Katie Mack
@astrokatie.com
Cosmologist, pilot, author, connoisseur of cosmic catastrophes. TEDFellow, CIFAR Azrieli Global Scholar. Domain verified through my personal astrokatie.com website. She/her. Dr.
Personal account; not speaking for employer or anyone else.
Personal account; not speaking for employer or anyone else.
My local library in Kitchener, Ontario, loans ice skates :)
February 7, 2026 at 2:32 PM
My local library in Kitchener, Ontario, loans ice skates :)
Definitely Brooklyn; not sure about the others
February 7, 2026 at 1:02 PM
Definitely Brooklyn; not sure about the others
I don’t think every library does it but many do! And most of the Brooklyn ones, it seems
February 7, 2026 at 5:23 AM
I don’t think every library does it but many do! And most of the Brooklyn ones, it seems
Best situation honestly
February 7, 2026 at 5:14 AM
Best situation honestly
You’re very kind Micah
February 7, 2026 at 5:11 AM
You’re very kind Micah
I’m immensely honored by this comparison
February 7, 2026 at 5:10 AM
I’m immensely honored by this comparison
It’s the turnover in the angular diameter distance, if that helps?
February 7, 2026 at 3:45 AM
It’s the turnover in the angular diameter distance, if that helps?
Yeah basically! You just have to account for cosmic expansion when you think about how much the light has spread out
February 7, 2026 at 2:44 AM
Yeah basically! You just have to account for cosmic expansion when you think about how much the light has spread out
People don’t talk about it nearly enough!!
February 7, 2026 at 2:41 AM
People don’t talk about it nearly enough!!
Did you read the alt text? 🙂
February 7, 2026 at 2:40 AM
Did you read the alt text? 🙂
You know that thing where the farther something is, the smaller it looks? That doesn’t quite work in an expanding universe. It’s true for a while but after a certain point, more distant things (of the same size) start to look BIGGER because their light has been traveling since the cosmos was small 🙃
February 7, 2026 at 2:33 AM
You know that thing where the farther something is, the smaller it looks? That doesn’t quite work in an expanding universe. It’s true for a while but after a certain point, more distant things (of the same size) start to look BIGGER because their light has been traveling since the cosmos was small 🙃
Yeah same! I spent a while many years ago trying to work out how the angular diameter distance turnover worked and at some point it was just like: Oh. It was literally just closer because the universe was smaller. 🤯
February 7, 2026 at 2:29 AM
Yeah same! I spent a while many years ago trying to work out how the angular diameter distance turnover worked and at some point it was just like: Oh. It was literally just closer because the universe was smaller. 🤯
I love that it is resolved and I love WHY it is resolved even though it is absolutely tiny and extremely far away 😁 (yay cosmology!)
February 7, 2026 at 2:15 AM
I love that it is resolved and I love WHY it is resolved even though it is absolutely tiny and extremely far away 😁 (yay cosmology!)
Agreed! (It took me a minute to process that you are presumably not talking about waiting for ***it*** to happen 😶)
February 7, 2026 at 2:11 AM
Agreed! (It took me a minute to process that you are presumably not talking about waiting for ***it*** to happen 😶)