Unanswered Questions on Light: Control & Visibility

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Controlling the length of a light beam is not possible in a preset manner; it can only be obstructed by an object. Light is visible when it enters the eye, and it travels in straight lines, requiring a medium like dust or smoke to reflect it for visibility. Daylight and air do not support visible light without a haze machine, as the plasma phenomenon is often the only option for visibility in those conditions. The discussion humorously references the idea of building a lightsaber, but the focus remains on the physics of light visibility. Overall, the conversation highlights the limitations of light control and visibility in practical scenarios.
julez520
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Hi

I have to question which i can not find any information on

!st question: is it possible to control the length of a light beam

2nd question: is there any form of light which are viable in daylight and air without the use of a haze machine

or is the plasma phenomenon the only visible light

Thanks

Julian
 
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You can control the length of a light beam by putting something in the way to block it!
You can't preset a light beam to only travel X metres.

You can only see light if enters your eye. Light travels in a straight line so the only way to see a light beam is to reflect light out of the beam into your eye (assuming you aren't looking directly into the source!) this is what dust or smoke does.
 
Someone wants to build a lightsabre, huh? ;)
 
Thanks for the reply s so far

and no light sabres lol
 
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