Monday, June 17, 2024
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As a child, I would always pick flight as my hypothetical superpower. Quite unfortunately, that is not what the human body is built for. My dreams may have come true, however, if I had been born an insect (though maybe this would have been unpleasant in a variety of other ways).
Insect flight varies drastically. Some beetles and bees look like they are fumbling along like they might fall out of the air any minute. Dragonflies, on the other hand, appear out of magic and zip and spin so fast your eyes can’t keep track of them.
In principle, flight is a balance of four forces: lift, thrust, weight, and drag. Enough lift to balance weight, enough thrust to balance drag, and you’re hovering! In practice, this is much more difficult. Insect flight is often put into two categories, differentiated by how their muscles cause their wings to flap.
Most insects have indirect flight muscles, where muscles are attached to the walls of the thorax (the large middle section of an insect). There are vertical muscles and longitudinal muscles. When they contract, they change the shape of the thorax and cause the wings to move. Vertical muscles pulling on the roof of the thorax raise the wings. Longitudinal muscles pulling the sides of the thorax cause the wings to lower.
Dragonflies (also damselflies and mayflies) have direct flight muscles, muscles that act directly on the wings. Each wing is connected to two muscles. The ‘elevator muscles’ closer to the base of the wing contract (or shorten) to raise it. The second muscle, the depressor muscle, further from the base of the wing contracts to pull the wing back down. This allows them to move each wing independently, which gives them lots of control over how fast they can change speed and direction.
This week, I was (again) working on demos about dragonfly flight. On Wednesday and Thursday, I enlisted the help of interns at the ACP office to figure out how to make a model of dragonfly direct flight muscles. While this is proving a bit more difficult than I originally thought, we have a couple of prototypes that may prove fruitful. This week, I also designed the SPS summer intern shirt (all these cows are physicists) and wrote a demo on thin-film interference (centred around dragonfly colouration, maybe I’ll talk about that next week). As the concepts in my demos are becoming more complicated, they are taking a little longer to write. Here’s to hoping I get all of them done! I’ve started to have demo days in preparation for next Saturday’s Astronomy on the National Mall. All of Friday, the other interns dropped by the ACP office I have claimed to test the demos they’ll run. Boomwhackers are a surprisingly big hit with college students (Reidyn wanted to play Crazy Train).
As for not-work activities this week: Monday, I climbed a very good tree. On Tuesday, I made too many scallion pancakes, and made peach sauce (I traded Charles food for hand-whipping whipped cream (it was a good deal)). On Wednesday, Charles and I went to our first-ever spin class (it was movie music-themed and also exhausting). Next week we’re making other interns go with us. Thursday, I stopped at the National Portrait Gallery. On Friday, several of us went to Jazz in the Garden (good music, wet grass). Saturday, Kai, Sonja, Jaden, Charles, Kaden, Evan and I set our intentions on a food festival near the Smithsonian but promptly turned around when we found out there was an entry fee. Instead, we spent the afternoon searching through the National Gallery for art that looked like each other (great success with Kai and Charles lookalikes), and animals that Did Not look like animals (Sonja and I were horrified (some painters did not know what dogs looked like)). Afterwards, I made my way to Maryland to meet Amanda, Jenna, Brad Conrad, and Jack Hehn for the National Orchestral Institute’s Symphonie Fantastique concert. Amanda and I were thoroughly shocked at the Symphonie lore (highly recommend reading it, Berlioz was a little insane). On Sunday, I went to Maryland (the other side) to spend some time with my great aunt and uncle and cousins. We had lunch, talked about books, and watched a movie (my cousins are so cool). I’m super grateful I have family in the area, and it was wonderful to hang out with them all day. All in all, fantastic week!
This week’s dragonfly is Nannothemis bella, the Elfin Skimmer. It is itty bitty (North America’s smallest!), should be listed as endangered in all parts of its range (I’m working on it), and is one of my favourite dragonflies.
Maia Chandler