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Ray Lee

@4raylee.mathstodon.xyz.ap.brid.gy

Culture is kept in our conversations, for some loose definition of 'conversation'. Black lives matter. I work in software with a team of physicists, MEs, EEs […] [bridged from mathstodon.xyz/@4raylee on the fediverse by fed.brid.gy ]

Posts Replies Media

Ray Lee @4raylee.mathstodon.xyz.ap.brid.gy · 16/10/2026

Most white dwarf stars are indeed white. But about 1 in 30 have cool enough atmospheres to let elements adjust their shine.

An image of 8 dwarf stars in different colors derived from their spectra. Blue, yellow, pink, salmon, purple, and green!

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Ray Lee @4raylee.mathstodon.xyz.ap.brid.gy · 19/01/2026

One of the best decisions I’ve made recently was to set an alarm for 15 minutes before #sunset. The stage before the show.

A view of the sky. Lots of little puffy clouds which will each capture a slice of the colours of sunset.

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Ray Lee @4raylee.mathstodon.xyz.ap.brid.gy · 07/08/2025

A guilty pleasure, picking up textbooks on topics I’ve already studied. First time through is the hard one. Though, book 5 looks new…

A picture of text on the inside of Volume 1: Classical Mechanics by David Tong, listing the books in his series. The text:

Lectures on Theoretical Physics
Volume 1: Classical Mechanics
Volume 2: Electromagnetism
Volume 3: Quantum Mechanics
Volume 4: Fluid Mechanics
Volume 5: You may need to be patient

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Ray Lee @4raylee.mathstodon.xyz.ap.brid.gy · 24/05/2025

"Use the most natural notation available to solve a problem." -- Peter Norvig Pictured is a dance in Beauchamp-Feuillet notation. It shows the connection between a dancer's motion and the music. "Like all forms of writing, choreography — literally the […] [Original post on mathstodon.xyz]

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Ray Lee @4raylee.mathstodon.xyz.ap.brid.gy · 16/01/2025

It's almost silly how nice command line tools have gotten. Today I'm glad for the `uv` Python project manager. If you're not already using Conda, uv is worth a look managing Python and packages. 'cuz life is always nicer when code works repeatably. Of […] [Original post on mathstodon.xyz]

A graphical plot of a few trigonometry functions appears in the terminal! Modern terminal emulators can render images.

Following is a transcript of the text recorded in the terminal session. The background of the terminal is partly transparent, showing a faint image of Yosemite.

Transcript follows:

❯ uv run --with matplotlib --with git+https://github.com/anntzer/mplterm@1d3631e ipython --pylab
Updated https://github.com/anntzer/mplterm (1d3631e)
Python 3.13.1 (main, Dec 3 2024, 17:59:52) [Clang 15.0.0 (clang-1500.1.0.2.5)]
Type 'copyright', 'credits' or 'license' for more information
IPython 8.31.0 -- An enhanced Interactive Python. Type '?' for help.
Using matplotlib backend: macosx

In [1]: matplotlib.use('module://mplterm')

In [2]: t = np.linspace(0,5,200)

In [3]: plt.fill_between(t, 2*np.cos(t), 3*np.sin(2*t), alpha=0.5)
Out[3]: <matplotlib.collections.FillBetweenPolyCollection at 0x11741eba0>

In [4]: plt.fill_between(t, 2*np.sin(t), 3*np.cos(2*t), alpha=0.5)
Out[4]: <matplotlib.collections.FillBetweenPolyCollection at 0x116e37110>

In [5]: plt.show()

# A graphical plot of the functions appears in the terminal! Modern terminal emulators can render images.

In [6]:

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Ray Lee @4raylee.mathstodon.xyz.ap.brid.gy · 13/12/2024

I’m embarrassed to admit how long I stared at this to piece it together. In my defense, Euclidean geometry is a comforting lie we tell schoolchildren, to avoid discussing other, more Lovecraftian horrors. Anyway, a cute visual set of constraints leading to […] [Original post on mathstodon.xyz]

A rectangle with an inscribed right triangle. The hypotenuse of the right triangle coincides with the base of the rectangle and it has length 1. The other two sides of the right triangle are labeled cos(theta) and sin(theta). The apex of the triangle splits the top side of the rectangle into segments of lengths cos^2(theta) + sin^2(theta).

The caption reads "A proof of cos^2(theta) + sin^2(theta) = 1"

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Ray Lee @4raylee.mathstodon.xyz.ap.brid.gy · 03/12/2024

More evidence space is jiggly! Pulsars are incredibly precise time keepers. They’re as heavy as stars and spinning, so changing their rotation rate isn’t something that happens quickly, unless something cosmic intervenes. If they do change their periods […] [Original post on mathstodon.xyz]

An image of our Earth measuring signals from two distant pulsars. The backdrop it’s spacetime itself jiggling (stretching and compressing) due to gravitational waves.

“Pulsar timing arrays use signals from pulsar to measure distortion in space-time. Credit: R. Hurt/CALTECH-JPL: NASA”

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Ray Lee @4raylee.mathstodon.xyz.ap.brid.gy · 21/10/2024

I eventually made peace with people who want their code to look like angry fruit salad. But this new trend of changing sizes and colors is a bridge too far.

$A screenshot of a web page that includes a C++ code listing. In the listing keywords are colorised, but lines which are (presumably) more important after in as larger font. There are at least three fonts sizes and multiple colors for a dozen lines of code. The lines with the largest font are chopped off in the right hand side, as the font for the important text is too large to show all the text. Contents follow, so I can read it too! — First let’s recap how lifetime parameters are declared and used. lifetimes1.cxx – (Compiler Explorer) #feature on safety // Function parameters have different lifetime parameters. // Return type is constrained by x's lifetime. auto f1/(a, b)(int^/a x, int^/b y, bool pred) safe -> int^/a { // Error: // function auto f1/(a, b)(int^/a, int^/b) -> int^/a returns // object with lifetime b, but b doesn't outlive a // return y; return pred ? x : y; } // Function parameters have a common lifetime parameter. auto f2/(a)(int^/a x, int^/a y, bool pred) safe -> int^/a { // Ok return pred ? x : y; } // Error: // cannot use lifetime elision for return type int^ auto f3(int^ x, int^ y) safe -> int^; In Safe C++, occurrences of the borrow type T^ in function declarations and in data members require$

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