The author takes her umpteenth picture of rocks. (Alice Li/The Washington Post) . . . She'll come back with a lot of pictures of cool rocks. I just returned from a backpacking trip in the Canadian Rockies, and, man-oh-man, was it beautiful: soaring mountain summits, lakes the color of Powerade, sweeping meadows studded with wildflowers in every color you can imagine. As you can see from the above photo, I had just as much fun studying the science of this landscape as I did hiking. Here are a few of the best facts I learned: | Peyto Lake in Banff National Park. (Sarah Kaplan/The Washington Post) The region's stunning pale blue and turquoise waters — which look more like a Sherwin-Williams paint swatch than an actual color found in nature — become that way, thanks to a phenomenon called "rock flour." The glaciers draped across many mountaintops work like giant sheets of sandpaper, grinding away at the rock as they flow ever so slowly downhill. When the glaciers melt in the spring and the summer, the resulting dust — or "rock flour" — is swept into rivers and lakes. The ultrafine particles are able to stay suspended in the water, rather than sinking to the bottom, and, when sunlight hits, the bits absorb the longest wavelengths (red, orange and yellow). What our eyes see are the blues and greens that get reflected back. | The seed stage of Anenome occidentalis. (Sarah Kaplan/The Washington Post) | This is the seed stage of Anemone occidentalis, also known as a pasqueflower or Western anenome. When they bloom, these flowers have lovely white blossoms, but around midsummer, they drop their petals and develop a silky, plumed seed head. I think the flowers look like Truffula trees from Dr. Seuss's "The Lorax," but they're also nicknamed "mouse-on-a-stick," "old man of the mountain," "moptop" and "towheaded baby." The plant's genus name comes from the Greek word "anemone," which means "daughter of the wind." Each feathery plume bears a tiny fruit containing the plant's seed. When a strong gust sweeps down from the mountaintops, it will loft the seed and carry it across the landscape, helping the plant disperse. | Watermelon snow in Kootenay National Park. (Sarah Kaplan/The Washington Post) In places where snow cover persists all year — like the high peaks of the Rockies — you can sometimes find pinkish "watermelon snow." This phenomenon has puzzled scientists going back to Aristotle. In the early 19th century, a British Arctic explorer returned home with samples from blood-red streams he spotted flowing down snowy slopes; a newspaper article from the time speculated that the color came from iron meteor deposits. It took a botanist to figure out the truth: The color is caused by a cold-loving algae called Chlamydomonas nivalis, which in addition to chlorophyll uses a reddish pigment for photosynthesis. — Sarah | | | | | |