Professor of Theoretical Physics at Caltech

Pasadena, CA
Joined October 2008
This is a Penrose illustration appreciation thread. Post your favorite figures below.
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David Simmons-Duffin retweeted
My statement on President Trump’s COVID-19 diagnosis:
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We were asked many times: "How close did the fire get?" We have the answer. (Video from SEP 17) Damage: Smoke and soot inside upper story of The Monastery but otherwise unscathed. How these heroic firefighters managed to save the building is incredible! #bobcatfire
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David Simmons-Duffin retweeted
But I do feel like my performative question-asking changes something imperceptible in the atmosphere of the mathematical spaces I inhabit. I like to imagine that the difference is that it's easier for others to find their voice as well. But who knows.
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David Simmons-Duffin retweeted
SoCal just experienced an M 4.5 quake, probably along the Puente Hills thrust fault system, the same one that ruptured in the 1987 Whittier Narrows earthquake. The aftershock forecast can be found here: earthquake.usgs.gov/earthqua…
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David Simmons-Duffin retweeted
.@Caltech operates the Mount Wilson seismic station. It has recorded all the important California earthquakes for 100 years. The #Bobcat fire threatens to destroy it today.
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David Simmons-Duffin retweeted
Shout-out to all the people who are like “you must not know any physicists” 🤣
It actually makes sense that the physicists didn’t know about college parties
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David Simmons-Duffin retweeted
It actually makes sense that the physicists didn’t know about college parties
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David Simmons-Duffin retweeted
Great interview of the mathematician @emilyriehl, a fascinating person and leader in the bewilderingly abstract realm of higher-category theory. Debut Quanta Magazine piece by @writesRCrowell, who leaves us eager for more quantamagazine.org/emily-rie…
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David Simmons-Duffin retweeted
We are delighted to introduce microCOVID.org, a tool to numerically estimate the COVID risk of specific ordinary activities. We hope you’ll use this tool to build your intuition about the comparative risk of different activities and to make safer choices!
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David Simmons-Duffin retweeted
I made a simulation of the 2d Ising model that you can yell at. You control the temperature through the computer microphone; the louder your voice, the larger the temperature. nabiliqbal.github.io/ising.h…
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David Simmons-Duffin retweeted
You can be forgiven for this one! This is a very slick way to lie with numbers. It could be taught in a class. The key lies in the fact that it is a plot of the CHANGE in the number of jobs, as opposed to the ABSOLUTE number. We can get a better handle using a sports analogy:
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David Simmons-Duffin retweeted
It seems important to know his actual birth-moment so that we can all enjoy an instant of infinite joy, rather than band-limit and smear the celebration of his life over something so coarse as an entire day. We should instantly go from waiting to celebrate to having celebrated.
Paul Dirac (1902-1984) contributed to the early development of quantum mechanics, born 8 Aug www-history.mcs.st-and.ac.uk…
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David Simmons-Duffin retweeted
I can’t believe I have to say this, but we can’t let Donald Trump open up the Grand Canyon for uranium mining.
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An inspirational profile of physics titan Juan Maldacena. He recalls the fear and uncertainty he felt early in his career about trying to be a theoretical physicist. symmetrymagazine.org/article…
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David Simmons-Duffin retweeted
On the FRONT PAGE of today's Toronto Globe & Mail: an article about my work on O Canada! Login required - sorry. tgam.ca/31dAg91
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David Simmons-Duffin retweeted
"Homophonic quotients of free groups" FTW: projecteuclid.org/download/p…
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