The discussion revolves around the behavior of light from lasers and torchlights, particularly in terms of visibility and interaction with the environment. Participants explore concepts related to light propagation, scattering, and potential experimental setups involving lasers.
Participants express differing views on the visibility of laser beams in a vacuum versus an environment with particles. There is also disagreement regarding the interaction of laser beams at a point of intersection, with some suggesting superposition effects while others deny any collision. The discussion remains unresolved on these points.
Participants reference various experimental setups and conditions that may affect the visibility and interaction of light, but these discussions are contingent on specific environmental factors and assumptions about light behavior.
Individuals interested in optics, laser technology, and experimental physics may find the discussion relevant, particularly those exploring light behavior and visualization techniques.
touqra said:Consider a situation where a friend have a red laser or a torchlight shining across the room. And you are standing at the side, perpendicular to the light beam. If light traverse in a straight line, why is that you can see the light shining across the room when you know that the light that comes out from the laser or the torchlight does not bend 90 degrees?
ZapperZ said:Hint: do you think you will see the light beam going across if, instead, this was done in a good vacuum (10^-5 torr would be sufficient)?
Zz.
P.S. Eeek! If I knew that you were also going to SPAM this question in other parts of PF, I wouldn't have responded.
JohnDubYa said:By the same token, how do you find laser beams? You spray smoke throughout the room. Haven't you seen this technique done in movies? The burglar enters the office, and sprays the interior with smoke from a can. The laser light beams magically appear.
Nothing at all. There is no collision.touqra said:I have one more question.
If let say the red laser is still shining across the room. But on top of that, another blue laser is also shining, but it is traversing perpendicular to the red laser beam. So, there would be a point, where both laser beam will meet each other. What actually happen at this point of collision?
JohnDubYa said:By the same token, how do you find laser beams? You spray smoke throughout the room. Haven't you seen this technique done in movies? The burglar enters the office, and sprays the interior with smoke from a can. The laser light beams magically appear.
Humm... My first optics/Laser class was done will smoking inside was PC. When we needed a beam finder the PROFFESSOR would light up a cig and start blowing smoke.swansont said:In the movies, maybe. Anyone doing that in an optics lab would be rudely introduced to some high-voltage equipment.
Integral said:Humm... My first optics/Laser class was done will smoking inside was PC. When we needed a beam finder the PROFFESSOR would light up a cig and start blowing smoke.
bootsam said:i shone a red laser through a prism then through the gap on some nail clippers as i reduced the gap manually and onto my wall, the laser dot reduced to a wide straight line as i reduced the clipper gap, brighter in the middle but the line was rotated 90deg to the orientation of the nail clipper slot. why is that? have i just carried out a very inpromptu diffraction experiment?