Here is a video of an experiment illustrating the wave-particle duality in action, and how an observer can actually change its outcome. Very interesting.
Dr. Quantum
Quantum Mechanics
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Ryan Rudolph
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Matt Gregory
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There is no proof of QM. There is only proof that there is something within the atomic structure.Because quantum mechanics has been proven over and over. There is no doubt of its truthfulness. We only have doubts about its interpretation.
There are dozens of mathematical theories relating to QM, but most of them are fanciful as they disassociate with cause and effect - in other words at some stage in the formulas they make assumptions that defy logic.
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Matt Gregory
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How would they prove it? By predicting what will happen with mathematics? I don't think that's a good way to prove it. Ptolemy could predict the movement of the planets with mathematics using a geocentric model of the solar system. Yet Copernicus showed that this was wrong. Well, not exactly wrong, but not as easy to use as a heliocentric model. QM is in an even worse predicament as it hasn't even developed a viable model yet. Yet everyone seems absolutely sure that we are capable of creating valid experiments.
Matt,
.
In science, proving something means being able to accurately predict what will happen. If you want more proof than that, you're jumping outside the realm and scope of science.How would they prove it? By predicting what will happen with mathematics? I don't think that's a good way to prove it.
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Matt Gregory
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Yes, you're right, but I don't think math alone is sufficient, is what I'm trying to say. There ought to be a workable conceptual model to direct the observational and mathematical investigations. It would make things more efficient. And more importantly, it would satisfy my curiosity about QM.
Last edited by Matt Gregory on Wed Feb 21, 2007 5:43 pm, edited 1 time in total.
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Dan Rowden
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Matt Gregory
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Has anyone even explained basic electrical phenomena? Like, how does resistance in a conductive material turn electrons into heat? How does a light bulb turn them into light?
If these types of questions were answered, then maybe it would help solve problems in QM (though, I must admit I don't know what the status is on these types of problems).
That brings me to another question. How the hell do they shoot electrons through the air(!)? It's not like you can hook up a wire to the positive pole of a battery and use the other end to shoot electrons out of it.
We're gettin' ripped off!
If these types of questions were answered, then maybe it would help solve problems in QM (though, I must admit I don't know what the status is on these types of problems).
That brings me to another question. How the hell do they shoot electrons through the air(!)? It's not like you can hook up a wire to the positive pole of a battery and use the other end to shoot electrons out of it.
We're gettin' ripped off!
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Ryan Rudolph
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Here are some of the many concepts and theories in QM:
A wave function (also called Schrodinger's Equation) is a differential equation in quantum theory that mathematically describes probability density of an object in space and time. WAVELENGTH Wavelength is a characteristic of electromagnetic radiation. It is the distance between two wave crests.
A plasma is typically an ionized gas, and is usually considered to be a distinct state of matter in contrast to gases because of its unique properties. "Ionized" means that at least one electron has been dissociated from, or added to, a proportion of the atoms or molecules. The free electric charges make the plasma electrically conductive so that it responds strongly to electromagnetic fields.
The electromagnetic field is a physical field that is produced by electrically charged objects and which affects the behaviour of charged objects in the vicinity of the field. The electromagnetic field extends indefinitely throughout space and describes the electromagnetic interaction, one of the four fundamental forces of nature. The field can be viewed as the combination of an electric field and a magnetic field.
a magnetic field is that part of the electromagnetic field that exerts a force on a moving charge. A magnetic field can be caused either by another moving charge (i.e., by an electric current) or by a changing electric field. The magnetic field is a vector quantity,
Electromagnetic radiation is generally described as a self-propagating wave in space with electric and magnetic components. These components oscillate at right angles to each other and to the direction of propagation, and are in phase with each other. Electromagnetic radiation is classified into types according to the frequency of the wave: these types include, in order of increasing frequency, radio waves, microwaves, terahertz radiation, infrared radiation, visible light, ultraviolet radiation, X-rays and gamma rays. In some technical contexts the entire range is referred to as just 'light'. [1]
The term electromagnetic pulse (EMP) has the following meanings:
1. The electromagnetic radiation from an explosion (especially a nuclear explosion) or an intensely fluctuating magnetic field caused by Compton-recoil electrons and photoelectrons from photons scattered in the materials of the electronic or explosive device or in a surrounding medium. The resulting electric and magnetic fields may couple with electrical/electronic systems to produce damaging current and voltage surges. See Electromagnetic bomb for details on the damages resulting to electronic devices. The effects are usually not noticeable beyond the blast radius unless the device is nuclear or specifically designed to produce an electromagnetic shockwave.
2. A broadband, high-intensity, short-duration burst of electromagnetic energy.
The photoelectric effect is a quantum electronic phenomenon in which photoelectrons are emitted from matter after the absorption of energy from electromagnetic radiation such as x-rays.[1] The effect is also termed the Hertz Effect[2], due to its discovery by Heinrich Rudolf Hertz,
wave-particle duality holds that light and matter exhibit properties of both waves and of particles. A central concept of quantum mechanics, duality addresses the inadequacy of conventional concepts like "particle" and "wave" to meaningfully describe the behaviour of quantum objects. The idea of duality is rooted in a debate over the nature of light and matter dating back to the 1600s,
Nonlocality: Within Bohm's interpretation, it can occur that events happening at one location in space instantaneously influence other events which might be at large distances: thus we say that the theory fails to obey locality, i.e., it is non-local. The response many physicists have to Bohm's theory is often related to how they regard this concept.
the EPR paradox is a thought experiment which challenged long-held ideas about the relation between the observed values of physical quantities and the values that can be accounted for by a physical theory. "EPR" stands for Einstein, Podolsky, and Rosen, who introduced the thought experiment in a 1935 paper to argue that quantum mechanics is not a complete physical theory. It is sometimes referred to as the EPRB paradox for David Bohm, who converted the original thought experiment into something closer to being experimentally testable.
The EPR experiment yields a dichotomy. Either
1. The result of a measurement performed on one part A of a quantum system has a non-local effect on the physical reality of another distant part B, in the sense that quantum mechanics can predict outcomes of some measurements carried out at B or
2. Quantum mechanics is incomplete in the sense that some element of physical reality corresponding to B cannot be accounted for by quantum mechanics (that is, some extra variable is needed to account for it.)
most physicists today regard the EPR paradox as an illustration of how quantum mechanics violates classical intuitions, and not as an indication that quantum mechanics is fundamentally flawed. – FUNNY!
Heisenberg uncertainty principle is a mathematical limit on the accuracy with which it is possible to measure everything there is to know about a physical system. In its simplest form, it applies to the position and momentum of a single particle, and implies that if we continue increasing the accuracy with which one of these is measured, there will come a point at which the other must be measured with less accuracy.
Spin is the angular momentum intrinsic to a body, as opposed to orbital angular momentum, which is the motion of its center of mass about an external point. In classical mechanics, the spin angular momentum of a body is associated with the rotation of the body around its own center of mass. For example, the spin of the Earth is associated with its daily rotation about the polar axis.
the angular momentum of an object rotating about some reference point is the measure of the extent to which the object will continue to rotate about that point unless acted upon by an external torque.
Bohm’s hidden variable theories are espoused by a minority of physicists who argue that the statistical nature of quantum mechanics indicates that quantum mechanics is incomplete. Albert Einstein, the most famous proponent of hidden variables, insisted that, "God does not play dice with the Universe" — meaning that he believed that physical theories must be deterministic to be complete[1]. If hidden variables exist, new physical phenomena beyond quantum mechanics are needed to explain the universe as we know it.
The Copenhagen interpretation is an interpretation of quantum mechanics formulated by Niels Bohr and Werner Heisenberg while collaborating in Copenhagen around 1927. Bohr and Heisenberg extended the probabilistic interpretation of the wavefunction, proposed by Max Born. Their interpretation attempts to answer some perplexing questions which arise as a result of the wave-particle duality in quantum mechanics, such as the measurement problem.
The meaning of the wavefunction
There is no quantum world. There is only an abstract physical description. It is wrong to think that the task of physics is to find out how nature is. Physics concerns what we can say about nature.
-- Aage Petersen paraphrasing Niels Bohr, Quantum Reality by Nick Herbert
There is no definitive statement of Copenhagen Interpretation since it consists of the views developed by a number of scientists and philosophers at the turn of the 20th Century. The following have been associated with the Copenhagen interpretation
1. A system is completely described by a waveform | ψ > , which represents an observer's knowledge of the system.
2. The description of nature is essentially probabilistic. Heisenberg's uncertainty principle ensures that it is not possible to know the values of all of the properties of the system at the same time; those properties that are not known with precision must be described by probabilities.
3. The probability of an event is related to the square of the amplitude of the waveform. (Max Born)
4. (Complementary Principle) Matter exhibits a wave-particle duality. An experiment can show the particle like properties of matter, or wave-like properties, but not both at the same time.
5. Measuring devices are essentially classical devices, and measure classical properties such as position and momentum.
The Copenhagen Interpretation denies that the waveform is real; it is a mathematical tool for calculating probabilities of specific experiments. The concept of collapse of a "real" waveform was introduced by John Von Neumann and was not part of the original formulation of Copenhagen Interpretation. There are some who say that there are variants of the Copenhagen Interpretation that allow for a "real" waveform, but it is questionable whether that view is really consistent with Positivism and some of Bohr's statements.
Niels Bohr emphasized that Science is concerned with the predictions of experiments, additional questions are not scientific but rather meta-physical. Bohr was heavily influenced by Positivism.
dark matter is matter, not directly observed and of unknown composition, that does not emit or reflect enough electromagnetic radiation to be detected directly, but whose presence can be inferred from gravitational effects on visible matter.
dark energy is a hypothetical form of energy that permeates all of space and has strong negative pressure.[1] According to the Theory of Relativity, the effect of such a negative pressure is qualitatively similar to a force acting in opposition to gravity at large scales.
Implicate and Explicate Order theory by David Bohm
A wave function (also called Schrodinger's Equation) is a differential equation in quantum theory that mathematically describes probability density of an object in space and time. WAVELENGTH Wavelength is a characteristic of electromagnetic radiation. It is the distance between two wave crests.
A plasma is typically an ionized gas, and is usually considered to be a distinct state of matter in contrast to gases because of its unique properties. "Ionized" means that at least one electron has been dissociated from, or added to, a proportion of the atoms or molecules. The free electric charges make the plasma electrically conductive so that it responds strongly to electromagnetic fields.
The electromagnetic field is a physical field that is produced by electrically charged objects and which affects the behaviour of charged objects in the vicinity of the field. The electromagnetic field extends indefinitely throughout space and describes the electromagnetic interaction, one of the four fundamental forces of nature. The field can be viewed as the combination of an electric field and a magnetic field.
a magnetic field is that part of the electromagnetic field that exerts a force on a moving charge. A magnetic field can be caused either by another moving charge (i.e., by an electric current) or by a changing electric field. The magnetic field is a vector quantity,
Electromagnetic radiation is generally described as a self-propagating wave in space with electric and magnetic components. These components oscillate at right angles to each other and to the direction of propagation, and are in phase with each other. Electromagnetic radiation is classified into types according to the frequency of the wave: these types include, in order of increasing frequency, radio waves, microwaves, terahertz radiation, infrared radiation, visible light, ultraviolet radiation, X-rays and gamma rays. In some technical contexts the entire range is referred to as just 'light'. [1]
The term electromagnetic pulse (EMP) has the following meanings:
1. The electromagnetic radiation from an explosion (especially a nuclear explosion) or an intensely fluctuating magnetic field caused by Compton-recoil electrons and photoelectrons from photons scattered in the materials of the electronic or explosive device or in a surrounding medium. The resulting electric and magnetic fields may couple with electrical/electronic systems to produce damaging current and voltage surges. See Electromagnetic bomb for details on the damages resulting to electronic devices. The effects are usually not noticeable beyond the blast radius unless the device is nuclear or specifically designed to produce an electromagnetic shockwave.
2. A broadband, high-intensity, short-duration burst of electromagnetic energy.
The photoelectric effect is a quantum electronic phenomenon in which photoelectrons are emitted from matter after the absorption of energy from electromagnetic radiation such as x-rays.[1] The effect is also termed the Hertz Effect[2], due to its discovery by Heinrich Rudolf Hertz,
wave-particle duality holds that light and matter exhibit properties of both waves and of particles. A central concept of quantum mechanics, duality addresses the inadequacy of conventional concepts like "particle" and "wave" to meaningfully describe the behaviour of quantum objects. The idea of duality is rooted in a debate over the nature of light and matter dating back to the 1600s,
Nonlocality: Within Bohm's interpretation, it can occur that events happening at one location in space instantaneously influence other events which might be at large distances: thus we say that the theory fails to obey locality, i.e., it is non-local. The response many physicists have to Bohm's theory is often related to how they regard this concept.
the EPR paradox is a thought experiment which challenged long-held ideas about the relation between the observed values of physical quantities and the values that can be accounted for by a physical theory. "EPR" stands for Einstein, Podolsky, and Rosen, who introduced the thought experiment in a 1935 paper to argue that quantum mechanics is not a complete physical theory. It is sometimes referred to as the EPRB paradox for David Bohm, who converted the original thought experiment into something closer to being experimentally testable.
The EPR experiment yields a dichotomy. Either
1. The result of a measurement performed on one part A of a quantum system has a non-local effect on the physical reality of another distant part B, in the sense that quantum mechanics can predict outcomes of some measurements carried out at B or
2. Quantum mechanics is incomplete in the sense that some element of physical reality corresponding to B cannot be accounted for by quantum mechanics (that is, some extra variable is needed to account for it.)
most physicists today regard the EPR paradox as an illustration of how quantum mechanics violates classical intuitions, and not as an indication that quantum mechanics is fundamentally flawed. – FUNNY!
Heisenberg uncertainty principle is a mathematical limit on the accuracy with which it is possible to measure everything there is to know about a physical system. In its simplest form, it applies to the position and momentum of a single particle, and implies that if we continue increasing the accuracy with which one of these is measured, there will come a point at which the other must be measured with less accuracy.
Spin is the angular momentum intrinsic to a body, as opposed to orbital angular momentum, which is the motion of its center of mass about an external point. In classical mechanics, the spin angular momentum of a body is associated with the rotation of the body around its own center of mass. For example, the spin of the Earth is associated with its daily rotation about the polar axis.
the angular momentum of an object rotating about some reference point is the measure of the extent to which the object will continue to rotate about that point unless acted upon by an external torque.
Bohm’s hidden variable theories are espoused by a minority of physicists who argue that the statistical nature of quantum mechanics indicates that quantum mechanics is incomplete. Albert Einstein, the most famous proponent of hidden variables, insisted that, "God does not play dice with the Universe" — meaning that he believed that physical theories must be deterministic to be complete[1]. If hidden variables exist, new physical phenomena beyond quantum mechanics are needed to explain the universe as we know it.
The Copenhagen interpretation is an interpretation of quantum mechanics formulated by Niels Bohr and Werner Heisenberg while collaborating in Copenhagen around 1927. Bohr and Heisenberg extended the probabilistic interpretation of the wavefunction, proposed by Max Born. Their interpretation attempts to answer some perplexing questions which arise as a result of the wave-particle duality in quantum mechanics, such as the measurement problem.
The meaning of the wavefunction
There is no quantum world. There is only an abstract physical description. It is wrong to think that the task of physics is to find out how nature is. Physics concerns what we can say about nature.
-- Aage Petersen paraphrasing Niels Bohr, Quantum Reality by Nick Herbert
There is no definitive statement of Copenhagen Interpretation since it consists of the views developed by a number of scientists and philosophers at the turn of the 20th Century. The following have been associated with the Copenhagen interpretation
1. A system is completely described by a waveform | ψ > , which represents an observer's knowledge of the system.
2. The description of nature is essentially probabilistic. Heisenberg's uncertainty principle ensures that it is not possible to know the values of all of the properties of the system at the same time; those properties that are not known with precision must be described by probabilities.
3. The probability of an event is related to the square of the amplitude of the waveform. (Max Born)
4. (Complementary Principle) Matter exhibits a wave-particle duality. An experiment can show the particle like properties of matter, or wave-like properties, but not both at the same time.
5. Measuring devices are essentially classical devices, and measure classical properties such as position and momentum.
The Copenhagen Interpretation denies that the waveform is real; it is a mathematical tool for calculating probabilities of specific experiments. The concept of collapse of a "real" waveform was introduced by John Von Neumann and was not part of the original formulation of Copenhagen Interpretation. There are some who say that there are variants of the Copenhagen Interpretation that allow for a "real" waveform, but it is questionable whether that view is really consistent with Positivism and some of Bohr's statements.
Niels Bohr emphasized that Science is concerned with the predictions of experiments, additional questions are not scientific but rather meta-physical. Bohr was heavily influenced by Positivism.
dark matter is matter, not directly observed and of unknown composition, that does not emit or reflect enough electromagnetic radiation to be detected directly, but whose presence can be inferred from gravitational effects on visible matter.
dark energy is a hypothetical form of energy that permeates all of space and has strong negative pressure.[1] According to the Theory of Relativity, the effect of such a negative pressure is qualitatively similar to a force acting in opposition to gravity at large scales.
Implicate and Explicate Order theory by David Bohm
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Matt Gregory
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I was thinking about the other Dr. Quantum video they had on there, which was about flatlanders who lived in two dimensions, and I just realized that they wouldn't get scared if Dr. Quantum put his finger in the flatland because they wouldn't be able to see anything if there was only two dimensions.
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Diebert van Rhijn
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What about a circular fleshy 'wall' appearing out of thin air?Matt Gregory wrote:I was thinking about the other Dr. Quantum video they had on there, which was about flatlanders who lived in two dimensions, and I just realized that they wouldn't get scared if Dr. Quantum put his finger in the flatland because they wouldn't be able to see anything if there was only two dimensions.
Or do you mean a visual sensor needs three dimensions to function?
A book from Rudy Rucker: The Fourth Dimension is a good introduction to these thought experiments. It goes a bit further than you might think!
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Matt Gregory
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Think about a 2D Cartesian plane and imagine looking at it from the side as if your eye were on the x-axis looking down it. You wouldn't be able to see it, there would be nothing to look at. I'm not talking about a thin third dimension the way it was depicted in the video but no third dimension at all.
Thanks, that book sounds interesting.
Thanks, that book sounds interesting.
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Diebert van Rhijn
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Okay, but you said the flatlanders wouldn't see anything. That assumes the flatlanders have no way to perceive 2D objects (or the 2D properties of 3D objects) which is quite an assumption since nothing about this 2D words has yet been defined apart from its existence as thought experiment. Since it was defined as a world with inhabitants it's implied that properties of things (eg length and width, x-y) are being perceived somehow by the inhabitants who have no height at all but still exist in their mathematical 'plane', invisible to us.Matt Gregory wrote:Think about a 2D Cartesian plane and imagine looking at it from the side as if your eye were on the x-axis looking down it. You wouldn't be able to see it, there would be nothing to look at. I'm not talking about a thin third dimension the way it was depicted in the video but no third dimension at all.
I've had it since ages and really gave me some playful perspectives on visualizing a 4D structure. Kind of mind bending.Thanks, that book sounds interesting.
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brokenhead
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brokenhead
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Just to clarify the above description of the Heisenberg Uncertainty Principle:
It is a mathematical expression of a physical limit. In other words, it is physically impossible to measure complementary quantities to arbitrary precision. Position and momentum are two such physical quantities. Energy and time form another pair.
It is a mathematical expression of a physical limit. In other words, it is physically impossible to measure complementary quantities to arbitrary precision. Position and momentum are two such physical quantities. Energy and time form another pair.
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brokenhead
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There have been many good popular books written by physicists since the early 1980's that explore quantum reality and relativity and seek to make these scientific ideas accessible to the public. I found that one book in particular, written by a journalist, had one of the most concise and accurate explanations of the core ideas of "modern physics." That book is The Making of the Atomic Bomb by Richard Rhodes, which I believe won a Pulitzer. It covers the science correctly and is a riveting historical work besides.
