References: 

General Relativity - Wikipedia

https://en.wikipedia.org/wiki/General_relativity

Field Equations - Warwick Department of Physics

https://warwick.ac.uk/fac/sci/physics/intranet/pendulum/generalrelativity/

Heisenberg’s Uncertainty Principle - Wikipedia

https://en.wikipedia.org/wiki/Uncertainty_principle

Stress-Energy Tensor - Wikipedia

https://en.wikipedia.org/wiki/Stress%E2%80%93energy_tensor

Einstein’s Field Equations - Wikipedia

https://en.wikipedia.org/wiki/Einstein_field_equations

Einstein Tensor - Wikipedia

https://en.wikipedia.org/wiki/Einstein_tensor

Pseudo-Riemannian Manifold - Wikipedia

https://en.wikipedia.org/wiki/Pseudo-Riemannian_manifold

Metric Tensor - Wikipedia

https://en.wikipedia.org/wiki/Metric_tensor

Ricci Curvature - Wikipedia

https://en.wikipedia.org/wiki/Ricci_curvature

Metric Tensor in General Relativity - Wikipedia

https://en.wikipedia.org/wiki/Metric_tensor_(general_relativity)

Schwarzschild Metric - Wikipedia

https://en.wikipedia.org/wiki/Schwarzschild_metric

Einstein’s Theory of General Relativity - SPACE.com

https://www.space.com/17661-theory-general-relativity.html

Gravitational Lensing - Wikipedia

https://en.wikipedia.org/wiki/Gravitational_lens

Laser Interferometer Gravitational Wave Observatory - Wikipedia

https://en.wikipedia.org/wiki/LIGO

Equivalence Principle - Wikipedia

https://en.wikipedia.org/wiki/Equivalence_principle

Gravitational Time Dilation - Wikipedia

https://en.wikipedia.org/wiki/Gravitational_time_dilation