the most impressive thing to me is that people managed to standardize and zero in a precise “second” especially back when seconds were kept by mechanical means. I wonder how they went about ensuring it.
is it not dependent on mass at all? It’s possible given that this is the metric system that this is actually just a convenient retroactive truth about meters. I suppose it wouldn’t necessarily be, but then you’re accounting for gravity as well, which means you’re going to need a pretty effective approximation there. As well as a way to account for any mechanical losses as well.
I’m not sure the metric system even existed when we developed the first mechanical time keeping devices.
0.3 % would correspond to 3 mm difference in length of the pendulum.
After an hour, the difference between real and measured time would already be 10.9 s, and over an entire day, it would accumulate to 261.3 s, way too much for useful long term measurements.
Yet, it is an useful approximation for qualitative measurements, e.g. when Galileo Galilei did his fall experiments, he might have used a prendulum instead of his pulse for measuring.
I’m not hauling this as the ultimate time keeping method. Friction in the system will mean you need to readjust it anyways.
It’s just a neat fact that pi^2 ~= g
the most impressive thing to me is that people managed to standardize and zero in a precise “second” especially back when seconds were kept by mechanical means. I wonder how they went about ensuring it.
A 1m pendulum has a 1 second half-period.
is it not dependent on mass at all? It’s possible given that this is the metric system that this is actually just a convenient retroactive truth about meters. I suppose it wouldn’t necessarily be, but then you’re accounting for gravity as well, which means you’re going to need a pretty effective approximation there. As well as a way to account for any mechanical losses as well.
I’m not sure the metric system even existed when we developed the first mechanical time keeping devices.
At least that’s an useful approximation, but too inprecise for accurate measurements over an entire day.
It’s only 0.3% off. You probably have more uncertainty on the length of the pendulum.
0.3 % would correspond to 3 mm difference in length of the pendulum.
After an hour, the difference between real and measured time would already be 10.9 s, and over an entire day, it would accumulate to 261.3 s, way too much for useful long term measurements.
Yet, it is an useful approximation for qualitative measurements, e.g. when Galileo Galilei did his fall experiments, he might have used a prendulum instead of his pulse for measuring.
I’m not hauling this as the ultimate time keeping method. Friction in the system will mean you need to readjust it anyways. It’s just a neat fact that pi^2 ~= g
Atomic measurments, it’s why atomic clocks are the most accurate.
that’s a recent invention though, the first mechanical time keeping devices are what’s interesting to me.
The atoms are the powerhouse of the clock.
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