Wow! I'm surprised that "candela" is an SI unit--I thought it would be describable in terms of the other SI units. It turns out that the SI units are meter, second, mole, ampere, kelvin, candela, and kilogram (not gram, surprisingly): https://www.nist.gov/pml/weights-and-measures/metric-si/si-units
micahtyong
I was wondering, what defines a "standard" candle such that it could be included as an SI unit? It turns out, there are some exact requirements for this.
[The standard candle is] equal to 1/60 of the luminous intensity per square centimeter of a black body radiating at the temperature of 2,046 degrees Kelvin
NKJEW
This also surprised me - plus it's sort of interesting that it's even needed when luminous intensity can be represented using other base SI units (whereas describing a meter in terms of a second doesn't really work the same way...as far as I know).
Wow! I'm surprised that "candela" is an SI unit--I thought it would be describable in terms of the other SI units. It turns out that the SI units are meter, second, mole, ampere, kelvin, candela, and kilogram (not gram, surprisingly): https://www.nist.gov/pml/weights-and-measures/metric-si/si-units
I was wondering, what defines a "standard" candle such that it could be included as an SI unit? It turns out, there are some exact requirements for this.
This also surprised me - plus it's sort of interesting that it's even needed when luminous intensity can be represented using other base SI units (whereas describing a meter in terms of a second doesn't really work the same way...as far as I know).