Category Archives: Physics

What does Gauß have to do with the nuclear arms race?

Veritasium: How An Algorithm Could Have Stopped The Nuclear Arms Race. (YouTube, 26:32min)

“The Fast Fourier Transform is used everywhere but it has a fascinating origin story that could have ended the nuclear arms race. […]
Thanks to Grant Sanderson of 3Blue1Brown for his helpful feedback on the script. His great video on the Fourier Transform is here”

3Blue1Brown: But what is the Fourier Transform? A visual introduction. (YouTube, 21min)

It blew my mind that Carl Friedrich Gauß found the discrete Fourier transform – 150 years earlier that Fourier.

Fourth State of Matter: Time Crystals

Physics Girl: BREAKING: New Phase of Matter. (YouTube, 15:34min) “What are time crystals? How do scientists make one on a quantum computer.”

See also these scientific papers:

Stanford News: Stanford physicists help create time crystals with quantum computers. “A team of researchers including ones from Stanford and Google have created and observed a new phase of matter, popularly known as a time crystal.” (Published November 30, 2021)

“In research published Nov. 30 in Nature, a team of scientists from Stanford University, Google Quantum AI, the Max Planck Institute for Physics of Complex Systems and Oxford University detail their creation of a time crystal using Google’s Sycamore quantum computing hardware.

“The big picture is that we are taking the devices that are meant to be the quantum computers of the future and thinking of them as complex quantum systems in their own right,” said Matteo Ippoliti, a postdoctoral scholar at Stanford and co-lead author of the work. “Instead of computation, we’re putting the computer to work as a new experimental platform to realize and detect new phases of matter.””, University of Hamburg: Researchers observe continuous time crystal. (Published June 10, 2022)

“Researchers from the Institute of Laser Physics at Universität Hamburg have succeeded for the first time in realizing a time crystal that spontaneously breaks continuous time translation symmetry. They report their observation in a study published online by the journal Science on Thursday, 9 June, 2022.”

Solar Eclipse on Mars

NASA Jet Propulsion Laboratory: NASA’s Perseverance Rover Sees Solar Eclipse on Mars. (YouTube, 49 seconds)

Note that the eclipse is shown in real-time – it only takes about 40 seconds!

“NASA’s Perseverance Mars rover used its Mastcam-Z camera system to shoot video of Phobos, one of Mars’ two moons, eclipsing the Sun. It’s the most zoomed-in, highest frame-rate observation of a Phobos solar eclipse ever taken from the Martian surface.

Several Mars rovers have observed Phobos crossing in front of the Sun over the past 18 years. Spirit and Opportunity made the first observations back in 2004; Curiosity in 2019 was the first to record video of the event. Each time these eclipses are observed, they allow scientists to measure subtle shifts in Phobos’ orbit over time. The moon’s tidal forces pull on the deep interior of the Red Planet, as well as its crust and mantle; studying how much Phobos shifts over time reveals something about how resistant the crust and mantle are, and thus what kinds of materials they’re made of.”

Link via Astronomy Picture of the Day.