Question about results of double slit experiment

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My apologies if this has recently been on this board. I have read many articles and watched many videos about this experiment, and I seem to be getting two different reports on the result of the double slit experiment. I am not sure which is true, please help.

So one brand of article on the experent indicates that an observation prior to the electon/photon hitting the screenl causes the particle to register on the screen as a classical particle. If it is not observed prior to hitting the screen, it produces wave- like interference patterns on the screen, even if a single particle were fired. This would indicate that there is something about the observation of the particle PRIOR to its hitting the screen which causes it to act like a classical particle. If it is not observed prior to hitting the screen, then it registers on the screen as a wave.

The other report I am getting is that the photon/electron always registers on the screen as a classical particle, but when fired many times the groupings of particles on the screen appear to take on the shape of a wave interference pattern. This would indicate that perhaps the particle acts as a wave and a particle, with the groupings being represented as a equation which demonstrates the probability that an electron acting as a wave will be found at any given point along that wave front. In this experiment, it is not necessary for the particle/wave to be observed before it hits the screen in order for it to behave like a particle. The act of observation at the screen records it every time as a particle. Wave interference patterns only appear when many particles are fired through the slits at the screen.

This is a question about the nature of the experiment and result, nothing more. Thanks in advance for the help!
 
Never done experiment with single photons so I cannot comment on that. My understanding from doing the experiment, is that it is always a wave and that single photons will not act classically.This is at least how my professor explained it when he threw the EQ’s into mathematica and was showing us result on a projector. I think this answered you ? if not maybe I can dig up my old lab reports.
 
What I came up with:

Matt 14: 22 Immediately Jesus made the disciples get into the boat and go on ahead of him to the other side, while he dismissed the crowd. 23 After he had dismissed them, he went up on a mountainside by himself to pray. Later that night, he was there alone, 24 and the boat was already a considerable distance from land, buffeted by the waves because the wind was against it. 25 Shortly before dawn Jesus went out to them, walking on the lake. 26 When the disciples saw him walking on the lake, they were terrified. “It’s a ghost,” they said, and cried out in fear. 27 But Jesus immediately said to them: “Take courage! It is I. Don’t be afraid.” 28 “Lord, if it’s you,” Peter replied, “tell me to come to you on the water.” 29 “Come,” he said. Then Peter got down out of the boat, walked on the water and came toward Jesus. 30 But when he saw the wind, he was afraid and, beginning to sink, cried out, “Lord, save me!” 31 Immediately Jesus reached out his hand and caught him. “You of little faith,” he said, “why did you doubt?” 32 And when they climbed into the boat, the wind died down. 33 Then those who were in the boat worshiped him, saying, “Truly you are the Son of God.”

Ps 42:7 – Deep calls unto deep at the noise of your waterfalls; all your waves and billows have gone over me.

Jonah 2:3 – For You cast me into the deep, into the heart of the seas, and the floods surrounded me; all your billows and your waves passed over me.

James 1: 5-8 If any of you lacks wisdom, he should ask God, who gives generously to all without finding fault, and it will be given to him. But when he asks, he must believe and not doubt, because he who doubts is like a wave of the sea, blown and tossed by the wind. That man should not think he will receive anything from the Lord; he is a double-minded man, unstable in all he does.

I hope this helps 😉
 
Protestor said:
Never done experiment with single photons so I cannot comment on that. My understanding from doing the experiment, is that it is always a wave and that single photons will not act classically.This is at least how my professor explained it when he threw the EQ’s into mathematica and was showing us result on a projector. I think this answered you ? if not maybe I can dig up my old lab reports.
Click to expand...
The looking glass universe series of videos and a series of articles by Andrew Zimmerman jones indicate the first report. The wiki article and an episode of nova hosted by Brian Greene indicate the second report. The videos can be found on YouTube. The articles come up in a google search. I’m confused.
 
The second version.

Whenever observed (whether at the detection screen or before), the photon acts like a particle.
 
And so when they observed that the conglomeration of photons/electrons were hitting the screen in a pattern resembling wave interference, they made the retrodiction that the particle had been behaving as a probability wave?
 
john330 said:
My apologies if this has recently been on this board. I have read many articles and watched many videos about this experiment, and I seem to be getting two different reports on the result of the double slit experiment. I am not sure which is true, please help.

So one brand of article on the experent indicates that an observation prior to the electon/photon hitting the screenl causes the particle to register on the screen as a classical particle. If it is not observed prior to hitting the screen, it produces wave- like interference patterns on the screen, even if a single particle were fired. This would indicate that there is something about the observation of the particle PRIOR to its hitting the screen which causes it to act like a classical particle. If it is not observed prior to hitting the screen, then it registers on the screen as a wave.

The other report I am getting is that the photon/electron always registers on the screen as a classical particle, but when fired many times the groupings of particles on the screen appear to take on the shape of a wave interference pattern. This would indicate that perhaps the particle acts as a wave and a particle, with the groupings being represented as a equation which demonstrates the probability that an electron acting as a wave will be found at any given point along that wave front. In this experiment, it is not necessary for the particle/wave to be observed before it hits the screen in order for it to behave like a particle. The act of observation at the screen records it every time as a particle. Wave interference patterns only appear when many particles are fired through the slits at the screen.

This is a question about the nature of the experiment and result, nothing more. Thanks in advance for the help!
Click to expand...
John
IMO the second article is wrong.
Single particles fired through a double slit will hit the screen only in areas corresponding to a diffraction pattern. They will form a classical pattern if there is only one slit or if they are observed by determining which of the two slits they go through. One explanation invokes the uncertainty principle. Measuring the particles location (the slit) precisely makes the momentum uncertain, (not measureable). Not knowing its precise location (not knowing which slit it goes through) allows you to know the wavelength by measuring the distance between the light stripes of the diffraction pattern. Other explanations invoke the collapse of the wave function. I’ve even read an explanation invoking the many world interpretation of the wave equations.
The bottom line: the phenomenon is real but we really don’t have a solid explanation.
Yppop
 
john330 said:
And so when they observed that the conglomeration of photons/electrons were hitting the screen in a pattern resembling wave interference, they made the retrodiction that the particle had been behaving as a probability wave?
Click to expand...
Correct.

For a mental picture of an idealized version of the experiment, imagine that the detection screen is divided into small pixels, like a digital camera, and that each pixel is a photon detector. If a photon hits a particular pixel, then that pixel amplifies the signal to the point where it is macroscopic, and can be recorded as a hit by the computer analyzing the experiment. Otherwise, the pixel does nothing.

For the first version to be a direct explication of the experiment, each pixel would have to be able to record the value of the wave function at that location, so that the entire wave function could be measured experimentally from just a single photon going through the slits. However, such pixels do not exist.
 
Just_Lurking said:
Correct.

For a mental picture of an idealized version of the experiment, imagine that the detection screen is divided into small pixels, like a digital camera, and that each pixel is a photon detector. If a photon hits a particular pixel, then that pixel amplifies the signal to the point where it is macroscopic, and can be recorded as a hit by the computer analyzing the experiment. Otherwise, the pixel does nothing.

For the first version to be a direct explication of the experiment, each pixel would have to be able to record the value of the wave function at that location, so that the entire wave function could be measured experimentally from just a single photon going through the slits. However, such pixels do not exist.
Click to expand...
Sweet. Now I understand. The particle certainly behaves as a particle, but may behave as a wave as well…of this it is impossible to be certain. Particle-wave duality is likely, but is only an educated guess at this point. Some of the literature out there over emphasizes the importance of observation in the experiment, as if the observer has a magical influence over the form that light takes. Thank you.
 
Just_Lurking said:
Correct.

For a mental picture of an idealized version of the experiment, imagine that the detection screen is divided into small pixels, like a digital camera, and that each pixel is a photon detector. If a photon hits a particular pixel, then that pixel amplifies the signal to the point where it is macroscopic, and can be recorded as a hit by the computer analyzing the experiment. Otherwise, the pixel does nothing.

For the first version to be a direct explication of the experiment, each pixel would have to be able to record the value of the wave function at that location, so that the entire wave function could be measured experimentally from just a single photon going through the slits. However, such pixels do not exist.
Click to expand...
yppop said:
John
IMO the second article is wrong.
Single particles fired through a double slit will hit the screen only in areas corresponding to a diffraction pattern. They will form a classical pattern if there is only one slit or if they are observed by determining which of the two slits they go through. One explanation invokes the uncertainty principle. Measuring the particles location (the slit) precisely makes the momentum uncertain, (not measureable). Not knowing its precise location (not knowing which slit it goes through) allows you to know the wavelength by measuring the distance between the light stripes of the diffraction pattern. Other explanations invoke the collapse of the wave function. I’ve even read an explanation invoking the many world interpretation of the wave equations.
The bottom line: the phenomenon is real but we really don’t have a solid explanation.
Yppop
Click to expand...
Yes, I am beginning to understand this. Knowing the position of the particle takes the focus off of its wave function, thus focusing on where it is rather than how it acts through time. Focusing on its wave function causes us to learn more about all of its parameters and less about where the particle is in the wavefront. Thanks so much!
 
Anyone who thinks they can " see " a single photon and to determine its causality is dreaming.

Linus2nd
 
Linus,
I am sure you have a vast supply of Aquinas’ thoughts stored in your neurons, which you use effectively when engaged in philosophical and/or theological arguments and I for one would never challenge you in those areas of knowledge. And if Aquinas made the statement “anyone who thinks they can " see " a single photon and to determine its causality is dreaming”: he would be correct because the only thing he had to see with was his own eye. And this from Wikipedia: "Although the retina can respond to a single photon, the neural filters only allow a signal to pass to the brain to trigger a conscious response when at least about five to nine arrive within less than 100 ms. If we could consciously see single photons we would experience too much visual “noise” in very low light, so this filter is a necessary adaptation, not a weakness".

On the other hand, immersing yourself in 13th century knowledge may have hampered your ability to dream, especially about single photons, something Aquinas could also not dream about. However there are dreamers that dream about “seeing” single photons and have made their dreams come true. There are ways the dreamers have developed that allow us to "see’ a single photon

youtube.com/watch?v=GzbKb59my3U

Yppop

.
 
The thing about photons, given that they are the whereby we see things: we are not going to see them. We might know of their behaviour, but seeing them? I don’t think so.
We can talk about seeing them in our mind’s eye because techniques involving the extension of our vision seem to be the primary way we have in science to know things. We like to reduce things to a visual model to make it understandable. No one is talking about what a photon tastes like, even though it is no more absurd that asking what it would look like IMHO. I haven’t thought this all out but I thought I’d share.
 
Thinking about this further on the way to and from the (not liquor) store, I think I do “taste” photons; their taste is the “spectrum” of events in the visual world that helps me connect with reality.
 
…like sun-dried tomatoes and lumps of coal, both are stored sunlight…
 
Aloysium said:
The thing about photons, given that they are the whereby we see things: we are not going to see them. We might know of their behaviour, but seeing them? I don’t think so.
We can talk about seeing them in our mind’s eye because techniques involving the extension of our vision seem to be the primary way we have in science to know things. We like to reduce things to a visual model to make it understandable. No one is talking about what a photon tastes like, even though it is no more absurd that asking what it would look like IMHO. I haven’t thought this all out but I thought I’d share.
Click to expand...
You need to think that out. Ask yourself what do you see if not light? And if light is photons, what do you see if not photons?
 
yppop said:
On the other hand, immersing yourself in 13th century knowledge may have hampered your ability to dream, especially about single photons, something Aquinas could also not dream about.
Click to expand...
Light was one of many things Thomas got wrong. He thought it was instantaneous:

newadvent.org/summa/1067.htm (I, 67, 2)

His sentence “For if light were a body, it would follow that whenever the air is darkened by the absence of the luminary, the body of light would be corrupted” is reminiscent of this April Fool’s paper about “darkons”:

wearcam.org/theory_of_darkness.html 😃
 
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