* Light travels at different speeds in different mediums. This is because the light interacts with the atoms and molecules of the medium, slowing it down.
* Water is denser than air. This means that light interacts more with the water molecules, slowing it down compared to air.
* When light enters a less dense medium (air), it interacts less. This allows it to travel faster.
Key takeaway: The speed of light is fastest in a vacuum, and it slows down in all other mediums, with the speed depending on the density of the medium.
