Age of the Universe with chatGPT5

I got a science degree in the 1990's and am running a few ideas on chatGPT5. 

I wondered if I could recreate the Edwin Hubble graph of the universe with modern data. 

Hubble looked at areas of the sky with his telescope where there appear to be fuzzy cloud type objects. In the Andromeda area could he saw a special type of variable star called a Cephid variable. Using this star allows you to calculate distance and he realised that Andromeda is so far away (2.5 million light years) that it was another Galaxy. 

The next step is the easy one you put the light from Andromeda through a prism (diffraction grating) and then you can see little black lines in the spectra like you see in our sun. However the absorption lines are slightly moved to the left a little bit and then you can calculate from this the blue shift and so the velocity of the Galaxy. 

So Hubble did this with 24 Galaxies and then plotted them onto a graph of Velocity vs Distance. He got a straight line and surprisingly saw 3 blue shifted Galaxies coming towards and 21 Galaxies flying away from us (red shifted). Also the further the Galaxy the faster the velocity.

This indicates that all of the Galaxies were at one time close together and that there was sort of an explosion that pushed them apart (Big bang)

I used chatGPT to recreate this graph and it looked up the modern data that we have in various star charts and it then plotted, it only could find data for 22 rather than 24:

The gradient of this graph is known as the Hubble constant (H).

Hubble got H to be 500 but he made an error in distance calculations but was correct in principle. My data gets H=59. 

To get the age of the universe you calculate 1/H

ChatGPT5 did all the conversion of H from  km s⁻¹ Mpc⁻¹ into 1/seconds.

I got the age of the universe to be 16.6 billion years. Not bad as it it is about 14 billion.

This all took about 5 minutes as I was sitting on my sofa having a cup of tea.