This isn’t random at all. Euler’s number is to processes what pi is to shapes You can find pi by approximating a circle by polygons with more and more sides and you can derive e by approximating the rate of change by smaller and smaller steps

Do you find the way statistics relates to scientific questions confusing and arbitrary? Do you like drawing owls? Then my free lectures are here for you

In my dept today we discussed deriving estimators from causal models. This can be opaque, but as a simple e.g. instrumental variable Z for estimating X on Y. Z –a–> X –b–> Y, and X <– U –> Y, where U is unmeasured, a and b are path coefs. We want to know b. How? >>

🚨Postdoc job alert🚨 Syracuse University Gravitational Wave group is hiring TWO postdocs to work on instrumentation. Are you an experimentalist? Do you like optics and lasers? Check these out! One position focuses on squeezed light, and one on high power lasers! Links below~

At the University of Wisconsin–Madison, we are excited to host 51 Pegasi b Fellows in the Department of Astronomy! Applications are due October 3, 2025. This was the fellowship that I had as a postdoc, and I’d be happy to chat if you think you might be interested in applying!

And so is the other 'UW' (University of Washington)!

NASA write up of Sabina Sagynbayeva's recent work, with Will M Farr at Flatiron Institute, mapping stellar surfaces of transiting exoplanet host stars! science.nasa.gov/missions/tess/…

Results from the first part of our fourth LIGO EGO & the Virgo Collaboration KAGRA Gravitational Wave Observatory observing run are out today! We're pleased to share the largest catalog of gravitational-wave observations with more discoveries of black holes and neutron stars 📰 arxiv.org/abs/2508.18082 #O4IsHere #GWTC4

New paper! In work led by Hannalore Gerling-Dunsmore, we show that magnetic fields generated self-consistently via the magnetorotational instability stabilize AGN accretion disks against self-gravity and fragmentation. (1/2)

I'm sad to report that Rainer (Rai) Weiss passed away yesterday at age 92. Rai developed the design for LIGO, he and Kip got it funded, trained countless researchers, and received the 2017 Nobel Prize. Rai always had time for students and treated us as equals.

🚨 New gravitational-wave results from LIGO–Virgo–KAGRA (GWTC-4) are out! So many exciting insights + gorgeous plots 🔥✨ Huge kudos to LVK for making data openly accessible 🙌 I made a (biased!) astro summary of key highlights 👉 bit.ly/3BYhxol

🚨 We’re hiring! The Department of Astronomy at the University of Illinois Urbana-Champaign invites applications for a tenure-track Assistant Professor position. Deadline: November 3, 2025 Please help spread the word. #astrojobs illinois.csod.com/ux/ats/careers…

The LIGO Scientific Collaboration will greatly miss our friend and colleague, Professor Rainer Weiss, whose immeasurable impact on gravitational-wave astronomy will be felt for generations to come ligo.org/professor-emer… Our thoughts are with Rai's family and friends

One of the most important contributions to the study of how stars evolve didn’t come from an astrophysicist, but instead a computer scientist. Bill Paxton — who died last month — revolutionized the field by creating the Modules for Experiments in Stellar Astrophysics (MESA). Read

New local H0 result from new, independent team! They use TRGB and ZTF Type Ia supernovae in early type hosts (rebuild both main parts of the distance ladder) and get an H_0 = 75.3 +- 2.9 km/s/Mpc. arxiv.org/abs/2508.20023 A breakdown below.

Please welcome the Fourth Catalog of Gravitational Waves! 208 cosmic discoveries in the last 9 years.

Gravitational wave frequency depends on black hole mass and orbit. LIGO detects signals from 10 Hz to kHz, which is within the audible range, so black hole mergers can be 'heard' by converting data into sound, even though they're not actually sound waves

Nature Astronomy: An international study co-authored by OzGrav Prof Ilya Mandel reveals massive stars are just as likely to form in close binaries in the early Universe as today, reshaping our understanding of stellar evolution & gravitational wave origins ozgrav.org/news/binary-st…

My Les Houches lectures are out (link in the replies): 1. Lightning review of LambdaCDM and Dark Energy 2. Review of EFTs and power counting in cosmology 3. In defense of Technical Naturalness 4. Why I haven’t given up on the cc problem

Pleased to share my graduate student, Qinyuan Zheng's new research on picoHertz gravitational waves! We can now probe gravitational waves with periods of hundreds of years by looking at drifts in the pulsar parameters. ui.adsabs.harvard.edu/abs/2025arXiv2…