Alex Ji
@alexji.bsky.social
940 followers 320 following 340 posts
Near-field Cosmologist and Assistant Professor of Astronomy and Astrophysics at University of Chicago. he/him
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Reposted by Alex Ji
mamasissiesays.bsky.social
I booked a photo session tonight bc I have very few pictures of my family together, but while I’m smiling & holding my children, I know I will hear this mother’s screams.

I don’t want my tax dollars supporting ICE agents dragging parents away from car line. And most moms in the US agree with me.
alexji.bsky.social
I’ve been asked to advise undergrads on how to get into grad school and this is all I can think about musgrave.substack.com/p/dont-do-a-...
Don't Do a Ph.D. Now
At least in the United States
musgrave.substack.com
alexji.bsky.social
Fair, but I think this is still less qualitatively different than you think; eg having tutored O(100) CS101-type students, something like 20-30% of people their attitude was “if i remove all the red squiggles from my IDE that means I did it right” until they learned otherwise
alexji.bsky.social
I think there's something where "did something that works" goes too far beyond "understanding what's actually happening" that is the issue here? And part of this is that abstractions that were initially leaky became more solid (e.g. no one worries about transistors failing now)
alexji.bsky.social
Yes, but in this analogy this is like asking gcc to make a fancy figure for you; like technically it's able to do this, but you need to give it more guidance?
alexji.bsky.social
I agree (though I didn't do binary!) and think there's a similar gap going from high level languages like python to LLM-based coding; there's something missing for most users. But at the same time, it really broadens access in a way that I think is valuable.
Reposted by Alex Ji
jocelynl.bsky.social
Armed, masked thugs are kidnapping our neighbors and terrorizing our communities

This was in front of an elementary school in the West Loop in Chicago today. Sharing because everyone needs to see what is happening here daily

Originally posted by @erynfreepress on IG. Her story is in the alt text
alexji.bsky.social
I’m no expert, but we did go from coding in binary -> assembly -> FORTRAN/C -> Java/C++ -> Python/R. At each step we traded raw efficiency(/energy cost) for user convenience. It does take different thinking and teaching/learning for each step. LLM coding seems like it will be the next step..
hormiga.bsky.social
Y'all. I just got ChatGPT to do everything in R for this manuscript. I mean EVERYTHING. And it's all legit and reproducible. I'm shook.

How are we mentoring our trainees in statistics now? Who needs to learn coding in R line by line, and who doesn't?

scienceforeveryone.science/statistics-i...
Statistics in the era of AI
How do we mentor, teach, and do stats when AI can do so much of the work?
scienceforeveryone.science
Reposted by Alex Ji
darrigomelanie.bsky.social
I feel like this photo of masked, armed men pepper spraying a pastor protecting his community is going to be a defining picture of this moment in America for a long, long time.
Reposted by Alex Ji
govpritzker.illinois.gov
We must now start calling this what it is: Trump’s Invasion. It started with federal agents, it will soon include deploying federalized members of the Illinois National Guard against our wishes, and it will now involve sending in another state’s military troops.
Reposted by Alex Ji
kevinmkruse.bsky.social
"There's artificial intelligence, and then there's actual intelligence."
merriam-webster.com
We are thrilled to announce that our NEW Large Language Model will be released on 11.18.25.
Reposted by Alex Ji
helenczerski.bsky.social
In discussion with a computer scientist from the University of Cambridge last night:

Me: "you've described some of the things that AI is good at. How would you describe the category of things it's not good at?

**pause**

Him: "Anything where it has to be right".
Reposted by Alex Ji
telescoper.bsky.social
R.I.P. George F. Smoot (1945-2025)

We will no doubt read many official obituaries in days to come, but all I can say is that he was a character, a very original thinker, a fine scientist, and a very nice man. Along with many others, I will miss him enormously.
R.I.P. George F. Smoot (1945-2025)
We will no doubt read many official obituaries in days to come, but all I can say is that he was a character, a very original thinker, a fine scientist, and a very nice man. Along with many others, I will miss him enormously.
telescoper.blog
Reposted by Alex Ji
alexip718.com
Here we go!

Over 13,000 H-1B workers have joined 200+ land-grant, sea-grant, and R1 research institutions so far this fiscal year.

I also found that public institutions in large, Republican states are disproportionately affected by Trump's $100,000 H1-B fee.

Find your state or your school:
thexylom.com
EXCLUSIVE: A new analysis by The Xylom's @alexip718.com shows for the first time just how much America’s top research institutions have grown to depend on H-1B skilled workers — and how this delicate balance might be disrupted by U.S. President Donald Trump’s crackdown on legal immigration.
The Most Detailed Maps of H-1B Visa Holders Joining America's Top Research Institutions
A new analysis by The Xylom shows for the first time just how much America’s top research institutions have grown to depend on the specialized knowledge of H-1B skilled workers — and how this…
www.thexylom.com
Reposted by Alex Ji
bencollins.bsky.social
We're actually having trouble securing a spot in Chicago, our hometown :(

(This is mostly because it's such short notice, btw.)

Let us know if you're interested in screening Bad Pedophile and you have a big space in town: [email protected]
bencollins.bsky.social
Do you want to screen Jeffrey Epstein: Bad Pedophile in your town or city, unlike a cowardly major movie chain?

Email us at [email protected].

We'll allow you to screen it for free.

Yes, again, this is real.
bencollins.bsky.social
A very big Onion announcement:

The Onion has spent the last two months working on a masterpiece.

It's a documentary titled Jeffrey Epstein: Bad Pedophile.

It's so good, in fact, we were set to release it in theatres nationwide on October 2nd.

Then two weeks ago, Charlie Kirk was shot.
Reposted by Alex Ji
jradavenport.com
Here is a review article I'm giving my students that Payne-Gaposchkin wrote a year before she died, where she reflects on what's been learned on variable stars in here career. She concludes: If I were beginning again, it is there [LMC/SMC] that I should search.

ui.adsabs.harvard.edu/abs/1978ARA%...
Reposted by Alex Ji
chigeek.bsky.social
The annual pumpkin display at the entrance of Governor Pritzker’s personal residence on Astor Street. He is the pumpkin king. Illinois produces the most pumpkins, including canned, than any other state in the U.S., twice as many as the next five states combined.
My photo taken last year of Governor J.B. Pritzker’s personal residence on Chicago’s Astor Street showcasing an impressive pumpkin and gourd display.
Reposted by Alex Ji
jessicacalarco.com
Yesterday's piece from @jamellebouie.net is the only high-profile piece I've seen that specifically discusses the watchlist, its effect on academics, and its effect on public attitudes toward academia as a whole. (gift link)

www.nytimes.com/2025/09/13/o...
Reposted by Alex Ji
ligo.org
A timeline of GW150914. A story that begins a billion years ago and ends with our first #GravitationalWave detection 10 years ago today

Discover more in the @ligomagazine.bsky.social ligo.org/wp-content/u...

#GW10Years ⚛️🧪🔭
Screenshot of the LIGO Magazine, showing a colorful numerical relativity simulation of GW150915 along with the headline "A perfect source: Timeline of GW150914".
alexji.bsky.social
CAL-CITE CAL-CITE CAL-CITE
saavikford.bsky.social
This is NOT A DRILL! It’s time to vote for THE BEST MINERAL…

CALCITE!!!

Thanks to its birefringence, under the name Icelandic spar, it made a critical contribution to our understanding of the wave nature of light! It even appears in the title of Christiaan Huygens ‘Treatise on Light’. ⚛️

#MinCup25
mineralcup.bsky.social
#MinCup25 Round 1 Match 4: This match of heavy hitters is bound to end in heartbreak as classic #calcite faces off against futuristic #perovskite.

We love them both, but only one can continue on to Round 2!

Vote: www.mineralcup.org/2025/vote/r1...
Results: www.mineralcup.org/2025/results...
Reposted by Alex Ji