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en-US Physics Forums RSS Feed This is the official global feed for PhysicsForums.com Thu, 21 May 2026 01:18:58 +0000 Thu, 21 May 2026 01:18:58 +0000 Physics Forums https://www.physicsforums.com/ Design example for commercial high speed pcb Thu, 21 May 2026 01:10:49 +0000 https://www.physicsforums.com/threads/design-example-for-commercial-high-speed-pcb.1085229/ 1085229 invalid@example.com (yefj) yefj Hello ,Is there a PCB example which is routing differential signal over many layers.where there could be many differential ports in between then.
Is there such real life example I could try to do EM simulation from it?
Thanks.]]> 3 "Critical" Triangle Problem Thu, 21 May 2026 00:36:51 +0000 https://www.physicsforums.com/threads/critical-triangle-problem.1085234/ 1085234 invalid@example.com (DanteKennedy) DanteKennedy No attempts to solve it by myself yet. It would be very nice if someone can help me]]> 0 Rate my photos on a scale of 1-5 please? Thu, 21 May 2026 00:04:30 +0000 https://www.physicsforums.com/threads/rate-my-photos-on-a-scale-of-1-5-please.1085199/ 1085199 invalid@example.com (BadgerBadger92) BadgerBadger92 I’d like to hear people’s critiques out of five. Please look at and rate all of them.

]]> 64 Does a Beveled Washer on an Inclined Surface Preserve or Cancel the Incline? Wed, 20 May 2026 22:10:39 +0000 https://www.physicsforums.com/threads/does-a-beveled-washer-on-an-inclined-surface-preserve-or-cancel-the-incline.1085224/ 1085224 invalid@example.com (Amaelle) Amaelle *Background**

I am designing a lower torso surrogate adapter for crash test dummy drop tower testing. The assembly works as follows:

- The **lower torso** (EN24T wedge) is bolted **flat** to the drop tower floor
- The top face of the wedge is inclined at **10.23°** — this is intentional...

Read more]]> 12 Magnetic monopole vs (g-2) Wed, 20 May 2026 21:33:57 +0000 https://www.physicsforums.com/threads/magnetic-monopole-vs-g-2.1085226/ 1085226 invalid@example.com (Roberto Pavani) Roberto Pavani While working on a preprint, I noticed what seems to be a straightforward logical chain that I haven't seen stated explicitly in the literature. I'd like to understand whether (a) it's well-known but considered too trivial to state, (b) it has been discussed somewhere, or (c) there's a flaw I'm...

Read more]]> 3 Wordle Lovers - Play the NYT Daily Game Wed, 20 May 2026 20:42:51 +0000 https://www.physicsforums.com/threads/wordle-lovers-play-the-nyt-daily-game.1016903/ 1016903 invalid@example.com (fresh_42) fresh_42 This thread is for all who like the daily Wordle game of the New York Times as much as I do.

The rules:

1) https://www.nytimes.com/games/wordle/index.html
2) Post your result.
3) Do not spoil the answer.]]> 8453 Independent researcher looking for fatal objections Wed, 20 May 2026 20:16:56 +0000 https://www.physicsforums.com/threads/independent-researcher-looking-for-fatal-objections.1085231/ 1085231 invalid@example.com (xxxbokitoxxx) xxxbokitoxxx Hi, I'm Carlos, an independent researcher from Spain with a background outside academic physics. I've spent several years working on a phenomenological framework connecting superconductivity, vacuum energy, and inertial coupling. Looking forward to getting feedback from people who actually know...

Read more]]> 1 How valid is the indivisible interpretation of quantum mechanics? Wed, 20 May 2026 19:59:39 +0000 https://www.physicsforums.com/threads/how-valid-is-the-indivisible-interpretation-of-quantum-mechanics.1085197/ 1085197 invalid@example.com (DarkloidNeos) DarkloidNeos I was reading up on the theory and apparently it's saying stuff that is in direct opposition with current views like how there is no wave function, but that quantum processes occur by randomness? I'm not sure how valid it might be but all I know is that it's a massive departure from the usual stuff.]]> 30 Share Animal Pictures: For Animal Lovers Wed, 20 May 2026 19:56:48 +0000 https://www.physicsforums.com/threads/share-animal-pictures-for-animal-lovers.583729/ 583729 invalid@example.com (micromass) micromass Post your favorite animal pictures here!]]> 3026 Some more of my photography Wed, 20 May 2026 19:50:51 +0000 https://www.physicsforums.com/threads/some-more-of-my-photography.1085230/ 1085230 invalid@example.com (BadgerBadger92) BadgerBadger92

]]> 1 Anyone like “2001: A Space Odyssey?” Wed, 20 May 2026 19:23:47 +0000 https://www.physicsforums.com/threads/anyone-like-2001-a-space-odyssey.1085218/ 1085218 invalid@example.com (BadgerBadger92) BadgerBadger92 I have always been a Stanley Kubrick fan, and 2001 is in my opinion one of his best besides “A Clockwork Orange” and “Dr. Strangelove.” All of them get the same rating to me.

My favorite scenes are where the apes evolve to humans and the wormhole scene at the end (at least I think it was a...

Read more]]> 6 Why does this not produce water pressure? Wed, 20 May 2026 19:21:02 +0000 https://www.physicsforums.com/threads/why-does-this-not-produce-water-pressure.1085225/ 1085225 invalid@example.com (questions8938) questions8938 I have a gravity water filter and rather than pay $$$ to buy an undersink pumped one I thought I could try and add a pump to the existing one instead but it is not working for some reason I can't figure out why.

You can see images of it here.

There is a top chamber where you place water...

Read more]]> 7 Making a Giant Telescope Mirror Takes Years Wed, 20 May 2026 14:29:51 +0000 https://www.physicsforums.com/threads/making-a-giant-telescope-mirror-takes-years.1085147/ 1085147 invalid@example.com (Hornbein) Hornbein ]]> 4 An AI to Write Data Analysis and Modeling Programs Wed, 20 May 2026 14:04:18 +0000 https://www.physicsforums.com/threads/an-ai-to-write-data-analysis-and-modeling-programs.1085228/ 1085228 invalid@example.com (Hornbein) Hornbein https://seas.harvard.edu/news/ai-system-automates-coding-scientific-research

They say it's faster and better than what humans can do. I believe it.]]> 3 Some Trap Drumming I Like Wed, 20 May 2026 12:38:29 +0000 https://www.physicsforums.com/threads/some-trap-drumming-i-like.1085090/ 1085090 invalid@example.com (Hornbein) Hornbein Unique line drumming. Such an original. John French.

For heavy beat drumming I can't get enough of 임영은 (Yeong eun). Catchy tune.

]]> 14 A question about special relativity Wed, 20 May 2026 10:51:24 +0000 https://www.physicsforums.com/threads/a-question-about-special-relativity.1085217/ 1085217 invalid@example.com (BadgerBadger92) BadgerBadger92 I have a question about special relativity, hopefully this isn’t a silly question.

If there are two things, one moving near the speed of light verses the ground, due to time dilation, wouldn’t the traveling body look like everything in it is moving slower according to the frame of reference on...

Read more]]> 8 Collection of Lame Jokes Wed, 20 May 2026 08:04:03 +0000 https://www.physicsforums.com/threads/collection-of-lame-jokes.25301/ 25301 invalid@example.com (quddusaliquddus) quddusaliquddus Lamest joke you know ... :zzz:]]> 24054 The Ultimate Fusion Keyboard Solo Wed, 20 May 2026 07:16:15 +0000 https://www.physicsforums.com/threads/the-ultimate-fusion-keyboard-solo.1085181/ 1085181 invalid@example.com (Hornbein) Hornbein

I paid hundreds of dollars (airplane ticket and lodging) to see this band back then. I did that because I know such things don't last more than a few years. To play like this you've got to be completely obsessed. Sooner or later you are going to want to have a larger life...

Read more]]> 1 Solid State Physics and Chameleon Color Changes Wed, 20 May 2026 07:11:56 +0000 https://www.physicsforums.com/threads/solid-state-physics-and-chameleon-color-changes.1083786/ 1083786 invalid@example.com (Shahzad Raza) Shahzad Raza Some days ago I was studying the phenomenon of color changing in chameleons so the question that arose in my mind that whether we can relate this to solid state physics too, besides optics and biophysics? As there is the role of nanocrystals that are present inside iridophores, in adjusting the...

Read more]]> 1 Random Photos Wed, 20 May 2026 05:46:04 +0000 https://www.physicsforums.com/threads/random-photos.994801/ 994801 invalid@example.com (Point Conception) Point Conception A topic for random photos: Ko-Larn island 7 km West of Pattaya

]]> 3696 Books on the philosophy of math Wed, 20 May 2026 00:29:59 +0000 https://www.physicsforums.com/threads/books-on-the-philosophy-of-math.1085222/ 1085222 invalid@example.com (BadgerBadger92) BadgerBadger92 I really want to know about the philosophy of math, mainly how math describes physical laws. How does physics become explainable from math?

Any good books on this topic?]]> 4 Deriving the "third" kinematic equation using graphs Tue, 19 May 2026 21:40:48 +0000 https://www.physicsforums.com/threads/deriving-the-third-kinematic-equation-using-graphs.1085200/ 1085200 invalid@example.com (brotherbobby) brotherbobby Problem Statement : For a particle moving in one dimension along the ##x## axis with constant acceleration ##a_0## (see figure alongside), the three well known equations of high school kinematics are ##(1)\; v_(t)=v_0+a_0t\quad (2)\...

Read more]]> 21 Good forums for physics beginners? Tue, 19 May 2026 21:31:54 +0000 https://www.physicsforums.com/threads/good-forums-for-physics-beginners.1085216/ 1085216 invalid@example.com (BadgerBadger92) BadgerBadger92 I’m looking for a good physics forums for beginners. I don’t want to use this forum because it’s for professionals, and whenever I ask a basic question I get flamed.

Any good suggestions?]]> 9 A counterexample to "the integral of the limit is the limit of the integral" Tue, 19 May 2026 19:32:39 +0000 https://www.physicsforums.com/threads/a-counterexample-to-the-integral-of-the-limit-is-the-limit-of-the-integral.1085205/ 1085205 invalid@example.com (pasmith) pasmith I was going to append this to @chwala's thread here, but thought it deserved a new thread.

For ##n \geq 1##, define $$f_n : [0,1] \to \mathbb{R} : x \mapsto \begin{cases} 1 & x = 0, \\ n(1 - nx) & x \in (0, \tfrac 1n], \\ 0 & x \in (\tfrac 1n, 1]. \end{cases}$$ (Note that ##f_n## is...

Read more]]> 1 On electron orbitals Tue, 19 May 2026 19:25:17 +0000 https://www.physicsforums.com/threads/on-electron-orbitals.1085221/ 1085221 invalid@example.com (BadgerBadger92) BadgerBadger92 I have always been fascinated the idea that electrons “pop in and out of existence” around an atom but from what I’ve read, they’re not “popping in and out of existence. What is actually going on?

Could it be the quantum foam?]]> 4 'F=ma' Physics competition preparation help Tue, 19 May 2026 19:01:39 +0000 https://www.physicsforums.com/threads/f-ma-physics-competition-preparation-help.1078291/ 1078291 invalid@example.com (mathisrad) mathisrad TL;DR Summary: How should I study for the F=ma competition as a total newby to competition physics?

Hi, next year I'm hoping to do the F=ma physics competition. I wanted to start preparing beforehand so Im not too panicked a day before the competition. Does anybody with experience in...

Read more]]> 7 The History of Various Anastethics and Remedies.... Tue, 19 May 2026 18:21:28 +0000 https://www.physicsforums.com/threads/the-history-of-various-anastethics-and-remedies.1084995/ 1084995 invalid@example.com (sbrothy) sbrothy Disclaimer: I have no medical training or schooling.

I know my website is a mess. I'm investing more time in the English version than in the Danish, which might be a little silly as my intended audience really is here at home in Denmark.

Unfortunately my laptop can hardly run Visual Studio...

Read more]]> 3 Field at a point on the axis of a ring with variable charge density Tue, 19 May 2026 15:55:26 +0000 https://www.physicsforums.com/threads/field-at-a-point-on-the-axis-of-a-ring-with-variable-charge-density.1085179/ 1085179 invalid@example.com (JesseAbberton) JesseAbberton I have great confusion regarding the question after reading the solution from the book. They haven't really correctly done the sign of the charge density if they have taken the angle as follows and the diagram i found a bit vague. Could somebody please help me out here? Thank you :)

]]> 9 AI Enriched Problem Solving Tue, 19 May 2026 15:52:59 +0000 https://www.physicsforums.com/threads/ai-enriched-problem-solving.1084382/ 1084382 invalid@example.com (Greg Bernhardt) Greg Bernhardt

This article is written by way of a reference for my longstanding PF colleague and prolific poster of challenging Maths/geometry problems @chwala . The particular post this article will discuss is an example of one such problem which he raised on Physics Forums.

...

Read more]]> 22 An "Untranslatable" Word? Tue, 19 May 2026 15:05:02 +0000 https://www.physicsforums.com/threads/an-untranslatable-word.1083626/ 1083626 invalid@example.com (Hornbein) Hornbein I don't know that any word is truly untranslatable, but I'd say the more words it takes to explain the meanings of a foreign word is a measure of translatability. So how about the common Indonesian word biji. It is usually translated as "seeds", but actually it means "a collection of...

Read more]]> 47 A homemade mechanics problem: A beetle on a globe Tue, 19 May 2026 14:43:42 +0000 https://www.physicsforums.com/threads/a-homemade-mechanics-problem-a-beetle-on-a-globe.1085196/ 1085196 invalid@example.com (wrobel) wrobel I composed a problem and initially thought it could be solved by purely analytical means, but it turns out it cannot.

The problem is as follows: a homogeneous ball of radius ##R## can rotate freely about its fixed center ##O##. Let ##J## denote its moment of inertia relative to an axis passing...

Read more]]> 22 The Quantum Mechanics of Experiments Tue, 19 May 2026 14:31:58 +0000 https://www.physicsforums.com/threads/the-quantum-mechanics-of-experiments.1085220/ 1085220 invalid@example.com (Morbert) Morbert A paper some people might find interesting: https://arxiv.org/abs/2603.25335

Froehlich's work has come up a few times here (E.g. https://www.physicsforums.com/threa...e-deeper-meaning-of-quantum-mechanics.972179/ ). It's a stochastic, histories based approach, but...

Read more]]> 0 Im an Independent researcher Tue, 19 May 2026 13:03:16 +0000 https://www.physicsforums.com/threads/im-an-independent-researcher.1085215/ 1085215 invalid@example.com (Fractochronex) Fractochronex I have a x account called fractochronex I would also like to meet people and discuss ideas, I have also posted some material on Zenondo.]]> 1 Uniform convergence and pointwise convergence Tue, 19 May 2026 11:52:09 +0000 https://www.physicsforums.com/threads/uniform-convergence-and-pointwise-convergence.1065346/ 1065346 invalid@example.com (chwala) chwala I am trying to follow this link:

https://people.math.wisc.edu/~angenent/521.2017s/UniformConvergence.html

...not getting it... of course i know what convergence is, just to mention for e.g given a sequence, ##\dfrac{1}{n}## I know that the sequence tends to ##0## or rather converges to...

Read more]]> 23 MOND disproved at large scales Tue, 19 May 2026 10:30:08 +0000 https://www.physicsforums.com/threads/mond-disproved-at-large-scales.1085219/ 1085219 invalid@example.com (timmdeeg) timmdeeg https://arxiv.org/pdf/2604.14327

Fig.1 and Fig.2 seem to show that MOND is disproved at large scales due to measurements of galaxy cluster velocities.

Supposed this holds, is it thinkable at all that MOND could be still true at galaxy scales?]]> 3 The optimal way of dividing the bet three ways Tue, 19 May 2026 05:52:20 +0000 https://www.physicsforums.com/threads/the-optimal-way-of-dividing-the-bet-three-ways.1085176/ 1085176 invalid@example.com (Hill) Hill If I bet ##s## with Svetlana, ##r## with Roberto, and ##j## with Jeff, my earnings would be,

if USA wins, ##-s+2r+ \frac 5 4 j##,

if England wins, ##s-r+\frac 5 4 j##,

if China wins, ## s+2r-j##,

where ##s+r+j=$100##.

I think that "the optimal way ... that ensures the largest...

Read more]]> 21 What empirical observation supports the axiom of continuous spacetime? Tue, 19 May 2026 05:22:16 +0000 https://www.physicsforums.com/threads/what-empirical-observation-supports-the-axiom-of-continuous-spacetime.1085153/ 1085153 invalid@example.com (swissgirl1999 Refer) swissgirl1999 Refer The Nobel Prize-winning experiments that form the observational foundation of Modern Physics consistently point toward discreteness rather than continuity.

I did not find an equivalent (or any at all) body of direct observation supporting the continuity axiom.

Here is a non-exhaustive list of...

Read more]]> 23 sweetspot of compression Tue, 19 May 2026 05:07:24 +0000 https://www.physicsforums.com/threads/sweetspot-of-compression.1085213/ 1085213 invalid@example.com (geekynerd) geekynerd each compression technique focuses on each aspects. Low storage space, faster opening speed, high quality storage cpu perfomace etc... But as a normal user i want to little bit of all of that. instead of being on one extreme what if we find a sweet spot in which every feature is not comprimised...

Read more]]> 2 Tail lift jerky when lowering — hydraulic issue? Tue, 19 May 2026 03:17:34 +0000 https://www.physicsforums.com/threads/tail-lift-jerky-when-lowering-hydraulic-issue.1085139/ 1085139 invalid@example.com (bwtom) bwtom My truck tail lift has started behaving strangely when lowering. It’s no longer smooth and now feels jerky, sometimes pausing mid-way before continuing down. It almost feels like the hydraulic pressure is unstable.

Hydraulic oil level looks normal and I don’t see any obvious leaks, but the...

Read more]]> 6 Best Jazz Concert of the 21st Century (So Far)? Tue, 19 May 2026 01:34:00 +0000 https://www.physicsforums.com/threads/best-jazz-concert-of-the-21st-century-so-far.1085212/ 1085212 invalid@example.com (Hornbein) Hornbein

I happened to tune in to the premier of this. I missed breakfast because I was afraid if I left and came back later it would no longer be accessible.

I like the playfulness. After all, don't we "play" music?

Patrick is the fastest I've ever heard (as well as his other...

Read more]]> 0 Extremely Weird Music Mon, 18 May 2026 23:33:01 +0000 https://www.physicsforums.com/threads/extremely-weird-music.1082868/ 1082868 invalid@example.com (Hornbein) Hornbein This Pete Cosey guitar solo is the weirdest thing I've ever heard. Saxophonist Dave Liebman said a good deal of cocaine was routinely consumed.]]> 27 ChatGPT Examples, Good and Bad Mon, 18 May 2026 22:25:58 +0000 https://www.physicsforums.com/threads/chatgpt-examples-good-and-bad.1048757/ 1048757 invalid@example.com (anorlunda) anorlunda I've been experimenting with ChatGPT. Some results are good, some very very bad. I think examples can help expose the properties of this AI. Maybe you can post some of your favorite examples and tell us what they reveal about the properties of this AI.

(I had problems with copy/paste of...

Read more]]> 527 Joint distribution of sequential variables Mon, 18 May 2026 22:12:49 +0000 https://www.physicsforums.com/threads/joint-distribution-of-sequential-variables.1085164/ 1085164 invalid@example.com (Gear300) Gear300 I am not too sure about parts (b) and (c). I guess it's reasonable to speak of a joint distribution of (X1,X2) after drawing both points.]]> 6 Explanation requested for a relativistic scenario wherein two seemingly valid measurement procedures lead to different results for the same observable Mon, 18 May 2026 18:06:19 +0000 https://www.physicsforums.com/threads/explanation-requested-for-a-relativistic-scenario-wherein-two-seemingly-valid-measurement-procedures-lead-to-different-results-for-the-same-observable.1085204/ 1085204 invalid@example.com (DemKal) DemKal Hi all,
Consider the following scenario.
Two poles are 100km apart in frame S; also, in frame S, a stopwatch A moves from left to right, at 0.999c, and starts to tick at the left pole and a stopwatch B moves from right to left, at 0.999c, and starts to tick at the right pole; S perceives these...

Read more]]> 7 Is Energy conservation among sectors (EM,GR,QM) a principle? Mon, 18 May 2026 17:42:49 +0000 https://www.physicsforums.com/threads/is-energy-conservation-among-sectors-em-gr-qm-a-principle.1085183/ 1085183 invalid@example.com (Roberto Pavani) Roberto Pavani Considering QM,EM,GR "sectors" we know that the energy conservation apply but this is a principle.

Noether theorem provides a justification of it for each sector but for the combined (intra-sector conservation) it seem a circular loop:
Energy is conserved through sectors -> I can write a...

Read more]]> 26 Great Cambrian Fossils Mon, 18 May 2026 17:41:49 +0000 https://www.physicsforums.com/threads/great-cambrian-fossils.1085037/ 1085037 invalid@example.com (BillTre) BillTre Here are some great pictures and an open access article from Quanta magazine of Cambrian fossils (like Burgess Shale) from Southern China.

Example:
Screenshot 2026-05-04 at 11.23.39 AM.webp

Screenshot 2026-05-04 at 11.23.39 AM.webp

]]> 2 RIP Carl H Brans (1935 - 2026), general relativity Mon, 18 May 2026 17:40:11 +0000 https://www.physicsforums.com/threads/rip-carl-h-brans-1935-2026-general-relativity.1084831/ 1084831 invalid@example.com (robphy) robphy https://en.wikipedia.org/wiki/Carl_H._Brans

https://cas.loyno.edu/news/mar-04-2...partment-physics-passed-away-february-26-2026
Carl Henry Brans, longtime member of the Department of Physics, passed away on February 26, 2026, at the...

Read more]]> 1 Question about entanglement and spacetime Mon, 18 May 2026 17:37:52 +0000 https://www.physicsforums.com/threads/question-about-entanglement-and-spacetime.1085158/ 1085158 invalid@example.com (SchrodingersRat) SchrodingersRat Hi everyone, this is my first post.

As anyone interested in physics I am somewhat familiar with the concept of entanglement. Also I have read that contrary to what most people think about this phenomenon, the particles involved are not always exactly synchronized but one can actually seem to be...

Read more]]> 10 Electrical breakdown signal across the oil film Mon, 18 May 2026 16:47:31 +0000 https://www.physicsforums.com/threads/electrical-breakdown-signal-across-the-oil-film.1085177/ 1085177 invalid@example.com (AY156) AY156 I am a mechanical engineer researching electrical damage in lubricated contacts. In my tests, I apply 18V DC across a steel ball-disc contact with an elastohydrodynamic lubrication film (more simply an oil film between 600-900 nanometers in thickness) between the surfaces. This film, according...

Read more]]> 10 hello, this is boombeam Mon, 18 May 2026 16:38:04 +0000 https://www.physicsforums.com/threads/hello-this-is-boombeam.1085206/ 1085206 invalid@example.com (boombeams0010) boombeams0010 hello, boombeam here, i'm only here to put on a post on the end and start of the universe connected with some logic, its bound to have mistakes im sure, but i didn't find any, there are smart people here so i'd like them to break it apart if they can, its a bit dark lets say]]> 1 Metal, Rock, Instrumental Rock and Fusion Mon, 18 May 2026 15:02:36 +0000 https://www.physicsforums.com/threads/metal-rock-instrumental-rock-and-fusion.1057436/ 1057436 invalid@example.com (billtodd) billtodd A classical from the previous century in Fusion:

A prog

Chord Change

And a little bit Metal:

Share your own from those genres.]]> 13 Propagation of Thunder Mon, 18 May 2026 14:58:35 +0000 https://www.physicsforums.com/threads/propagation-of-thunder.1085168/ 1085168 invalid@example.com (Hornbein) Hornbein Recently there was a thunderstorm here of great power. There would be a bright flash then after ten seconds a rumble that would build up for two seconds, then a sound as though someone were hitting a bass drum hard outside the walls. I would have expected that that shock wave would be the...

Read more]]> 9 Solar Activity and Space Weather Update thread Mon, 18 May 2026 14:22:28 +0000 https://www.physicsforums.com/threads/solar-activity-and-space-weather-update-thread.923468/ 923468 invalid@example.com (Stavros Kiri) Stavros Kiri I am picking this up as a continuation and extension of the idea laid out e.g. in @davenn 's thread
"The Sun today - 9 July 2017 - nice spot group"
https://www.physicsforums.com/threads/the-sun-today-9-july-2017-nice-spot-group.919696/

See also (for continuity purposes)...

Read more]]> 456 Sharing my 32 years of experience in nuclear engineering Mon, 18 May 2026 14:15:14 +0000 https://www.physicsforums.com/threads/sharing-my-32-years-of-experience-in-nuclear-engineering.1085201/ 1085201 invalid@example.com (JFB) JFB Hello everyone.

My name is Jean-François, and I've worked in the nuclear sector for 32 years, specializing in data management related to radiation protection and nuclear waste management. I'd like to share the knowledge I've acquired over the years, and I'd be delighted if it could be useful to...

Read more]]> 1 Near-Earth Object/Asteroid 2026 JH2 Mon, 18 May 2026 11:28:53 +0000 https://www.physicsforums.com/threads/near-earth-object-asteroid-2026-jh2.1085194/ 1085194 invalid@example.com (Astronuc) Astronuc A near-earth asteroid was discovered on 10 May 2026. It is expected to pass close to earth, 91,000 ± 4,500 kilometres (56,500 ± 2,800 mi) from Earth on 18 May 2026,.

https://en.wikipedia.org/wiki/2026_JH2
https://www.minorplanetcenter.net/db_search/show_object?object_id=2026+JH2...

Read more]]> 2 Hedging on a weather prediction Mon, 18 May 2026 10:07:56 +0000 https://www.physicsforums.com/threads/hedging-on-a-weather-prediction.1085160/ 1085160 invalid@example.com (Hill) Hill Let the person bet ##x## with Ra and ##100-x## with Su. If it rains on Sunday, the earnings are ##\frac 4 3 (100-x)-x##. If it's sunny, the earnings are ##\frac 3 2 x - (100-x)##.
##\frac 4 3 (100-x)-x=\frac 3 2 x - (100-x) \Rightarrow x \approx 48##.
I'd like to get a confirmation that my...

Read more]]> 11 Consistent histories -- particle positions prior to measurement Mon, 18 May 2026 09:54:08 +0000 https://www.physicsforums.com/threads/consistent-histories-particle-positions-prior-to-measurement.1085187/ 1085187 invalid@example.com (nickv2423) nickv2423 I’m having a tough time understanding the CH interpretation. Only one of the histories happens when a measurement is made, but it seems to me it is saying that even prior to measurement a particle (ie electron) has a position and trajectory that we just don’t know about unlike standard QM. Is...

Read more]]> 23 Programming Jokes: Lame, Science & Math Jokes! Mon, 18 May 2026 07:14:59 +0000 https://www.physicsforums.com/threads/programming-jokes-lame-science-math-jokes.1046996/ 1046996 invalid@example.com (Wrichik Basu) Wrichik Basu We have threads on lame jokes and science jokes. But then, we also have a thread on bad math jokes. So, why not create one specifically for programming jokes?

Let me start:

]]> 488 Space Stuff and Launch Info Mon, 18 May 2026 06:39:30 +0000 https://www.physicsforums.com/threads/space-stuff-and-launch-info.879196/ 879196 invalid@example.com (1oldman2) 1oldman2 Due to the constant never ending supply of "cool stuff" happening in Aerospace these days I'm creating this thread to consolidate posts every time something new comes along. Please feel free to add random information if its relevant. So to start things off here is the SpaceX Dragon launch coming...

Read more]]> 1643 The Lagrangian of a free particle ##L=-m \, ds/dt## Mon, 18 May 2026 02:21:12 +0000 https://www.physicsforums.com/threads/the-lagrangian-of-a-free-particle-l-m-ds-dt.1081329/ 1081329 invalid@example.com (Kostik) Kostik In Dirac's "General Theory of Relativity" (p. 52), he postulates that the action for a free particle of mass ##m## is $$I=-m \int ds$$ hence the Lagrangian is $$L=-m\frac{ds}{dt} = -m\frac{\sqrt{\eta_{\mu\nu}dx^\mu dx^\nu}}{dt}
\, .$$ To confirm that ##-m## is the correct coefficient, he assumes...

Read more]]> 4 Net magnetic force in discontinuous circuits? Sun, 17 May 2026 22:24:09 +0000 https://www.physicsforums.com/threads/net-magnetic-force-in-discontinuous-circuits.1085189/ 1085189 invalid@example.com (aslan666) aslan666 This post raises a fundamental question about the violation of Newton's third law in electromagnetism and possible conclusions.

There are textbook examples in electromagnetism in which you may notice that the third law of Newton may not hold in its conventional form. That does not necessarily...

Read more]]> 6 Fundamental Physics Sun, 17 May 2026 17:24:14 +0000 https://www.physicsforums.com/threads/fundamental-physics.1085192/ 1085192 invalid@example.com (Peter33) Peter33 Here, many issues are discussed without bias—unlike in mainstream science.]]> 4 New EM spectrum designation between UV and X-rays Sun, 17 May 2026 15:54:58 +0000 https://www.physicsforums.com/threads/new-em-spectrum-designation-between-uv-and-x-rays.1085188/ 1085188 invalid@example.com (nightvidcole) nightvidcole I propose a pedagogically useful, and physically and economically descriptive region between UV and X-rays (or, if you like, straddling the boundary between the two).

The basic physics here is dramatically different from both "traditional" UV and "traditional" X-rays, because of one very...

Read more]]> 5 Problems with DNS records Sun, 17 May 2026 15:29:43 +0000 https://www.physicsforums.com/threads/problems-with-dns-records.1085131/ 1085131 invalid@example.com (sbrothy) sbrothy A silly prefix for this question I know but that was as close as I could get.

Initially I didn't really think of this forum as a place for intricate IT developer or adminstrator questions but I heard through the grapewine that there's a not insignificant number of retired IT folks here...

Read more]]> 21 What is new with Koide sum rules? Sun, 17 May 2026 14:39:00 +0000 https://www.physicsforums.com/threads/what-is-new-with-koide-sum-rules.551549/ 551549 invalid@example.com (arivero) arivero I am detaching this to BSM because it is already getting too much parameters in the bag.

What has happened this year is that Werner Rodejohann and He Zhang, from the MPI in Heidelberg, proposed that the quark sector did not need to match triplets following weak isospin, and then empirically...

Read more]]> 332 Who is your favorite Jazz musician and what is your favorite song? Sun, 17 May 2026 13:02:44 +0000 https://www.physicsforums.com/threads/who-is-your-favorite-jazz-musician-and-what-is-your-favorite-song.1051251/ 1051251 invalid@example.com (BadgerBadger92) BadgerBadger92 I have always liked Jazz music (and blues, electric blues to be particular)

Who is your favorite musician and song?

I’ve always liked Herbie Hancock, especially his song “Maiden Voyage.”

]]> 352 What fun could you have with a fountain design in artificial gravity? Sun, 17 May 2026 11:11:04 +0000 https://www.physicsforums.com/threads/what-fun-could-you-have-with-a-fountain-design-in-artificial-gravity.1085166/ 1085166 invalid@example.com (DaveC426913) DaveC426913 Backstory (TL;DR):

I've been searching for an allegory/symbolism for a journey to - and creation of - a colony inside an asteroid.

I played around with Greco-Roman legends, notably Aeneus' escape from Troy and journey by sea to a new land where he created what would become...

Read more]]> 40 Buoyancy and gravity Sun, 17 May 2026 10:54:00 +0000 https://www.physicsforums.com/threads/buoyancy-and-gravity.1084909/ 1084909 invalid@example.com (TheOldDog) TheOldDog Fairly simple - I think - but I may have missed something; HS physics was decades ago.

If a boat in a body of water on Earth has a draft of 1m, will the draft of the boat in a similar body of water on, say, Mars have the same draft? (Assume the same temperature of water.) I figured the change...

Read more]]> 32 Physics/math: how much knowledge does a high school teacher need? Sun, 17 May 2026 06:48:04 +0000 https://www.physicsforums.com/threads/physics-math-how-much-knowledge-does-a-high-school-teacher-need.1084863/ 1084863 invalid@example.com (haushofer) haushofer Dear all,

as some of you may know I'm a math/physics teacher at a teachers education in Holland, where we prepare teachers at pre-university level high school. We focus mainly on teachers who are already licensed to teach in the first three years of pre-university high school ("2nd degree")...

Read more]]> 15 Cover songs versus the original track, which ones are better? Sun, 17 May 2026 04:47:06 +0000 https://www.physicsforums.com/threads/cover-songs-versus-the-original-track-which-ones-are-better.1050205/ 1050205 invalid@example.com (pinball1970) pinball1970 Which songs were performed, arranged or produced better in a cover than the original version?
Which songs should have been left well alone?

Also, I think restricting the covers just to released singles will restrict some interesting stonkers and stinkers so album tracks are allowed.]]> 2472 Random Thoughts 7 Sun, 17 May 2026 01:34:35 +0000 https://www.physicsforums.com/threads/random-thoughts-7.1056780/ 1056780 invalid@example.com (Evo) Evo Time to start a new thread.

Here is the last page of part 6.

https://www.physicsforums.com/threads/random-thoughts-part-6.875108/page-317#post-6960672]]> 2020 Hantavirus outbreak aboard ship MV Hondius; virus present in Argentina Sun, 17 May 2026 01:27:34 +0000 https://www.physicsforums.com/threads/hantavirus-outbreak-aboard-ship-mv-hondius-virus-present-in-argentina.1085074/ 1085074 invalid@example.com (Astronuc) Astronuc Several days ago, an outbreak of Hantavirus was reported aboard cruise ship MV Hondius, which apparently set sail from Argentina.

PRAIA, Cape Verde (AP) — Footage obtained by The Associated Press of a cruise ship at the center of a rare-virus outbreak shows deserted decks and...

Read more]]> 20 Weird News Compilation Sun, 17 May 2026 01:02:35 +0000 https://www.physicsforums.com/threads/weird-news-compilation.878428/ 878428 invalid@example.com (Evo) Evo I'm always finding weird things in the news and thought it might be fun if we all shared odd stories we came across. Please feel free to post odd, funny or unusual stories in this thread.

Turns out that Zoobyshoe beat me in posting about this in another thread, so he will officially be known...

Read more]]> 2139 Inductive load contradicting short circuit load Sat, 16 May 2026 23:37:27 +0000 https://www.physicsforums.com/threads/inductive-load-contradicting-short-circuit-load.1085180/ 1085180 invalid@example.com (yefj) yefj Hello , As you can see in the simulation when we have a short load we have 0 impedance in the end because its 0 ohms.
On the other hand as you can see below in the simulation when we have inductive load then we have negative bump in the tdr.
A shorting via can ve viewed as inductor because its...

Read more]]> 8 Collection of Science Jokes P2 Sat, 16 May 2026 19:36:19 +0000 https://www.physicsforums.com/threads/collection-of-science-jokes-p2.847743/ 847743 invalid@example.com (Greg Bernhardt) Greg Bernhardt Old thread: https://www.physicsforums.com/threads/science-jokes.4463/page-44

My wife just drew this

]]> 4077 What Is The Data Center Story? Sat, 16 May 2026 18:38:56 +0000 https://www.physicsforums.com/threads/what-is-the-data-center-story.1085182/ 1085182 invalid@example.com (Hornbein) Hornbein I want to know what the data center craze is about. I was able to find only superficial discussions. Can anyone recommend a good online reference? In particular, it seems to me that sooner or later there will be a shakeout and the centers belonging to the losers will go bust. Second...

Read more]]> 4 Do Dark Energy and the Casimir effect indicate Exotic Matter could exist? Sat, 16 May 2026 13:49:26 +0000 https://www.physicsforums.com/threads/do-dark-energy-and-the-casimir-effect-indicate-exotic-matter-could-exist.1085141/ 1085141 invalid@example.com (okabe rintarou) okabe rintarou I have a conceptual question about whether certain physical phenomena suggest that exotic matter is possible in our universe.

From my understanding, there are two phenomena that seem to behave inversely to normal matter:

Dark Energy: It is spread evenly throughout the universe (almost like a...

Read more]]> 16 Today I Learned Sat, 16 May 2026 11:10:30 +0000 https://www.physicsforums.com/threads/today-i-learned.783257/ 783257 invalid@example.com (Greg Bernhardt) Greg Bernhardt Every day we learn new things. Sometimes it's just a small fact or realization. No matter how trivial or random, let's start recording our daily lessons.

Please start off with "Today I learned". Keep commentary to a minimum and just LIKE posts. I'll start!

Today I learned that you clean...

Read more]]> 6916 Geometry of Bluetooth Field Sat, 16 May 2026 10:25:59 +0000 https://www.physicsforums.com/threads/geometry-of-bluetooth-field.1085167/ 1085167 invalid@example.com (Twodogs) Twodogs I am curious about an experience using earbuds with a smart phone music app. With smartphone on the porch, I was roaming the garden listening to music on a pair of earbuds. At a some distance from the smart phone the signal began to break up into a staccato of brief fragments which were just...

Read more]]> 10 Bali: No Word For A Branch Sat, 16 May 2026 05:47:49 +0000 https://www.physicsforums.com/threads/bali-no-word-for-a-branch.1085169/ 1085169 invalid@example.com (Hornbein) Hornbein In Balinese there is no word for the branches of a tree. If branch falls off you call it "fallen wood."]]> 3 Housecat Reproduction Sat, 16 May 2026 03:40:29 +0000 https://www.physicsforums.com/threads/housecat-reproduction.1084990/ 1084990 invalid@example.com (Hornbein) Hornbein Start with one hundred housecats. Given unlimited resources, in seven years you will have a billion housecats.]]> 35 David Reich on human genetics Fri, 15 May 2026 21:51:43 +0000 https://www.physicsforums.com/threads/david-reich-on-human-genetics.1085172/ 1085172 invalid@example.com (BillTre) BillTre Here is a short video by David Reich. He is one of the top experts in the world on population genetics of different groups in the present and past.
It is short video and explains how he got into the field.
This field is in an exploratory phase in its development. Most things now involve...

Read more]]> 2 Biographies, History, Philosophy of Physics Fri, 15 May 2026 15:29:21 +0000 https://www.physicsforums.com/threads/biographies-history-philosophy-of-physics.1060020/ 1060020 invalid@example.com (sbrothy) sbrothy arXiv: physics.hist-ph. History, philosophy:

Berta Karlik -- The Grande Dame of the Vienna Radium Institute

Berta Karlik was an Austrian physicist who was not only among the early radioactivity researchers and nuclear physicists in Vienna, but also pioneered a woman's academic...

Read more]]> 295 Questions: Multi-particle entanglement, speed of light, electron orbitals Fri, 15 May 2026 15:08:00 +0000 https://www.physicsforums.com/threads/questions-multi-particle-entanglement-speed-of-light-electron-orbitals.1085165/ 1085165 invalid@example.com (MDH72) MDH72 1. As well as an entangled pair of electrons, particles, photons or whom ever is buddied up, are there entangled triplets? Quadruplets?
2. Is it generally accepted that electro/magnetic waves travel at c, dependent upon the medium of course?
3. What is a nominal time period of one orbit of the...

Read more]]> 5 The Universe’s Brightest Explosions Were Discovered by Accident Fri, 15 May 2026 14:49:33 +0000 https://www.physicsforums.com/threads/the-universes-brightest-explosions-were-discovered-by-accident.1085134/ 1085134 invalid@example.com (spacestorm) spacestorm One of my favorite scientific twists:

Satellites designed to catch nuclear detonations accidentally discovered gamma-ray bursts — the brightest known explosions in the universe.

For years, nobody knew whether the signals were nearby, galactic, or cosmological. Now we know they’re tied to...

Read more]]> 2 The problem of points Fri, 15 May 2026 12:44:17 +0000 https://www.physicsforums.com/threads/the-problem-of-points.1085046/ 1085046 invalid@example.com (Gavran) Gavran Two players, A and B, are playing a game, and the probability that either player wins a round is 1/2. They contribute equally to a prize pot. The game ends when one of the players wins six rounds. The game is interrupted for some reason when player A wins 5 rounds and player B wins 3 rounds. How...

Read more]]> 4 Continuously Variable Transmission Idea Fri, 15 May 2026 12:14:26 +0000 https://www.physicsforums.com/threads/continuously-variable-transmission-idea.1084988/ 1084988 invalid@example.com (rajava007) rajava007 I made a CVT (Continuously Variable Transmission) that uses two differentials to first split power between two gear ratios based on torque (1:1 and 2:1), and then recombine the separate rotations into a single output via a second differential. Yes, I did test this out, and it works. However...

Read more]]> 68 Math major jobs in the space industry Fri, 15 May 2026 10:09:03 +0000 https://www.physicsforums.com/threads/math-major-jobs-in-the-space-industry.1085148/ 1085148 invalid@example.com (mr3000) mr3000 I’m looking for jobs in the space industry that I can get with a degree in math. Are there any? What are they? Thanks in advance :)]]> 3 'How Does Your Garden Grow' thread - raised beds Fri, 15 May 2026 03:28:26 +0000 https://www.physicsforums.com/threads/how-does-your-garden-grow-thread-raised-beds.1079882/ 1079882 invalid@example.com (DaveC426913) DaveC426913 I was going to post this in the HDYGG thread but it's locked.

I am planning to build raised beds for gardering, mostly due to my Everlovin's diminishing ability to garden at ground-level. It sounds like it'll be mostly veggies. Zucchini, carrots, onions, tomatoes, basil, lettuce, beans, peas...

Read more]]> 40 The electric field inside an insulating infinite length solid cylinder Fri, 15 May 2026 02:03:28 +0000 https://www.physicsforums.com/threads/the-electric-field-inside-an-insulating-infinite-length-solid-cylinder.1085163/ 1085163 invalid@example.com (JesseAbberton) JesseAbberton TL;DR: Suppose there is a cylinder with infinity length and a radius R. At distance R/2, we have to find the electric field present inside. Confirmation needed regarding the method.

We are given volumetric charge density as ## \rho ## and we have to find the field at the distance R/2. Is...

Read more]]> 1 Mechanical advantage, or just a redirection of force? Fri, 15 May 2026 00:36:57 +0000 https://www.physicsforums.com/threads/mechanical-advantage-or-just-a-redirection-of-force.1085159/ 1085159 invalid@example.com (garyTheSnail) garyTheSnail In the following image, does the 4 x 4 post offer a mechanical advantage or does it just redirect force? Thank you in advance.
Reference video: ]]> 6 Looking for academic resources and review papers regarding the theoretical mechanisms of proton decay limits and GUT predictions Fri, 15 May 2026 00:09:09 +0000 https://www.physicsforums.com/threads/looking-for-academic-resources-and-review-papers-regarding-the-theoretical-mechanisms-of-proton-decay-limits-and-gut-predictions.1085006/ 1085006 invalid@example.com (yisyelkencisi) yisyelkencisi i've been studying proton stability and i'm particularly interested in how Grand Unified Theories (GUTs) predict baryon number violation, in contrast to the Standard Model. could you recommend some comprehensive review papers on this topic?

i’m also interested in recent experimental results...

Read more]]> 1 Kitten Lovers: Cuteness Overload Thu, 14 May 2026 23:05:10 +0000 https://www.physicsforums.com/threads/kitten-lovers-cuteness-overload.130472/ 130472 invalid@example.com (Evo) Evo This was just so damned cute, it deserved it's own thread.

Whenever I see cute kittens I can't help thinking of MIH, Tsu, Ivan, and Integral, and now Moonbear.

Moonbear, how's the kitty doing? We need an update!

This is quite the socially adept kitten, covering a yawn.

]]> 3881 Axiomatic Primitive Thu, 14 May 2026 21:34:54 +0000 https://www.physicsforums.com/threads/axiomatic-primitive.1085162/ 1085162 invalid@example.com (E Jacques) E Jacques Hello. É Jacques here.
Looking for alignment with my axiomatic primitive, stated in it’s derivative as: “energy is fundamental informative”.
I hope it stimulates conversation. Cheers!]]> 1 YouTube Classics, Part Deux Thu, 14 May 2026 18:28:27 +0000 https://www.physicsforums.com/threads/youtube-classics-part-deux.826985/ 826985 invalid@example.com (lisab) lisab A continuation of YouTube Classics.

Playing trombone to 'wildlife':

]]> 828 Drawing Acceleration Diagram with Coriolis Acceleration Thu, 14 May 2026 17:29:02 +0000 https://www.physicsforums.com/threads/drawing-acceleration-diagram-with-coriolis-acceleration.1085019/ 1085019 invalid@example.com (jojosg) jojosg I'm not confident in my acceleration Diagram because this question should have coriolis acceleration but I don't know how to draw it in acceleration diagram. Help would be appreciated.

$$V_D = 4.1 \, \text{cm} \times (2 \, \text{m/s}) / 1 \, \text{cm} = 8.2 \, \text{m/s}$$

$$\omega_{BC} =...

Read more]]> 1 New Member Message Thu, 14 May 2026 13:43:10 +0000 https://www.physicsforums.com/threads/new-member-message.1084652/ 1084652 invalid@example.com (DavidL070949) DavidL070949 Hi. Just joined. Looks like a fun and helpful forum.]]> 3 Lunar robots - AI guidance where low latency control is impossible Thu, 14 May 2026 12:51:19 +0000 https://www.physicsforums.com/threads/lunar-robots-ai-guidance-where-low-latency-control-is-impossible.1084322/ 1084322 invalid@example.com (Al_) Al_ For controlling robots on the Moon, for mining or construction.

We have robots that can copy human movements from camera vision. Factory robots can perform simple tasks after being shown what to do. But first-person controlled robots don't work very well with a one-second delay each way.

I...

Read more]]> 2 Magnetic Resonance physics question: RF pulse role and 'in-phase' Thu, 14 May 2026 09:25:05 +0000 https://www.physicsforums.com/threads/magnetic-resonance-physics-question-rf-pulse-role-and-in-phase.1064803/ 1064803 invalid@example.com (Astrocyte) Astrocyte Hi, after I majored in physics, I moved to the field of medical physics. However, I cannot understand some of their explanations. One of them that is bothering me a lot is RF pulse and in-phase.

What we measure in MRI is the magnetization of water particles. The magnetization comes from the sum...

Read more]]> 16 Just another math nerd Thu, 14 May 2026 01:00:28 +0000 https://www.physicsforums.com/threads/just-another-math-nerd.1085130/ 1085130 invalid@example.com (hval) hval Ive worked in predictive analytics and big data architecture. And started some big puzzles years ago that are ready to show people. I originally focused on wicked problems - the seemingly impossible problems that occur in a multi-polar world - and the skills developed over many different...

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