The First Grandpa Simpson Sighting of the Year

I haven’t done much fist-shaking from the porch recently, but here’s to changing that. Today’s curmudgeonly two-fer have one thing in common: overselling the product, in a way. The thing is, I don’t think they need the false advertising, whether it’s on purpose or owing to some comprehension gap. Ignore the rant if you wish, and just enjoy the technology/math-based artistry of these pieces.

Fascinating 3D-Printed Fibonacci Zoetrope Sculptures

These 3d-printed zoetrope sculptures were designed by John Edmark, and they only animate when filmed under a strobe light or with the help of a camera with an extremely short shutter speed.

… just like any other object would. Maybe it’s just me, but this sounds like the author is implying this is special to this particular class of structures — it’s not. That’s just how the strobe effect works.

Marvellous rube goldberg mechanical lightswitch covers

These are wonderful. But having a few gears doesn’t turn it in to a Rube Goldberg device; it’s not just a matter of being slightly more complex than it needs to be — in this case, mostly by adding one layer of complexity. There are no chain reactions and no diversity of mechanism, two hallmarks of such devices.

It Don't Mean a Thing …

King of the swingers: photographer builds giant pendulum to make amazing art

The [2D] swings combine with each other to create swirling designs called Lissajous figures.

The patterns are so stunning that machines like Blackburn’s Y-shaped pendulum were made commercially in the Victorian era. They became known as “harmonographs”, since the variation in images results from the variation in harmonies between the different swings.

Turning Up and Turning Down and Turning In and Turning 'Round

I want a doctor to take your picture
So I can look at you from inside as well

Stop-Motion Animation Reveals the Insides of Objects Sanded Down Layer by Layer

Laurin Döpfner … used an industrial sander to grind down logs, electronics, and even a skull in thin layers which he then photographed to create this amazing stop motion video. Each object is comprised of about 100 different photos

I like the walnut the best, I think.

It’s Not All Black and White

Incredible art piece dances with polarized light

There’s a video in the link with the art, which is a weird combination of kinetic sculpture and optical effects from polarizers. You don’t discern the actual motion of the polarizers, but you see a motional effect from the overlap. Sort of an opto-kinetic sculpture.

One thing:

Polarizers are pieces of plastic made to only allow (or disallow) the transmission of light with certain polarizations. Natural light has a mixture of all different polarizations of light, and so any one of these polarizers only filters out a portion of the light. However, if you stack two with complementary polarizations, such as one that blocks about 50% of light and another that blocks the other 50% of light, then you end up with a totally opaque whole.

To quote a phrase: that’s not how this works! That’s not how any of this works! Simple filters don’t add linearly (they multiply — two simple 50% filters would block 75% of the light), and polarizers don’t block half each. What’s actually going on is that one polarizer sets the polarization of the light (filtering the fraction that is cross-polarized), and then the second one blocks more light, both acting according to the Law of Malus

\(I=I_0 \cos^2 \theta\)

All the light is blocked for perpendicular orientations of the polarizers, and at varying levels of light at other angles. Randomly polarized light isn’t blocked by 50% — the transmitted intensity is roughly 75%. You can see single polarizers in the video, and tell they aren’t blocked by half.

The second piece is in color but only has a still shot, so I don’t know if this is color filters or polarization with birefringent materials. I’ve posted static shots of birefringent materials before, both using a static linearly polarized source (LCD); having the background and/or foreground polarization and birefringent material move might make for an interesting display.