1. Reflection:

* First Mirror: Light enters the periscope and hits the first mirror at an angle. This mirror is angled at 45 degrees to the incoming light. This angle causes the light to reflect off the mirror and change direction by 90 degrees.

* Second Mirror: The light then travels down the periscope tube and hits the second mirror, which is also angled at 45 degrees. This mirror reflects the light again, changing its direction by another 90 degrees.

2. Final Direction:

* The second reflection directs the light upwards, allowing you to see an object that is otherwise hidden from view.

In short, a periscope uses two mirrors to redirect light, allowing you to see around corners or over obstacles.

Key Points:

* Total Internal Reflection: In some periscopes, the mirrors might be replaced with prisms that utilize total internal reflection. This means the light is reflected within the prism itself, rather than bouncing off a separate surface.

* Image Orientation: The image seen through a periscope is often reversed left to right. This is because the two reflections flip the image horizontally.

Let me know if you'd like more details on any aspect of how light works in a periscope!