Why I can burn a paper with magnifying glass and sun?

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SUMMARY

The discussion explains the phenomenon of burning paper using a magnifying glass and sunlight, emphasizing the role of concentrated light energy. A magnifying glass focuses sunlight into a small area, raising the temperature of the paper above its combustion point due to the concentration of energy. The process involves exciting electrons in the paper, leading to chemical reactions that release energy in the form of heat and light. Key concepts include activation energy, combustion, and the principles of refraction and concentration of light.

PREREQUISITES
  • Understanding of electromagnetic waves and light properties
  • Basic knowledge of chemical reactions and activation energy
  • Familiarity with the concept of combustion and exothermic processes
  • Knowledge of optics, specifically refraction and magnification
NEXT STEPS
  • Research the principles of activation energy and its role in chemical reactions.
  • Explore the concept of combustion and the conditions required for it to occur.
  • Learn about refraction and how it affects light behavior in different media.
  • Investigate the relationship between energy concentration and temperature increase in materials.
USEFUL FOR

This discussion is beneficial for students of physics and chemistry, educators explaining the principles of light and energy, and anyone interested in the practical applications of optics and combustion.

  • #31
Sorry to interrupt you here, but if the chemical reaction of combustion is occurring only at the paper, then why is light coming from the entire flame, which may be several cm long?

It follows it's not just the paper that's burning, also gases emitted from it when heated are burning. What gases would paper emit when heated?
 
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  • #32
Ulysees said:
Sorry to interrupt you here, but if the chemical reaction of combustion is occurring only at the paper, then why is light coming from the entire flame, which may be several cm long?
That's what burning is. This is a different discussion.
 
  • #33
Ulysees said:
Sorry to interrupt you here, but if the chemical reaction of combustion is occurring only at the paper, then why is light coming from the entire flame, which may be several cm long?

It follows it's not just the paper that's burning, also gases emitted from it when heated are burning. What gases would paper emit when heated?

light doesn't *come* from the flame. The appearance of light from somewhere makes you assume that there is a flame there. And yes.. as dave suggested this is a totally different discussion. We are mixing optics, thermodynamics and atomic structure all at the same time which a good combination makes not :D
 
  • #34
And how I can determine, how big I'll see the http://laser.physics.sunysb.edu/~jennifer/pictures/refraction.gif" Why X is like on the picture?
 
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  • #35
> light doesn't *come* from the flame.
> The appearance of light from somewhere makes you assume that there is a flame there

And what is the deep philosophical difference between these two? :-p Of course there is light coming from the flame! Of course there is a flame 2 centimetres from the paper! It's gas. Anyway, this is too philosophical for me :-p. See you guys.
 
  • #36
is a magnifying glass and the sun a form of clear heat?
 
  • #37
rena g said:
is a magnifying glass and the sun a form of clear heat?

This thread is 3 years old. You should start a new thread to ask your question.

In asking your question, you should describe what you mean by "clear heat", since there is no such scientific term.
 

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