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Wrichik Basu

How is black fire made?

Sodium flames can appear black in the light of a sodium lamp. Natasha explains the physics behind it. COPYRIGHT: The Royal Institution, Britain.

Wrichik Basu, Dec 12, 2018
Akash47 likes this.
    • UmWhut
      So, if the light of the sodium flame was brighter in that wavelength than that of the sodium street light, would the street light appear dark or does which sodium spectral emitter that appears black depend on which emitter has the least or most excited sodium compared to any excess at a lower state?
      In other words, if you put the flame close behind the sodium light and turned off the sodium light, would there be a point in the photon energy drop from the street light in which it appeared to have a portion blacked out due to it being the absorber rather than the cooling sodium flames further away from the point of its ignition after the alcohol has burned off? Would a beam of same wavelength light directed onto sodium salts appear as a black spot on the sodium?

      It is confusing for me to understand otherwise about why the street light and the sodium doped flame do not both have areas of black at the same time in each others presence or how which emitter decides to appear black while the other stays yellow since some video shots appear to show the alcohol sodium solution flame not directly in front of the sodium street light yet the flame still is the only yellow emitter that appears black without having to look at the street light through the flame in order for the flame to appear black..

      . I think I may be confusing it a bit with polarization effects rather than being absorbed due to trying to figure out what selects from the the 2 emitter the one which will continue to be seen as a light emitter and the other to appear black absorber, while both are in each other's presence doing the same thing.. emitting yellow light.
    • Wrichik Basu
      I believe it would be better if you post a question in the main forums with a link to this page. You will get quicker replies, because I will be away for some time from now.
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