Mastodawn

Astronomy sidequest: woodworking!

A few weeks ago I broke the DIY table I built to polish telescope mirrors, so I added some more screws and rebuilt it. It must keep mirrors at elbow height during polishing, and is weighed down to withstand sideways forces from friction. I copied the truss design from the guide on https://stellafane.org/tm/atm/mirror-general/materials.html , but this rebuild uses two screws per strut for added rigidity. I have employed advanced metrology equipment (pictured) to verify its surface isn't tilted.

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hillexed Mar 17

@stevenray more likely that's astigmatism in your lens or atmospheric distortions of a bright star. Saturn doesn't look like that right now and it's too small to see rings without a telescope

hillexed Mar 9

The local electronics store had a wireless rainbow internet controllable 10 feet of LEDs product on sale for $15. I'm going to buy one and maybe I can detach the LED strip and replace the controller with something I can program

hillexed Feb 9

Ugh, Joey is totally in the pocket of Big Kangaroo

hillexed Jan 24

It has been several months of assembling and tinkering and troubleshooting to get here, but my bath interferometer is finally working! Now I can feed these images of concentric circles into software and analyze the shape of my mirror down to tens of nanometers!

These pictures show a laser beam, split in two by a beam splitter cube, interfering with itself. The dark zones show regions where one beam travelled an integer plus a half number of wavelengths farther then the other beam, so when they add back together they're out of phase and cancel out. A linear polarizing filter on my camera I got helps equalize the brightnesses and make the pattern clearer. The resulting pattern can be interpreted almost like a topographic map of the mirror, where a single ring is all at the same "height" from my 3D printed testing apparatus.

#diy #interferometry #hillescopemaking

hillexed Jan 24

My weather app is sending me annoying nag notifications asking me to check the weather

hillexed Jan 13

The laser beams in my interferometer seem to have a dark stripe down the center that makes it very annoying to align. I think it's an issue with the laser itself, since even without the rest of the optics the laser outputs a weirdly off-center beam

hillexed Jan 10

In Jump Up, Super Star, Pauline sings "you know that you're my super star / no-one else could take me this far" to Mario. However, we now know that Donkey Kong could have also taken her this far. I'm so tired of politicians lying for votes

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hillexed Dec 26

several hours of fixing my code and remembering how electromagnetic waves are constructed later, my simulation works!
Green means strong electric field, red means strong magnetic field. Yee

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hillexed Dec 25

@latuernich probably but what if I found out the hard way