Why Doesn't My Homemade Nitrogen Tube Light Up in the Microwave?

Click For Summary

Discussion Overview

The discussion revolves around the phenomenon of gas discharge in sealed glass tubes when exposed to microwave radiation. Participants explore why a homemade nitrogen tube does not emit light as observed in other experiments, considering factors such as gas composition and pressure.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • One participant recalls a demonstration involving a physicist using a sealed argon or nitrogen tube in a microwave, which emitted visible light, and questions why their homemade version does not produce the same effect.
  • Another participant suggests that pressure is a critical factor affecting the emission of light, referencing Paschen's law.
  • A third participant notes that the tubes typically contain low-pressure argon or neon in an evacuated environment, implying that pressure conditions are essential for the observed phenomenon.
  • A later reply inquires whether reducing the pressure in their homemade tube would result in light emission.

Areas of Agreement / Disagreement

Participants express uncertainty about the specific conditions required for light emission in their homemade setup, with multiple viewpoints on the importance of pressure and gas composition. The discussion remains unresolved regarding the exact requirements for achieving the desired effect.

Contextual Notes

Limitations include the lack of detailed information on the specific gas mixtures used, the exact pressure conditions in the homemade tube, and the potential effects of the lexan lid on the experiment.

cragar
Messages
2,546
Reaction score
3
I remember seeing a physicist on TV putting an argon or nitrogen sealed glass tube in a microwave and when he turned it on the tube started flashing an emitting visible light,
So how come when i put a sealed glass jar that i glued a lexan lid on in the microwave it does not emit light , i realize that the air in the jar is a mixture of gases , there is probably something fundamental i am missing .
 
Science news on Phys.org
cragar said:
I remember seeing a physicist on TV putting an argon or nitrogen sealed glass tube in a microwave and when he turned it on the tube started flashing an emitting visible light,
So how come when i put a sealed glass jar that i glued a lexan lid on in the microwave it does not emit light , i realize that the air in the jar is a mixture of gases , there is probably something fundamental i am missing .

The factor you're missing is pressure:
http://en.wikipedia.org/wiki/Paschen's_law
 
The tubes are filled with low-pressure argon or neon in an otherwise evacuated tube.
 
Thanks for the answers ,
so if i evacuated some of the air in the tube , and reduced the pressure would it emit light .
 

Similar threads

  • · Replies 207 ·
7
Replies
207
Views
15K
  • · Replies 12 ·
Replies
12
Views
5K
  • · Replies 21 ·
Replies
21
Views
6K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 4 ·
Replies
4
Views
5K
  • · Replies 11 ·
Replies
11
Views
5K
Replies
14
Views
3K
  • · Replies 16 ·
Replies
16
Views
6K
  • · Replies 8 ·
Replies
8
Views
5K
  • · Replies 1 ·
Replies
1
Views
3K