Interaction between blackbodies in relation to the second law

  • Thread starter Shunyata
  • Start date
  • #1
3
0

Main Question or Discussion Point

I am trying to understand the behavior of blackbodies in interaction with each other.

Conditions as follows.

[itex] 1)[/itex] There are two blackbodies, say [itex]B_1[/itex] and [itex]B_2[/itex], with corresponding temperature [itex]T_1[/itex] and [itex]T_2[/itex].

[itex]2)[/itex] Initially [itex]T_1>T_2[/itex].

[itex]3)[/itex] [itex]B_1[/itex] and [itex]B_2[/itex] have thermal contact only through radiation exchange.

And finally my question,

Can [itex]B_2[/itex] give energy to [itex]B_1[/itex] or is this prevented by the second law?
 

Answers and Replies

  • #2
cjl
Science Advisor
1,799
385
Sure it can. In fact, it always will be. However, B1 will always be giving more energy to B2 than the reciprocal effect, so the net energy exchange will always involve B1 giving energy to B2.
 
  • #3
3
0
Is it as simple as

[itex]dQ\Big( \frac{1}{T_2} - \frac{1}{T_1}\Big)=dQ\Big( \frac{T_1-T_2}{T_1T_2}\Big)>0,[/itex]

if [itex]dQ=dQ_1 - dQ_2[/itex] is the net-heat where positive direction is from [itex]B_1[/itex] to [itex]B_2[/itex] and [itex]dQ_1>dQ_2[/itex]?
 

Related Threads on Interaction between blackbodies in relation to the second law

Replies
1
Views
2K
Replies
1
Views
356
  • Last Post
Replies
1
Views
687
Replies
16
Views
754
Replies
21
Views
3K
  • Last Post
2
Replies
32
Views
4K
Replies
10
Views
2K
  • Last Post
Replies
4
Views
799
  • Last Post
Replies
0
Views
1K
  • Last Post
Replies
2
Views
2K
Top