Help: Planck Scale and Fine Structure Constant

1Truthseeker
Messages
43
Reaction score
0
Could someone explain the relationship between the FSC and the Planck Scale? What are they in relation to each other. I know what the Planck Scale is, and I even have a loose understanding of the FSC, but what of them in contrast and comparison? And how does the FSC affect QM, if at all?

Thanks!

-Truth

PS - my apologies, it should read "Planck Constant"!
 
Last edited:
Physics news on Phys.org
I am not sure I understand your question. One of the beauties of the fine structure constant is that it is unitless, i.e., independent of any scale or system of units.
Bob S
 
Both describe the very very tiny. I would like to know the difference between them. And how they are related, if at all?
 
\alpha = \frac{e^2}{\hbar c\,4\pi\epsilon_0}
That's the relationship... both of them are numbers that keep popping up in important physics formulas. They're universal constants. I'm not really sure what else you're after.
 
diazona said:
\alpha = \frac{e^2}{\hbar c\,4\pi\epsilon_0}
That's the relationship... both of them are numbers that keep popping up in important physics formulas. They're universal constants. I'm not really sure what else you're after.

Why is the reduced Planck constant inversely proportional to the fine structure constant?
 
Last edited:
1Truthseeker said:
Why is the reduced Planck constant inversely proportional to the fine structure constant?
The reduced Planck constant is given by

h-bar = e2/(4πε0cα).

So the reduced Planck constant is scale dependent on a lot of factors, excluding only 4, π, and α, which are scale independent (unitless).

A better question is why does the reduced Planck constant depend quadratically on the fine strucure constant in

h-bar = mec2α2/(2cR)

where mec2 is the electron mass and R is the Rydberg constant.

Most fundamental is the ratio of the Rydberg energy RE = 13.606 eV to the electron mass:

RE//mec2 = α2/2 which is unitless and therefore scale independent.

Bob S
 
Insights auto threads is broken atm, so I'm manually creating these for new Insight articles. Towards the end of the first lecture for the Qiskit Global Summer School 2025, Foundations of Quantum Mechanics, Olivia Lanes (Global Lead, Content and Education IBM) stated... Source: https://www.physicsforums.com/insights/quantum-entanglement-is-a-kinematic-fact-not-a-dynamical-effect/ by @RUTA
If we release an electron around a positively charged sphere, the initial state of electron is a linear combination of Hydrogen-like states. According to quantum mechanics, evolution of time would not change this initial state because the potential is time independent. However, classically we expect the electron to collide with the sphere. So, it seems that the quantum and classics predict different behaviours!
Back
Top