why is that double slit's equation is : (theta)=m(lambda)/d, while diffraction gratings. sin(theta) = m(lambda)/d. Why does diffraction grating require a sine of theta while double slit doesn't? thanks
Dear Doc: I was trying to calculate the 2nd order spreading angle produced in a red laser beam (lamda=635nm) passing throw a peeled DVD acting like a diffraction grating (d=740nm). But aplying the formula the sin(theta) results greater tan one!!!. What is wrong? 2x635nm/740nm>1
Yes as time goes on. Also I would like to ask, why is the light intensity pattern for the diffraction grating more sharper than the double slit interference ?
Ultimately, you should think of the light intensity pattern as a statistical result from many millions of individual photons hitting the screen. If you just let a few photons hit, you can't even determine where the fringes are, let alone expect any steady relationship. However, if you compare one burst of millions of photons to another, subsequent burst of millions of photons, they'll show the same distribution pattern. Statistics, though. Diffraction grating = hundreds of reinforcing slits.
It was made by Cornell in the 1950's. We're lucky to have dozens left at my school. A web search for "cornell diffraction plate" will reveal that lots of colleges in the US are still using them. However, I cannot find any for sale anywhere since the advent of the internet. I think they were lithographs that were photographically reduced and encased between two glass plates. If you succeed in making them or their replacement, I would buy twenty of them for $10 each. Hit me up.
@@DocSchuster To make diffraction gratings requires a special and rare printer. I did all the research and it is doable. i just can't now remember the details. The printers exist but not at your neighborhood print shop. The company that made these templates has gone long out of business. Mayfield Publishing was acquired by McGraw Hill and Mcgraw assures me they do not make these at all. It was originally designed by Cornell Aerospace Labs... ie C.A.L. in Buffalo, New York circa late 50's.
I love it when the student becomes the teacher! Rock on.
Thank you doc Schuster, i start to love physic because of you...keep making great video.
I had so much fun watching this!! Great lesson :)
You're one of not many teachers who are not actually boring! Cheers.
Fantastic! Love how you explain. Entertaining in a way. Keep it up.
Thanks!
You can probably explain string theory to a 6 year old
Thanks! I'm glad they are useful for you.
You helped me a lot with my IB physics, thank you!
splendid teaching doc....u rock!!!!!!
We were not taught this topic at College. But I found your video via askiitians.com.
Thank you so much. Understood everything perfectly ❤️
To UK students - this is perfect for G482 OCR AS a-level physics just to let you know...
Students in New Zealand - This is great for NCEA level 3 Physics
Love your lectures, sir.
You're definitely going to be the next "JustMathTutoring" guy for physics!
Id love this video so so so much more if they didn't change the bloody specification this year ;(
Thanks Doc!
Thank you so much
sheldon is that you?
Werble Werble Werble.
oh don't worry! just worked it out! thanks for the great video
dude u rock!
can you please use one sentence to sum up what is diffraction grating
why is that double slit's equation is : (theta)=m(lambda)/d, while diffraction gratings. sin(theta) = m(lambda)/d. Why does diffraction grating require a sine of theta while double slit doesn't? thanks
***** For small angles, sin(theta) is approximately theta in radians. This approximation is made frequently in physics.
Dear Doc: I was trying to calculate the 2nd order spreading angle produced in a red laser beam (lamda=635nm) passing throw a peeled DVD acting like a diffraction grating (d=740nm). But aplying the formula the sin(theta) results greater tan one!!!. What is wrong? 2x635nm/740nm>1
I am watching all your interesting physics videos from Bangladesh.. thanks sir...
Does the light intensity remain constant in the double slit interference pattern, or does it change ?
Do you mean constant as time goes on?
Yes as time goes on. Also I would like to ask, why is the light intensity pattern for the diffraction grating more sharper than the double slit interference ?
Ultimately, you should think of the light intensity pattern as a statistical result from many millions of individual photons hitting the screen. If you just let a few photons hit, you can't even determine where the fringes are, let alone expect any steady relationship. However, if you compare one burst of millions of photons to another, subsequent burst of millions of photons, they'll show the same distribution pattern. Statistics, though.
Diffraction grating = hundreds of reinforcing slits.
What do you mean by someone's principle? It is Huygens principle!!
what is the plate you used the black one with various types of slits can u name it please
at 3:44
It was made by Cornell in the 1950's. We're lucky to have dozens left at my school. A web search for "cornell diffraction plate" will reveal that lots of colleges in the US are still using them. However, I cannot find any for sale anywhere since the advent of the internet. I think they were lithographs that were photographically reduced and encased between two glass plates. If you succeed in making them or their replacement, I would buy twenty of them for $10 each. Hit me up.
Sure Man thanks!
@@DocSchuster To make diffraction gratings requires a special and rare printer. I did all the research and it is doable. i just can't now remember the details. The printers exist but not at your neighborhood print shop. The company that made these templates has gone long out of business. Mayfield Publishing was acquired by McGraw Hill and Mcgraw assures me they do not make these at all. It was originally designed by Cornell Aerospace Labs... ie C.A.L. in Buffalo, New York circa late 50's.
Doc Physics what is the exact name of the plate you used?
They say CAL in the corner and they are very old. I don't know any more. Sorry!
Thank you Chris :D
Slightly confused on what you did at 10:26 to get to 3.96x10-7 m. Any help?
just plug in the values of wavelength, m and theta. We'll get the answer 3.96 x 10^-7
3:20 a what ??? "Cow plate" ???
OK ... it's a Cornell plate and they are not made or sold anywhere. Anyone wanting one will have to steal it from your school physics lab.
hi rooney
8:13 Yo.
Not the right way of teaching...