We aren’t sure if [Looking Glass Universe] didn’t trust the accepted number for Planck’s constant, or just wanted the experience of measuring it herself. Either way, she took some…
I didn’t watch the video, but this is a classic lab experiment we do for high school students. A variable resistor to adjust to threshold voltage (just before the led lights up), a multimeter to find said voltage, and knowing the wavelength of the led, voila, you get quite a surprisingly accurate Planck constant within the same order of magnitude, and even within the first digit ‘6’. It surprises our students immensely.
I didn’t watch the video, but this is a classic lab experiment we do for high school students. A variable resistor to adjust to threshold voltage (just before the led lights up), a multimeter to find said voltage, and knowing the wavelength of the led, voila, you get quite a surprisingly accurate Planck constant within the same order of magnitude, and even within the first digit ‘6’. It surprises our students immensely.