Another Role for Corpuscles in the Double-Slit Experiment?
Under the current theory for light, it is alleged to have both wavelike and particle-like properties, called the “wave-particle duality.” One of the earliest experiments indicating the wavelike aspect was the “double-slit” experiment performed by Young in 1801 (graphic above).
At that time, it allegedly refuted Newton’s postulate of a particle nature to light in favor of light being purely a wave. Not until the discovery of the photoelectric effect a century later did light’s potential behavior as a particle become rejuvenated. This paper examines how the particle nature of light may be consistent with its wavelike behavior via analysis of the double-slit experiment from a particle perspective.
Another Role for Corpuscles in the Double-Slit Experiment?
Raymond HV Gallucci, PhD, PE
8956 Amelung St., Frederick, Maryland, 21704
e-mails: [email protected], [email protected]
The classic double-slit experiment, first performed by Young in 1801, is often cited as proving the dual wave-particle nature of light, with an emphasis on the wave aspect. In fact, when first conducted, the conclusion refuted Newton’s postulate of a corpuscular nature to light in favor of light being purely a wave.
Not until the discovery of the photoelectric effect did light’s potential behavior as a particle become rejuvenated. This paper examines a possibly enhanced role for light’s corpuscular nature beyond what is currently assigned as a result of the double-slit experimental results in hope of opening yet another avenue of exploration into the still mysterious nature of light.
- Introduction
The double-slit experiment suggests the alleged wave-particle duality of light. First performed by Young in 1801, this experiment splits a light wave into two that later combine via a phase shift to create an interference pattern. Reputedly it is the wave nature of light that causes the interference, producing bright and dark bands on a screen – a result that would not be expected if light consisted of particles. However, the light is always absorbed at discrete points as individual particles (not waves). Furthermore, detectors at the slits find that each detected photon passes through one slit (as would a classical particle), and not through both slits (as would a wave), suggesting wave–particle duality. Electrons also exhibit the same behavior when fired toward a double slit. [1]
When the “single-slit experiment” is conducted, the pattern is a diffraction pattern in which the light is spread out rather than one corresponding to the size and shape of the slit, expanding as the slit width decreases. When Young first demonstrated this phenomenon, it indicated that light consists of waves vs. Newton’s corpuscular theory, later rejuvenated via the photoelectric effect. Today the double-slit experiment is used to support light having both wave and corpuscular properties, the former usually being easier to comprehend from the results than the latter. This paper attempts to offer one possible avenue of exploration to support the latter.
- Light as Corpuscles
Assume that a photon can be represented by a ball bearing (incompressible), but that its collision with an impenetrable barrier in which there is a slit wide enough for the ball to pass through cleanly will be less than totally elastic. If the ball hits the barrier head-on (impact angle α of 0), it is stopped completely, implying that the ‘reaction’ vector is exactly equal to the ‘impact’ vector (assumed, for convenience, to have a magnitude [length] of unity). For less than head-on impacts (up to a ‘just miss’ at α = 90o), the reaction vector will have length < 1 at angle α, deflecting the ball while still allowing it to pass through the slit at an angle θ = 90o – α). This is illustrated in Figures 1 and 2. The impact vector will always have length 1 downward vertically. The reaction vector will have length = cos α with vertical and horizontal components of (cos α)2 and (sin α)(cos α). Therefore, the ‘deflection’ vector will be the vector sum of the impact and reaction vectors, with length = ([1 – {cos α}2]2 + [sin α]2[cos α]2)1/2 and direction θ = 90o – α relative to vertically downward.
Passing through a single slit, a symmetric pattern peaked at the center will result on a screen placed parallel to the barrier. As the balls travel past the screen (some deflected, most not), they will strike the screen at a horizontal location of cos θ. If we make a leap of faith and assume the intensity at each screen position is proportional to the length of the deflection vector, the pattern shown in Figure 3 results, based on the calculations from Table 1. This leap of faith represents the assumption that most balls pass through the slit without deflection, leading to peak intensity toward the center, which is represented by the length of the deflection vector as shown in Table 1 (deflection angle = 90o).
To expedite subsequent calculations using the screen pattern, a regression fit to the data in Table 1 (representing the ‘right side’ of the curve in Figure 3, i.e., for horizontal position ≥ 0) yielded the following, also shown in Figure 3: [2]
y = 1.701/(x + 1.524), x ≥ 0
where y = length (of deflection vector) and x = horizontal position. The ‘left side’ of Figure 3 is just a mirror image of the right. The result somewhat resembles the typical pattern exhibited by single slit diffraction (Figure 4), albeit with a sharper peak.
Now consider the double slit counterpart where the ball bearings are shot through two slits a distance of 0.5 unit apart (relative to the horizontal scale on the screen). If there is no interaction among the balls after passing through the slits, the expected screen pattern would just be the summation of two single-slit patterns with center peaks 0.5 unit apart, as shown in Figure 5.
Figure 1. Geometry of Ball Bearing Impact with Slit Barrier
Figure 2. Schematic for Reaction Vector
Table 1. Data for Single Slit Screen Pattern
Figure 3. Single Slit Screen Pattern (Scaled)
Figure 4. Diffraction Pattern for Single and Double Slit Experiment [3]
What if the ball bearings collide with one another after passing through the slits? This, is not expected to occur for the single slit arrangement, since each ball bearing, representing a photon, retains its initial speed even after impacting the barrier; so any two passing even very close, but still ever so slightly offset, in time will never collide even if their trajectories intersect. With the double slit arrangement, multiple balls can pass, some deflected, such that intersecting trajectories, with just the right time offset, can result in (assumedly) totally elastic collisions between a pair. These would rebound off one another and continue at their pre-collisional speed and reverse deflection angle. Figure 6 illustrates the presumed geometry.
While ‘outward’ collisions are possible, I assume the propensity for these to be much less than that for ‘inward’ collisions, so outward collisions are ignored. From Figures 1 and 2, with the results from Table 1, the deflection vectors’ length and direction, V(θ) and W(ϕ) in Figure 6, are known. Therefore, assuming D = 0.5 (distance between slits), the following transcendental equation can be solved to obtain the horizontal locations where the deflected balls strike the screen after collision:
V(θ)2 + W(ϕ)2 = (0.5)2 + 2V(θ)W(ϕ)cos(θ + ϕ)
Solutions to this equation are provided for the range of impact angles from 0 to 90o in Table 2.
An interesting property of the family of results is symmetry about impact angles for vector 1 of 15o and 75o, with no solution between 30o and 60o. For the lower range of impact angles, collisions satisfying the transcendental equation occur when the sum of the deflection angles (θ + ϕ) = 150o, with each angle constrained to the range from 60 to 90o. Over this range, the pair of ball bearings strike the screen between horizontal locations -23.4 to -11.6 and 11.6 to 23.4. For the upper range of impact angles, collisions satisfying the transcendental equation occur when the sum of the deflection angles (θ + ϕ) = 30o, with each angle constrained to the range from 0 to 30o. Over this range, the pair of ball bearings strike the screen between horizontal locations -0.20 to -0.08 and 0.08 to 0.20, essentially indistinguishable from the central peak and constrained within the distance between slits of 0.5 (-0.25 to 0.25).
To illustrate the possible effect of these ‘preferred collisions’ and their potential resultant ‘buildup’ at the horizontal locations on the screen, we arbitrarily double the length of the deflection vectors shown for the ranges of horizontal locations in Table 2 for the lower range of impact angles for vector 1 (i.e., -23.4 to -11.6 and 11.6 to 23.4 for impact angles from 0 to 30o) for the summation shown in Figure 5. The result is Figure 7.
Figure 5. Non-Interacting Double Slit Screen Pattern (Scaled)
While this only crudely approximates just one pair of secondary peaks for the double slit pattern shown in Figure 4, it nonetheless offers a potential avenue of investigation toward the possibility that at least part of the explanation for the unique diffraction pattern for light in the double slit experiment could arise from light’s corpuscular nature. One might imagine that with better modeling of the potential for collisions between photon corpuscles after passage through the double slit, peaks other than just the central might result, perhaps approaching the pattern currently attributed exclusively to the wave nature of light.
- Summary
The double-slit experiment is often cited as indicating the dual wave-particle nature of light, with the emphasis on the wave aspect, which is usually easier to comprehend. Any corpuscular behavior by light is limited to absorption at discrete points as individual particles and detectors at the slits suggesting that a photon passes through one slit (as would a classical particle), and not through both slits (as would a wave). This paper attempts to offer one possible avenue of exploration to support an enhanced role for the corpuscular nature of light than has previously been attributed.
- References
- https://en.wikipedia.org/wiki/Double-slit_experiment.
- http://www.xuru.org/rt/NLR.asp#CopyPaste.
- http://www.bing.com/images/search?q=double+slit+ diffraction&qpvt=double+slit+diffraction&qpvt=double+slit+diffraction&FORM=IGRE.
Figure 6. Assumed Geometry for Ball Bearing Collisions after Passing ‘Inward’ through Double Slits
Table 2. Solutions to Transcendental Equation for ‘Inward’ Collisions
Figure 7. Interacting Double Slit Screen Pattern (Scaled)
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jerry krause
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Hi Raymond,
In Physics by Marshall and Pounder I read: “In order to obtain two sources of light in phase with each other, pass light through a very narrow slit, from which because of diffraction it will spread out considerably in direction. Let this light illuminate some distance further along it path two narrow slits, close together.”
This does not seem to be the situation you describe with words and illustrate with a figure.
Have a good day, Jerry
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Ray Gallucci
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Figure 6 shows light, as corpuscles, passing through the pair of narrow slits. A typical schematic is shown in https://en.wikipedia.org/wiki/Double-slit_experiment. I have only a single light source, which by its very nature must be in phase with itself. Figure 4 matches the traditional schematic for this experiment in the reference. Figure 1 shows the situation per slit, which is then combined later for the double slit when the calculations are performed.
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jerry krause
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Hi Ray,
Thank you responding to my comment.
Bob Beatty brought the following to my attention.
https://www.sciencenews.org/blog/scicurious/wikipedia-science-reference-citations?utm_source=email&utm_medium=email&utm_campaign=latest-newsletter-v2
I checked out the wikipedia article to which you referred. The first figure there shows electrons (a particle because it has a tiny rest mass) being shot from a point source. Hence, these electrons have a near single trajectory when they encounter the double slits. In your model you have your ball bearings encountering the double slits with a distribution of trajectories. Which you use to give the same result as an electron as a wave.
I understand the single slit described by Marshall and Pounder was to produce photons with a single trajectory, that they acknowledge will be diffracted by passing through the single slit.
A problem with what you propose is that it cannot be tested unless the size of your ball bearings approach the size of electrons.
Have a good day, Jerry
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Ray Gallucci
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The “ball bearing” was just an image for the concept of a light “corpuscle” (which those who believe light is composed of particles would call a photon). No actual sizes were suggested, nor could any version of this experiment determine if light was indeed a particle or wave or some combination IF the result is the diffraction pattern typically associated with a wave. My goal was just to offer an option which would allow a corpuscular nature of light to be consistent with what is typically assumed to be an experiment “proving” light to be a wave. I am on the fence as to the true nature of light, but feel that, if it is truly a wave, then some sort of medium is involved (typically termed an “aether”).
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jerry krause
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Hi Ray,
Thank you again for your response. This what science should sometimes be. We need to establish what another is considering and why.
“My goal was just to offer an option which would allow a corpuscular nature of light to be consistent with what is typically assumed to be an experiment “proving” light to be a wave. I am on the fence as to the true nature of light, but feel that, if it is truly a wave, then some sort of medium is involved (typically termed an “aether”).”
I have recently written to John O’ about a fact I have observed. Also no one writing for or against the GHE considers any quantum mechanical ideas.
Why do you suppose this is? I consider that Richard Feynman in The Feynman Lectures on Physics answered this question: In the 3rd Volume he began: “Quantum mechanics is the description of the behavior of matter and light in all its details and, in particular, or the happenings on an atomic scale. Things on a very small scale behave like nothing that you have any direct experience about. They do not behave like waves, they do not behave like particles, they do not behave like clouds, or biiliard balls, or weights on springs, or like anything you have ever seen. … Because atomic behavior is so unlike ordinary experience, it is very difficult to get used to, and it appears peculiar and mysterious to everyone–both to the novice and to the experienced physicist. Even the experts do not understand it the way they would like to, and it is perfectly reasonable that they should not, because all of direct, human experience and of human intuition applies to large objects.”
It is true that “all of direct, human experience applies to large objects.” But it is not true that no human intuition applies only to large objects.
About an year earlier Linus Pauling wrote, in his preface to the 3rd Ed. of College Chemistry: “The theories of greatest value in modern chemistry are the theories of atomic and molecular structure, quantum theory (quantum mechanics), and statistical mechanics. I believe that the concepts involved in these theories can be learned by the beginning student of chemistry sufficiently well for him to apply them in correlating and understanding the facts of descriptive chemistry. Moreover, the fundamental experiments upon which these theories are based can be understood by the beginning student. The theories in their detailed mathematical treatment can then by studied later.”
You agree with Feynman and state I have to rationally understand small matter (atoms, electrons, light, etc) to the extent I will substitute my rational reasoning for what cannot be correct because I cannot understand it.
Note: Pauling referred to the experiments of physicists which results forced them (physicists) to turn to the ideas of quantum mechanics which did explain what had indirectly been observed.
Thank you for the opportunity to share this with you in a natural sort of way.
Have a good day, Jerry
“
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jerry krause
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Please correct my lack of proofreading.
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Ray Gallucci
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I did not advocate you abandon rational reasoning in any of my responses. I only clarified what MY reasoning was in developing this alternative explanation for the double-slit diffraction pattern supposedly explainable only by light as a wave and not as a particle. You are free to question whatever and however you wish. My only goal in responding was to clarify what I thought might be misunderstanding or misinterpretation. I, too, find quantum mechanics “mysterious” and am not a fan of quarks and “particles” below the proton-neutron level (even neutrinos require a stretch of belief).
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jerry krause
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Hi Ray,
If rational reasoning is accepting what, cannot be explained, simply because it works; I do not abandon rational reasoning. For long ago Newton stated he accepted gravity because it works even though he had no idea of its cause.
But I still do not understand why you have trouble accepting that a electron is diffracted just as radiation (a light wave or a photon) is. And why do you see a need of an “aether”.
EnergynEntropy
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What puzzles is where all the energy required to sustain infinite states for Schrödinger’s cat coming from?
The cat is dead, the cat is alive, the cat dying, jumping, crawling, sitting, laying, and so on?
On Earth, the best of Internal Combustion Engines wouldn’t make it beyond 6 million km of useful energy-travel when it ultimately starts failing and disintegrating, and that with regular oil and filter change?
Why we never find the engine turning a near brand-new after that service, but in the junkyard?
Surprisingly, though, in each and every time, the useful energy produced by the engine never exceeds the energy put into constructing it?
Shouldn’t quantum mechanics be revisited and put in the context of Energy & Entropy?
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Ray Gallucci
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I just wanted to point out that I did not “state [that you] have to rationally understand small matter (atoms, electrons, light, etc) to the extent [you] will substitute [your] rational reasoning for what cannot be correct because [you] cannot understand it.” That was your statement, not mine. Regarding electrons, I have not even addressed electron diffraction in my article, although as a particle it could also exhibit similar behavior in double slit diffraction as a light “particle” according to my proposal. But I don’t see the need for a medium for electron propagation since it is not envisioned as traveling at a constant speed. The whole goal of my analysis was to show that light, as a particle, could still exhibit a diffraction pattern in the absence of a medium. It is not diffraction that leads me to believe light requires a medium, but its alleged constant speed, characteristic of a wave, not a particle. That was the subject of my other articles. Here I only look at diffraction and the possibility that a particle could exhibit a wave-like pattern without actually having a wave-like nature.
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jerry krause
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Hi Ray,
“The whole goal of my analysis was to show that light, as a particle, could still exhibit a diffraction pattern in the absence of a medium.”
What do you mean by “in the absence of a medium”?
You conclude: “Here I only look at diffraction and the possibility that a particle could exhibit a wave-like pattern without actually having a wave-like nature.”
I ask: Why doesn’t a ball bearing have a wave-like nature as an electron (a particle) has a wave-like nature?
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ray gallucci
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An electron may or may not be a particle (if there is an aether, it could be some manifestation of that?), but if it is, it could exhibit a wave-like diffraction pattern via the double slit experiment as would a ball bearing or a light particle via the mechanism I develop in my article. Since the accepted theory is wave-particle duality for light, matter, etc., mainstream does not try to answer the potential contradiction, but merely says the entity behaves like a particle when it needs to or like a wave when it needs to. My more recent article on light as a matter wave examines others’ theories which attempt to explain this apparent paradoxical behavior. In this article, I onIy attempted to show that one could obtain the wave-like diffraction pattern without requiring the entity to have the dual nature – a particle nature alone could suffice. Since no one knows what electrons, light (photons), sub-atomic “particles,” etc., really are, there is plenty of room for speculation, even if mainstream physics says the topic is closed. “Absence of a medium” means I do not require an “aether” for the diffraction pattern of the double-slit experiment in my article. Also, that I suspend disbelief in the constancy of light speed if there is no medium to force it to behave like a wave. But, as I show in my more recent article, others have developed theories that allow light’s wave-like behavior without an “aether.”
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Bob Builder
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I invite those interested to take a look at de Broglie-Bohm Pilot Wave Theory… a deterministic, predictive and non-local (just as quantum mechanics is) theory which explains the wave-like behavior of particles (and the particle-like behavior of waves) without conflating the two, while remaining in complete agreement with General Relativity, and while resolving several of the problems inherent in the Copenhagen Interpretation, such as the measurement problem.
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