Chris Walter
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chriswalter.fediscience.org.ap.brid.gy
Chris Walter
@chriswalter.fediscience.org.ap.brid.gy
100 followers 8 following 42 posts
Professor of physics at Duke University. Studies particle physics and cosmology. Works on Super-Kamiokande and also LSST at the Vera C. Rubin Observatory.

[bridged from https://fediscience.org/@ChrisWalter on the fediverse by https://fed.brid.gy/ ]
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chriswalter.fediscience.org.ap.brid.gy
@briankrebs Cool! It is in fact quite amazing now what you can do with a phone camera. I had time to play with this when I was living in Chile working on commissioning a new telescope last year.

I also have a 15pro. If you can use a travel tripod you can get […]

[Original post on fediscience.org]
The Milky Way is painted across the sky. At the base of the image a telescope dome and instrument towers are illuminated by the moon.
October 20, 2025 at 11:56 PM
chriswalter.fediscience.org.ap.brid.gy
@ryanfb and others who work with papyrus:

If you find yourself on the island of Ortigia in Syracuse in Sicily, there is a small interesting papyrus museum. It is not really about manuscripts, it is about papyrus itself, how it is made, its history etc […]

[Original post on fediscience.org]
A sign with text in Italian that says: Museum of Papyrus International Institute of Papyrus A room in the museum. Two statuary busts are in front of an open window framing a bright blue sea. A courtyard with a well with two small papyrus plants in front.
July 27, 2025 at 10:03 PM
chriswalter.fediscience.org.ap.brid.gy
Last night in Toyama Japan, as I left the sushi restaurant where I ate dinner, the scene reminded me of Edward Hopper's painting 'Nighthawks' .
The view from outside a sushi restaurant. It is dark outside and we see a colorful scene through the window. A chef stands behind the counter next to a large fish tank and four diners are arrayed around him at the bar. The wooden walls are covered in descriptions of menu items.
May 26, 2025 at 12:50 AM
chriswalter.fediscience.org.ap.brid.gy
#silentsunday
A river with rocks causing the water to foam white makes its way through a steep lushly forested valley in the mountains of central Japan. It is misty and cloudy and the trees are bright green. Mozumi, Japan, near Kamioka Town and the site of the Super-Kamiokande particle physics detector.
May 25, 2025 at 8:04 AM
chriswalter.fediscience.org.ap.brid.gy
When you teach computational physics you quickly find out that Gauss basically invented all of it before we even had computers.

E.g. the FFT was discovered by Carl Friedrich Gauss in 1805, when he was 28 years old. (Footnotes 7,8).
Two footnotes shown at the bottom of the page in a textbook: (From Computational Physics by Mark Newman). 7) What with Gaussian quadrature, Gaussian elimination, the Gauss—-Newton method, and now the fast Fourier transform, Gauss seems to have discovered most of computational physics more than a century before the computer was invented. 8) In much of the computational physics literature you will see the fast Fourier transform at- tributed not to Gauss but to the computer scientists James Cooley and John Tukey, who published a paper describing it in 1965 [Cooley, J. W. and Tukey, J. W., An algorithm for the machine calcu- lation of complex Fourier series, Mathematics of Computation 19, 297-301 (1965)]. Although Cooley and Tukey’s paper was influential in popularizing the method, however, it was, unbeknownst to its authors, not the first description of the FFT. Only later did they learn that they’d been scooped by Gauss 160 years earlier.
March 4, 2025 at 4:54 PM
chriswalter.fediscience.org.ap.brid.gy
What to do when Einstein makes a 10 minute comment in German on your seminar:

'Dr. Einstein accepted Dr. Tolman’s invitation to interrupt... After the “father of relativity” had commented in German for more than ten minutes, Dr. E. C. Watson suggested that […]

[Original post on fediscience.org]
Jan. 8, 1932: Dr. Richard C. Tolman, left, and professor Albert Einstein stand in front of a blackboard at Caltech. Tolman led a seminar at Caltech for more than 50 scientists.
December 10, 2024 at 9:19 PM
chriswalter.fediscience.org.ap.brid.gy
My last view of La Serena and Coquimbo from the plane as I leave Chile to return home after the last year working on commissioning the @VRubinObs. I could see the observatory in the distance as we flew past and thought of all my friends working down there […]

[Original post on fediscience.org]
The deep blue sea of Chile’s coast is ringed by a desert tinged land.
December 4, 2024 at 9:20 PM
chriswalter.fediscience.org.ap.brid.gy
5:00 am on Sunday morning in Chile:

Orion and Jupiter hover over the moonlit dome of the @VRubinObs.

(If you live in the northern hemisphere, note the orientation of Orion)

#Astrodon #observatory
A large observatory with a reflective dome is seen at night against a dark black sky. The dome is shining with the light of the moon and the constellation Orion can be seen hovering over it. To the right the planet Jupiter can also be seen.
November 26, 2024 at 3:30 PM
chriswalter.fediscience.org.ap.brid.gy
An Andean condor is seen flying by the @VRubinObs weather tower this afternoon.

#Astrodon #BirdPhotogaphy
A large Andean condor with outstretched wings soars next by a red and white weather tower.
November 13, 2024 at 5:38 PM
chriswalter.fediscience.org.ap.brid.gy
The view from the smaller auxiliary calibration telescope of the @VRubinObs on Wed night as we prepared to go on-sky.
The shutter of a large observatory is open on the top of a mountain. It's the end of sunset and the glowing horizon can still e seen. The observatory is "sphinx"-like instead of int he shape of dome with the "head" on top containing the telescope.
November 1, 2024 at 10:51 PM