Gravity. We all experience it but no-one really knows what it is. Around the year 1700 English physicist and mathematician Sir Isaac Newton developed his law of gravity after seeing an apple fall from a tree. It not only applied to the motion of objects on our planet, it was also used to predict the orbits of the planets in our solar system. But Newton had a secret. He described gravity as a “force” that pulled an object with a smaller mass (like an apple) towards an object with a larger mass (like the earth). The problem was that although he knew how gravity behaved, he had no idea why it did what it did. It wasn’t electrical or magnetic, so it really couldn’t be called a force at all.
Newton’s laws were accepted as absolute truth until the early 20th century when scientists discovered that the planet Mercury’s orbit couldn’t be predicted using his equations. It was very close but it was out, which opened the door to searching for a whole new theory that could account for Mercury’s anomaly. Enter German physicist Albert Einstein. He had a totally new way of looking at physics, and it challenged many things science at that time accepted as fact. After receiving a letter of inquiry from English scientist Arthur Eddington at the Royal Observatory in Cambridge (where Newton had been the director hundreds of years earlier) Einstein began working on the Mercury problem. He eventually came up with a solution that would lead to the development of his General Theory of Relativity.
Newton assumed that his laws applied to everyone, everywhere but Einstein’s work led him to the conclusion that time and space are subjective. They are experienced differently depending upon the perspective of the viewer. Newton treated gravity as a linear force but Einstein perceived it as a curvature in the space-time continuum. An object with a greater mass causes a distortion of space itself resulting in smaller objects being pushed into an orbit pattern. Picture a stretched out tablecloth with a watermelon placed in the middle forming a depression. If an orange is thrown onto the cloth the curvature of the fabric will result in the orange rolling around the watermelon in a circular motion, just as the planets in our solar system revolve around the sun.
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Einstein’s theory had been published without much fanfare until Eddington devised an experiment to test it. By photographing stars before and then during a solar eclipse he was able to prove, as predicted, that starlight would be bent by the sun. Einstein became a superstar virtually overnight, and the scientific world accepted his General Theory of Relativity as the new truth. It remained pretty much unchallenged for most of the 20th century until some flaws were discovered.
It seemed that his theory didn’t work at the subatomic level or when looking at singularities – incredibly small particles with an almost infinite mass called Black Holes. What happens at these two extremes can be explained using Quantum Mechanics but it’s a band aid solution that physicists like Stephen Hawking are trying to reconcile with Relativity Theory to create a single cohesive theory. Some scientists even believe that there may be a hypothetical particle with zero mass called a Graviton that could account for gravity, but there’s no proof that they even exist. The scientific community badly needs to find one theory that can be applied to every situation, but at the moment they’re not even close. It’s a big problem. Theoretical physicists Michio Kaku (who developed String Field Theory), Andrew Strominger (Harvard) and Max Tegmark (MIT) all agree that physics is kind of a mess right now and nobody has a clue what to do next. Einstein’s theory is still being used for many applications, as is Newtonian physics but some of its assumptions may actually be…wrong. (see the video clip below)
That’s a not-so-brief overview of the science behind this story but even more interesting is looking at the scientists themselves. When Einstein and Eddington were corresponding World War One had already started, and what they were doing was considered conspiring with the enemy – a treasonable offence. In addition, Newton was an icon of British science and a lot of folks weren’t too happy about a German physicist proving him wrong. Both scientists had a deep desire to discover truth and a disregard for the limitations imposed by national borders. But that’s not all they had in common. They were both outspoken pacifists. Eddington was a Quaker who abhorred violence and Einstein described himself as not only a pacifist but a militant pacifist. It’s hard to imagine the ethical struggle Einstein must have gone through when the university he worked for developed the chlorine gas used to kill thousands of young soldiers in the trenches of WW1. Newton may not have identified himself as a pacifist but a couple of his quotes indicate that he definitely had pacifist leanings. For example , “We build too many walls and not enough bridges.” and “I can calculate the motion of heavenly bodies, but not the madness of people.”.
It’s also interesting to examine their views on religion. As a Quaker, Eddington was probably the most “religious” of the three but Newton and Einstein had remarkably similar ways of looking at God. Newton was an Anglican who appreciated God’s sense of order when he created the universe but he had trouble accepting some church doctrine, such as the existence of the Trinity. When there were things he couldn’t explain (like defining gravity) he felt that he was leaving room for God. The obvious problem for anyone subscribing to a God of the Gaps theory to account for the things that science doesn’t understand, is that as science discovers more and more, their God becomes smaller and smaller.
Einstein often spoke of how wonderful God’s universe was because of its simplicity, harmony, beauty and elegance. In his opinion God could have created a chaotic universe but he chose not to. What Einstein couldn’t buy into was the concept of a God who answers personal prayer and gives us a ticket to heaven. Statements he made about his lack of belief in that kind of God were sometimes used by atheists who claimed that he agreed with their worldview. This angered him because he considered himself to be an agnostic, not an atheist.
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When astronauts look down on the Earth from space they often say that all of our political and religious disagreements seem insignificant. They see the world as a beautiful place with no borders, where the concept of war just seems ridiculous. Their perspective changes how they look at life. I think the same is true for scientists who never leave terra firma but keep their minds fixed on extraordinary, celestial things.
It somehow transforms them.
It may be a little scary to even try to envision a universe with no end. Is it possible that it endlessly expands until matter turns into pure light and time turns in on itself? It’s inconceivable to us mere mortals but it’s also a very good reason to end the Lord’s Prayer with the words “For thine is the kingdom and the power and the glory, forever and ever (and ever and ever). Amen.”