The bouncing back of a ray of light, sound, or heat when it hits a surface that it can't go through is called reflection.

Here's a breakdown:

* Light Reflection: This is the most common example we see. When light hits a mirror, it bounces back and we see a reflection.

* Sound Reflection: This is how echoes are created. Sound waves bounce off surfaces like walls or cliffs, creating a delayed sound that we perceive as an echo.

* Heat Reflection: Heat, which is a form of electromagnetic radiation, can also be reflected. This is why light-colored surfaces stay cooler in the sun - they reflect more heat.

Let me know if you have any other questions!