# Exploring the Three Slit Interference Pattern: Differences and Effects

• sqljunkey
In summary, the interference pattern with three slits is the same as with two slits. There is no difference.
sqljunkey
sqljunkey said:

Based on this I was wondering how the interference pattern with three slits instead of two would look. Is there a difference; is there more interference fringes? Or does the interference pattern become more pronounced since there is more light coming from a third slit.
The answer would depend on the level at which you are actually asking the question. Before launching into the quantum nature of this, it is best to grasp fully the classical wave approach. Many threads like this one take two parallel quadrature paths with loads of misunderstandings of what people are actually saying.
They say (not surprisingly) that superposition seems to apply here - when done properly. It's a scenario that I have never thought about but it is 'reasonable'. However, it cannot be something that can be detected in everyday life because the effect would be so small and hard to detect. There must be a finite probability that photons could creep along the surface of the plate and emerge from another slit. Yet again, I look for analogous behaviour in an RF model with three radiating elements and there would be no surprise to find currents flowing across the support structure from one side to the other and radiating from other (effectively parasitic) elements. The wave approach doesn't involve the 'S shaped path' that is suggested by the diagram in the link (and I think that there may be a bit too much made of that form of interpretation) - an unspecified path for the Energy ("coupling") would suffice.
"Is there a difference; is there more interference fringes?" The ideal three slit pattern is easy to calculate. Here is a link. There are no surprises in the ideal result and it would be reasonable to add in some other contributions from small delayed contributions to the outer slit waves. That would be one step up in complexity.
Whether or not people like the wave approach to a problem like this, it will give a good indication of what to expect with a 1% leakage across the slit plate (much more than you would expect here). The patterns quoted in the paper will have been derived that way, I'm sure.

sophiecentaur said:
Whether or not people like the wave approach to a problem like this, it will give a good indication of what to expect with a 1% leakage across the slit plate (much more than you would expect here).
You mean something other than the wave approach would be something like this, https://en.wikipedia.org/wiki/De_Broglie–Bohm_theory ?

sqljunkey said:
You mean something other than the wave approach would be something like this, https://en.wikipedia.org/wiki/De_Broglie–Bohm_theory ?
All I'm saying is that a conventional wave-based calculation (with some additional contributions) will give 'an answer'. Attempts to analyse the situation based on that S shaped line in the picture can't go anywhere because that S shape is only an indicator that some energy can be considered as taking another way through the system*. The picture (as with the wiggly line in a Feynman Diagram) is not intended (imo) to be taken at face value.
*What happens if the plate is many wavelengths thick, for instance? will varying thicknesses produce different patterns?

sophiecentaur said:
*What happens if the plate is many wavelengths thick, for instance? will varying thicknesses produce different patterns?
Well let me ask you the same then(lol), if you vary the thickness of the plate, can you still use the same wave-based calculations to arrive at an answer?

sqljunkey said:
Well let me ask you the same then(lol), if you vary the thickness of the plate, can you still use the same wave-based calculations to arrive at an answer?
Why not? And you have to bear in mind that the probability calculation of 'what a photon will do' use the same maths as doing it, assuming EM waves are involved. I really don't see the objection to thinking in terms of waves whenever possible. In the case of three slits, there would seem to be (at least in principle) a way to describe how the energy is flowing in wave terms.
Nowadays (and since 'my time'), there are a number of pretty good numerical methods which give accurate predictions of how RF signals find their way around complicated antenna systems. Perhaps someone could put me right about this but any convincing argument would need to come from a pretty good level of understanding of the classical and quantum approach.

heh ok. Yes the wave method does give useful information. I just think that thinking about trajectories will give you more insight into what is actually happening, although this is all very questionable.

sqljunkey said:
I just think that thinking about trajectories will give you more insight into what is actually happening, although this is all very questionable.
Very questionable indeed. We know what a photon is doing at the moment that a dot appears on the screen - it is interacting with and being absorbed by the screen material. But thinking about what it's doing when at any other time is just going to add confusion; even the assumption that it has a trajectory to think about is wrong.

Nugatory said:
But thinking about what it's doing when at any other time is just going to add confusion; even the assumption that it has a trajectory to think about is wrong.
pilot wave ideas are not so confusing. the trajectory adapts based on the system and the trajectory is known(at least to the trajectory itself). Trying and failing to measure the trajectory taken is not a theory. lul. But what do I know, this all is ludicrous.

sqljunkey said:
. I just think that thinking about trajectories
Interesting concept when you consider that a photon has no actual position and that it 'experiences" no time (according to the majority opinion). You really need to be careful to avoid treating photons like little bullets.

RobertoV

## 1. What is the three slit interference pattern?

The three slit interference pattern is a phenomenon that occurs when light passes through three narrow slits and creates a pattern of bright and dark bands on a screen. This pattern is a result of the interference of light waves from the three slits.

## 2. How is the three slit interference pattern different from the double slit interference pattern?

The three slit interference pattern is different from the double slit interference pattern because it involves three slits instead of two. This results in a more complex interference pattern with additional bright and dark bands.

## 3. What factors affect the three slit interference pattern?

The three slit interference pattern can be affected by several factors, including the distance between the slits, the wavelength of the light, and the angle of incidence of the light. Changes in these factors can alter the intensity and spacing of the interference pattern.

## 4. What are the practical applications of studying the three slit interference pattern?

Studying the three slit interference pattern can help scientists understand the behavior of light waves and how they interact with each other. This knowledge can be applied in fields such as optics, telecommunications, and astronomy.

## 5. How does the three slit interference pattern demonstrate the wave nature of light?

The three slit interference pattern is a clear demonstration of the wave nature of light. The pattern is created by the interference of light waves from the three slits, which can only occur if light behaves like a wave. This phenomenon cannot be explained by the particle nature of light.

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