Gravity

Gilbert, AZ, April 2, 2020 at 13:46

The explanation of gravity all started with an apple. Story goes that Sir Isaac Newton was sitting underneath an apple tree when one fell and hit his head. Contrary to popular belief, truth be told that it didn’t quite hit his head; however, he was observing the apple falling and questioning why it fell to the ground and not upwards. This gave him an “ah-ha” moment and thus the birth of his theory of gravity. He explains that every mass in space attracts every other mass and there is a gravitational force between the two. He used his theory to explain why the moon doesn’t fall towards Earth, nor the Earth towards the sun. He also used this idea to prove Kepler’s theory of planetary motion.

In space there is zero gravity which is why this astronaut floats around and does not fall down to Earth. The moon has less mass than Earth and therefore, the gravity is about 1/6th compared to Earth’s. Newton went on to develop his Laws of Motion, which is enough information to do another blog post.

Did you know, how fast an object must travel to escape Earth’s gravitational pull? The answer is about 25,020 mph, which is called the escape velocity.