I have seen some of your videos before and i love them.but i can not open them now.

that was a cool video

Dear Robert - I love your videos and use them as a constant source of inspiration when presenting science concepts to children myself. However, my understanding of what is happening here is a little different than the picture you present. Please correct me if I am wrong.

I thought was that the main factor determining pitch here is length rather than mass - the length of resonator being directly related to the wavelength of the standing wave produced, regardless of the diameter - of course with a tube of fixed diameter, the two are directly proportional, and yes increasing the vibrating mass with the same energy will have the effect you describe, but I find that two tubes of equal length but different diameter still produce the same pitch - however maybe the energy required to sound that note will be more (as more mass must be vibrated as you point out). this would I believe make the sound richer in tone quality, but not necessarily change the pitch.
I note that your larger flute was longer as well as wider.

I was just playing about with stuff I have here to test my thoughts, and as the pipes I had were a little too wide to blow, I was working by striking the end of the pipe - maybe this difference affects my findings

I find three factors generally determining pitch in acoustic musical instruments - length, tension (in strings or drumheads) and harmonic overtones (as in the bugle, tabor pipe, etc.) I have been trying to build exhibits for our museum to illustrate these principles (we have a pipe organ made with plastic pipes to show the effect of length, for example) and would really like further clarification if my understanding is wrong.

I puzzled a little about the fact that lower strings on a guitar or piano are often thicker, but my hypothesis is that lower pitches sound quieter to our ear, so we use a thicker string to increase the energy required to vibrate it and thus increase the volume of the sound - now to think of an experiment to test that one out.........

yours, with deepest respect

richard - a fan

Discovery Museum of Tampere, Finland

your alsom lolololololol hahahahahahahahahahahahahah

this is a wonderful musical flute playing video