Einstein's poetry

Theory of relativity (Special and General)

When Einstein  published the special theory of relativity in 1905, he changed how time was perceived. Time is not independent of space, instead there is a continuous realm called the space-time continuum, that spins the fabric of the cosmos. The reason it was called the special theory of relativity was because Einstein couldn't incorporate gravity into his equations. The calculations would hold true but in a gravity free space. The faster an object moves, the slower time will run for it. Because of this reason, there is a threshold to the speed of any object in space (c). The calculation of speed of any object (including light) would remain the same irrespective of the frame of reference.


After 1905, it took Einstein 10 more years before he could incorporate gravity into his calculations and publish the general theory of relativity, which would correct Newton's laws of gravity. The fascinating thing about the general theory of relativity is that gravity is often imagined as force pulling two objects with mass towards each other. Although it feels that way, what is really happening is that gravity creates a bend in space time fabric. Let's say that light comes near an object with a heavy mass, the warping of space-time will lead that photon to move along a different path in space time. External observers would interpret this as the force of gravity. Although Einstein did get the Noble prize, it was not for his work on relativity but for his paper on photoelectric effect.

Super massive black holes

A black hole describes the effect of general theory of relativity very well. Black holes are immensely compressed and dense objects in space. They are hard to detect because they don't emit radiation in the visible spectrum (but they do emit hawking radiation). They can be detected through the movement of visible objects such as stars around them. There is a high chance that these is a massive black hole at the center of the milky way. There were two interesting events that happened in the last few years. One was the detection of the Higgs Boson (or graviton) through the LIGO experiment in the US. This was join venture between MIT and Caltech, for which three physicists including Kip Thorne won the Noble prize in 2017. The second was the recreation of the black hole through the creation of a massive telescope through images taken from different telescopes across the earth, created by team led by Katie Bouman.

An interesting thing that happens when objects come near a black hole is that time stops. The reason this happens is that time passes slowly near an object with large mass. Once an object crosses the event horizon of the black hole, there is no coming back, even light cannot escape it. It is assumed that the laws of physics break down post the event horizon. There is an interesting reference to this in sci-fi thriller, Interstellar. Everyone probably remembers the time difference between the shuttle in orbit and crew on the planet, which is caused by the massive black hole Gargantua. Actually I am not referring to that one, but the scene where Cooper plunges into the black and enters the Tesseract, which is a 4D hypercube. One of the theories is that the directionality or arrow of time is not defined by laws of physics (some theories saying entropy of a system only increases so arrow of time can flow only in one direction). If the direction of time is not defined, it could mean that we could  access time from the past (in a Tesseract). As per string theory only the string of a graviton is not tied to a brane and hence can independently access different points in time, and that's how Cooper communicated with his daughter, through the magnificent and complicated force of gravity.


Incomplete. Next up - String Theory