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It was inevitable that it was measured to be constant. You need to build a measuring apparatus out of physical matter and use its physical properties to measu
by DonaldFisk 10y ago
It was inevitable that it was measured to be constant. You need to build a measuring apparatus out of physical matter and use its physical properties to measure things. Use of any reasonable measuring apparatus will have the built-in assumption that c and h are constant, and either particle masses or G is constant, allowing you to measure combinations of lengths, times, and masses.
- euyyn 10y ago> Use of any reasonable measuring apparatus will have the built-in assumption that c and h are constant The speed of light was measured constant by the famous Michelson-Morley experiment, whose apparatus didn't have any built-in assumption about c (nor had anything to do with h).
- DonaldFisk 9y agoThe Michelson-Morley Experiment showed that light velocity had the same magnitude in different directions. One metre is defined to be the length of the path travelled by light in a vacuum in 1/299 792 458 seconds. Therefore, c = 299 792 458 metres per second. The second is defined in terms of the frequency of electromagnetic radiation emitted during a transition between two specific states in a caesium atom. In other words, it's a unit of time as measured on a kind of atomic clock, which by convention is constant. It's an open question whether a second on a pendulum clock is the same as one measured on an atomic clock for all time, as that depends on G.