How are G, ħ & c measured??
Dec 26, 2014 #2 PAllen Science Advisor 9,090 2,317 Did you make any attempt to answer this on your own? As shown by the most trivial look up, you find that c is defined (not measured), and the measures of the others are described as below: http://en.wikipedia.org/wiki/Speed_of_light http://en.wikipedia.org/wiki/Gravitational_constant#History_of_measurement http://en.wikipedia.org/wiki/Planck_constant#Determination All of them may considered defined in some systems of units (for example, G is simply defined as 1 in some unit systems). Last edited: Dec 26, 2014
Did you make any attempt to answer this on your own? As shown by the most trivial look up, you find that c is defined (not measured), and the measures of the others are described as below: http://en.wikipedia.org/wiki/Speed_of_light http://en.wikipedia.org/wiki/Gravitational_constant#History_of_measurement http://en.wikipedia.org/wiki/Planck_constant#Determination All of them may considered defined in some systems of units (for example, G is simply defined as 1 in some unit systems).
Dec 26, 2014 #3 mfb Mentor Insights Author 36,557 13,696 Wikipedia and Google are better starting points for basic question like this.