The Case of the curiously ringing cymbal

reply to post by CircleOfDust

Yes, I had a drum set, believe it or not! I was pretty good.
They are thick, but I don't think it's always about the mass. Sometimes its about the resonance.
Trust me, I'm just guessing here. I've never done this experiment..But I do know my Flash made a POP sound ,then an upward frequency charging sound after discharge.

reply to post by Arbitrageur


whell, at least were talking about science rather than hating on it. that's a step in the right direction.

If I may inject a little humor.
This is an exaggerated version of what I am talking about.
Martin's Camera.

reply to post by tgidkp


That was my guess too.... going by the K.I.S.S principle.


Totally over my head but will speculate and tip toe out on a limb here... perhaps the frequency is similar to the effect of lightening, thunder (yet beyond human hearing)... that sparking vibration speaking to that which is tuned to receive the signal in this case it was the cymbal and for the observer it was the Genesis of thought from sound and observation.

Excuse my speculative intrusion into this interesting thread... I feel like the Cadbury's gorilla suit sitting at Phil Collins drum set relying on the guy inside the suit to start playing the drums for the song... In The Air Tonight.

I'm not equally in love with Martin's Camera and the gorilla.

It's a rather easy thing to grasp if we can dispense with all the science falsely so called and just accept that light has mass and therefore momentum. Why can't we use O's razor in this instance? Which takes a measure of faith not science, that light has mass or that light can have momentum without mass?

edit: meant now, not 'not'

Originally posted by Arbitrageur
Edit to add: before you dismiss your momentum figures (and I'm not saying momentum is the cause of the sound, but neither do I dismiss the possibility), consider the sensitivity of human hearing:

Well, I suppose its possible to do a test.
We could get somebody who has a cymbal to drop a grain of sand on it from a certain height, to give it the same momentum that I calculated earlier.
Then the question - does it produce the SAME sound that a flash does. Not any detectable sound, it has to be the same sound if momentum is the cause.

So.. how much does a grain of sand weigh? Searching the net gives answers from 1 to 20 milligrams, so I'll just choose 10 milligrams for this calculation.

So fast does it have to be travelling to give the 0.00034grams.m/s momentum I calculated earlier?
Speed (momentum/mass) is 0.034 meters per second.

How high do you have to drop an object before it reaches this speed?
Bit of calculator work, I find it needs to fall for 3.469x10^-3 seconds,
and then the distance under gravity will be 6x10^-5 meters.

So if we drop a grain of sand 0.00006 meters (0.06 mm) above a cymbal, it should produce the SAME sound effect that people hear with the flash, if momentum is to blame.

Somebody should try it, but I still dont think its the answer. I'm still blaming the air heating up causing some kind of pressure wave.

reply to post by alfa1

In a vacuum.
You left out drag.

I'm sticking with sympathetic sonic vibrations from the flash kit.
I truly think it would make a cymbal ring.

Does anyone have metallic wind chimes? That might be a good substitute, to at least get some type of ringing.
The bonus is you'll have different resonances, that might produce a brighter ring.

Originally posted by Phage
reply to post by alfa1

 

In a vacuum.
You left out drag.

Yes I did.
I thought about including it, but didnt think it would add to the clarity of the post given the extremely short distance my hypothetical grain of sand would travel.

Thinking about it further, at that small distance and an object the size of a grain of sand, I suspect one would also have to start thinking about silly inter-atomic issues like electrostatics and van der Waals forces.

reply to post by alfa1

I wasn't really serious but a grain of sand probably has a pretty low terminal velocity.
On the other hand, performing the experiment in a vacuum could be revealing.
I wonder if the effect might be similar to what is seen with a radiometer, having to to with heating.

in the remake of the time machine the professor shows his class a experiment in a vacume where light moves the blades of a fan when exposed to the light so light must have mass

and i have seen vids of a chi expert ringing a bell when over 30 foot away in a temple

reply to post by geobro

and i have seen vids of a chi expert ringing a bell when over 30 foot away in a temple

I've seen vids of Chris Angel walking on water.

Originally posted by Phage
reply to post by geobro

 

and i have seen vids of a chi expert ringing a bell when over 30 foot away in a temple

I've seen vids of Chris Angel walking on water.

in a couple of thousand years their will be a religion to his many miracles and people will regoice in the name of chris

Originally posted by geobro
in the remake of the time machine the professor shows his class a experiment in a vacume where light moves the blades of a fan when exposed to the light so light must have mass

I've seen the original, but not the remake.
Are you talking here of a radiometer?

I think they are commonly said to be in a vacuum, but this is not strictly true. Its just a very low low pressure.
They dont work in a true vacuum. And in any case, it sounds like the explanation given in the movie also wrong.

reply to post by CircleOfDust


Interesting thread, shame it's based on another of your "i can't explain this so all of science is wrong".

Cymbals are extremely sensitive to air vibrations. There is an effect called cymbal ringing where just talking in the same room as a cymbal causes it to ring loudly. Drummers have various damping methods to stop their cymbals ringing from the slightest noise.

I would bet a pound to a penny that the ringing is caused by the sudden heating of the air, which is enough to cause a 'popping' sound. If you can hear it you can bet the cymbal is sensitive to it.

If the flash duration is about 1/2000 of a second the frequency would be in a good range to ring the cymbal.

reply to post by CircleOfDust


Technically speaking, most things shake when hit with soundwaves. Each action having an equal and opposite reaction, means that any soundwave impacting any surface, pushes upon it, and is pushed back in return. I believe that is the reason that Sonar technology can work.

Also, if you were using an old flashgun, you might want to try repeating the experiment with newer technology of the same type. The reason I suggest that, is because old tech was sometimes pretty energy inefficient, and it may be as other posters have mentioned, either a sound wave, like in cymatic effects, or an electromagnetic effect which caused the cymbal to ring out.

reply to post by alfa1


that is the one thanks ps the remake is great directed by his grandson ?

Originally posted by alfa1
So if we drop a grain of sand 0.00006 meters (0.06 mm) above a cymbal, it should produce the SAME sound effect that people hear with the flash, if momentum is to blame.

Somebody should try it, but I still dont think its the answer. I'm still blaming the air heating up causing some kind of pressure wave.

Aside from the air resistance problem Phage mentioned, the sand grain is not reflected from the cymbal like the photons, or at least it doesn't seem to be.

I found an explanation by a physicist discussing momentum, and I haven't ruled out that momentum might explain some or all of the effect, but I think you may have a good possibility about the air heating up, though that would seem to be more of a possibility when the flash hits the shoebox (which seems less reflective, which would absorb more energy, making the heating prospect more likely) than the cymbal which is more reflective. I'm open to either explanation if they can be confirmed by experiment, or it could even be some combination of the two. Here's the explanation I found:

Ask the Physicist

QUESTION:
Just conducted a "singing cymbal" experiment .( aimed a camera flash at the cymbal from 1.5 m away and caused the cymbal to chime.) Was this caused by photon pressure? Or was this somehow an example of momentum ( even though photons have no mass?) It was a really well received demonstration (my class project) I'm trying to write up a lab report and just really am not sure which if any of these directions I should pursue.

ANSWER:
You ask if the effect was caused by photon pressure or momentum—there is really no difference, pressure is force over an area and forces are caused by changing momentum. You need a brief tutorial on Newtonian physics, quantum physics, and special relativity. The relativity part: the momentum p of a particle is related to the particle's total energy E by E2=p2c2+m2c4 where c is the speed of light and m is the mass. So, you see, a massless particle has momentum since, if m=0, p=E/c. The quantum physics part: The energy of a photon is also related to the frequency f of the electromagnetic radiation, E=hf where h is Planck's constant; so, p=hf/c. So, assuming that the photons are reflected from the cymbal, each photon has a change in momentum of Δp=2hf/c because it reverses direction. Finally the Newtonian physics part: How do you change the momentum of something? Exert a force on it. So, the cymbal exerts a force on each photon to reverse its direction; but Newton's third law says that if the cymbal exerts a force on the photon, the photon exerts an equal and opposite force on the cymbal. If there are N photons per second hitting the cymbal, the average force on the cymbal is F=2Nhf/c (because Newton's second law says that force is the rate of change of momentum) and the average pressure is P=F/A=2Nhf/(cA) where A is the area over which photons are spread. Of course, your photons have a whole range of frequencies since you are using white light, so that formula for average pressure is not really right since you do not have one f in your flash; a blue flash would be more effective at causing a pressure pulse than a red flash.

reply to post by alfa1


are you sure they don't work in a complete vacuum?

reply to post by EasyPleaseMe


You certainly do have your work cut out ahead of you, for you first will have to convince CERN of your conclusions instead. Do that, and then we'll talk.