Theory of special relativity and general relativity | Spacetime theory

The theory of relativity considered to be remarkable discovery in the fields of physics.

Theory special relativity says - at higher speed time moves slowly and vice a versa. This is a law which has been observed by Einstein whereas time run faster where gravitational forces are less, this is general relativity.

It's not relevant in our day to day life because there is nothing on earth which travels at a speed of light to understand this concept. It is essential to realize that our everyday experiences are a tiny fraction of what the universe can do. Relativity helps us understand the extreme conditions that exist in the cosmos.  Things on earth are quite slow; even a jet plane speed is too minuscule to observe this theory. Our everyday experiences don't prepare us for the strange and counterintuitive behaviors of the universe at high speeds or under intense gravity. You must be wondering then why it is considered to be so important?

This theory is relevant to understand nature of this universe and can be seen in GPS technology. GPS satellites rely on precise time measurements. Relativity predicts that time passes differently at different speeds and gravitational strengths. Without accounting for these relativistic effects, GPS would be inaccurate. Some observations:

• Clocks moving at high speeds (like GPS satellites) run slower relative to clocks on earth.
• GPS works by measuring the time it takes for signals from different satellites to reach your devise

This gives us concept of inter-connectedness of space and time. [We think space and time as separate entities]. Albert Einstein revolutionized our understanding of the universe by combining space and time into a single concept called spacetime.

Spacetime is four-dimensional fabric - length, width and height in space and fourth is Time.

Any object with mass in space curve spacetime (creating a dent). This curvature is what we perceive a is gravity.