The acoustic signatures of many animals contain features we humans cannot appreciate, given the limited range of frequencies we can hear. In fluid dynamics and many other fields, scientists and engineers have to find ways to analyze and decompose time-series data—like acoustic pressure signals—into useful quantities. Mark Fischer uses one tool for such analysis, a wavelet transform, to turn the calls of whales, birds, and insects into the colorful snapshots seen here. Wavelet transforms are somewhat similar to Fourier transforms but represent a signal with a series of wavelets rather than sinusoids. They’re also widely used for data compression. (Image credits: M. Fischer/Aguasonic Acoustics; via DailyMail)
When I was a kid, I liked to dive underwater in the pool and sit at the bottom, looking up at the peculiar dancing sky the water made overhead. Photographer Mark Tipple takes it further, capturing images of the ocean from below the surface as waves roll in. His photos show swimmers and surfers diving to escape a roiling wave that, from below, bears a surreal similarity to the underside of a thundercloud in a summer storm. This is part of the beauty of fluid dynamics. Despite their differences, water and air obey the same physics. (Photo credits: Mark Tipple; via io9)
A mix of mouse stem cells that have been encouraged to develop into specialized cells. Each color is a specific cell type that developed from the previously uniform collection of cells. (via)
As the Arctic warms, methane that was previously trapped by permafrost rises from the muddy bottom of lakes to escape into the atmosphere. Here the first clear ice of the fall has trapped the rising methane bubbles, allowing scientists an opportunity to estimate the amount of methane being released. When spring arrives and the lakes melt, the methane will rise again. (Photo credit: M. Thiessen/National Geographic)
Though the temperature usually stays below freezing, the weather seems to be warming up. Yesterday, I was able to go for an eight mile bike ride through the streets and woods. There was a constant drizzle of light rain. The tires splashed through melting ice stained brown from the salts applied to the roads. And the woods gave off an inviting smell. I’m looking forward to warmer days, ones I can spend outside. I still walk barefoot, but it isn’t the same in snow. I do so love nature, but it’s more enjoyable when your face isn’t numb.
I just learned that many scientists agree with at least one aspect of my theory of reality. Spacetime is indeed granular. I need to move relatively fast. Also, I’m sitting in a bathtub at the moment. Thought everyone should know that.