- Joined
- Nov 2, 2012
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Not really smoke, per se. I was messing around with some sulfur, heating it up enough that it had melted and was boiling a bit. The sulfur was not burning, but was evaporating due to heat. The "smoke" therefore consists of solidified sulfur particles, rather than combustion products. I'm not sure if the particles are crystalline or amorphous spheroids, but either way they should be fairly pure sulfur.
As I understand it, both crystalline substances and amorphous spheres can act as retro-reflectors. Crystalline things act as corner reflectors and spherical retroreflectors are what is used in reflective clothing and whatnot. Here is what I noticed:
The vaporizing sulfur did put particles into the air, but not very many. Certainly far less than would be given off by incense. The visibility of outgoing laser beams was much higher compared to using combustion smoke to scatter the light. However, the visibility was only enhanced when the beam was viewed along and near the beam axis. More than 45 degrees of angle resulted in much less enhancement, with no enhancement at all when I viewed the beam perpendicular. Clearly, the particles tended to reflect the light back 180 degrees, thus acting as if they were retroreflective.
The visibility of an oncoming beam (reflected from a mirror) was also enhanced, but it wasn't much brighter than the outgoing beam. I tried this with red, blue, green, and violet lasers. The violet laser was barely affected at all, but it's a fairly low power unit anyway.
Interesting effect though, figured I would mention it.
As I understand it, both crystalline substances and amorphous spheres can act as retro-reflectors. Crystalline things act as corner reflectors and spherical retroreflectors are what is used in reflective clothing and whatnot. Here is what I noticed:
The vaporizing sulfur did put particles into the air, but not very many. Certainly far less than would be given off by incense. The visibility of outgoing laser beams was much higher compared to using combustion smoke to scatter the light. However, the visibility was only enhanced when the beam was viewed along and near the beam axis. More than 45 degrees of angle resulted in much less enhancement, with no enhancement at all when I viewed the beam perpendicular. Clearly, the particles tended to reflect the light back 180 degrees, thus acting as if they were retroreflective.
The visibility of an oncoming beam (reflected from a mirror) was also enhanced, but it wasn't much brighter than the outgoing beam. I tried this with red, blue, green, and violet lasers. The violet laser was barely affected at all, but it's a fairly low power unit anyway.
Interesting effect though, figured I would mention it.