How does the sun burn without oxygen?

  • Context: High School 
  • Thread starter Thread starter Anna Blanksch
  • Start date Start date
  • Tags Tags
    Oxygen Sun The sun
Click For Summary

Discussion Overview

The discussion centers on the question of how the sun can continue to "burn" in the absence of oxygen, exploring the mechanisms of energy production in stars, particularly through nuclear fusion. The scope includes conceptual clarifications and technical explanations related to astrophysics.

Discussion Character

  • Conceptual clarification, Technical explanation, Debate/contested

Main Points Raised

  • One participant notes that on Earth, fire requires oxygen, prompting the question of how the sun can burn without it.
  • Another participant explains that all stars, including the sun, produce energy through nuclear fusion, driven by intense heat and pressure.
  • A different participant points out that the term "burn" is used colloquially in this context, suggesting a distinction between fire and the processes occurring in the sun.
  • Further, a participant elaborates that nuclear fusion involves the joining of atomic nuclei, specifically hydrogen fusing into helium in the sun's core, facilitated by high temperature and pressure.
  • One participant introduces the idea that oxygen is a product of stellar fusion processes and can act as an intermediate in further fusion reactions, referencing the CNO cycle.
  • Another participant adds that only extremely massive stars can fuse oxygen, which requires exceptionally high core temperatures, indicating a specific condition for this process.

Areas of Agreement / Disagreement

Participants express differing views on the use of the term "burn" in relation to nuclear fusion, with some emphasizing the colloquial nature of the term while others argue for its applicability in certain contexts. The discussion includes multiple competing perspectives on the role of oxygen in stellar processes, indicating that consensus has not been reached.

Contextual Notes

The discussion reflects varying interpretations of the term "burn" and its scientific implications, as well as the conditions under which different fusion processes occur in stars. There are unresolved aspects regarding the specifics of fusion reactions and the role of oxygen in these processes.

Anna Blanksch
Gold Member
Messages
15
Reaction score
0
On Earth, fire needs oxygen. If space has no oxygen, how does the sun continue to burn? Thanks! :) Ω
 
Astronomy news on Phys.org
All stars burn due to nuclear fusion. Intense pressure creates intense heat. This heat and pressure drives the reaction.
 
Used here, the word "burn" is colloquial, not scientific.
 
The cool thing is that the sun doesn't really "burn" like fire does!

You're right that fires require oxygen as a reactant, but the sun runs on nuclear fusion. Nuclear fusion is the joining of atomic nuclei together and it's possible because of the high temperature and pressure in the sun's core. In the core, hydrogen nuclei fuse with other hydrogen nuclei to form helium (and this can happen with heavier and heavier nuclei with even more pressure and temperature) and photons, basically.
 
Additionally, one of the products of stellar fusion processes is oxygen, which is then used as an intermediate(catalyst) in further production of helium nuclei(wiki: the CNO cycle).
So if one is so inclined as to call fusion "burning", then we have to admit that oxygen IS used in at least some "burning" in stars.
 
Only extremely massive stars can fuse oxygen. It requires a core temperature over a billion degrees. A star this massive is called a type II supernova progenitor.
 

Similar threads

  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 29 ·
Replies
29
Views
3K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 14 ·
Replies
14
Views
3K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 27 ·
Replies
27
Views
3K
  • · Replies 0 ·
Replies
0
Views
2K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 17 ·
Replies
17
Views
4K
  • · Replies 25 ·
Replies
25
Views
4K