<bosons>
○○○○○○○○○○ (num of balls=10)
UUUUUU (num of boxes=6)
assuming that one can put any number of indistinguishable balls into one box
eg : putting the 3 balls into the first box,
the 3 balls of the rest into the forth one, and put the rest into the last one
⇔
○○○|||○○○||○○○○
⇔
15C5 = 15C10 = 6H10
in general, if num of balls = r, num of boxes = n, then (n+r-1)C(n-1) = (n+r-1)C(r) = nHr
<fermions>
○○○ (num of balls=3)
UUUUUUUUUU (num of boxes=10)
assuming that one can put only one ball into one box, what is called, the Pauli exclusion principle ( each ball indistinguishable )
eg : putting the one ball into the first box,
the one of the rest into the ninth one, and the last one into the last one
⇔
10C3
in general, if num of balls = r, num of boxes = n, then nCr
<classical particles>
(1)(2)(3) (num of balls=3)
UUUUUU (num of boxes=6)
assuming that all balls can go to any one of the six boxes
(each ball identical) all balls can take any one of the boxes.
⇔ repeated permutation, 6^3
in general, if num of balls = r, num of boxes = n, then n^r
Write a comment