10.2M views · Feb 19, 2013 · 7:40 · 1 HN recommender · 3 mentions · discussed 2019–2021
Veritasium revisits Thomas Young's original double slit experiment with light, showing how interference supports the wave nature of light. It uses a pond-wave demonstration to explain the pattern.
Why Hacker News points people here: HN cites it in double slit debates for its grounded demonstration of interference as classical wave behavior.
“Here's the important part of the video, in my opinion”HN comment, 2021
“Here's the important part of the video, in my opinion”
Pond-wave demo showing how interference explains double-slit light behavior
Here's the important part of the video, in my opinion: this video Basically, two floating balls are used to create waves on the surface of a pond... From the waves created; from their interference patterns on the surface of the pond, we can see exactly how light behaves in the double-slit experiment.
“trying to see some actual evidence [1] of the experiment”
Shows actual evidence of the double slit experiment
I just stumbled upon Veritasium a week ago while learning about the double slit experiment in quantum theory and trying to see some actual evidence [1] of the experiment. [1]: this video
> We speak of "noise" (interference) Note that interference here has a very technical meaning that is NOT noise. (Sorry for the all-caps, but it's very important in these experiments.) I think you don't understand the important point in the double slit experiment. Let's try to explain it, but it's a long explanation. --- First you must understand the single slit experiment. If the slit is thin enough you get a nice diffraction patter. If this spread was caused by dust or something like that, a good guess is that the image gets a gaussian blur like exp(-x^2). In a diffraction experiment, the image you get is something like sin²(x)/x². (You should draw them in Wolfram Alpha or something.) The main difference is that the first one is always positive, so you get light everywhere, but it get's dimmer very soon. The second one has a lot of zeros, so you get strips of light and darkness. The math details are complicated, so let's ignore them. You can do this experimentally. In the lab we used two razorblades with some screws to move them arcuately. There should be plenty of recipes in Internet to reproduce it. You can try it in more dusty environments, and clean environment. Sharp razorblades, not sharp razorblades. Wind or not wind. Try it a few times until you get use to the images it produces. You will notice that the cleaner environment produce the better results, so I hope you will get convinced that it's not caused by the dust or something You can probably buy some single slit
