B Testing the effect of Gravity at home....

[russ_watters]

Music in a group requires coordinating movements between different people with probably microseconds precision. Watch videos of a drumline to see such precision visually.

The real problems with dropping two objects, especially of different weights, are that it isn't a decisive movement, isn't the same movement for each hand and small variations in hand position and friction can significantly affect the outcome. This can be fixed by using a decisive release mechanism instead of dropping manually.

 

[Ibix]

do not think that "reaction time" is the correct figure of merit here.

I've just been dropping a pair of marbles on to blutack, so they thump but don't bounce. I dropped one from 10cm and the other from 15, 20, and 30cm. I reckon that there was a single sound for the 10cm vs 15cm drop, a just about noticeable d-dump sound with the 20cm vs 10cm trial, and a clear double sound with the 30cm vs 10cm trial. I wasn't blinded or anything, so treat with caution, but that suggests that a 30ms difference isn't detectable, 60ms is just about, and 100ms is clear.

Considering that the guy in the video is dropping from waist height (~1m) I get a drop time of 450ms, suggesting that around 10-15% difference in drop times would be audible.

There's a lot to criticize about that experiment. I was just letting go of the marbles not using a mechanism, I didn't clean them after their impacts on the blutack, and I wasn't blinded to the release heights. But there are some rough numbers. Could probably do something more sophisticated if someone has a suggestion for an adjustable height simultaneous release mechanism...

 

[jbriggs444]

An on-point experiment gets high marks in my book. Nicely low tech too.

 

[hutchphd]

1869?
That's the kind of little mistake that makes me question the whole thing...

And a bit of dyslexia might be excused but it was 1687 according to my researches...