Is it possible to reproduce Double-slit experiment at home with sunlight probably in a larger scale? Thanks for all the answers (and special thanks to Chris for the effort),so i understand that it could be done with sunlight ,since im not a physicist and i don't know how it really works, i would ask why only thin slits works? and what is the limit? Young's equation explains the relation between wavelength, distance between slits, distance between centers of each line of light on the screen and distance between screen and the slit, but i didn't find anything about thickness of the slits.
4 Answers
We know from Francesco Maria Grimaldi that his experiment was done with darkened window and a little hole in the sheet, a mirror outside the window, to redirect the sunlight into the room and - a surprising easy idea in the 16th century - a bird feather.
To make the intensity distribution on the observation screen less blurry, one has to put a transparent colored foil into the sunlight beam. As it is known, the sunlight is a mix of all colors and every color has its own intensity distances and this intensities will overlapping each other.
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Yes; it has been done in this Veritasium video with a typical result given at e.g. 3:30.
The incoherentness of sunlight is not 100% complete and it can certainly diffract; it's just a little more blurry when it does because the Sun is a macroscopic angular size and so forth.
It's worth remembering, as pointed out in the comment section of that video, that the full name of the experiment is Young's double-slit experiment, performed by Thomas Young in 1801, over a hundred years before anyone came up with the idea of lasers, and over a hundred and fifty before we had built any. Thomas Young's method was indeed to allow a beam of sunlight to enter a dark room where it hit his two slits.
In terms of how you can build one, my first thought would be that you'd either want to slice two slits in aluminum foil with a sharp knife, or if you need smaller resolution, slice one slit in aluminum foil and then stretch a thread of some sort so that it sits inside the gap. Paper could also be used; see e.g. these Instructables.
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I do these experiments at home all the time using a laser and guitar strings. Usually I use only one string as Thomas Young used only one hair in his original experiment. Coherent photons are projected onto a screen from the two edges of the wire. I have also developed a simulator for single or multiple slits that shows both the calculations and the visual of the interference patterns. If you can direct intense enough sunlight onto a wire in a dark room you can get these results.
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I think it is not possible do this at home because it requires accurate and precise instruments.
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