News for hackers. Stuff that matters.

A comment on 'Temperamental' Big Ben was ringing up to six seconds late. Parent comment

Re:'Temperamental' Big Ben was ringing up to six seconds late by richmarr on Wednesday August 26, 2015 @04:47AM (#10121813)
For a frictionless pendulum in a vacuum this is certainly true.

The article repeatedly says they add weights to the pendulum though, which makes me wonder whether either (a) it's some connected mechanism they add weights to, or (b) this is somewhere reality diverges from the simple model.

[ Parent | on HN ]
Re:'Temperamental' Big Ben was ringing up to six seconds late by rtkwe on Wednesday August 26, 2015 @09:49AM (#10122795)
https://youtu.be/5qEPDXDVxvw?t=169

They're added directly to the 'pendulum shelf' which looks like it's right at the top of the pendulum. That would adjust the length up (shorter) by a tiny amount by shifting the center of mass of the pendulum up. This squares with the simple model of a pendulum.

[ Parent | on HN ]
Re:'Temperamental' Big Ben was ringing up to six seconds late by joe5150 on Wednesday August 26, 2015 @01:10PM (#10124445)
It's true the weight and shape of the bob will have an effect on the air friction applied to the system, but for a pendulum of this scale, the effect of adding a coin or two will be a negligible change in drag compared to the relatively significant change in the pendulum's center of mass.
[ Parent | on HN ]