Can a nuclear reaction violate the first law of classical thermodynamics?

  • Context: Undergrad 
  • Thread starter Thread starter Felgar
  • Start date Start date
  • Tags Tags
    Reference
Click For Summary

Discussion Overview

The discussion revolves around whether nuclear reactions can be seen as violating the first law of classical thermodynamics, particularly in the context of mass-energy equivalence and the historical separation of conservation laws. Participants explore the implications of nuclear processes on classical thermodynamic principles.

Discussion Character

  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • One participant argues that nuclear reactions appear to violate the classical laws of conservation of mass and energy when considered separately, as mass is lost during these reactions.
  • Another participant asserts that nuclear reactions do not break any laws of thermodynamics, suggesting that energy should be understood to include mass-energy equivalence as described by Einstein's theory.
  • A participant references Einstein's work, indicating that the laws of conservation of mass and energy were unified through relativity, thus suggesting that the first law of thermodynamics is not violated when considering mass-energy conservation together.
  • One participant expresses frustration in finding credible sources that distinguish between classical and modern thermodynamics, indicating a need for clarity in definitions.

Areas of Agreement / Disagreement

Participants do not reach a consensus; there are competing views on whether nuclear reactions violate classical thermodynamic laws, with some arguing for a strict classical interpretation and others advocating for a modern understanding that incorporates mass-energy equivalence.

Contextual Notes

Participants highlight the historical context of conservation laws and the evolution of thermodynamic principles, but there are unresolved assumptions regarding the definitions of classical versus modern thermodynamics.

Felgar
Messages
19
Reaction score
0
Hi Guys,

I'm in an argument with someone on another forum (car forum no less) and he refuses to accept that nuclear reactions break the first law of classical thermodynamics. I'm only trying to show him that before energy and mass were shown to be interchangeable, the laws of conservation energy and of conservation of mass is the classical sense are violated by nuclear/radioactive processes. However, it's so commonly accepted now that mass-energy is conserved together rather than separately, I can't find a valid and credible source that distinguishes between classical and more modern thermodynamics.

Can anyone help with a link? Thanks guys.
 
Science news on Phys.org
I am not aware of nuclear reactions breaking any laws of thermodynamics.
 
Just that taken separate from each other, the laws of conservation of mass and conservation of energy don't hold, because we'll lose mass in a nuclear reaction. Not until the revelation that e=mc^2 and the combination of the two laws do we actually get a conservation law that is not broken.

quoted from
Relativity, the Special and General Theory
by Dr. Einstein

"Before the advent of relativity, physics recognized two conservation laws of fundamental importance, namely the law of conservation of energy and the law of the conservation of mass; these laws appeared to be quite independent of each other.
By means of the theory of relativity they have been united into one law... "
 
You shouldn't see this as a violation of the 1st law of thermodynamics, you should rather consider that in the first law, energy can now (since Einstein) include what is available through E = mc^2 in the case where you have nuclear reactions.
 
Alrighty then... No wonder it was hard to find that reference. Heh.

And yeah, obviously that's what makes the most sense. But the argument was about the classical definition which I was arguing wuold have to be observed in the strictest sense. But yeah, whatever.
 
Last edited:

Similar threads

Graduate 1st law of thermodynamics with chemical reaction?
  • · Replies 25 ·
Replies
25
Views
4K
Graduate Average temperature in a greenhouse
  • · Replies 2 ·
Replies
2
Views
3K
Graduate 1st law, 2nd law, entropy by Gyftopoulos / Beretta is confusing
  • · Replies 7 ·
Replies
7
Views
3K
Chemistry Show that book levitation by absorption of heat violates 2nd law
  • · Replies 13 ·
Replies
13
Views
3K
High School Infrared Detectors & The 2nd Law of Thermodynamics
  • · Replies 152 ·
6
Replies
152
Views
12K
Undergrad Lab energy available in threshold (endothermic) reactions
  • · Replies 5 ·
Replies
5
Views
5K
High School Can Classical Forces Explain Nuclear Fission and Fusion Reactions?
  • · Replies 1 ·
Replies
1
Views
2K
Graduate Blackholes and 2nd Law of Thermodynamics
  • · Replies 3 ·
Replies
3
Views
3K
Undergrad Is Mechanical Energy Conservation Free of Ambiguity - follow up
  • · Replies 77 ·
3
Replies
77
Views
7K
Are Exothermic Reactions a Violation of the Law of Conservation of Mass?
  • · Replies 2 ·
Replies
2
Views
2K