The Smell of Molten Projects in the Morning

Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.

Category: Science

If you measure something often enough, it becomes science

Monthly Science: Solar Eclipse 2017

An hour before the festivities started, I lashed together an official NASA-approved pinhole eclipse viewer from available materials:

Eclipse 2017-08-21 – pinhole projector

Although the solar disk showed up fine on the white paper screen, the Pixel’s camera can’t show the notch growing on the left side, even with HDR+ mode in full effect:

Eclipse 2017-08-21 – pinhole projector – interior

As usual for astronomy around here, clouds threatened the outcome:

Eclipse 2017-08-21 – high clouds

Near the maximum, the skies cleared:

Eclipse 2017-08-21 – maximum – lens flare

Although it’s not proof, there’s a definite bite out of the lens flare at about 4 o’clock:

Eclipse 2017-08-21 – maximum – lens flare – detail

The maples south of the driveway produced lower-contrast images better suited to silicon sensors:

Eclipse 2017-08-21 – maximum – shadows

And, although everyone was specifically enjoined not to do this, because UV reflection = blindness, the obligatory solar eclipse selfie:

Eclipse 2017-08-21 – obligatory selfie

I’m sure similar lens flares count as UFOs in someone’s telling of the tale.

We planned to dance naked in the yard, but our neighbor’s lawn crew picked that moment to scalp his grass and we chose discretion over valor …

2017-09-01
Sharp EL-531W vs. EL-531X Calculators

(Typo in the permalink: should be W vs. X. Fixing it will break all the auto-linkies. Hate it when that happens.)

When our lass first began using calculators, I put a pair of Sharp EL-531W calculators in harm’s way around the shop, where they still reside. The new EL-531X seems to have an identical key layout and internal logic (*), as well as the same under-ten-buck price, but I don’t like it nearly as much:

Sharp EL-531W EL-531X calculators

It’s maybe 10 mm wider and doesn’t fit readily in my hand. I’m sure the rounded-rectangle stylin’ mimics a phone, but the cheapnified keys look ugly (particularly the ones around the arrow keys at the top) and don’t feel nearly as good.

The new one fills a gap next to the lathe, where it should collect plenty of swarf.

(*) Including engineering notation with multiple-of-three exponents, which I regard as vital.

2017-08-30
Cocooning

Each of the three Mystery Caterpillars wandered around the aquarium for a few minutes, found a spot surrounded by leaves, and tucked themselves into their cocoons.

The smallest one went first and probably got the best site:

Mystery Caterpillar – Cocoon 1

The medium one:

Mystery Caterpillar – Cocoon 2

The largest caterpillar munched the leaf around the new cocoon and removed some of the silk (?) wrapper. It looks like the caterpillar’s fur falls off and becomes insulation inside the wrapper.

The large one with mostly black fur managed to bind two leaves together:

Mystery Caterpillar – Cocoon 3

The Monarch remained calm, well above the scramble:

Monarch Chrysalis – with skin

The caterpillar’s skin (or whatever it is) remained loosely attached to the outside.

All of which puts me in mind of Della Lu:

FINAL WARNING!
PROJECTION WILL SELF-ENCLOSE.
CONTINUE?

I wonder what they’re thinking after they type Y E S …

2017-08-27
Sandisk Extreme Pro MicroSD Card: End of Life?

The Sandisk Extreme Pro 64 GB MicroSD card in the Sony HDR-AS30V died on the road once more, got reformatted, worked OK for a while, then kicked out catastrophic I/O errors after being mounted, so I swapped in the High Endurance card:

Sandisk – 64 GB MicroSDXC cards

The Extreme Pro still passes the f3probe tests, so it’s not completely dead, but if I can’t trust it in the helmet camera, it’s dead to me.

It survived 17 months of more-or-less continuous use, although we didn’t do nearly enough riding for three months early this year. Call it 14 months x five rides / week x 1 hour / ride = 300 hours of recording. Multiply by 4 GB / 22.75 minutes to get 3 TB of video, about 50 times its total capacity.

The never-sufficiently-to-be-damned Sony cards failed after less than 1 TB and 15-ish times capacity, making the Sandisk Extreme Pro much better. However, it’s painfully obvious these cards work better for low-intensity still-image recording, rather than continuous HD video.

Using them as Raspberry Pi “hard drives” surely falls somewhere between still cameras and video, although Octoprint’s video snapshots and streaming media must make ’em sweat.

We’ll see how Sandisk’s High Endurance memory works in precisely the application it’s labeled for.

2017-08-22
Mystery Caterpillars

This being caterpillar season, we put a mystery egg mass on a Swiss Chard leaf into a small container:

Mystery Caterpillar – eggs on Swiss Chard

I think the darker egg was a dud, because two days later they all hatched and ate their egg cases, leaving that one behind:

Mystery Caterpillar – hatched

Mary deported them to the trash, put two on a leaf in an aquarium on the kitchen table, and, eight days later:

Mystery Caterpillar – 8 days

They’ve been chowing down on spare garden greenery; unlike Monarchs, they eat what’s set before them.

One has dark “fur”:

Mystery Caterpillar – black morph

The second is lighter:

Mystery Caterpillar – brown morph

A third caterpillar escaped the trash can apocalypse and also resides in the aquarium, albeit stunted by its ordeal:

Mystery Caterpillar – pale morph

They’re too bristly to be Wooly Bears. I’m sure they’ll turn into nondescript brown moths.

2017-08-20
Monthly Image: Cross-striped Cabbageworm

In the normal course of events, this critter would become an undistinguished brown moth:

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Right now, it’s a two-day-old cross-striped cabbageworm. Its kin are voracious consumers of Brassicacae out in the garden and Mary’s raising it as a show-n-tell exhibit for her Master Gardener compadres; she advised it to not start any long novels.

Taken hand-held with the Pixel XL through a clip-on 10x macro lens.

2017-08-15
Monarch Caterpillar Windshield
The Monarch Butterfly egg produced a teeny caterpillar:

Monarch caterpillar – 3 mm – 2017-08-02

Each time it molts, it eats all of its skin except for the transparent cap over the first body segment:

Monarch Windshield – 2017-08-09

If the rest of the caterpillar were behind the windshield, it’d be feet-upward with its “face” at the top.

The picture comes from a focus-stacked set of microscope images captured with VLC; I turned the positioner’s elevation knob the smallest possible amount between each of 16 images along the 1 mm (-ish) height of the capsule. This magic incantation applies more weight to high-contrast and high-entropy regions:
```
align_image_stack -C -a monarch vlcsnap-2017-08-09-18h4*
enfuse --contrast-weight=0.8 --entropy-weight=0.8 -o Monarch_Windshield.jpg monarch00*
# empty line to reveal underscores in previous line
```
That came out pretty well.
2017-08-12