# What does the unit "Js" of the Planck constant mean?

Summary:
what means unit j.s in plank constant As Planck's constant is the smallest unit of energy so what this unit j.s
what means unit j.s in plank constant As Planck's constant is the smallest unit of energy so what this unit j.s

Have you tried to google what “Js” stands for? What did you find?

Also Plancks constant is not an energy (as you would discover by finding out what the ”J” in Js means).

Fouzan Alaa Almassry
gmax137
Fouzan Alaa Almassry
vanhees71
Gold Member
Well, first of all the unit Js (Joule times second) tells you that ##\hbar## cannot indicate an energy to begin with, because the unit of energy within the SI is J and not Js.

As I've said very many times in the last few days, the unit Js also gives a hint, what ##\hbar## might indicate. It's a fundamental constant of nature and thus provides a natural measure for some quantity with the unit Js, and that's the same as the unit length times momentum. In turn this indicates that it's the natural measure for phase space volumes, and this turns indeed out to be correct when you consider statistical physics of a many-body system.

Have you tried to google what “Js” stands for? What did you find?

Also Plancks constant is not an energy (as you would discover by finding out what the ”J” in Js means).
He searched on Google, but did not give an adequate answer and did not give the meaning of this unit

Planck's constant is important in QM but it is not the smallest unit of energy. It's not even a measure of energy. As you note, its units are ##Js##.

Have you tried to google what “Js” stands for? What did you find?

Also Plancks constant is not an energy (as you would discover by finding out what the ”J” in Js means).
The Planck constant, or Planck's constant, is the quantum of electromagnetic action that relates a photon's energy to its frequency. The Planck constant multiplied by a photon's frequency is equal to a photon's energy. The Planck constant is a fundamental physical constant denoted as {\displaystyle h}
, and of fundamental importance in quantum mechanics. In metrology it is used to define the kilogram in SI units.[2]

PeterDonis
Mentor
2020 Award
He searched on Google, but did not give an adequate answer and did not give the meaning of this unit

Who is "he"? If you mean you searched, the word "he" doesn't make sense. If you mean you think @Dr.AbeNikIanEdL was supposed to search Google and come up with the answer for you, no, that's not what he was saying. He was saying you should do the searching, and then post again here if you have questions about what you find.

PeterDonis
Mentor
2020 Award
The Planck constant, or Planck's constant, is the quantum of electromagnetic action that relates a photon's energy to its frequency.

That's the physical problem that originally motivated Planck to come up with his constant, but its physical applications are not limited to that.

The Planck constant multiplied by a photon's frequency is equal to a photon's energy. The Planck constant is a fundamental physical constant denoted as {\displaystyle h}, and of fundamental importance in quantum mechanics. In metrology it is used to define the kilogram in SI units.[2]

Do you have a question about any of these things?

vanhees71
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