Kathy Loves Physics

exchemist said:
What do you want to discuss?
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Hi, exchemist,

Max Planck Quantum Theory

7:25 min.

Energy equals aitch times Nu [nju:/ni].

Since frequency is a number over a time (second) then
the formula is not about Energy but Power (energy in one second)

and

Planck constant is about energy of One cycle.

That is what I don't understand.

It would be nice if someone explains that formula to me.

Thank you.
 
O. W. Grant said:
Hi, exchemist,

Max Planck Quantum Theory

7:25 min.

Energy equals aitch times Nu [nju:/ni].

Since frequency is a number over a time (second) then
the formula is not about Energy but Power (energy in one second)

and

Planck constant is about energy of One cycle.

That is what I don't understand.

It would be nice if someone explains that formula to me.

Thank you.
Click to expand...
The dimensions of Planck's constant, h, are ML²/T whereas those of energy are ML²/T². So for example the SI units of h are J-sec.

As you rightly say the dimensions of frequency are 1/T, so for example Hz.

Thus the dimensions of hν are those of energy, not power: J-sec x 1/sec = J.

In fact, the dimensions of Planck's constant, viz. energy x time, are those of an important quantity in physics, known as "action". This is a foundational concept in Hamilton's formulation of mechanics, which is how Schrödinger approached the question of how the electron behaves in an atom and which led to his famous equation Hψ = Eψ, in which H is something called the Hamiltonian operator.

But Planck derived h empirically, before that.
 
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