FireGarden
Philosopher
- Joined
- Aug 13, 2002
- Messages
- 5,047
So it is your belief, that in math, if your figures don't mesh with your current belief system, it is OK to personally add something to those figures to make them mesh.
Maths is abstract.
The aim of using maths in science is to model the universe. If you have no reason to suppose the universe is changing size, then yes: You will likely construct a model which describes a static universe.
Sitting in a room performing calculations will not reveal the secrets of the universe to you. Contrary to what Artistotle might have thought.
Not until you mentioned that was your take on what was said. But as I have pointed out, the book said that Eddington's experiment proved "general relativity to be true". What you imply after that is dependent on whether you read only one paragraph like you did or the whole chapter like I did.
The impression I get is that they think the theory Eddington's experiment supported is one which described an expanding universe. It was not. Not even Friedmann's solution did that -- it described a universe which was changing size. It could have been contracting.
Out of all the possible mathematical models, how does a scientist decide which is most accurate? In this case, Hubble looked through a telescope. Quite a few hundred times I should imagine.
Their language could have been clearer in the Eddington paragraph, but they clearly say it was Friedman that found the problem with the constant in the next paragraph.
Friedmann found that Einstein's static solution was not the only solution. That is all he did. He did not prove that universe was expanding or contracting. He showed that it was mathematically possible for the universe to change size and be consistent with Einstein's field equations.
Again: The error Friedmann pointed out was not an error which Einstein made in the general relativity paper he published in 1915. It was an error Einstein made before he criticised Friedmann's 1922 paper.
Their language wasn't clear in the Eddington paragraph. But it becomes clearer when they talk about Hubble, de Sitter, Wilson etc.
Their language was misleading. That is why you were misled into thinking that Eddington's experiment had something to do with showing that the universe is expanding.
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