John F. Wu (@jwuphysics) / X

John F. Wu

3,454 posts

John F. Wu

@jwuphysics

Associate Astronomer and Applied AI @SpaceTelescope. Secondary appointments in @JohnsHopkins Astro + CS. Opinions my own. He/him. 🦋 @jwuphysics.bsky.social

Baltimore, MD, USA

Joined June 2020

Pinned
John F. Wu
@jwuphysics
Dec 5, 2025
New blog post. In the era of LLMs, what does learning look like? What happens when are overconfident in our understanding due to AI sycophancy? Is it even useful to use LLMs for education without outsourcing our thinking? jwuphysics.github.io/blog/2025/12/l…
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John F. Wu
@jwuphysics
Oct 28, 2020
Replying to @lqfacts
Whoa, careful there. You might accidentally teach Republicans the definition of marginal tax rates!
John F. Wu
@jwuphysics
Dec 16, 2021
CNN is selling NFTs of Hubble Space Telescope images and thanks I hate Web3 more than ever
John F. Wu
@jwuphysics
Oct 5, 2021
I don't think it's an exaggeration to say that some of the biggest astronomical discoveries in the 2020s are only going to be made possible through self-supervised learning (SSL). arxiv.org/abs/2110.00023
John F. Wu
@jwuphysics
Nov 2, 2025
Super common pathway. Towards the end of my PhD in Physics/Astro, I trained my first deep neural net on a GeForce 780 after watching @jeremyphoward on the @fastdotai lectures. Now I'm tenure-track faculty in (astro)physics, but still maintain strong curiosity in AI/ML
Yuchen Jin
@Yuchenj_UW
Nov 2, 2025
Met a Meta AI researcher. He studied Physics in China, came to the US for a PhD in Physics, and then fell in love with AI, despite never having studied computer science. He watched Andrej Karpathy and Andrew Ng, bought a GPU, read every arXiv paper title daily, and dived into
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John F. Wu
@jwuphysics
Dec 17, 2021
I am so freaking excited to share that I'll be joining @STScI as a tenure-track Assistant Astronomer next year!
John F. Wu
@jwuphysics
Jun 4, 2021
Vision transformers (ViT) and MLP-Mixer models tend to produce sharp loss landscapes. Thus, they stand to benefit most from the recently proposed sharpness-aware minimization (SAM) optimizer! (see Foret et al. 2021, ICLR for more on SAM) arxiv.org/abs/2106.01548
John F. Wu
@jwuphysics
May 29, 2025
Nice post on USAID spending by @slatestarcodex
Sorry, I Still Think MR Is Wrong About USAID
From astralcodexten.com
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John F. Wu
@jwuphysics
Jun 28, 2021
Replying to @WhoIsNickCage
Yes fellow patriots support Ben & Jerry's, champion of conservative values, instead. It's the only way to own the libs (and antifa)
John F. Wu
@jwuphysics
Aug 12, 2024
My twitter feed became absolute garbage overnight... Did this happen to anyone else? It's full of nonsense about JD Vance, "the most beautiful Olympic athletes", and other crap I do not care about. Used to be exclusively astronomy, machine learning, and software engineering...
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John F. Wu
@jwuphysics
Aug 23, 2021
Replying to @astrobites
Is this a power law?
John F. Wu
@jwuphysics
Aug 16, 2022
🚨🚨 Astronomy job alert! 🚨🚨 STScI is hiring *several* Astronomer (tenure-track, 50% research) and Scientist (20-50% research) positions! Lots of priorities this cycle: Exoplanets, IR Imaging/Surveys, UV spectroscopy, and General Astronomy! Apply: recruiting2.ultipro.com/SPA1004AURA/Jo…
John F. Wu
@jwuphysics
Aug 28, 2020
I'm excited to share Part 2 of my blog series on visualizing and interpreting trained CNNs using @PyTorch, @fastdotai, and @matplotlib! We train a CNN classifier and then implement the Grad-CAM algorithm for image attribution in this post: jwuphysics.github.io/blog/galaxies/…
John F. Wu
@jwuphysics
Apr 24, 2025
Thanks (partly) to Gemini, I've migrated my Substack and even older blog back onto my website
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