Multi Slit Experiment

Now I wonder what would happen if the slits were in a curved surface, all slits an equal distance from the source?

I think I know, but I will keep my opinions to myself until I am satisfied.

A practical application is a phased array radar. (It works with sonar as well.) Instead of swinging a big radar dish to look in another direction, control signals are sent to radar elements to control the delay, changing the look direction almost instantaneously.

https://en.wikipedia.org/wiki/Phased_array

Not a phased array, a multi slit photon experiment with a curved target where all slits are equidistant from the source.

What type of interference pattern would be created ?

Here you can vary number of slits, width of slits, and spacing to see the diffraction pattern. The source is at infinity so the wavefronts are in a plane parallel to the plane of the slits.

If you had a point source and the slits were on a circle centered on that point source, I believe you would have the same kind of pattern only in radial coordinates (r,θ) rather than Cartesian coordinates (x,y). The main lobe (non-defracted) would propagate radially outward. The side lobes would propagate outward from the circle in a line at some angle to the radial direction. So, looking at the circle, you would see a bright spot where your line of vision intersected the circle at that angle.

If you want to find out, you could get some flexible diffraction grating from Amazon and wrap it around a colored LED.

I may have discussed this before, if so I have forgotten the answer. I was in a tire store around Christmas, and the was an aquarium about 15 feet from the Christmas tree. The aquarium had 2 inch thick glass. When I sat down to wait, at a 90 degree angle to the aquarium I looked straight ahead and saw a 3d image of the tree about 10 feet in front of the aquarium. I could shift my view and get a image of all sides, but only from the spot I was sitting.

There are multiple surfaces in this question: the first surface reflection of the glass, the second surface of the glass, the deflection and reflection of the water, and the first surface and second surface of the opposite wall of the aquarium, and back through the other surfaces to the focal point

No laser was involved, and a 3d image was created.

There are some complicated calculations involved here I am sure, but my understanding of how this was done is beyond me.

Sounds like this could be a very lucrative way to produce a 3d image for entertainment without the glasses if someone can figure out and exploit this for commercial use. Also imagine highway signs. A motorcycle* or bicycle projecting an image of a car ahead or a semi in front of it to avoid collisions. Movie theaters, televisions, etc.

No extra power needed, purely passive, just the right arrangement of reflective deflective surfaces.

All comments and contributions are very much appreciated.

*an electronic train whistle would also get drivers attention.

Maybe the next guy who sat in that chair invented this thing...

From what I have read, many years ago, it was invented by a kid playing around with a broken mirror.

He wondered what a fly with compound eyes saw.

So he broke a mirror into thousands of pieces and he noticed that every fragment had a complete image from a different angle. Lining a parabolic reflector with the crushed mirrors produced a 3d image at the focal point of the parabola.

This might work with the proper design to extend the focal point to hundreds of feet. The focal point is a ratio of diameter to depth.

A parabola about 1.37 inches deep and 9inches wide would give focal distance of about 94 feet. If I did my math right.

The problem might be getting the strength and size of the image bright enough and large enough at that distance but I am sure there are experts that can solve that easily.

https://www.analyzemath.com/parabola/focus-of-parabola-calculator.html

I have one of these. It consists of two parabolic mirrors that fit together. The one on the top has a hole in the center.

The object to be displayed is placed at the bottom, at the focal point of the top mirror. Light from the object reflects off the top mirror, travels straight down, reflects off the bottom mirror, and is refocused to an image at the hole in the top mirror.

It is not a hologram!

Was the Christmas tree image inverted? If the aquarium were acting like a lens, the image would be inverted, which may not have been obvious if only a small part of the real image were visible. The image may be either larger or smaller than the object. The sizes are proportional to the distances from the lens.

https://web.pa.msu.edu/courses/2000fall/phy232/lectures/lenses/images.html#:~:text=Real%20images%20are%20those%20where,length%20of%20a%20converging%20mirror.

I may have discussed this before, if so I have forgotten the answer.

Yeah, I think we figured it out back then when we were all younger and less forgetful ...

https://cr4.globalspec.com/thread/132452/An-Accidental-Hologram

Point of order RE: Train Whistle.

If the sound device is air or electric, it is properly called a horn. If the device is steam, then it is properly called a whistle.

I tried to remember my physics classes from 65+ years ago! Got that it had something to do with interference patterns, but details refused! Confirmed by your reference.

Likewise with the memories.

Objects in the rear view memory seem closer than they really are.

Memories from the past seem easily retrieved, except for certain things; Usually the things I try hardest to recall. Like a roach, they run from the searching light.

Sometimes they come rushing unbidden from the past, with no discernable connection to the present, a smell, a certain feeling of Deja Moo(I've heard this BS before).

I can remember formulas, procedures, etc., Constants, K Factors, etc. but don't ask me what I had for breakfast.

So sit back and enjoy the ride as we travel along this roller coaster, strapped in facing backward, looking back at all the highs and lows, never knowing where we are going, only where we have been.

Worry? Who me?

There are only two things in life to worry about: If you are sick or if you are well.

If you are well, you have nothing to worry about. If you are sick, there are only two things to worry about: Are you going to live or die.

If you live, you have nothing to worry about. If you die, you only have two things to worry about: Are you going to heaven or hell.

If you go to heaven you have nothing to worry about,

If you go to hell, you will be too busy shaking hands with your friends to have time to worry.

Don't worry!

Hakuna Matata!

https://www.youtube.com/watch?v=OvOhdd5R-sw

My question about the equidistant multi slit experiment is still open for discussion.

All contributions will be appreciated and welcome.

This reminds me of the convergence of old analog color tv's.

3 Electron guns aiming for the same spot to achieve color.

The guns were stacked in a triangle so it was a different distance for each and there were magnetic rings around the neck to the tube to adjust the path to the proper spot.

100% convergence was impossible, only the center 60%- 80% was watched anyway, so the further you looked form center the more the lines diverged. There was static convergence and dynamic convergence adjustments, which are self explanatory.

Sony Trinitron solved this problem with their single gun technology.

All moot now ,and ancient history.

As I said, memories from the rear view memory.

Now I wonder what would happen if the slits were in a mirrored surface and if the source was equidistant from between the two mirrored slits? Lots of questions about the information and experiments not performed.

How about if in the interior of a totally mirrored sphere?

Would there be a laser-like interference pattern in the center that reinforced itself?

Are there any physicists in here?

A link to a good source for answers would be appreciated.

I cannot get to the Oregon State site from which these lessons were sourced.