# 100 years of General Relativity Part 4: Gravity causes time to slow down

Friends,

This is the fourth part of the VERITAS series on General Relativity. Just to remind our readers: We are doing this series on Einstein’s Theory of Relativity to celebrate the 100th Anniversary of General Theory of Relativity. If you have missed any of the first three parts, you can read them here:
https://unvarnishedveritas.wordpress.com/tag/100-years-of-general-relativity/

In the previous part we discussed the fundamental idea behind General Relativity- The Equivalence Principle. We used the equivalence principle to show that light is bent by gravity. And then we reasoned that gravity bends space-time and that objects moving along this distorted space-time seem to be moving under the influence of a force. If you have not read that part( or the previous ones), I suggest you read them before reading this one.

In this episode of this VERITAS series we will show how gravity causes time to slow down. We will also consider a practical application of this phenomenon.

# 100 years of General Relativity Part 3: Gravity bends Space-Time

Friends,

This is the third part of the VERITAS series on General Relativity. Just to remind our readers: We are doing this series on Einstein’s Theory of Relativity to celebrate the 100th Anniversary of General Theory of Relativity. If you have missed any of the first two parts, you can read them here:
https://unvarnishedveritas.wordpress.com/tag/100-years-of-general-relativity/

In the previous part we reviewed the Special Theory of Relativity that Einstein proposed in 1905. That theory combined space and time into a single concept, space-time and showed us that time does not flow equally for every object in the universe- time is a relative concept and its flow can vary based on the observer’s frame of reference. We also learnt that if an observer finds that two observations are simultaneous, a different observer in a different reference frame may not find those events simultaneous. We also learnt about some amazing and fantastic consequences of Special Relativity- time dilation, length contraction, twin paradox etc. If you have not read the VERITAS on Special Relativity, I suggest you read it before you start reading this one.

Around 1907 Einstein started think about expanding Special Theory of Relativity to include non-inertial( accelerating) frames. As we have already discussed, Special Relativity only considered uniformly moving frames. In 1907 Einstein was still working as a clerk in the Swiss patent office. His 1905 papers had created quite a stir in the scientific community. But he was still unknown outside the scientific community.