Happy to help!

Best physics teaching videos on youtube! Many thanks sir

The monster truck Chopped Sir Issac Newton :'(

beautiful

What an amazing video! Thank you!

Doc, your explanation is MUCH better than my teacher's! Thank you!

Brilliant explanation!

Thank you, the general rate of change really helped

Thank you so much!!

thank you, greaters from Ecuador

“And the heaven We created with might, and indeed We are (its) expander.” (Quran 51:47)

@alext9067

7 жыл бұрын

Great find. Gotta take a look at some of that. That's gold.

nc vid. really helps. the only prob is the marker sound because its really annoying to listen to while you write

Thank you so much for your videos! I've learned so much physics from your videos alone I'm still confused about the observed wavelength though. Would you be able to describe your thought process if possible? I've tried but still don't quite fully understand it :(

@DocSchuster

9 жыл бұрын

Indigo For a moving source? I would just take a photograph of the wave and measure the distance between peaks! It would work fine in water...

@indigo6493

9 жыл бұрын

Doc Schuster Ok, I'll make sure to try that! Thank you Doc! :)

Is the monster truck moving in constant velocity? If he isnt, what would be the solution?

so if u=v then 1-(u/v) is 0 then you are dividing by 0, but then if the waves are EM then this is impossible because u cannot = v because the truck cannot go at the speed of light. so if you could get faster than the speed of light it would be kind of like a sonic boom but a solar boom?

@DocSchuster

9 жыл бұрын

Ben Boys Whoa. An energy boom! You would make arbitrarily large electric and magnetic fields, which could actually rip apart anything in their path!

Anyone recommend a software to measure the frequency change of a moving sound?

@ronalddobos8390

7 жыл бұрын

theclassyinternaut audacity, i guess, hope im not too late :D

If a star, moving towards earth, emits green photons, due to the doppler effect, here on earth the photons would be more blue. So they gained energy. From where?

@udithkumarv734

6 жыл бұрын

Fransamsterdam maybe the kinetic enery of the star is transfered to the photon

So I understand that in the case of a moving observer, the effective velocity is changed. But what changes in the case of a moving source? Would it be the effective frequency? (Ie the pitch heard by listener?)

@DocSchuster

10 жыл бұрын

Yes. Doppler is all about appearances. But I agree that it feels a bit different if the source is moving. I.e., does the emitted frequency actually exist anywhere? It only gets more fun when you do it in two dimensions!

@Neekodeos

10 жыл бұрын

Doc Schuster Hopefully that won't come until upper divs! Also, one more thing about Doppler. Are there any physical differences between a source approaching a static listener and a listener approaching a static source? i.e. Will one case cause the listener to hear a different 'pitch' than the other? Mathematically it looks like both would result in the same frequency heard by listener, but just want to make sure I'm not neglecting any exceptions (for an intro physics class with 1D doppler)

@DocSchuster

10 жыл бұрын

YES! They are quite different! At low speeds, they are similar, but moving at the speed of sound. If the observer is approaching the source, you just get twice the f-prime. But what happens if the source approaches you at v-wave?

@Neekodeos

10 жыл бұрын

Doc Schuster If the source approaches you at v-wave , then the denominator of the frequency heard by the listener equation approaches 0- the sound barrier. So I guess 'low speeds' would qualify as anything less than the speed of sound since that is where the equation "fails"?

@DocSchuster

10 жыл бұрын

Heh - the equation is just doing just fine. It's telling you that something awesome is happening. Wik: sonic boom. Graph the two functions that shift frequency and see where they begin to diverge. I'd call up to that point "low speeds." Of course, defining divergence is a judgement call.

Give me moooore! What happenss when u get hit by sonic boom?

you have no idea how confused i was

+doc Schuster

The experience must be painfull!

what if u=v or u greater than v

@DocSchuster

8 жыл бұрын

+Aditi Jain Well, it's no problem if you're going toward the source. But what if you're going away?!?!

You enthusiastically explain Doppler in light in terms of moving source but don't even mention light when you analyse the moving observer case. All Einsteinians do so - they think they know how the moving source changes the wavelength but feel it would be too absurd and therefore dangerous to say that the moving observer also changes it. (And if the motion of the observer cannot change the wavelength of the incoming light, one should sing "Goodbye Einstein" instead of "Divine Einstein".) Yet the Einsteinian interpretation of Doppler - moving source is just as absurd as that of Doppler - moving observer. Consider a stationary source emitting light waves towards a stationary observer. IN THE SYSTEM OF THE SOURCE, the frequency is f, the speed of the waves is c and the wavelength is λ=c/f. The source starts moving with (small) speed v towards the observer. IN THE SYSTEM OF THE SOURCE, the frequency becomes f', the speed of the waves c' and the wavelength λ'=c'/f'. Crucial questions: f' = ? ; c' = ? ; λ' = ? Possible answers: (A) f' = f ; c' = c-v ; λ' = (c-v)/f (B) f' = f ; c' = c ; λ' = λ (A) is valid for other kinds of waves (e.g. sound) but is obviously invalid for light. (B) implies that, since the wavelength of the light leaving the moving source remains unchanged (λ'=λ), the frequency shift measured by the observer (from c/λ to (c+v)/λ) is caused by a shift in the speed of the light relative to the observer (from c to c+v), in violation of Einstein's relativity. Einsteinians teach (A) but explain only λ' and don't even think of c': ebooks.adelaide.edu.au/o/orwell/george/o79n/chapter2.9.html "Crimestop means the faculty of stopping short, as though by instinct, at the threshold of any dangerous thought. It includes the power of not grasping analogies, of failing to perceive logical errors, of misunderstanding the simplest arguments if they are inimical to Ingsoc, and of being bored or repelled by any train of thought which is capable of leading in a heretical direction. Crimestop, in short, means protective stupidity."

Suggestion for the presenter. 1.) Pull the camera back a bit, so your drawing on a slightly large scale easier to see and differentiate, stay away from the edges so information isn't cut off / lost 2. ) don't put more than one unrelated calculation, or piece of information on the same page at the same time 3. ) prepare a script that you can read from directly during your presentation, so your speaking won't be confusing jumpy to already struggling students. 4.) Make all marks, notes and drawings as simple, and carefully drawn as possible. Your trying to cram way to much into a single session. Split things up, and the clarity will allow better absorption "pun intended" by your viewers, a bigger salary, and more popularity will result.

@DocSchuster

8 жыл бұрын

+Peter Mullen Thanks!

@alext9067

7 жыл бұрын

Peter, I hope you're not suggesting Doc turn it into one of those robotic videos. I, for one, like Doc's style. I tend to nod off at the other vids.

P.s. vote jop for head master

borinnnnnnnnnnnnnnng

@DocSchuster

8 жыл бұрын

+Rashid Suwaidi Put it on 2x speed if you're looking for excitement?