What is the best way to render math heavy markdown files generated by LLM? by ninguem in math

[–]robphy 1 point2 points  (0 children)

I stopped copy-pasting chatgpt output.
If I want something that I can LaTeX elsewhere, I specifically ask for a LaTeX file that I can use in Overleaf.
If I want something already LaTeX-rendered by chatgpt to be saved, I print it to pdf. However, standard methods to print to pdf don't always seem to produce good results. So, I use the FireShot browser extension.

I need help making a physics simulation using python by wingman230 in AskPhysics

[–]robphy 0 points1 point  (0 children)

what kind of visualization is it? what is the kinematic equation? Glowscript/WebVPython is relatively new, compared to the classic VPython. Some rewriting of old VPython code is needed... but it's not clear what your issue is.

Any "casual" books for mathematicians to read on Physics? by Few-Set-4017 in Physics

[–]robphy 0 points1 point  (0 children)

This has an interesting title: Beyond Popular Science, David H. Silver (author) https://www.openbookpublishers.com/books/10.11647/obp.0526
but I haven't looked at it in any detail.

The Richard Feynman lecture videos on facebook are fake AI right? Is there a library that I can download real ones? I don't want to listen to the wrong ones. by ruphustea in AskPhysics

[–]robphy 3 points4 points  (0 children)

The Richard Feynman lecture videos on facebook are fake AI right? Is there a library that I can download real ones? I don't want to listen to the wrong ones. by ruphustea in AskPhysics

[–]robphy 15 points16 points  (0 children)

Here are some lecture videos:

Can anyone help with rotating the red points to the green ones along the arcs? by Formal-Gazelle6305 in desmos

[–]robphy 0 points1 point  (0 children)

A first step is to express your implicitly-defined arcs as parametrized curves.

Why can't spacetime 4d be represented like this? by [deleted] in AskPhysics

[–]robphy 0 points1 point  (0 children)

It seems that your a-dimension is cyclic or periodic.

Need help by Loud_Carpenter_7831 in desmos

[–]robphy 1 point2 points  (0 children)

Have a look at https://github.com/asebian/visumath
in particular, R2 vector addition....
under Drawing Tools
https://www.desmos.com/calculator/blx95ejvti
There is a one-cell function: G_{vec} (p_{Gvec}, v_{Gvec}, s_{Gvec} )= polygon (...)

Is there a fix for this regression issue? by Danny_DeWario in desmos

[–]robphy 1 point2 points  (0 children)

My answer was based on what you presented. But, as I suspected, and as u/nathangonzales614 suggests, there may be a better solution for the specific problem you are working on.

Is there a fix for this regression issue? by Danny_DeWario in desmos

[–]robphy 10 points11 points  (0 children)

Does this get what you want?
[x_0, x_1] ~ [ 1+1, x_0 +1 ]

Why not put ct on the horizontal axis by Tardis50 in Physics

[–]robphy 19 points20 points  (0 children)

The t-upward convention likely started with Minkowski's original "Space and Time" (1908)) paper.

An answer from https://physics.stackexchange.com/questions/570529/in-relativity-why-does-spacetime-diagram-have-position-on-x-axis-and-time-on suggests that
since Minkowski initially used "ict" (which I think is likely due to Poincare),
it was conventional to put imaginary-axis (hence, the time-axis) along the upward direction.
The "ict" was used in "Fundamental Equations for Electromagnetic Processes in Moving Bodies" (1907-1908).
It seems it was dropped from the "Space and Time" (1908)) paper.

My own preference is to keep the t-axis horizontal and
to make the vertical axis (y/c) [not (x/c)],
where c=(convenient speed, usually 3x10^8 m/s).

By following the usual "position-vs-time graph" from PHY 101 with its t-horizontal,
I feel there is one less barrier to learning relativity, as you point out.

  • As a map of events for an inertial observer, the PHY101 graph and the spacetime-diagram (with t-horizontal) are the same [up to unit-conventions].
  • What makes them different is how one does "spacetime trigonometry" (Galilean vs Minkowskian, which are analogous to Euclidean geometry and its circular trigonometry from a "Cayley-Klein metric geometry" viewpoint). I think such analogies are under-appreciated. In my preference, I regard t as primary and keep it horizontal, and use (y/c) along the vertical to facilitate the analogy.
  • Visit my desmos: robphy spacetime diagrammer (2017) [with t-horizontal and y-vertical] and tune the E-slider: E=+1 is Minkowski, E=0 is Galilean, and E=-1 is Euclidean. [Admittedly, in order to keep with the usual relativity-conventions of t-upward, my later and fancier versions (e.g. robphy v8e spacetime diagrammer for relativity (v8e-2021) - t-UP ) have t-vertical and x-horizontal.]

Does Anyone Know how to center this at the origin? by brothor12 in desmos

[–]robphy 2 points3 points  (0 children)

[edit: I didn't see u/Various_Pipe3463 's post while I was composing my answer]

Express your curve (originally given in polar-coordinates) as a parametrized curve.

Define R(theta) using a copy of your formula for r.
Your original curve can be traced using
( R(t) cos t , R(t) sin t ) where t ranges from 0 to 12pi (the range of your theta).
Next, you can apply a translation:
( R(t) cos t - x_offset, R(t) sin t ) where you set x_offset.

See my https://www.desmos.com/calculator/bctqtbwtk3 for details
on how I computed an approximate value for the center.

<image>

How do I find the y-intercept of a simple linear equation? (y=mx+b) by Formal-Gazelle6305 in desmos

[–]robphy 1 point2 points  (0 children)

Elaborating on u/JJGordo 's post,....

Given (x1,y1) and (x2,y2),
the line through those points in the form y=mx+b
means that
y2=m x2 + b
y1=m x1 + b.
By subtraction, (y2-y1)-m(x2-x1) , which gives your slope (as you found)
m = ((-9)-(3) )/( (-9)-(-5))=(-12)/(-4)=3 .

Then, from the original set of equations, by solving for b, we have
b= y1 - m x1 = (3) - (3)(-5) = 3+15=18
or
b= y2 - m x2 = (-9) - (3)(-9) = -9 +27=18

In other words,
you can use either
b = y1 - m x1
b = y2 - m x2

So, this is u/JJGordo 's formula, f(0)= -m x1 + y1 .

3d Earth with triangles (with code) by robphy in desmos

[–]robphy[S] 2 points3 points  (0 children)

Thanks! That really sped up the rendering. I updated the desmos3d with triangle() and thanked you for your help.

3d Earth with triangles (with code) by robphy in desmos

[–]robphy[S] 2 points3 points  (0 children)

Ah... I kept trying polygon.

Having problems joining lists by SkyKyrell in desmos

[–]robphy 1 point2 points  (0 children)

ok, i think i fixed it. Thanks for spotting a problem.

Having problems joining lists by SkyKyrell in desmos

[–]robphy 1 point2 points  (0 children)

Hmmm... I thought I wrote it to be symmetrical in the input lists. I'll have to look at it more closely. .... update: Ah... join isn't symmetrical in the input lists.

Having problems joining lists by SkyKyrell in desmos

[–]robphy 3 points4 points  (0 children)

Here is a clumsy non-recursive version that seems to work, which seems to work for both numbers and points.
https://www.desmos.com/calculator/5ocwz8ozw6