Interference Demo: Double Slit

This is a demonstration of double slit interference with slit separations of 0.25 mm and 0.5 mm, with slit widths of 0.04 mm in each case. The 0.5 mm separation gives more closely spaced interference fringes than the 0.25 mm separation.
This demonstration was created at Utah State University by Professor Boyd F. Edwards, assisted by James Coburn (demonstration specialist), David Evans (videography), and Rebecca Whitney (closed captions), with support from Jan Sojka, Physics Department Head, and Robert Wagner, Executive Vice Provost and Dean of Academic and Instructional Services.

[@shadanali5858]

i only read it in books but now i visualized it as well thankyou!!!

[@ankitkeshri8316]

Thank You sir For practical of Interference to understand this topic more clearly and deeply. THANKS 🙂

[@beartimejollys_fitness]

why does no one turn on a measuring device and show the wave pattern on the wall change to particle pattern in real time? why can't i find a video with this demonstrated in real time instead of just simulated?

[@naabzable]

Why can't I find anyone answering this question !?!

[@Akaniiii]

because the scale at which this collapse of the wave function occurs is not visually observable. It's too small to be able seen on video. hence the simulations.

[@StuartBermingham]

I think to see that effect you need to fire a single photon or particle at a time which will still show an interference pattern after a while once many have been fired. Then if you interact with the particle before it goes through the slits the interference pattern will disappear. The reason you won’t see that here is firing a single photon or particle at a time isn’t something you can do with a makeshift at home experiment.

[@sahiljahagirdar1733]

Because that expt is for electrons and not light

[@dipankarsaha1685]

Thank you Rahul sir for forwarding it to uss

[@Lazuray666]

Can you explain how it's affected when observed and if the interference behaves differently if its specifically observed by a measuring instrument, or is it any object or device? Thank you.

[@sussybaka356]

YOU have my respects

[@PlayEase_IND]

what happened to the fact that the fringe width of dark as well as bright fringe being equal?

[@AfterWorkGoGo]

Why we can't see one slit after observed?

[@jebaaniqa3382]

Thank you sir 💜

[@lakshaybhardwaj3502]

Why central Maxima width is double than others?

[@antonyshigin4977]

@@lakshaybhardwaj3502 Because the constructive interference is maximum at that point.

[@priyadutta9212]

Nice 👍

[@kingtahir2491]

Now find the position of 5th bright Fringe 😶

[@sajanhnp3479]

Width Bright and dark Fringes are different why... And also intensity is not Uniform

[@payalnarwal]

♥️♥️🙏

[@ishan_j0shi]

can you do this with a white light source

[@ahmedhilaly8375]

Ishan Joshi I think no.because it has 7 colours in it

[@kshitiznavediya9470]

we can only do this by monochromatic source of light

[@adityabute2107]

@@ahmedhilaly8375 yes we can we have studied in physics you will get dark spot of violet then red and so on you can also check it out on google

[@jatinsoni524]

You can do it with white light but you will observe colour dispersion,because white light is polychromatic(have more than one type of wavelength) so it will split us

[@sayand3361]

the original double slit conducted by young was with white light

[@lakshaybhardwaj3502]

Why central Maxima width is double than others?

[@jatinsoni524]

Central maxima is not double in lenght Near the center the sepration b/w maxima and minima is so small that we often see it as a big bright spot but it is not

[@kentdavidge6573]

@@jatinsoni524 this answer is RIGHT.

[@antonyshigin4977]

Because the constructive interference is maximum at that point. Hence its intensity is higher than other maxima

[@nickkjel1899]

Ashwin choudhary was here

[@anuragsinghdevm]

How can a single beam of light pass through two different slits at the same time???

[@jacobvandijk6525]

A beam has a certain width. So if the slit-separation is smaller than this width, the beam can shine on both slits. In more technical terms, I think it has to do with the coherence area of the light source.

[@shyamsinghkarayat7670]

But in interference all the fringes have same intensity. Here the central bright is wider I think it's diffraction

[@jatinsoni524]

Intensity is not constant,as we move from 1 maxima to adjcent minima intensity vary as a function of cos²(∆ø/2) also what we learn theoretically is with approximations so intensity varies It is not diffraction because green light is used which is monochromatic (having only one wavelength),for diffraction we have to use polychromatic light

[@kentdavidge6573]

@@jatinsoni524 this answer is actually WRONG.

[@tashadurrahman]

@@jatinsoni524 Wrong bro.. diffraction is not what you think it is

[@jacobvandijk6525]

You can give us any set of numbers. There is nothing to check here.

[@lamao1151]

It's diffraction

[@subhramohanty1846]

No, it isn't

[@lakshaybhardwaj3502]

@@subhramohanty1846 Why central Maxima width is double than others?

[@kingzaib8074]

@@lakshaybhardwaj3502 it isn't actually double But due to constructive interference Brightness is observed