How can we be sure of Planck’s constant when we have never measured anything to that accuracy?

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Any constant in physics or chemistry comes from experimental design and consistency in measurements. For example, if you divide multiple of pressure and volume with the multiple of moles and temperature, you will get the constant R for any ideal gas.

However, given how small planck’s constant is, how can we assume its accuracy?

In: Physics

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Anonymous 0 Comments

Using formulas, we can substitute in observations we have and solve for the observations that are too small (or too big) to make.

Here’s the *simplified* process for deriving Planck’s Constant:

1. Take a black hole that absorbs ALL radiation that touches it. Classical mechanics couldn’t explain radiation *from* a black hole like this.

2. Planck suggested that light could be emitted or absorbed as a set amount, instead of a wave with continuously varying wave.

3. He then suggests that the energy of a photon (the set amount) is proportional to its frequency. That gives you E = f * h, where “h” is some standard amount you need to modify the frequency.

4. When you observe data from black-hole body radiation, you can mathematically analyze the distribution of energy to give you “h”. This is Planck’s constant.

**Generally, this formula is written as E=hv, but I used “f” for “frequency” to make it easier to follow.*

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