Monday, July 22, 2024
By:
Dear dragonflies, I love you. We’ve covered all the dragonfly physics topics in the SOCK, so now it is time to move on to fun facts. Fun fact number one: dragonflies do backflips.
This super awesome fact was discovered by scientists Dr Jane Wang, Dr James Melfi and Dr Anthony Leonardo at Cornell University and Howard Hughes Medical Institute, who published their findings in the 2022 paper Recovery mechanisms in the dragonfly righting reflex. How did they do this? Well, it started with catching a bunch of dragonflies. If you have never gone insect collecting before, I will tell you that you must be prepared to look silly. You must stand in dragonfly habitat (usually a pond or bog), body tense, ready to move. Your eyes must dart, inspecting the water’s surface for any movement. Then, the moment you see a flash of colour, a glint of a dragonfly speeding past you, you must strike. Swing your net quickly through the air and pray you aim correctly, twist it so your dragonfly doesn’t fly out, and fingers crossed, you have a dragonfly.
These scientists attached motion-tracking dots to the wings and bodies of dragonflies and then turned them over and let them drop in front of a high-speed camera. This wasn’t quite enough to see how the dragonflies were righting themselves, so they used the videos to create 3D models of the process.
Using some complicated mathematical modelling, they could see exactly how these dragonflies fell. The dragonflies pitched their left and right wings at different angles, causing their bodies to rotate around the vertical axis until they were right-side-up. They did backflips! Even cooler? These dragonflies did the same thing unconscious (albeit a little slower).
This prompted a new question: how do the dragonflies know they are upside down? Dr Wang and her colleagues covered the eyes of these dragonflies and repeated these experiments. These new blind dragonflies couldn’t flip themselves, meaning they use their eyes (well, a pair of compound eyes and three ocelli, or simple eyes) to figure out if they’re right-side-up.
There were further experiments that pre-positioned the dragonflies' wings at certain angles or used dead dragonflies. These informed the scientists that muscle tone and wing posture are important to this backflip mechanism. It is not something they do actively, but rather a passive response!
Weekly dragonfly rant, complete. My projects? Still in progress. On Monday, I went to ACP-DC after dropping my girlfriend off at the Amtrak station (sad sad sad). There were some trials and tribulations in filming my first demo instructional video, but I ended the day with content (success!). On Tuesday, Kai and I drove into ACP-Maryland so I could pack boxes. 100 bottles of glycerin? Done. 100 packs of straws? Not done. I need more straws. We headed back to DC where I met my mum and brother for dinner (they’re here!) and finished the day with Kaden’s dewormabration (see Kaden’s blog for more information) and The Bachelorette. Wednesday, there was more ACP-Maryland (I got a ride from my mum, wahoo!). I packed bubble solution (very bubbly), tongue depressors, and stirrer sticks. Sonja and I headed back to DC together and then I had family dinner again.
New exciting things happened on Thursday–we went to NIST! There were some helpful presentations on what we should do with our lives post-grad, ‘Newton’s apple tree’ (not sure how much I believe in it), and some amazing tours. We also heard Dr Sarah Horst speak about the Dragonfly mission to Titan, which was incredible. I stand by my statement that it does Not look like a dragonfly. It is a rotorcraft. Friday I was back in ACP-DC to film and edit videos (I think it’s going well?). In the afternoon, Amanda, Charlotte and I walked to Georgetown and got piercings! Then, I met my cousins and mum for drinks.
I spent the weekend with my family. We went to the portrait gallery and had dinner with my great aunt and uncle. We ended the day with Trivial Pursuit and all did horribly (apologies to my girlfriend, I did not defend her win streak). Sunday, we had brunch and checked out the DuPont farmer’s market and Eastern market. I ate some yummy cheese. In the evening, I made cookies (miso brown butter chocolate chip, but not enough miso). As Kai said: busy as a bee!
This week’s dragonfly is the Common Darter, Sympetrum striolatum. It is the species Dr Wang and her colleagues used for their experiments! It is one of the most common dragonflies in Europe.
Maia Chandler