Category: Ropes

Measuring the Height of Trees with a Clinometer/Laser Rangefinder: Sine works better than Tangent

When I first got interested in measuring the heights of trees, after reading a wonderful book called The Wild Trees: A Story of Passion and Daring by Richard Preston, I thought that finding the tangent was the best way to calculate the height of a tree. After all, I didn’t have a way to measure the hypotenuse — the distance from me to the top of the crown. However, a laser rangefinder let’s you calculate that distance, which in turn makes it much easier to get an accurate reading for the height of a tree. Thanks to the Eastern Native Tree Society (ENTS) for posting a helpful article about this.

Here’s a link to the article.

And a file download:

    Tree_Measuring_Guidelines-revised1Download

    Ropes: Giant Knitting

    Crochet and Knit for Math and Coral Reef Conservation

    A few years ago, I learned how to crochet and knit, inspired by a lecture by mathematician Dana Taimina, and taught by friends. Through Taimina’s lecture, I learned about The Coral Reef Project. You can watch Margaret Wertheim’s TED talk here. As I love to climb, it seemed only natural to experiment with knitting and crocheting using climbing ropes.

    How to Make Giant Knitting Needles

    How to make giant knitting needles using tape, candle holders, and garden stakes (purchased in Boulder, CO at Greenwood Wildlife Thriftshop and McGuckin Hardware, where people were super friendly and helpful):

    makinggiantknittingneedles

    Thanks to Green Guru for donating used climbing ropes.