# Thread: Understanding of space by amateur astronomer

1. Originally Posted by BABOafrica
I have always been suspicious of "inflation". I see it as a mathematical "fix" for BB theory. I find it hard to swallow the notion that space expands.
Some skepticism of inflation is healthy, that said, I think you are in for a shock: You don't even need inflation to get space expanding. The entire Big Bang theory is about space expanding. The entire Robertson-Walker metric (which describes a homogeneous universe) is about space expanding or contracting.

That said, this might make you feel a little better: If you accept the notion that "gravity" is curved space time, and that mass can stretch and bend space time, then maybe it is not so weird to think that the entire universe might stretch as well.

Now, mind you, I'm the kind of person who is suspicious of imaginary numbers because I think taking the square root of -1 is a neat mathematical trick but, in reality, a trick that allows us only the limited power of manipulating numbers without really knowing what we are doing. Therefore, I am suspicious of the "knowledge" that is gleaned from theories that depend on it.
If it makes you feel better, you can replace imaginary numbers with matrix algebra to derive all the same mathematical results. Consider the following matrix:

[ 0 -1 ]
[ -1 0 ] = "imag"

And the identity matrix

[ 1 0 ]
[ 0 1 ] = "one"

Then clearly, imag * imag = - one

Now you can re-derive all the results from complex algebra in the language of matrices.

2. ## The Following 2 Users Say Thank You to DanielC For This Useful Post:

BABOafrica (07-08-2011),chas53 (07-07-2011)

3. Just want to say that I am especially grateful for the insight on the matrix maths as a logical way of thinking our way through the business of imaginary numbers.

The Robertson-Walker metric is also completely new to me, so I'll have to look into that.

Many thanks,
Joe

4. ## The Following User Says Thank You to BABOafrica For This Useful Post:

chas53 (07-08-2011)

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