many mainstream physicists regard this interpretation as little more than wishful New Age thinking, but not all. A few physicists have embraced this view and have developed descriptive variations of quantum theory that do accommodate such ideas.
It should be emphasized that at present no one fully understands quantum mechanics. And thus there is no clear authority on which interpretation is more accurate.
Additional Resources
BOOKS
Davies, P. C. W. The Ghost in the Atom: A Discussion of the Mysteries of Quantum
Physics.
Feynman, Richard. QED: The
Strange Theory of Light and Matter.
Press, 1985.
Greene, Brian. The Elegant Universe: Superstrings, Hidden Dimensions, and the Quest
for the Ultimate Theory. Vintage, 2000.
Hawking, Stephen. A Brief History of Time: The Updated and Expanded Tenth
Anniversary Edition. Bantam, 1998.
Heisenberg, Werner. Physics and Philosophy: The Revolution in Modern Science. Harper
and Row, 1958.
Heisenberg, Werner. Physics and Beyond: Encounters and Conversations. Harper and
Row, 1971.
Herbert, Nick. Quantum Reality: Beyond the New Physics. Anchor Books, 1987.
McFarlane, Thomas. The Illusion of Materialism: How Quantum Physics Contradicts the
Belief in an Objective World Existing Independent of Observation. Center Voice: The
Newsletter of the Center for Sacred Sciences, Summer-Fall 1999.
Zukav, Gary. The Dancing Wu Li Masters. Bantam Books, 1990.
INTERNET
Heisenberg and Uncertainty: A Web Exhibit American Institute of Physics
www.aip.org/history/heisenberg/
Measurement in Quantum Mechanics: Frequently Asked Questions edited by Paul Budnik
www.mtnmath.com/faq/meas-qm.html
The Particle Adventure: An interactive tour of fundamental particles and forces
Lawrence Berkeley National Laboratory www.particleadventure.org
Discussions with Einstein on Epistemological Problems in Atomic Physics, Niels Bohr (1949)
www.marxists.org/reference/subject/philosophy/works/dk/bohr.htm