Gravity – Newton and Einstein definition – demonstration

Gravity is a very interesting topic, its understanding is improving with time from Newton’s idea to Einstein’s imagination. In our workshop, we discussed the theory of Gravity according to Newton and Einstein. It was discussed with a demonstration/model about space bending with the help of a rubber/polyethene sheet with a heavy ball in the centre and light ball around it.

Also, kids were taught what is a theory and it can change from time to time. Science is a formalisation of observation and reasoning of the observation that can change over time as it happened in the case of Gravity. This thought process is the basis for them to understand why so many different definitions are around on a single concept.

Theory of Gravity as per Newton

During a thought experiment about the apple falling from tree and sky, he thinks there is some magnet kind of force which is attracting apple down. He realised the earth is like a big magnet which attracts everything towards it.

If force holding the things is bigger than gravitational force things don’t fall. That is the reason tree can hold the apple or any fruit. But when apple become big or ripe, the holding force become weaker than earth’s attraction force and the apple fell down.

Theory of Gravity as per Einstein

According to Albert Einstein gravity is not an ordinary force but, rather a property of spacetime geometry.Einstein realised that massive objects caused a distortion in space-time. Imagine setting a large body in the centre of a strong fabric which is fixed from the ends. The body would press down the fabric, causing it to dimple or vibrate. If we take a marble rolled around the edge would spiral inward towards the body, pulled in much the same way that the gravity of a planet pulls at rocks in space. Below picture depicts the earth and the moon in a space-time.

Demonstration