Flexible Muscle-Based Locomotion for Bipedal Creatures

currentsinbiology:

Sounds you can’t hear can still hurt your ears
A wind turbine, a roaring crowd at a football game, a jet engine running full throttle: Each of these things produces sound waves that are well below the frequencies humans can hear. But just because you can’t hear the low-frequency components of these sounds doesn’t mean they have no effect on your ears. Listening to just 90 seconds of low-frequency sound can change the way your inner ear works for minutes after the noise ends, a new study shows.

“Low-frequency sound exposure has long been thought to be innocuous, and this study suggests that it’s not,” says audiology researcher Jeffery Lichtenhan of the Washington University School of Medicine in in St. Louis, who was not involved in the new work.

 The functioning of the inner ear is at least temporarily altered by exposure to low-frequency sounds.  Alex Luengo/iStockphoto/Thinkstock

currentsinbiology:

Sounds you can’t hear can still hurt your ears

A wind turbine, a roaring crowd at a football game, a jet engine running full throttle: Each of these things produces sound waves that are well below the frequencies humans can hear. But just because you can’t hear the low-frequency components of these sounds doesn’t mean they have no effect on your ears. Listening to just 90 seconds of low-frequency sound can change the way your inner ear works for minutes after the noise ends, a new study shows.

“Low-frequency sound exposure has long been thought to be innocuous, and this study suggests that it’s not,” says audiology researcher Jeffery Lichtenhan of the Washington University School of Medicine in in St. Louis, who was not involved in the new work.

 The functioning of the inner ear is at least temporarily altered by exposure to low-frequency sounds.  Alex Luengo/iStockphoto/Thinkstock

(via scientificillustration)


fuckyeahfluiddynamics:

In February 2013 a meteor streaked across the Russian sky and burst in midair near Chelyabinsk. A recent Physics Today article summarizes what scientists have pieced together about the meteor, from its origins to its demise. The whole article is well worth reading. Here’s a peek:

The Chelyabinsk asteroid first felt the presence of Earth’s atmosphere when it was thousands of kilometers above the Pacific Ocean. For the next dozen minutes, the 10 000-ton rock fell swiftly, silently, and unseen, passing at a shallow angle through the rarefied exosphere where the molecular mean free path is much greater than the 20-m diameter of the rock. Collisions with molecules did nothing to slow the gravitational acceleration as it descended over China and Kazakhstan. When it crossed over the border into Russia at 3:20:20 UT and was 100 km above the ground, 99.99997% of the atmosphere was still beneath it.

Because the asteroid was moving much faster than air molecules could get out of its way, the molecules began to pile up into a compressed layer of high-temperature plasma pushing a shock wave forward. Atmospheric density increases exponentially with depth, so as the asteroid plunged, the plasma layer thickened and its optical opacity rapidly increased. About one second later, at 95 km above the surface, it became bright enough to be seen from the ground. That was the first warning that something big was about to happen. #

How often are scientific articles that gripping?! Kring and Boslough provide some excellent descriptions of the aerodynamics of the meteor and its airburst. Be sure to check it out. (Photo credit: M. Ahmetvaleev; paper credit: D. Kring and M. Boslough; via io9)

fuckyeahfluiddynamics:

In February 2013 a meteor streaked across the Russian sky and burst in midair near Chelyabinsk. A recent Physics Today article summarizes what scientists have pieced together about the meteor, from its origins to its demise. The whole article is well worth reading. Here’s a peek:

The Chelyabinsk asteroid first felt the presence of Earth’s atmosphere when it was thousands of kilometers above the Pacific Ocean. For the next dozen minutes, the 10 000-ton rock fell swiftly, silently, and unseen, passing at a shallow angle through the rarefied exosphere where the molecular mean free path is much greater than the 20-m diameter of the rock. Collisions with molecules did nothing to slow the gravitational acceleration as it descended over China and Kazakhstan. When it crossed over the border into Russia at 3:20:20 UT and was 100 km above the ground, 99.99997% of the atmosphere was still beneath it.

Because the asteroid was moving much faster than air molecules could get out of its way, the molecules began to pile up into a compressed layer of high-temperature plasma pushing a shock wave forward. Atmospheric density increases exponentially with depth, so as the asteroid plunged, the plasma layer thickened and its optical opacity rapidly increased. About one second later, at 95 km above the surface, it became bright enough to be seen from the ground. That was the first warning that something big was about to happen. #

How often are scientific articles that gripping?! Kring and Boslough provide some excellent descriptions of the aerodynamics of the meteor and its airburst. Be sure to check it out. (Photo credit: M. Ahmetvaleev; paper credit: D. Kring and M. Boslough; via io9)


when we recognize the battle against chaos, mess, and unmastered complexity as one of computing science’s major callings, we must admit that “Beauty is our Business”
fuckyeahfluiddynamics:

The human eye has a thin tear film over its surface to maintain moisture and provide a smooth optical surface. The film consists of multiple layers: a lipid layer at the air interface to decrease surface tension and delay evaporation; an aqueous middle layer; and an inner layer of hydrophilic mucins that keep the film attached to the eye. The entire film is a few microns thick, with the lipid layer estimated to be only 50-100 nm thick and the mucin layer just a few tenths of a micron. The aqueous portion of the tear film is supplied from the lacrimal gland in the corner of the eye. In the animation above, the fresh aqueous fluid is fluorescent. It gathers in the corner of the eye several seconds after a blink due to reflex tearing. The tear fluid then flows around the outer edges of the eye until the subject blinks and the fresh tear gets distributed throughout the film. (Research credit: L. Li et al.; original video)

fuckyeahfluiddynamics:

The human eye has a thin tear film over its surface to maintain moisture and provide a smooth optical surface. The film consists of multiple layers: a lipid layer at the air interface to decrease surface tension and delay evaporation; an aqueous middle layer; and an inner layer of hydrophilic mucins that keep the film attached to the eye. The entire film is a few microns thick, with the lipid layer estimated to be only 50-100 nm thick and the mucin layer just a few tenths of a micron. The aqueous portion of the tear film is supplied from the lacrimal gland in the corner of the eye. In the animation above, the fresh aqueous fluid is fluorescent. It gathers in the corner of the eye several seconds after a blink due to reflex tearing. The tear fluid then flows around the outer edges of the eye until the subject blinks and the fresh tear gets distributed throughout the film. (Research credit: L. Li et al.; original video)