The plates are like puzzle pieces under the land, and under us.  It is far beneath the Earth's crust, and when the lava from the mantle and the core of the Earth, the plates vibrate violently, rubbing against the side of the other, causing the Earth to shake.  It's mainly when the core decides to let out … Read more

In a controlled experiment, scientists don't change a variable.  It is the OTHER experiment that they change the variable in.  Scientists change only one and keep the other one original because the purpose is to figure out which solution is better than the other.  If they change both at the same time, then their conclusions would all be … Read more