Recent content by robphy

I didn’t catch that myself until I read her Wikipedia page. My subset comment was about the links to the two Wikipedia pages I posted.

Some history behind the Perimeter Institute for Theoretical Physics in Waterloo, Ontario. (I visited PI when it was just the brownstone on King and Dupont (Google Maps) [in the video at &t=2m21s] to visit my advisor who was spending a sabbatical there. I've never been to the current site (Google...

https://en.wikipedia.org/wiki/Category:Danish_women_scientists https://en.wikipedia.org/wiki/Category:Danish_scientists Although these probably need some editing.... because currently ##\nsubseteq##

https://en.wikipedia.org/wiki/Carl_H._Brans https://cas.loyno.edu/news/mar-04-2026_carl-henry-brans-longtime-member-department-physics-passed-away-february-26-2026 Carl Henry Brans, longtime member of the Department of Physics, passed away on February 26, 2026, at the age of 90 loynocas -...

Instead of initial and final, it might be better to use event-labels: at event A, at time ##t_A##, the position is ##x_A##, and the velocity is ##v_A##, and the acceleration is ##a_A##. Encourage good bookkeeping, especially for multi-stage processes, like your posed problem.

Did you mean non-inertial motion? So, with your ##a=9.8\rm\ m/s^2##, upward-increments along the Velocity-axis are associated with "downward acceleration". Interesting presentation. I never thought of , for constant-acceleration, $$v_{i} ,\ v_{f} \quad = v_{avg} \mp (a\Delta t)/2 \quad =...

From https://trautman.fuw.edu.pl/publications/scientific-articles.html 39. (with W. Kopczyński) Simple spinors and real structures, J. Math. Phys. 33, 550–559 (1992) https://trautman.fuw.edu.pl/publications/Papers-in-pdf/77.pdf 40. (with W. Kopczyński) Spacetime and Gravitation, PWN and J...

https://en.wikipedia.org/wiki/Hot_for_Teacher (1984) https://en.wikipedia.org/wiki/Van_Halen (1984) Van Halen - Hot For Teacher (Castle Donington, Monsters of Rock Fest, UK 08-18-1984) (HD 60fps) - Van Halen - Hot For Teacher (Official Music Video) (2026) Hot for Teacher — Van Halen (Drum...

Rush performs Finding My Way live | 2026 Juno Awards https://www.rush.com/tour/fifty-something/

A Celebration of C.N. Yang and His Impact on Stony Brook Wang Center Theater, Stony Brook University Thursday, March 12, 2026 1:00 PM http://insti.physics.sunysb.edu/itp/images/CNY-Program-March12.pdf C.N. "Frank" Yang and Stony Brook - SBU Conferences and Special Events (4h05m stream)

There is a Levi-Civita tensor ( https://en.wikipedia.org/wiki/Levi-Civita_symbol#Example:_Minkowski_space ), which is the volume element ( https://en.wikipedia.org/wiki/Volume_element#Volume_element_of_manifolds ). This is what is used in the definition of the magnetic field associated with a...

As I mentioned in another thread, I think it's appropriately posted in GD (as "news") ... but afterwards, it would be good if it were moved to "History".

Rattlesnake (2016) https://en.wikipedia.org/wiki/Rattlesnake_(King_Gizzard_&_the_Lizard_Wizard_song) https://en.wikipedia.org/wiki/Flying_Microtonal_Banana https://en.wikipedia.org/wiki/King_Gizzard_&_the_Lizard_Wizard https://kinggizzardandthelizardwizard.com/ (2016) King Gizzard & The Lizard...

Probably useful (especially for conventions --- it's ##(-,+,+,+)##; it uses Carroll's text) https://ocw.mit.edu/courses/8-962-general-relativity-spring-2020/resources/mit8_962s20_pset03/ from https://ocw.mit.edu/courses/8-962-general-relativity-spring-2020/pages/assignments/...

If you right-click on the equation in my post, you can see the ##\LaTeX##-code used to create it.