Raphael Bousso
@bousso.bsky.social
300 followers 69 following 44 posts
Theoretical physicist: gravity, quantum information, black holes, cosmology. Professor at UC Berkeley
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bousso.bsky.social
Congratulations to my wonderful colleague John Clarke! And to Berkeley, and to UC. And to everyone who still believes that foundational research is worth investing in
John Clarke, UC Berkeley emeritus professor, awarded 2025 Nobel Prize in Physics | Letters & Science
ls.berkeley.edu
Reposted by Raphael Bousso
adernburg.bsky.social
3 new Physics Nobel Laureates from the University of California! 🥂🤙 (and one less parking space for the rest of us at Berkeley 🙃)
bousso.bsky.social
Everything is completely normal. Nothing to see here
Reposted by Raphael Bousso
physicsmatt.bsky.social
Academic freedom is "do you want the next generation of medical doctors to be trained?" It is "do you want vaccines?" It is "do you want your kids to learn true things?"
Reposted by Raphael Bousso
katzish.bsky.social
On behalf of the hundreds of thousands of children he killed?
mattpeterson.bsky.social
Elon says he was punched in the face by his 5-year-old son.
bousso.bsky.social
Rubio just told 275000 people who did nothing wrong that he plans to destroy everything they worked for their entire life. This is utter madness and depravity
U.S. Will ‘Aggressively’ Revoke Visas of Chinese Students, Rubio Says
www.nytimes.com
bousso.bsky.social
Ask ChatGPT! But here what we need is the "generalized" second law, which involves areas of causal horizons. The GSL is a conjecture. If it was false, then ordinary thermodynamics would become meaningless if black holes exist. And we have considerable evidence by now for the existence of black holes
bousso.bsky.social
If you don't take this limit, then the battle is veiled in fog. It's harder to formulate the GSL precisely. But it is also harder to claim that a bounce happened. The reason is that now spacetime geometry fluctuates, and saying a "a bounce happened" requires a well-defined notion of time ordering
bousso.bsky.social
You can think of the theorem as saying that the Generalized Second Law implies a singularity and thus is incompatible with bounces and baby universes forming inside a black hole. Both of these conflicting notions are completely well defined only in the limit of infinitely many matter fields
bousso.bsky.social
In a universe with many matter fields, the geometry does not fluctuate. Then we know what we mean by the Generalized Second Law of Thermodynamics, and we know what we mean by a Bounce (or cyclic) Cosmology. My recent theorem says you can't have both.
Reposted by Raphael Bousso
bousso.bsky.social
Science in the US is being actively destroyed simply by deliberately doing nothing. This article does not mention DOE, NSF, etc but it’s the same story. Processing freeze means: grants appear on paper but disappear in real life
The hidden ways Trump, DOGE are shutting down parts of the U.S. government
Limits on spending have incapacitated parts of agencies as varied as the National Park Service and the Pentagon.
www.washingtonpost.com
bousso.bsky.social
Brian Greene is a national treasure, a singular amalgam of grace, professionalism, and brilliance. Also, he's pretty good at explaining stuff
youtu.be/16kzFN0SWYg
Is Gravity the Hidden Key to Quantum Physics?
YouTube video by World Science Festival
youtu.be
Reposted by Raphael Bousso
joshtpm.bsky.social
What's happening with these grants is much more complicated and mostly unknown. None of the NIH have been officially cancelled. The NIH was just ordered to stop paying. They got the Unis to enforce silence on their own campuses because they thought they were "negotiating" and cld get the funds back.
bousso.bsky.social
My kingdom for a moderately okay government
graemesmith.bsky.social
delighted that Canada can get so enthusiastic about a moderately okay government
Reposted by Raphael Bousso
dangaristo.bsky.social
In addition to the terminations of existing awards, new NSF grants are still stopped completely since DOGE was granted access to systems a week ago.

Last Thursday, an agency spokesperson said "NSF continues to issue awards." That does not appear to be the case.
Graph of NSF awards. Compares April 2024 to April 2025, which levels off.
bousso.bsky.social
Francis was not a friend of the rich and powerful. Even yesterday, after meeting with JD Vance, he cried out against his barbarism: "How much contempt is stirred up at times towards the vulnerable, the marginalized, and migrants."