## Tuesday, 11 May 2021

### Cosmic distance measures

I am still trying to prove the relationships between different cosmic distance measures$$d_L=\left(1+z\right)d_M=\left(1+z\right)^2d_A$$and I'm sill not there. on the way I came across a nice graph on Wikipedia comparing them for various $z$ and wondered if I could reproduce it. My version and the Wikipedia one are shown below, I was pleased.
 Spot the difference

Here's how and my first attempts at proving that formula: Commentary 8.5.4 More distances.pdf (10 pages)

## Tuesday, 4 May 2021

### Three years old

The very first post on this blog was on Thursday, 15 March 2018. So we're over three years old and now getting nearly 3,000 pageviews per month. There was a mysterious big uptick in September last year.