fuckyeahphysica: Black Holes are not so Black - Part 2 In part 2 of the series, we wish to explore w
fuckyeahphysica:Black Holes are not so Black - Part 2In part 2 of the series, we wish to explore why light behaves in a peculiar fashion near heavy objects. But before doing that we need to expand our understanding of gravity.Redefining GravityWhen we usually talk of Gravitation we are bound to think like Newton, where objects are assumed to exerting a force upon each other. Like imaginary arrows of force in space. But this picture, although good for high school crumbled, with the advent of Einstein’s theory of Relativity. What is the Space-Time Fabric?Think of spacetime fabric as an actual cloth of fabric. When you place an object on the fabric, the cloth curves. This is exactly what happens in the solar system as well. The sun with such a huge mass bends the space-time fabric. And the earth and all the planets are kept in orbit by following this curvature that has been made by the sun.The earth - moon system can be thought of in the same manner. A natural question to ask at this juncture would be:Why don’t planets just swirl into the sun?To put it bluntly, they stay in their orbits because there is no other force in the Solar System which can stop them.The Solar System was formed from a rotating cloud of gas and dust which spun around a newly forming star, our Sun, at its center. The sun did pull objects towards itself. But the planets that we see today were resilient and stuck with their course. And time passed, the net force acting on them turned to zero and will continue to be zero.Gravity and LightLight is affected by the Gravity. This was discussed in a previous post about Gravitational Lensing. The gravitational field of a really massive object is super strong. And this causes light rays passing close to that object to be bent and refocused somewhere else.This is a consequence of the fact that space- time curvature is bent by objects which have a huge mass. When light is passing through this dent the rays of light are directed in another direction. And this causes effects like gravitational lensing.The spookiness of the face in the image is also attributed to Gravitational Lensing.TL;DR - Light bends around heavy objects because heavy objects bend space time. ;)** If you still find it hard to visualize gravitational Lensing. Take a wine glass and just place it on a graph sheet and explorePC: zmescience, oberlin -- source link