Degrees of freedom in the energy density formula for black body radiation

  • #1
I'm looking for a conceptual explanation of a formula in Quantum Mechanics Demystified introduction. They introduce you to the theoretical black body radiation experiment, where demonstrated how a classical approach leads to the ultraviolet catastrophe.

In the explanation they have the following formula for energy density u([itex]\nu[/itex],t):

u = ( number degrees of freedom for frequency [itex]\nu[/itex]) x (average energy per degree of freedom)

My understanding is that that degrees of freedom is the number of variables that you can vary in the formula.

Since the degrees of freedom vary, I'm assuming that under certain temperatures and frequencies, the formula can be simplified and reduced? This would in turn change the degrees of freedom? Please let me know if I'm understanding it correctly.
 

Answers and Replies

  • #2
anorlunda
Staff Emeritus
Insights Author
9,154
6,150
It is not just a mathematical abstract. They mean the 3 degrees of position in space and the 3 degrees of momentum in space. I may have missed some, but the number of degrees of freedom is not reduceable by math.
 

Related Threads on Degrees of freedom in the energy density formula for black body radiation

  • Last Post
Replies
4
Views
4K
  • Last Post
Replies
6
Views
3K
Replies
2
Views
3K
Replies
74
Views
28K
Replies
4
Views
7K
Replies
15
Views
6K
  • Last Post
Replies
5
Views
4K
  • Last Post
Replies
2
Views
2K
  • Last Post
Replies
3
Views
2K
Top