Introducing spacetime

Origin of the spacetime

Spacetime is the fabric of universe which holds all the matter and energy .It’s origin is quite unknown . According to Newton space and time was thought to be different entities in contrary to the facts lately discovered explains they are united and coexists . Earlier space and time were thought to be absolute in the sense that they are constant for all observers whether they are at rest or moving close to speed of light

Classical physics considered electromagnetic light as one of noblest things of universe and in classical physics speed of light tends to infinity . But later it was determined that speed of light is a finite quantity and found out to be ' c '

So what is the spacetime ?

When Albert Einstein was thinking about gravity he was not convinced with the Newton’s idea of gravity. Which is one of the fundamental forces in the universe and which is very weak in nature, this force when compared to other forces in nature like electrostatic and electromagnetic is very weak .

Instead of having an absolute space and time in the universe, Einstein claimed that space and time is not absolute and the idea does not exists instead space and time united is more likely an elastic fabric and it’s called spacetime

This spacetime fabric being elastic in nature under the influence of matter and energy it can undergo warping called spacetime warping ( change in geometry of the spacetime). This warping can be imagined like a ball placed on a trampoline .

So in order to explain the elliptical circular and linear motions of heavenly bodies in the universe this geometry of spacetime plays a very important role

What makes the heavenly bodies like sun moon and earth move in different directions

We know that a moving body in a particular direction will continue to move until and unless an external force is applied. When we consider forces acting on huge bodies on a large scale it is the gravitational force according to Newton due to the mass of the body .

“According to Einstein this gravitational force is the consequence of the warping of spacetime”