This is mesmerizing...

[Nevilledog]

Link to tweet

[Biophilic]

1. NO, no f'ing way. Did that really happen? That is sooooo cool. nt

[tblue37]

2. K&R & thanks. nt

[Retired Engineer Bob]

3. Google pendulum wave

https://sciencedemonstrations.fas.harvard.edu/presentations/pendulum-waves

[rsdsharp]

4. Cool

[Phoenix61]

5. Science and math are super cool! nt

[Tanuki]

6. My favorite reply from the thread:

Link to tweet

Thanks for posting this, Nevilledog!

[reACTIONary]

7. So how did they get away with the cover of ....

... Stairway to Heaven? I thought that was pretty aggressively protected.

[scipan]

8. WOW. Did it do this thing, then reverse itself?

My mind ^

[eppur_se_muova]

10. Nothing reversed itself ... a faster pendulum gets ahead of the slower one by a few

degrees of phase in each cycle, until eventually it is 360, then 720, then 1080 degrees ahead -- which all look the same as being in-phase. Past the halfway mark of the cycle, say, 300 degrees behind looks the same as 60 degrees ahead.

Someone fine-tuned the lengths of those strings very carefully, so that the ratios of their lengths are as close as possible to the ratio of the squares of successive integers. (The period of a pendulum is proportional to the square root of its length.)

So the second shortest pendulum is, say, (52/51)^2 times the length of the shortest, the next longest is (53/51)^2 as long, etc. up to (65/51)^2. When the shortest has swung through 65 cycles, the next shortest will have swung through 64, etc., all the way down to 51.

[scipan]

12. Thanks for the explanation!

I was actually not realizing they were acting completely independently.
The period of a pendulum is proportional to the square root of its length.

[Sogo]

16. Thanks for that amazing explanation....

....not that I actually followed, but still, amazing....

[alfredo]

17. Violin Pases

Last edited Thu Aug 5, 2021, 08:57 AM - Edit history (1)

[yonder]

20. Very cool as well

[alfredo]

21. A favorite

Big fan of Pina

[Iggo]

25. Were the violins out of phase from the very beginning?

Last edited Sat Aug 7, 2021, 08:46 AM - Edit history (1)

I didn’t even notice til almost two minutes in.

(When a girl is twirling, nothing else matters.)

[TexasBushwhacker]

9. I wonder if you could do something similar

by keeping the length of the pendulums the same but having balls that were lighter and heavier.

[eppur_se_muova]

11. No. The period of a pendulum is independent of mass.

(At least neglecting friction and air resistance.)

https://en.wikipedia.org/wiki/Pendulum_(mathematics)#Rule_of_thumb_for_pendulum_length

[burrowowl]

13. Kick

[onethatcares]

14. Wow

I really like "Stairway to Heaven".....never though I'd hear it played on the piano..

[2naSalit]

15. I watched without the sound on...

That was a cool display of the energy forms on the planet or something. I wonder how they went about deciding which colors were place in what place in the lineup of the spheres.

[krispos42]

18. That was really awesome! eom

[Upthevibe]

19. Kick....n/t

[lark]

22. Wow!

Amazing!

[Stuart G]

23. I think it is animated...not real...(my opinion only...looks too good to be true!!)

[Ocelot II]

24. Nope, it's real. That's how pendulums work.

See the explanations elsewhere in this thread.

[3catwoman3]

26. How cool would it be to have a miniature of that...

...on your desk?!

[Nevilledog]

27. I had the same thought!