Who was Einstein?
Albert Einstein was a German theoretical physicist. His most noted theories include the general theory of relativity, the special theory of relativity, the photoelectric effect and many more. He was awarded a noble peace prize in the sciences in 1921.
The General Theory of Relativity
In 1916 Einstein published the geometric theory of gravitation, better known as the general theory of relativity. The focus of this theory: the curvature of spacetime is directly related to whatever matter is present. This explanation builds off of newton’s laws of gravitation. Imagine a thin rubber sheet represents a plane of space, when an object like the sun is dropped onto that sheet it creates a valley. All objects close to this dip will fall towards it, however with a fast enough velocity the objects will never reach the center.
This phenom is also applicable when talking about light. Einstein hypothesized that when light reaches the earth from a distant star, the star location that we see is not the actual location of the star. He believed that the light, if traveling around a large object like the sun, would actually bend around the sun.
As can be seen in the exaggerated model above the light bends around the sun. The hypothesis however was very difficult to prove.
There are two main ways to observe this phenomenon and to measure its effects.
The way is to observe a solar eclipse.
Since, light bends around the moon, when the moon covers the entirety of the sun, sun ray still shine through. Below, is a negative image of a solar eclipse in 1919, this was a great picture for scientists because it showed Einstein’s theories to be true. In 1953, when the total energy was calculated from the light that bent around the moon, it matched up perfectly with Einstein’s theory.
When asked what he would think if the data didn’t match his theory, Einstein replied “Then I would feel sorry for the dear Lord. The theory is correct anyway.”
Another way this phenomenon can be observed without permanently damaging your retinas is by watching a lunar eclipse … oh wait, you missed it, it was during passover.
Anyway, the moon is still a visible red during total eclipse. This light isn’t coming from earth or the glowing cheese on the moon. This light that hits the moon still comes from the sun, only it has been around the earth this time.
Many of the stars that are observed through powerful telescopes can also be seen if full because of this phenomenon. On rare occasions, astronomers had to correct for the same star appearing multiple times because it bent in multiple ways around another star.