We connect light, sound, and ocean waves to address these questions: Why do "dead zones" and loud locations exist near speakers? Why does light diffract?
Had to watch this for school and its probably the only enjoyable video I've had to watch for this class all year and I've actually been able to retain the information, thank you!! :D
Brilliant question. I have yet to set up this experiment in a room with no significant reflections (a recording studio, f'rinstance), so I'm not sure. But I imagine you're on to something. As the sources grow closer, the separation of the "bright" and "dark" fringes increases, so I imagine the width of the quiet point would as well. In short, I think your ear could experience perfect silence if you set up the experiment carefully. Try it!
Hugely important: L1 and L2 are the distances from source 1 and source 2 to the observer, respectively. When the difference between those path lengths is one wavelength, the waves from the two sources are in phase and add constructively. Read that again 'cuz it's so important.
Thank you sir, well explained mostly and very interesting presentation with coherence. I enjoyed your video and wish I could be as effective in explaining things as you are.
DO IT. Physics is better with popcorn, too. But make sure to take breaks to work problems and maybe teach a new concept to a friend. Then you'll know you're learning, not just watching.
Oh, man. What a mess. My training is in NMR, and you do NOT want to listen to your receiver (i.e. amplify its signal) when you're still transmitting. Interference could certainly occur, but more importantly, the transmission will dwarf the echo and screw up your signal. Go further back or shorten your pulse. Blech. I'm intrigued, though. Can you post a link to the signal you pick up?
but remember never point the lead guitar players amp directly at the sound man because he will never be in the speaker to begin with.....:) This is a very complicated subject in mixing sound as even monochromatic audio from the speaker arrays arrives at everybody's head at different times and different db levels, so I call em sweet spots and weak spots, usually you can move a few feet if you have festival seating arrangements and find a sweet spot, or if you want to just talk find a node.. the best example I ever experienced of this was testing horns on a football field one day using a 500 hz test tone...very unnerving to say the least. great lesson.
What I'm trying to get at is sound reflection off of a flat surface. One could perhaps see the reflected sound as coming from a "source" that is the same distance on the opposite side of the reflective surface. Could you then, if the source is a couple and a half wavelengths from the surface, form a line of destructive interference?
Hi Doc. I was wondering if you could explain what would happen in the area between the speakers. I suppose it would rely on how far the sound sources are from each other. If a multiple of the wavelength, I suppose it would form straight line between them of constructive interference. If it was a couple and a half wavelengths, it would form a line of destructive interference?
Are the points of "quiet" large enough to totally encompass the human ear? That is, in real life could I experience quiet points (meaning I really hear NO sound) by walking up and down the line? Or would I still hear something because although the dead center of my eardrum might be at a quiet point, immediately adjacent to that (and still on my eardrum) is a non-quiet point? Put another way: How "big" are the quiet points?
so question if we are talking about light waves rather than sound, when the two troughs meet would the light be twice as bright still? as the two crests would?
Hi Doc. I have another question. I'm doing research on SONAR using LFM chirps (230 - 330kHz chirp). Is it at all possible for the transmitted wave to interfere with the wave that reflects? The chirp is quite long (100ms), and the target is only 10m away (flat alumium plate) which means that the return will reach the receiver before the chirp has finished transmitting. Will interference occur? I'm wondering because the frequency isn't constant.
Hello! I have a doubt. You used two coherent sources (same frequency, same wavelength) that are moving with the same velocity radially outward. I'm assuming they send out a disturbance at the same time too. So, they must travel the same distance in the same time. That means they'd form crests and troughs at the same time. Say they form the first crest at time t1. The two crests overlap to form a ''super crest'' And then go on to form two different troughs that also intersect at the same time. How then would a crest from source 1 and trough from source 2 ever overlap? Just pertaining to the example above.
Never accept. Clearly, as you point out, the difference could be ANYTHING. But IF the difference IS lambda (i.e., the observer is in the right spot), CONSTRUCTIVE INTERFERENCE HOORAH! You with me? Oh, and it's also constructive if the observer happens to be at delta(L) = 2*lambda and 3* and 4* etc.
Does anyone else thinks this guy is a genius at teaching?
yes
yes I do :D
Had to watch this for school and its probably the only enjoyable video I've had to watch for this class all year and I've actually been able to retain the information, thank you!! :D
same
Preparing for my physics finals, I find your videos extremely helpful. Your explanations are the best. :)
PokeRapper5000 same ☺
watching you with double speed is so entertaining
k=it really is XD
Brilliant question. I have yet to set up this experiment in a room with no significant reflections (a recording studio, f'rinstance), so I'm not sure. But I imagine you're on to something. As the sources grow closer, the separation of the "bright" and "dark" fringes increases, so I imagine the width of the quiet point would as well. In short, I think your ear could experience perfect silence if you set up the experiment carefully. Try it!
another nice lecture,cool.thank you , cause i had trouble understanding why waves defract through slits.
I just had an "aha moment". Thanks!
Yessssss, finally someone with good physics videos!
Hugely important: L1 and L2 are the distances from source 1 and source 2 to the observer, respectively. When the difference between those path lengths is one wavelength, the waves from the two sources are in phase and add constructively. Read that again 'cuz it's so important.
and he has a smiley face drawn on his hand for us. What a legend!!
I really like that video! It's hard to explain such things (especially if they're obvoius for you) in so nice and nooormal language!
He is genius in explaining things...I consider them lucky whom he teach...!! This was amazing
Dayummm these videos are solo helpfull ....lubh from india💓
best explanation of diffraction ever
Painstaking preparation for presenting complicated topic in such simple manner. Kudos !
👌👌👌
Oh God. Mayn you are a life saver, I was stuck on this topic and you just made it crystal clear. Stay Blessed, you are doing good work. 😊
very nice teaching style, Doc. thank you
Thank you sir, well explained mostly and very interesting presentation with coherence. I enjoyed your video and wish I could be as effective in explaining things as you are.
Thank you so much Doctor! Your videos are extremely helpful!!
Thank you so much! This was very clear.
Gr8 channel m8, i r8 8/8. May the MLG physicists be with you.
This guy is good at explaining, but I feel like he says anything that pops into his mind! 😄 Well, gr8 video anyway!
You just made my textbook make x2000000000 more sense
I could watch these all day.
DO IT. Physics is better with popcorn, too. But make sure to take breaks to work problems and maybe teach a new concept to a friend. Then you'll know you're learning, not just watching.
Bless you Doc Schuster.
nah whats up Doc. Great video you saved me in my science class!
majestic approach sir.......:)
You are so good at teaching physics.
Absolutely. I've got more videos on waves that go into more depth, too.
Excellent!!!!!
very nice Doc, thank U
WOW. Very good!
Oh, man. What a mess. My training is in NMR, and you do NOT want to listen to your receiver (i.e. amplify its signal) when you're still transmitting. Interference could certainly occur, but more importantly, the transmission will dwarf the echo and screw up your signal. Go further back or shorten your pulse. Blech. I'm intrigued, though. Can you post a link to the signal you pick up?
genious representation..liked and added to playlist
Great video :3
Ahh! Just how do you do it doc?!? Being sooo great at teaching things!
really easy to undestand. thanks
Thank you Doc :)
Thank youuuuuu
but remember never point the lead guitar players amp directly at the sound man because he will never be in the speaker to begin with.....:)
This is a very complicated subject in mixing sound as even monochromatic audio from the speaker arrays arrives at everybody's head at different times and different db levels, so I call em sweet spots and weak spots, usually you can move a few feet if you have festival seating arrangements and find a sweet spot, or if you want to just talk find a node..
the best example I ever experienced of this was testing horns on a football field one day using a 500 hz test tone...very unnerving to say the least.
great lesson.
What I'm trying to get at is sound reflection off of a flat surface. One could perhaps see the reflected sound as coming from a "source" that is the same distance on the opposite side of the reflective surface. Could you then, if the source is a couple and a half wavelengths from the surface, form a line of destructive interference?
great explanation!
Thank you!
For the explanation on lambda and half lambda, doesn't l1 also change distance from the original if moved along a line?
Good video it was
amazing explanation!!
faze is trash
Hi Doc. I was wondering if you could explain what would happen in the area between the speakers. I suppose it would rely on how far the sound sources are from each other. If a multiple of the wavelength, I suppose it would form straight line between them of constructive interference. If it was a couple and a half wavelengths, it would form a line of destructive interference?
better than my teacher s explanation
gosh im totally addicted to ur lesson
I'm much better for you than heroin!
what is coherent and incoherent?
guy ur so freaky and inspiring!
That's a fun combo. Thanks, yo!
I actually enjoyed the messy diagrams..and , 4 times the intensity and twice the amplitude.
Are the points of "quiet" large enough to totally encompass the human ear? That is, in real life could I experience quiet points (meaning I really hear NO sound) by walking up and down the line? Or would I still hear something because although the dead center of my eardrum might be at a quiet point, immediately adjacent to that (and still on my eardrum) is a non-quiet point? Put another way: How "big" are the quiet points?
so question if we are talking about light waves rather than sound, when the two troughs meet would the light be twice as bright still? as the two crests would?
YEP! It took me two years to find and answer this question. You're probably a professor by now.
Hi Doc. I have another question. I'm doing research on SONAR using LFM chirps (230 - 330kHz chirp). Is it at all possible for the transmitted wave to interfere with the wave that reflects? The chirp is quite long (100ms), and the target is only 10m away (flat alumium plate) which means that the return will reach the receiver before the chirp has finished transmitting. Will interference occur? I'm wondering because the frequency isn't constant.
Thanks dr physics!!!!
You betcha!
Hello!
I have a doubt. You used two coherent sources (same frequency, same wavelength) that are moving with the same velocity radially outward. I'm assuming they send out a disturbance at the same time too. So, they must travel the same distance in the same time. That means they'd form crests and troughs at the same time. Say they form the first crest at time t1. The two crests overlap to form a ''super crest''
And then go on to form two different troughs that also intersect at the same time. How then would a crest from source 1 and trough from source 2 ever overlap? Just pertaining to the example above.
sir how can I know the distance between two constructive or destructive points ????
you rock
Awesome doc. Do you also teach thermodynamics
+sharat mylavarapu You bet! I've got all of a first-year university course up in here. Welcome.
Hi,
Any way of contacting with you???
Regards
Shahriar Aziz Aakash I can hear you just fine! Thanks for watching!
Is this hight school level?grade 11?
ESZQCYHNMKO EWK 12 I think
OH, MAN! What am I trying to say??
Makes since but pretty long video.
Never accept. Clearly, as you point out, the difference could be ANYTHING. But IF the difference IS lambda (i.e., the observer is in the right spot), CONSTRUCTIVE INTERFERENCE HOORAH! You with me? Oh, and it's also constructive if the observer happens to be at delta(L) = 2*lambda and 3* and 4* etc.