This month, a century ago, Albert Einstein wrote down the gravitational field equations. General Relativity is still the most beautiful theory discovered by the human intellect. There are two nice articles on this:
- The New York Times: A Century Ago, Einstein’s Theory of Relativity Changed Everything.
- The Economist: The most beautiful theory
The most fascinating result of General Relativity is that the universe is dynamic. Both articles give a brief history of what was on Einstein’s mind. When he found that his equations tell us that the universe is dynamic (i.e., either expanding or contracting), Einstein could not come to terms with it, initially. He then added a term to his field equations, perfectly allowed, to produce the result that the universe is static. This is called the cosmological constant term. However, Willem de Sitter came up with a solution for the field equations with this cosmological constant term, in which the universe is dynamic. This probably embarrassed Einstein, who later called it (adding the cosmological constant term) the greatest blunder of his life. However, physicists later concluded otherwise because there is no reason why this term shouldn’t be there. At any rate, Einstein’s General Relativity tells us that the universe is dynamic and only later did experiments verify this fact.
General Relativity also gives us a starting point – a scientific nature of inquiry – in asking about life, universe and everything. In a film, A Brief History of Time, Roger Penrose says:
I think I would say that the universe has a purpose, it’s not somehow just there by chance … Some people, I think, take the view that the universe is just there and it runs along – it’s a bit like it just sort of computes, and we happen somehow by accident to find ourselves in this thing. But I don’t think that’s a very fruitful or helpful way of looking at the universe, I think that there is something much deeper about it.