Answer:
gravity
Explanation:
as the earth rotates on an axis, it causes an effect known as centripetal acceleration with is an acceleration that pulls objects towards the center of the object. in planets, we call this Gravity
travel through a vacuum at the speed of light. Other waves need a medium; sound waves need molecules that vibrate.
Answer:
The center of the Milky Way most likely contains a supermassive black hole.
Explanation:
Because it is an eleptical galaxy, it has a little rotation to it but not enough to flatten out so the center will contain a supermassive black hole.