Laser Spirograph

With an upcoming open house, everyone around the observatory is frantically trying to get everything in place. There will be all manner of science exhibits throughout the observatory headquarters complex. Exhibits about our research, controlling the telescopes, an IR camera display (Get your portrait in IR!), liquid nitrogen ice-cream, just a lot of fun.

Laser Spirograph
A two mirror laser spirograph build
I am coordinating an exhibit we named Optics Lab… As you would expect, most of the exhibits in our area teach basic optics, light, lenses, etc. Understanding light and optics is a basic skill in a large observatory. We will have a few lenses on rails, a laser ray-trace table with acrylic lenses, an exhibit on polarization, and even a simple laser interferometer.

When attempting to teach something, a little eye-candy is helpful to catch the attention of the audience, particularly kids. Our group includes a laser engineer and a laser tech, so the use of lasers was obvious. There is little that catches the eyes of a kid faster than a bright laser beam. One of the first ideas they tossed on the table was a laser spirograph. After a few moments thought the answer was clear… I can build that!

SpiroLaser PCB
Schematic for the SpiroLaser control PCB
Time to dig about in the scrap box! Actually more than a few boxes in my case, I am a bit of an electronics pack rat. A green laser module… Check! Small DC motors… Check! A few voltage regulators… Check! A couple potentiometers… Check! First surface mirrors… Check! In an hour of rummaging about I quickly located everything that was needed.

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Postcard from the Reef – Idol

The moorish idol (Zanclus cornutus) is one of the most memorable fish on a Hawaiian reef. They are commonly seen grazing along the open reef in shallow water. I often find these fish in caves as well, which seems quite odd as few daytime fish venture into the dark. The sponge and algae covered walls apparently provide good grazing.

Moorish Idol
Moorish Idol (Zanclus cornutus) in a cave

Counting Whales

At some points there were half a dozen different groups of whales in sight at the same time. The spotters called whale activity in a confusing chorus of activity and locations. The annual Hawaiian Islands Humpback Whale National Marine Sanctuary Ocean Count picked a pretty good day. Given the recent winter storm I had half expected to be rained out, some of the east Hawai’i sites were, but we had perfect conditions.

Counting Whales
Counting whales at MM7 north of Kawaihae
Last month a thin haze that hampered visibility, the resorts on the far shore barely visible. This year we could count tourists on the beach at the Mauna Lani about 10 miles away. Some of the whales we spotted were in front of Kiholo Bay about 16 miles to the south. When the visibility is good, the Mile Marker 7 is one of the best whale watching sites in the entire island chain.

Not that we always needed to look that far, often enough the whales were at the base of the bluff, just a few hundred yards below us. In one half hour data interval we counted 24 breaches. Just a few whales around.

No argument, it was a good morning to be counting whales. From the looks of the preliminary results, our site counted far more whales than any other site across the islands. No surprise, this stretch of coast is always thick with whales. The only sites that challenge MM7 are the sites just north and south, Lapakahi and Pu’ukohola Heiau, from the data those folks had a good day as well.