Thursday, November 27, 2025

I See The Murmurations

I see the murmurations of the black-birds
And stand there in awe of the numbers
I think about the effort it took
To get them all there

- CosmicLettuce

(text generated by me, image generated from Grok)

Saturday, November 15, 2025

Magnetometer Bike Ride

A bike ride with the magnetometer on my phone recording at about 60Hz.  I've got x, y, z, and r axis data:







And here are the corresponding power spectra (spectrograms):






Wednesday, November 5, 2025

Bike Ride Spectrogram

This is a spectrogram of the accelerometer data collected on my smartphone as I ride my bike.  The y-axis is the time (it was about a 909 second -- 15m 9s -- ride) and goes from top to bottom.  The x-axis is the frequency (0 to about 100Hz) and goes from left to right.  Lots of interesting harmonics and other complex structures.  This is sampling every 100 measurements, or at about 2 Hz (once every 0.5 seconds):


The plot above is also the sum of the x, y, and z axes.  Here are the individual axes:

X:

Y:

Z:


Here's a plot of the z amplitudes (in g's) versus time (x-axis, seconds).  This is sampling about every 0.5 seconds.


Here's the same data, but just every data point with no skipping:


Here's another ride earlier that day, going the opposite way.  This is the x-axis g-force on the smartphone accelerometer:






Thursday, October 23, 2025

Happy Mole Day!

Happy Happy Happy Mole Day!

This is my third favorite number!  Behind pi and e.