Jesse Rogerson

You should you have to.

We're not part of teams.

We're all part of the group.

We're all working together.

So this was a, I teach a course called history of astronomy and we do the entire history of astronomy.

It's mostly from a European perspective, unfortunately, but it does a decent job of covering the story from early, early humans, 10,000 years ago or so up until today.

And one of the big parts we focus on is ancient Greek astronomy and like

from 600 BCE to about 200 CE or so, that ancient Greek into ancient Rome.

And one of the most notable people during that time was this guy named Hipparchus.

Hipparchus was apparently one of the best observers on the planet.

He would go out, he would observe the sky, and he made very meticulously drawn maps, according to lore.

Now, his original maps of the sky have been lost, but they were copied and changed and added to by other philosophers of the time, Ptolemy and Al-Sufi, to name a couple.

But the original maps of Hipparchus have apparently not...

been seen so enter this group what they did is they what what people used to do is they used to reuse parchment paper parchment you know if nobody's been using it for a while they would like use some chemicals they would wash off all the ink and then they would write over top of it and so they've been this group has been

looking at all these old ancient parchments and finding and seeing that there's there is you can see it with your eyes that there's stuff smudged on there from like the last time it was used but how do you like get the information out and they use a technique called x-ray fluorescence and they the the different inks light up in different ways depending on the light that you hit on it and if you do it in in the correct way you can see like layer one layer two layer three layer four all the way down

What did they discover in these old parchments or whatever?

My favorite result so far is that they found Hipparchus' catalog.

They found that it was as precise as someone would have said from hundreds of years ago, so the lore lived up.

But what I really love about this story is you have Hipparchus' maps.

And then you can compare them to Ptolemy's maps and see what was taken and what was changed and what was added.