Tuesday, July 31, 2018

Moved to Piers Park!

Welcome back blog readers!

Kayaking with kids
     This week has been an exciting change from Blacks Creek to Piers Park! The schedule for Piers Park is a bit more variable: we're at the park on Mondays, Wednesdays, Thursdays, and Fridays, but on Tuesdays we go to Courageous Sailing at the Charlestown Navy Yard and on Thursdays we go to Community Boating after lunch. Unlike Blacks Creek, we mostly do fishing at Piers. Generally, the programming consists of lawn games/name games (like capture the flag, everyone's it tag, where the wind blows), then activities on the dock (fishing mainly, with intermittent sailing and kayaking). After a lunch break, we get back together for an activity (e.g. learning about recycling, salinity) and some more dock activities before we pack up and head home.
Teaching kids how to fish

     We caught an assortment of sea life throughout the week at Piers Park. I started out the week catching a spider crab, which kinda looks like a rock with long legs (it looked more like a rock than the rock crab we caught, interestingly enough). On Tuesday we caught a lobster, which up until then I didn't know lobsters could be caught on fishing hooks, but empirical evidence has proven me wrong. The lobster was a keeper, meaning that it was between a minimum and maximum length (these limits are in place to try to make sure lobsters don't go extinct. Young and old lobsters get to live, basically.) Michael let the lobster go after the kids played with it because it was a female lobster and would eventually give birth to more lobsters. Some other animals we caught were rock gunnel, perch, green crabs, a starfish, and minnows.

Rock Gunnel
Rock Crab

     One of my favorite activities this week was teaching kids about refractometers. I'll explain in further detail how refractometers work below but for the kids I gave them a brief lesson on what salinity is and how to read a refractometer. I explained (in simpler terms than I use in this blog) that the number they read on the refractometer corresponds to the amount of salt in the water in a unit called parts per thousand (n molecules of salt in 1000 molecules of water, where n is the value on the refractometer). In order to fully explain refractometers we'll have to go over how refraction works, and how different substances have different values on the refractive index. Basically, the higher the difference in refractive index values two substances have, the more light bends when crossing the border between those substances. It's why objects in water appear closer than they actually are: water has a higher value on the refractive index than water, so light bends towards the observer when crossing the water-air border. The other concept refractometers use is a phenomenon called internal reflection. Internal reflection occurs when light hits the border between substances of differing refractive index values on the side of the higher refractive index value. At an angle called the critical angle, or any angle with a lesser value than the critical angle, light bounces off of the border rather than passing through and refracting. Now that we've gone over refractive indices and internal reflection, we can get back to refractometers. Refractometers bounce and refract light in such a way that slight differences in water samples, like salinity, will refract water and change the angle that the light is approaching to an angle less then the critical angle, creating internal reflection. This is what creates the different areas in the lens of the refractometer: the blue and white areas that, when you look at the border between them, give you a numerical value for the salinity of the sample in ppt.

Image result for refraction
Visual representation of refraction
I love working at Piers Park. It's such a great change of pace from Blacks Creek, and a much easier commute as well (Wonderland -> Maverick rather than Wonderland -> State -> Downtown -> North Quincy). The activities are varied enough to be interesting, but not so much that there's nothing to get used to. I can take some kids kayaking if I need some exercising, or I can help kids fish if I want to teach them stuff. I get to see 3 different sites working with the Piers Park group (Piers Park, Courageous Sailing, and Community Boating Institute) and everyone I worked with this week have been fantastic. I'm thankful that I'm working at Piers next week as well.

Song of the week: La Di Da by The Internet

See you in the next blog!
~Colin McRae

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