How do we define a standard candle? Is the brightness of all the candles the same, or does it depend on the chemical properties of candles? If the brightness of different candles differs, how did Bouguer determine which candle to use as the "standard" candle?
ZizhengTai
This is regarding the "equally bright" point--I remember we briefly mentioned in class that human eyes/ears don't perceive the intensity of light/sound linearly to their physical intensity (i.e. energy).
In the case of light, I learned in one episode of MKBHD that when phone companies say there is a X% increase in brightness, they usually mean increase in nits. For example, 400 nits to 500 nits is a 25% increase. However, this doesn't mean the screen will appear 25% brighter to the human eyes, because we don't perceive brightness linearly w.r.t. nits.
How do we define a standard candle? Is the brightness of all the candles the same, or does it depend on the chemical properties of candles? If the brightness of different candles differs, how did Bouguer determine which candle to use as the "standard" candle?
This is regarding the "equally bright" point--I remember we briefly mentioned in class that human eyes/ears don't perceive the intensity of light/sound linearly to their physical intensity (i.e. energy).
In the case of light, I learned in one episode of MKBHD that when phone companies say there is a X% increase in brightness, they usually mean increase in nits. For example, 400 nits to 500 nits is a 25% increase. However, this doesn't mean the screen will appear 25% brighter to the human eyes, because we don't perceive brightness linearly w.r.t. nits.