Recent content by robphy

Here are some interesting ones that showed up in the Mathematics search Sundes - Introduction to Scientific Programming with Python https://link.springer.com/book/10.1007/978-3-030-50356-7 Weigand - The Legacy of Felix Klein https://link.springer.com/book/10.1007/978-3-319-99386-7 Model and...

I see that Springer has a bunch of other titles under Open Access (https://www.springernature.com/gp/open-science/about/the-fundamentals-of-open-access-and-open-research) PHYSICS: link.springer.com/search?query=physics&content-type=Book&openAccess=true&dateFrom=&dateTo=&sortBy=newestFirst (see...

Maybe it's time to have a look inside? With my samsung, i did have to order a board when the display got glitchy and finally went black. It was a $25 attempt.. so we tried it. Unfortunately, it failed. So, it prompted a new samsung tv. (I don't have the required skills to troubleshoot the...

Strong suggestions: The position-vs-time graph of a situation (also known as a spacetime diagram) [like the ones I have been drawing] tells a story of the situation that is often more clear than a series of casually written sentences. - In relativity, as you have been reminded, sentences must...

Quantum Mechanics Done Right The Shortest Path from Novice to Researcher James K. Freericks Textbook / Open Access © 2026 https://link.springer.com/book/10.1007/978-3-031-87845-9

Just a postscript... (thanks to a mentor for re-opening this to allow me to make this hopefully-helpful comment) Since the OP recently posted a simiilar question at https://physics.stackexchange.com/questions/874984/how-can-a-clock-show-two-different-time-7sec-and-15sec-reciprocal-time-dilatio...

Girl U Want (1980) https://en.wikipedia.org/wiki/Girl_U_Want https://en.wikipedia.org/wiki/Devo (1980) Devo - Girl U Want (Live on Fridays 1980) - (1980) Girl U Want (Official HD Music Video) - (1982) Devo - Freedom of Choice/Girl U Want EZ (In Studio Practice 1982) &t=5m14s --alternate studio...

Is there a URL that always points to the latest post in a thread?

Why would you be banned?

I remember selecting black after having chosen red, trying to get out of red. Similarly for blue. UPDATE: I see now that I should select "remove formatting".

Here's my graphical attempt to help you @Mike_bb . After a summary-and-diagram, there is a second diagram with an exercise for you to do. First, here's a simplified summary of radar measurements by Alice (in red) and by Bob (in blue). Let P' be the event "[on Bob's worldline] Bob's...

I think you need to write out... I'm going to use "reads" to avoid possible misinterpretations when using anything suggesting what it "visually looks like". According to observer A, E1 (clock A reads 100) and E2 (clock B reads 80) are simultaneous. According to observer B, E3 (clock B reads...

If these quantities are associated with units, inserting the units could help clarify the order of operations.

Once I have defined a light-clock diamond (in my local region), and make reasonable assumptions of homogeneity and isotropy, I can idealize tiling my spacetime with my diamonds. This is analogous to starting with a unit square on my sheet of graph paper and idealize extending it out to the...

Here are operational definitions using a radar method (which was my "a-ha moment"[1][2] in relativity). To assign coordinates to a distant event Z, an inertial observer (wearing a wristwatch) can use a radar method: note the wristwatch-reading ##t_s## when sending the light-signal that can...