Recent content by Will Flannery

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    How is Physics taught without Calculus?

    "Regarding simulation: time should not be wasted in core physics classes on simulations." If we step back a minute, what is physics? Ans: creating mathematical models of physical systems and analyzing the model to be able to predict how the physical system performs. In classical physics, the...
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    How is Physics taught without Calculus?

    When I was a freshman at UF taking an honors physics class I thought, gee, why are we learning Newtonian physics when Einsteinian physics is more than half a century old? When I graduated with a PhD many years later and went to work analyzing rocket trajectories for the Star Wars program, I...
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    I Can time on elliptical orbit be expressed analytically?

    The original question, 'Can time on elliptical orbit be expressed analytically?' is a little vague. I think it means can the time into an orbit, i.e. the time since the planet was at the orbit pericenter (point of closest approach) be expressed as a function of the true anomaly (the angle of...
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    B Solving Kepler's 1st law as a function of time

    jebez: (irony, sarcasm) ...... I didn't notice the price! I bought the book several years ago and it wasn't expensive, I just checked and found 1 copy ! for #30.00 https://shopatsky.com/products/solving-keplers-equation Inverting Kepler's equation (not Kepler's 1st law), i.e. calculating...
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    B Solving Kepler's 1st law as a function of time

    From the title, I think you want to be able to calculate orbit position as a function of time? That's known as Kepler's Problem, which is to solve Kepler's Equation, which can be derived from Kepler's 3 laws. Kepler's equation - https://en.wikipedia.org/wiki/Kepler's_equation Kepler's problem...
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    Physics education is 60+ years out of date

    There are 2 things to consider, are the Nature Physics quote and the APS/AAPT quote authoritative, i.e. correct, and, if they are correct, are they important? To answer these questions it’s necessary to understand the context. There is the academic context – for 20-30 years there have been...
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    Physics education is 60+ years out of date

    Dale: "Do they provide any evidence to support that claim? " One of the authors, Caballero, is a one of the top honchos at PICUP, and he wrote a paper on the subject a few years ago ... "Prevalence and nature of computational instruction in undergraduate physics programs across the United...
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    Physics education is 60+ years out of date

    <Mentor’s note: this thread is closed as a duplicate of https://www.physicsforums.com/threads/the-coming-revolution-in-physics-education.954664/ > In the March 2024 issue of Nature Physics 'Computing in Physics Education' (https://www.nature.com/articles/s41567-023-02371-2) we read: "In the...
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    Are there any really good resources on modelling with differential equations?

    Yes, my book .... Mathematical Modeling and Computational Calculus See also ... The Coming Revolution in Physics Education A Revolution in Physics Education Was Forecast in 1989, Why Hasn't It Happened? What Will It Take? A New Curriculum for Classical Physics
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    What to cover in a differential equations module?

    I'll give a controversial opinion .... assuming that the DE module is for a physics program. I'd begin by pointing out that classical physics is based on analyzing differential equation models of physical systems, but that, unfortunately, differential equation models of most physical systems...
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    YouTube Playlists for Solving Math and Physics Exercises?

    I have a couple of playlists .. one for systems modeled by ODEs ... and one for systems modeled by PDEs - All the vids follow the same sequence - state the governing laws of physics for the system, model the system with DEs, translate the model to computational statements using Euler's...
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    Teaching approximation techniques in basic courses

    "Not sure how universal it is, but my experience through half of my undergrad education gave me the impression that 90% physics was about exactly solvable problems." Your impression was the result of an illusion. In reality very few problems in physics have exact solutions - even in...
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    Analytical solution for freefall....

    ? That doesn't make sense, I want it to be read... even debugged if necessary ... Generally, things become much clearer when you actually have to program them and check if they work ... For example, it took me over an hour, and many corrections, to get that program to work.
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    Analytical solution for freefall....

    That's not math, that's MATLAB. In any case, now the question is, why does every book ignore the problem of an analytical solution for the 1-D gravity problem (as noted in the ref. in the wiki article, the guy looked at 100 physics books) and what is the solution? From the reference in the...
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    Analytical solution for freefall....

    By Jove ! ... and I've only been Matlabbing for 100 years ! G=6.7e-11; % gravitational constant m^3/(kg*s^2) mEarth = 5.9742e24; % mass of Earth in kg rEarth = 6.378e6; % radius of Earth in m mu = G*(mEarth + 1); y0 = rEarth; t = 1; x = (3/2*(pi/2-t*sqrt(2*mu/y0^3)))^(2/3); y1...
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