If light hits a mirror and then switches direction

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SUMMARY

When light hits a mirror, it does not slow down to change direction; instead, it is absorbed and re-emitted by the mirror. This process differs from refraction, where light changes phase velocity when entering a medium. In the case of conventional rear-surface silvered mirrors, light travels slower than its normal speed in air while passing through the glass before being reflected. Front-surface silvered mirrors, commonly used in telescopes and optometry, reflect light directly back into the air without traversing glass.

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  • Understanding of light behavior, specifically reflection and refraction
  • Familiarity with the concept of phase velocity
  • Knowledge of optical components, particularly mirrors
  • Basic principles of physics related to light speed
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if light hits a mirror and then switches direction...

if light hits a mirror at a 90 degree angle, wouldn't it HAVE to travel slower than the speed of light when it hit the mirror?
 
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No. Why?
 


When light reflects from a mirror, it is absorbed by the mirror and re-emited. It does not "stop" and change direction.
 


HallsofIvy said:
When light reflects from a mirror, it is absorbed by the mirror and re-emited. It does not "stop" and change direction.

I meant more what hallsofivy guessed. That is interesting though. Would the angles of reflection the same for a solid object bouncing off a wall? it seems odd that light's angle of reflection wouldn't be jumbled around somehow while it was absorbed by the mirror.
 


Just a niggle, here. If light hits a conventional rear-surface silvered mirror it will travel slower than its normal speed in air when it hits the glass, until it is reflected by the silvering and re-exits the glass and re-enters air. This is not situation with a front-surface silvered mirror like those used in telescopes or the larger flat mirrors that are used to allow optometrists/ophthalmologists to test your visual acuity in small exam rooms. In such cases, the light is reflected right back into the air and does not have to traverse any glass.
 

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