August 15, 2007: Astronaut Clay Anderson snapped one of the all-time great selfies, capturing himself as well as Earth and the International Space Station, reflected in his helmet visor. (NASA)
A sand pendulum that creates a beautiful pattern only by its movement.
But why does the ellipse change shape?
The pattern gets smaller because energy is not conserved (and in fact decreases) in the system. The mass in the pendulum gets smaller and the center of mass lowers as a function of time. Easy as that, an amazing pattern arises through the laws of physics.
You could be forgiven for thinking that the otherworldly rock formations in these pictures come from another planet, or from a sci-fi movie perhaps. But they’re actually called sand tufas and they come from right here on earth.
A tufa is a peculiar form of calcium carbonate, and they’re created when calcium-bearing freshwater springs well up through alkaline lake water (which is rich in carbonates). The carbonate and calcium combine and, over centuries, these elements form unusual spires, towering columns, and strange cauliflower-shaped mounds which can reach heights of up to nine metres (30ft). Tufas can only form underwater, and they’re only exposed when lakes are drained or dry out over many years. Check out this collection of pictures compiled by Bored Panda to see these curious formations for yourself.
Via + image credits
If you’re suffering from post-con depression (like we are), there’s hope! Here’s a list of other awesome cons in the Seattle area that might be of interest to you:
Norwescon (April 2-5, 2015) norwescon
Sakura-Con (April 3-5, 2015) sakuracon
Shatterdome Seattle (May 3, 2015) shatterdomeseattle
PAX Prime (Late August)
BrickCon (October 3-4, 2015)
GeekGirlCon (October 10-11, 2015) geekgirlcon
Short Run Comix & Art Festival (October 31, 2015)
Jet City Comic Show (Oct 31 - Nov 1, 2015) shortrunseattle
Sherlock Seattle (was Jan 9-11, 2015) sherlock-seattle
Let us know if we’ve missed any and we’ll add them to the list!
you wanna see some badass shit from the early 20th century?? The Lumière brothers created the first full color photograph… in fucking 1903! So these dudes dyed potatoes (in red, blue, and green), mashed them down into just pure fuckin’ starch, and used these dyed potato starches as filters to block out/let in certain wavelengths of light. They coated one side of a glass plate with the starches and sensitized the other side with a mixture of gelatin and light sensitive materials (silver nitrate) and loaded these plates in their cameras.. This is a really simple explanation of the process and I may have missed some things A few of my favorite autochrome photos:
Tyler Hoechlin @ emeraldcitycomicon 2015, Seattle