T
Thing
Guest
Anyone like to try explaining it. How a photon can be in two places but not at the same time.
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B
Bob_Crowley
Guest
Double or nothing?Anyone like to try explaining it. How a photon can be in two places but not at the same time.
J
James_S_Saint
Guest
Did you mean “explain the principles”? Or the religion?Anyone like to try explaining it. How a photon can be in two places but not at the same time.
B
Bob_Crowley
Guest
I assume this is the sort of thing you’re talking about, which I lifted off the web. I think Quantum Physics would be fascinating, but I know next to nothing about it. I’d like to know more, but I would have to teach myself as I would be unlikely to take a degree in it.Anyone like to try explaining it. How a photon can be in two places but not at the same time.
Can you recommend any good books on the subject which a reasonably intelligent (well, able to read and write) layman might find informative?
The web description is below.
"This description assumes an understanding of Interference and Diffraction. Go and check it out if you haven’t already.
When you think about light as a collection of photons, the bands created on a screen when you shine a light through a diffraction grating actually represent the statistical probability that a photon will hit that part of the screen.
This is easier to understand if you allow only a few photons through to the slits. If you only have one slit, the screen would look like this: (diagram not repeated here).
The photons will hit the screen mostly in the direct line of sight
from the slit. Thus, the probability is higher that a photon will hit
in the direct line of sight of the slit than in places far away from the slit.
If you have two slits, the probability changes because of interference:
A higher concentration of photons exists at the bands.
But what if you only let one photon at a time go through a two slit grating? You would expect the scatter of photons on the screen to look like the scatter from a one slit grating, since a single photon has nothing to interfere with. After all, if a single photon goes through one slit, how can it “know” that the other slit even exists?
But, to the great surprise of quantum physicists, the scatter of the photons let through one at a time is identical to the scatter of the photons let through all at once! The photon did somehow “know” about the other slit. So which slit does a single photon go through? The answer is the photon goes through both slits at the same time. The photon(according to modern theory) becomes two ghost photons, allowing a single photon to interfere with itself. Hard to imagine? You’re in good company."
T
Thing
Guest
Thats exactly it. A photon in two places but not at the same time.
T
Thing
Guest
Photons don’t have Mass, or do they…
J
James_S_Saint
Guest
They have what is called “rest mass” when they “land” or are absorbed. But while in flight, they have merely momentum. The distinction had to be made to make the math work out right.
Wiki:
J
Just_Lurking
Guest
T
Thing
Guest
Thanks guys.
J
James_S_Saint
Guest
An easy way to understand what photons are doing is to imagine them somewhat as a bicycle wheel spinning radially at the speed of light while also traveling along its axis at the speed of light.
The outer tire is the “expansion wave” portion of the energy involved. The “spokes” and axle are the “compression” portion of the energy that holds the outer tire in orbit.
But now imagine that spinning wheel approaching the ground at an angle with a “clockwise spin” as seen from behind. As the spinning wave touches the ground, it reflects back up. But if you now look at that wave, again from behind, you will see that it has the opposite spin - counter-clockwise. Reflections cause photons to reverse their spin.
But the more interesting effect is when these spinning waves interfere with each other and a detector. Because they are spinning at the speed of light, they have inherent inertia laterally and thus have “particle” type properties. But because they are only spinning in 2 dimensions and traveling at the speed of light vectorially, they also have wave characteristics void of inertia along that vector.
In effect, they are half way to becoming a particle. If you merely spin them in the transverse direction, flipping on their axis, they would become inertial particles that could no longer travel so fast nor display wave interferences because they would bounce off of each other rather than merely interact with their spinning waves.
The outer tire is the “expansion wave” portion of the energy involved. The “spokes” and axle are the “compression” portion of the energy that holds the outer tire in orbit.
But now imagine that spinning wheel approaching the ground at an angle with a “clockwise spin” as seen from behind. As the spinning wave touches the ground, it reflects back up. But if you now look at that wave, again from behind, you will see that it has the opposite spin - counter-clockwise. Reflections cause photons to reverse their spin.
But the more interesting effect is when these spinning waves interfere with each other and a detector. Because they are spinning at the speed of light, they have inherent inertia laterally and thus have “particle” type properties. But because they are only spinning in 2 dimensions and traveling at the speed of light vectorially, they also have wave characteristics void of inertia along that vector.
In effect, they are half way to becoming a particle. If you merely spin them in the transverse direction, flipping on their axis, they would become inertial particles that could no longer travel so fast nor display wave interferences because they would bounce off of each other rather than merely interact with their spinning waves.
Y
yppop
Guest
Thing
Bob Crowly quote
Another explanation of the double slit exp. uses the concept of parallel universes to hypothesize a “shadow” photon to provide the interference (CH2. of The Fabric of Reality, David Deutsch).
I assume this is the sort of thing you’re talking about, which I lifted off the web. I think Quantum Physics would be fascinating, but I know next to nothing about it. I’d like to know more, but I would have to teach myself as I would be unlikely to take a degree in it.
Bob Crowley
Masters by Gary Zokov.
Most books that I have read, (I am always on the look out for new ones) deal mostly with cosmology, string theory, and parallel universes. Few books are totally devoted to quantum mechanics. However you can find extended discussion of “quantum weirdness”, in the following:
*The Self-Aware Universe *by Amit Goswami
*The Elegant Universe *by Brian Greene.
If you want to expand your knowledge of modern science, just about any book by Paul Davies is worth your time.
Yppop
That’s easy. Imagine a photon at point A that one second later is at point B. Same photon in two separate places, not at the same time. The big mystery—and I think this is what you meant to say—is that a single photon can be in two separate places, AT THE SAME TIME. This is called the principle of superposition.
Bob Crowly quote
The infamous double slit experiment as you described is explained (??) by what is called the complementary principle, which implies that a quantum entity is either a wave or a particle depending on how a person sets up the experiment to observe it. That takes care of this bit of quantum weirdness with a hand wave. However there is another aspect of the double split experiment that you didn’t mention and that is: if a single photon passes through a single slit and the second slit is opened AFTER the photon passes through the single slit, the photon will land only in locations associated with an interference pattern.
Another explanation of the double slit exp. uses the concept of parallel universes to hypothesize a “shadow” photon to provide the interference (CH2. of The Fabric of Reality, David Deutsch).
I assume this is the sort of thing you’re talking about, which I lifted off the web. I think Quantum Physics would be fascinating, but I know next to nothing about it. I’d like to know more, but I would have to teach myself as I would be unlikely to take a degree in it.
Bob Crowley
The popular primer on QM, (an old book) is The Dancing Wu Li
Masters by Gary Zokov.
Most books that I have read, (I am always on the look out for new ones) deal mostly with cosmology, string theory, and parallel universes. Few books are totally devoted to quantum mechanics. However you can find extended discussion of “quantum weirdness”, in the following:
*The Self-Aware Universe *by Amit Goswami
*The Elegant Universe *by Brian Greene.
If you want to expand your knowledge of modern science, just about any book by Paul Davies is worth your time.
Yppop
E
Ender
Guest
This is great. I like the analogy. I don’t understand it, but I like it. I’m having trouble grasping how something without mass can spin.
Ender
M
MindOverMatter
Guest
Well… if its impossible for one photon to be in two places at the same time; then the only possible way round it is to say that the same photon is being seen in two places but in two different time states brought together into in one instant.Anyone like to try explaining it. How a photon can be in two places but not at the same time.
Otherwise, one has to believe that the logically impossible can happen.
However, if that which is necessarily real, necessarily imposes a state of irrationality as its logical end, then perhaps in that respect the logically impossible can happen so long as its the natural outgrowth of a logical absolute. But i don’t believe that.
J
James_S_Saint
Guest
I’m currently trying to put together a book to explain this stuff and I could go on forever with it, but without pictures it gets very difficult to envision from merely words.
Mass is not actually a “thing” really. It is an effect. When a wave is altering space as fast as logically/mathematically possible, any other field trying to enter that space basically bounces off of the leading ramp of the initial change wave. This is how things become “hard” and particle like. The exact manner the wave is spinning is what produces its inertial, magnetic, and gravitation properties.
A spin is maintained due to the inner most portion of a wave pulling in (contracting), like having an proton at the center except there is no particle there, while the outer ring is trying to expand and would be like a electron stretched into a ring shape, but again, there is no actual particle involved. The outer ring is held in place by its effort to travel tangent to the radius while the inner contracting forces are trying to pull it into the center. It is very similar to an orbiting bit of matter being held in place by gravity. You need to read the book.
But that same picture of the spinning wheel can be used to understand why things cannot travel faster than light and why relative time slows at such extreme speeds.
Picture that same wheel traveling in the plane of its spin rather than in the direction of its axle. Even spinning in place at one point along the edge, the outer wave is traveling at the speed of light. This speed is a logical maximum that literally nothing in any universe could ever exceed.
But now imagine that wheel is getting pushed such that the rest of the wheel is traveling near that same speed laterally. That one point on the wheel could never have been accelerated faster than it was already going. That means that the “spokes” of the wheel have to bend in order to maintain the spinning while the wheel increases in lateral velocity.
At a maximum speed for the entire wheel, all points on the wheel would have to be going the same speed in the same direction and thus not actually spinning at all. The wheel would have to be flat.
But those “spokes” do not bend quite so easily, because even though they are not traveling AT the speed of light, they are close already even when the wheel is spinning in place and more over, they get compressed such as to increase density. That takes serious effort because every wave is trying to alter its space as fast as possible. The more dense the space becomes, the harder it is to alter.
Thus moving a tiny particle at the speed of light requires an infinite amount of energy because you are trying to make the wheel change space faster than logically possible. You are trying to create a discontinuity in space with the leading wave ramp becoming exactly vertical. This would require that space instantaneously change from one state to another as the wheel spun. Such instantaneous alterations are logically impossible.
And in addition, the time slows because as the density of the space increases, it takes longer to change it. Thus the propagation speed reduces and everything about the particle takes longer. We measure that “space density” issue as gravity or a “mass field”.
Quantumization is another interesting effect that arises down the road a bit, but is much like a drop of water always being basically the same size while dripping out of a buck.
T
Thing
Guest
Let us know when your book is ready, I’ll pick up a copy.
J
James_S_Saint
Guest
Well thank you, but that might be a long time.
Although from what I am hearing, I only have until Dec 21, 2012.
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Nyarlathotep
Guest
Wow. For some reason the hours and hours I spent listening to the Feynman Lectures all of a sudden make sense now.
It sounds like you’re well on your way to writing a terrific book. Take heed, however: make sure to nail down all the theory so that even idiots like me can get it (e.g., explaining that mass is not a “thing” is tremendously helpful), before getting into all that math-y type stuff.
(P.S., notice that all the Catholics tend to spell “Mass” with a capital “M”. Old habits…)
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James_S_Saint
Guest
Well thank you.
I very much believe in what my signature says. Unfortunately, I am not all that good at it. All I can do is keep trying.
H
hecd2
Guest
I am interested in your ideas here. Now, to be accepted, any new ideas in science need not only to explain the new unexplained phenomenon better than existing theories, but explain all the other stuff the existing theories explain at least as well as they do.I’m currently trying to put together a book to explain this stuff and I could go on forever with it, but without pictures it gets very difficult to envision from merely words.
Mass is not actually a “thing” really. It is an effect. When a wave is altering space as fast as logically/mathematically possible, any other field trying to enter that space basically bounces off of the leading ramp of the initial change wave. This is how things become “hard” and particle like. The exact manner the wave is spinning is what produces its inertial, magnetic, and gravitation properties.
A spin is maintained due to the inner most portion of a wave pulling in (contracting), like having an proton at the center except there is no particle there, while the outer ring is trying to expand and would be like a electron stretched into a ring shape, but again, there is no actual particle involved. The outer ring is held in place by its effort to travel tangent to the radius while the inner contracting forces are trying to pull it into the center. It is very similar to an orbiting bit of matter being held in place by gravity. You need to read the book.
But that same picture of the spinning wheel can be used to understand why things cannot travel faster than light and why relative time slows at such extreme speeds.
Picture that same wheel traveling in the plane of its spin rather than in the direction of its axle. Even spinning in place at one point along the edge, the outer wave is traveling at the speed of light. This speed is a logical maximum that literally nothing in any universe could ever exceed.
But now imagine that wheel is getting pushed such that the rest of the wheel is traveling near that same speed laterally. That one point on the wheel could never have been accelerated faster than it was already going. That means that the “spokes” of the wheel have to bend in order to maintain the spinning while the wheel increases in lateral velocity.
At a maximum speed for the entire wheel, all points on the wheel would have to be going the same speed in the same direction and thus not actually spinning at all. The wheel would have to be flat.
But those “spokes” do not bend quite so easily, because even though they are not traveling AT the speed of light, they are close already even when the wheel is spinning in place and more over, they get compressed such as to increase density. That takes serious effort because every wave is trying to alter its space as fast as possible. The more dense the space becomes, the harder it is to alter.
Thus moving a tiny particle at the speed of light requires an infinite amount of energy because you are trying to make the wheel change space faster than logically possible. You are trying to create a discontinuity in space with the leading wave ramp becoming exactly vertical. This would require that space instantaneously change from one state to another as the wheel spun. Such instantaneous alterations are logically impossible.
And in addition, the time slows because as the density of the space increases, it takes longer to change it. Thus the propagation speed reduces and everything about the particle takes longer. We measure that “space density” issue as gravity or a “mass field”.
Quantumization is another interesting effect that arises down the road a bit, but is much like a drop of water always being basically the same size while dripping out of a buck.
Let’s stick with the OP and consider light and photons. The question was about the quantised Young’s experiment. I don’t think your explanation involving the analogy of bicycle wheels actually addressed this specific observation. Would you like to expand on how the quantised Young’s experiment is explained by your ideas?
Let’s now consider elementary diffraction theory - you should be able to use your formulation to arrive at the Fresnel-Kirchoff diffraction integral or something equivalent for the general case of diffraction at an aperture. You should then be able to solve the general case for particular cases of Fraunhofer diffraction, say a rectangular aperture, involving decaying sinusoids of the form sin(x)/x; or for a circular aperture in the form of Bessel functions. Can you? And we haven’t asked anything about rigorous diffraction theory involving surface currents.
By the way, the idea of pure logical/mathematical limits to the speed of light and other bodies seems strange. The speed of light in vacuo is finite - I’d be interested in any *mathematical *or *logical *argument that limits action to this speed independent of observation. There is no way that I know of to sit in a darkened room with a wet towel round your head and *mathematically *or *logically *prove that there is a speed limit of exactly 299,792,458 metres per second in this and every conceivable universe.
Alec
evolutionpages.com
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MindOverMatter
Guest
Perhaps we cannot measure the particular speed of light with pure logic, but surely if we agree that logical truth applies to and is known from our experience of the real, then we can certainly know what is ontologically impossible.
What is meaningful about the idea of light moving at an infinite speed?
There is no meaning in that idea.
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