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.
#KatieTrainDay postscript with final travel-time accounting: I departed Aldershot Station at 11:43am (scheduled departure had been 9:01am, and I had arrived early) and I rolled into NYC at about 12:45am. So 13 hours station-to-station, but about 18.5 hours door-to-door.
January 27, 2026 at 4:15 PM
#KatieTrainDay postscript with final travel-time accounting: I departed Aldershot Station at 11:43am (scheduled departure had been 9:01am, and I had arrived early) and I rolled into NYC at about 12:45am. So 13 hours station-to-station, but about 18.5 hours door-to-door.
What this means, of course, is: another train 🚇 #KatieTrainDay
January 27, 2026 at 6:07 AM
What this means, of course, is: another train 🚇 #KatieTrainDay
I have arrived in New York! I made it! I am here! #KatieTrainDay
January 27, 2026 at 6:04 AM
I have arrived in New York! I made it! I am here! #KatieTrainDay
No views of the city yet but the Moon is bright across the Hudson. #KatieTrainDay
January 27, 2026 at 5:40 AM
No views of the city yet but the Moon is bright across the Hudson. #KatieTrainDay
Somewhere out there in the darkness there is a tall bright city, shining in neon and headlights through layers of ice and hard-trampled snow. Somewhere in that city is a small quiet room with a bed. Someday perhaps I may find that bed. But for now: all is train. #KatieTrainDay
January 27, 2026 at 5:07 AM
Somewhere out there in the darkness there is a tall bright city, shining in neon and headlights through layers of ice and hard-trampled snow. Somewhere in that city is a small quiet room with a bed. Someday perhaps I may find that bed. But for now: all is train. #KatieTrainDay
I’m now 10 hours into this journey and starting to get tired of being on the train. We’ve stopped at Albany and are currently sitting in a dark carriage waiting for a locomotive change. The announcement says we’re 2.5 hours from our destination once we’re moving again. Hopefully soon. #KatieTrainDay
January 27, 2026 at 2:47 AM
I’m now 10 hours into this journey and starting to get tired of being on the train. We’ve stopped at Albany and are currently sitting in a dark carriage waiting for a locomotive change. The announcement says we’re 2.5 hours from our destination once we’re moving again. Hopefully soon. #KatieTrainDay
The sun has set and with that the view has shifted from all white to all black. Several passengers are snoring. I have been working - there’s plenty of room for my laptop and notebook and the wifi is solid. Took a dinner break for the cafe car’s vegan bbq burger, which was… fine. #KatieTrainDay
January 27, 2026 at 12:18 AM
The sun has set and with that the view has shifted from all white to all black. Several passengers are snoring. I have been working - there’s plenty of room for my laptop and notebook and the wifi is solid. Took a dinner break for the cafe car’s vegan bbq burger, which was… fine. #KatieTrainDay
Somewhere between Rochester & Syracuse. Sky has cleared and is now wonderfully blue and pink, but as we travel the snow kicked up by the front of the train still lends the view some vague Snowpiercer vibes. My car is now half full but everyone is quiet. We’re all in this together. #KatieTrainDay
January 26, 2026 at 9:57 PM
Somewhere between Rochester & Syracuse. Sky has cleared and is now wonderfully blue and pink, but as we travel the snow kicked up by the front of the train still lends the view some vague Snowpiercer vibes. My car is now half full but everyone is quiet. We’re all in this together. #KatieTrainDay
We are on the move again! 🚂
Just after we started, Amtrak guy walked through car talking to other employee saying, in an exasperated tone, "He said it's probably gonna happen again. Every time, we just have to keep on resetting it."
Meanwhile, scenery is… very white. #KatieTrainDay
Just after we started, Amtrak guy walked through car talking to other employee saying, in an exasperated tone, "He said it's probably gonna happen again. Every time, we just have to keep on resetting it."
Meanwhile, scenery is… very white. #KatieTrainDay
January 26, 2026 at 9:04 PM
We are on the move again! 🚂
Just after we started, Amtrak guy walked through car talking to other employee saying, in an exasperated tone, "He said it's probably gonna happen again. Every time, we just have to keep on resetting it."
Meanwhile, scenery is… very white. #KatieTrainDay
Just after we started, Amtrak guy walked through car talking to other employee saying, in an exasperated tone, "He said it's probably gonna happen again. Every time, we just have to keep on resetting it."
Meanwhile, scenery is… very white. #KatieTrainDay
Two unfortunate developments: other passengers have discovered my train car, and we are currently stopped due to “some mechanical issues.” They are going to troubleshoot. Meanwhile, apparently we get free water and snack packs in the cafe car. #KatieTrainDay
January 26, 2026 at 8:37 PM
Two unfortunate developments: other passengers have discovered my train car, and we are currently stopped due to “some mechanical issues.” They are going to troubleshoot. Meanwhile, apparently we get free water and snack packs in the cafe car. #KatieTrainDay
Back on the train and moving again! By using the clever technique of walking a little farther from the door and passing through the vestibule between cars I have ended up with an entire train car to myself! It is wonderfully quiet and peaceful. Time for a snack and some laptop work. #KatieTrainDay
January 26, 2026 at 7:05 PM
Back on the train and moving again! By using the clever technique of walking a little farther from the door and passing through the vestibule between cars I have ended up with an entire train car to myself! It is wonderfully quiet and peaceful. Time for a snack and some laptop work. #KatieTrainDay
Just crossed to the U.S. at the Niagara Falls train border. Off train for passport checks. Two women who’d been sitting across from me were apparently planning to get off at the CANADA-side Niagara station & missed the announcement. But they have crossed over now; fate unclear. #KatieTrainDay
January 26, 2026 at 6:57 PM
Just crossed to the U.S. at the Niagara Falls train border. Off train for passport checks. Two women who’d been sitting across from me were apparently planning to get off at the CANADA-side Niagara station & missed the announcement. But they have crossed over now; fate unclear. #KatieTrainDay
The train people felt bad about the delay and gave us all free hot drinks.
#KatieTrainDay
#KatieTrainDay
January 26, 2026 at 5:18 PM
The train people felt bad about the delay and gave us all free hot drinks.
#KatieTrainDay
#KatieTrainDay
On my way! You’ll just have to imagine a proud dramatic train whistle sounding here. (Thx @peacewind.aero for video.) #KatieTrainDay
January 26, 2026 at 5:16 PM
On my way! You’ll just have to imagine a proud dramatic train whistle sounding here. (Thx @peacewind.aero for video.) #KatieTrainDay
I assume that Zerzan, the DOT’s general counsel, has no idea that there are two more words after “flood the zone” in that saying, or how appropriate they are in this instance. 😑
January 26, 2026 at 2:28 PM
I assume that Zerzan, the DOT’s general counsel, has no idea that there are two more words after “flood the zone” in that saying, or how appropriate they are in this instance. 😑
The only good thing about all this is that it has brought to my attention that the Greenland flag frickin’ rules. #Erfalasorput
January 17, 2026 at 1:00 PM
The only good thing about all this is that it has brought to my attention that the Greenland flag frickin’ rules. #Erfalasorput
Having a friend like @charlottereads.com who knows books and knows me definitely has its benefits 🎁😍✈️
(The publication date is 1944, and it appears to be a first edition)
(The publication date is 1944, and it appears to be a first edition)
December 25, 2025 at 10:30 PM
Having a friend like @charlottereads.com who knows books and knows me definitely has its benefits 🎁😍✈️
(The publication date is 1944, and it appears to be a first edition)
(The publication date is 1944, and it appears to be a first edition)
This paper contains some good arguments about an issue that concerns me a lot when I hear my colleagues talking about LLM use in developing their research:
Whose ideas are you presenting as your own?
(Though the fatalist argument the authors make at the end of paper is disappointing/bizarre.)
Whose ideas are you presenting as your own?
(Though the fatalist argument the authors make at the end of paper is disappointing/bizarre.)
December 14, 2025 at 12:38 PM
This paper contains some good arguments about an issue that concerns me a lot when I hear my colleagues talking about LLM use in developing their research:
Whose ideas are you presenting as your own?
(Though the fatalist argument the authors make at the end of paper is disappointing/bizarre.)
Whose ideas are you presenting as your own?
(Though the fatalist argument the authors make at the end of paper is disappointing/bizarre.)
Falsely asserting that I’m already using your AI slopbot is not going to convince me to actually do so, Google 😒
December 12, 2025 at 2:55 AM
Falsely asserting that I’m already using your AI slopbot is not going to convince me to actually do so, Google 😒
I went to the local Christmas market and the highlight was meeting Holly the dog in her Mrs Claus outfit 😍
December 7, 2025 at 2:45 AM
I went to the local Christmas market and the highlight was meeting Holly the dog in her Mrs Claus outfit 😍
YouTube is doing a year-end summary thing and mine is… not a surprise 🙃
Shoutout to @skepchick.org, @acollierastro.bsky.social, and @flightchops.bsky.social!
Shoutout to @skepchick.org, @acollierastro.bsky.social, and @flightchops.bsky.social!
December 6, 2025 at 1:37 AM
YouTube is doing a year-end summary thing and mine is… not a surprise 🙃
Shoutout to @skepchick.org, @acollierastro.bsky.social, and @flightchops.bsky.social!
Shoutout to @skepchick.org, @acollierastro.bsky.social, and @flightchops.bsky.social!
Spent a couple days this week in the annual meeting of the Governing Board for the Waterloo Centre for Astrophysics at @uwaterloo.ca. It’s great to be part of such a productive and impactful organization! (In addition to being on the board, I’m also an Associate Member) uwaterloo.ca/astrophysics...
December 5, 2025 at 11:55 PM
Spent a couple days this week in the annual meeting of the Governing Board for the Waterloo Centre for Astrophysics at @uwaterloo.ca. It’s great to be part of such a productive and impactful organization! (In addition to being on the board, I’m also an Associate Member) uwaterloo.ca/astrophysics...
how your e-mail finds me
November 23, 2025 at 9:07 PM
how your e-mail finds me