It takes light approximately 100,000 years to travel from one end of the Milky Way Galaxy to the other.

Here's why:

* Size of the Milky Way: The Milky Way is a massive spiral galaxy, with a diameter estimated to be about 100,000 light-years.

* Speed of Light: Light travels at an incredible speed, about 299,792,458 meters per second.

* Calculation: Since a light-year is the distance light travels in one year, 100,000 light-years represents the time it takes light to cross the galaxy's diameter.

Important Note: This is a rough estimate as the Milky Way's size is not perfectly defined and has areas of greater density and areas with less.