Young's Double Slit Experiment lab

In summary: For the future a more careful reading of the lab assignment would have helped.Er... I don't think that it was a matter of understanding what far-field means. The OP was asking for an explanation of why the distance between the viewing screen and the distance between successive maxima are proportional. This is a fundamental property of the double slit experiment, and can be derived mathematically using simple trigonometry. The OP was also asking for an explanation of what is happening in the lab, and the answer provided did not address that. In summary, the conversation revolved around a lab involving the wave nature of light, specifically the Young's double slit experiment. The group discussed the relationship between the distance from the slits to the viewing screen and
  • #1
braeden
2
0
In class we did a lab regarding the wave nature of light. We pretty much conducted Young's double slit experiment. For the lab we were supposed to establish the relationship between the distance from the slits to the viewing screen and the distance between successive maxima. Can anyone explain to me, physics wise, why as the distance between the viewing screen the distance between successive maxima increases proportionally as well. I can obviously figure it looking at the formula but need a explanation of what's going on for my lab. Thanks
 
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  • #2
braeden said:
In class we did a lab regarding the wave nature of light. We pretty much conducted Young's double slit experiment. For the lab we were supposed to establish the relationship between the distance from the slits to the viewing screen and the distance between successive maxima. Can anyone explain to me, physics wise, why as the distance between the viewing screen the distance between successive maxima increases proportionally as well. I can obviously figure it looking at the formula but need a explanation of what's going on for my lab. Thanks

Er... this is straightforward trigonometry.

These maxima and minima are at particular angles. So if you look at the first maximum, it comes out of the slit at a fixed angle. So if you consider A as the distance to the screen and O is the distance to the first maximum, then if you keep the angle [itex]\theta[/itex] fixed, can't you see that O will get larger as A increases?

right-triangle.JPG


Your a trig. function (I'll let you figure this out yourself which one is relevant) to relate the angle, distance A, and distance O, you should be able to get the exact relationship between all three.

In the future, please write down exactly the mathematical description that you know, and start from there.

Zz.
 
  • #3
ZapperZ said:
Er... this is straightforward trigonometry.

These maxima and minima are at particular angles.

In the future, please write down exactly the mathematical description that you know, and start from there.

Zz.

It almost appears as if you are trying to make the original question sound as dumb. I wouldn't approve of that, because it is not obvious at all why the maxima and minima would come at particular angels. They do so only as an approximation when the distance between the slits is signifigantly smaller than the other distances in the situation. In order to prove this nicely, one of the most obvious ways (IMO) is to apply the approximation

[tex]
\sqrt{1 + x} \approx 1 + \frac{x}{2}
[/tex]

So that's the level of math that is required for this.
 
  • #4
jostpuur said:
It almost appears as if you are trying to make the original question sound as dumb.

Er... no. I was pointing out the nature of the problem. Indicating that this is probably a math question might provide the OP a place to look. Furthermore, the OP indicated that he/she has the mathematical "formula" to look at. Knowing exactly what it is is the starting point since that is something the OP knows.

My philosophy in teaching has ALWAYS been to start where the understanding stops!

I wouldn't approve of that, because it is not obvious at all why the maxima and minima would come at particular angels. They do so only as an approximation when the distance between the slits is signifigantly smaller than the other distances in the situation. In order to prove this nicely, one of the most obvious ways (IMO) is to apply the approximation

[tex]
\sqrt{1 + x} \approx 1 + \frac{x}{2}
[/tex]

So that's the level of math that is required for this.

Do you really think that, at this level, this is not a far-field situation? Near-field 2-slit experiment is highly unusual. Based on the description given in the OP, I see this as being a standard, straightforward 2-slit experiment in an intro lab. Do you see otherwise?

Zz.
 
  • #5
I believe the original problem was a far-field situation. I also believe that braeden has had difficulty understanding what it means.
 

What is Young's Double Slit Experiment lab?

Young's Double Slit Experiment lab is a classic physics experiment that demonstrates the wave-like nature of light. It involves shining a beam of light through two small slits and observing the interference pattern that is created on a screen.

What materials are needed for the Young's Double Slit Experiment lab?

The materials needed for this experiment include a laser or light source, two small slits, a screen, a ruler or measuring tape, and a dark room to conduct the experiment in.

How does the Young's Double Slit Experiment lab work?

The experiment works by shining a beam of light through two small slits, which creates two coherent sources of light that interfere with each other. This interference results in an interference pattern, which can be observed on a screen placed behind the slits.

What is the significance of the Young's Double Slit Experiment lab?

The experiment is significant because it provides evidence for the wave-like nature of light, which was a topic of much debate in the scientific community in the 19th century. It also serves as a foundation for understanding other wave phenomena, such as diffraction and interference.

How can the results of the Young's Double Slit Experiment lab be explained?

The results of the experiment can be explained by the principle of superposition, which states that when two waves meet, their amplitudes add together. In the case of the double slit experiment, this results in areas of constructive interference (bright fringes) and destructive interference (dark fringes) on the screen.

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