When a seed is planted in the ground, the roots tend to grow downward in search of water and nutrients. But what happens when there is no “down” for the roots to grow? Scientists sent seeds to the International Space Station and were surprised to see what plants did without gravity to guide their roots downward.
To keep droplets of liquid floating in midair, the device in the video above relies on a hum of sound just above the range of human hearing. This technology, called an acoustic levitator, suspends these tiny balls of liquid using two speakers that project sound waves in opposite directions, counteracting the force of gravity. Originally, NASA developed the device to simulate microgravity. Now researchers at Argonne National Lab are using it as a way to evaporate drug compounds in midair so they take on a more potent chemical form than they would in a container.
What’s the News: Some bacteria can live in extreme “hypergravity,” found a new study published in the Proceedings of the National Academy of Sciences, surviving and reproducing in forces 400,000 times greater than what’s felt on Earth. These findings fit with the idea that microbes carried on meteorites or other debris—a ride that would have subjected them to hypergravity-strength forces—may be the ancestors of life on Earth.
Cats have been our companions for almost 10,000 years. They have been worshipped by Egyptians, killed (or not) by physicists, and captioned by geeks. And in all that time, no one has quite appreciated how impressively they drink. Using high-speed videos, Pedro Reis and Roman Stocker from the Massachusetts Institute of Technology has shown that lapping cats are masters of physics. Every flick of their tongues finely balances a pair of forces, at high speed, to draw a column of water into their thirsty jaws.
Read the rest of the post at Not Exactly Rocket Science, where Yong explains that each sip is a tug-of-war between inertia and gravity. Here’s a little of that high-speed video:
80beats: Your Cat Controls You With an Un-Ignorable Purr
Discoblog: Calvin Klein’s Obsession for Men (and Cats)
Discoblog: High-Tech Cat@Log System Announces When Your Cat Is Scratching Himself
DISCOVER: Egyptians Not the First to Tame House Cats
The two newest planets spied by the Kepler space telescope are locked in a forever back-and-forth.
When Kepler’s scientists saw a star 2,000 light years away dim slightly, they knew there was the chance it was the telltale signature of a planet passing in front. But when the calculations were done and the confirmation came in, they found a surprise—what they’d seen was actually two planets transiting in front of the star.
NASA says it’s the first time they’ve ever caught such a sight, and today the scientists officially announced the finding with a study in Science. While other studies have found multiple planets around a single star–in fact, it happened earlier this week–those studies have used different planet-detection techniques like the wobble method.
The two worlds, both gas giants, do more than orbit the same star on the same plane, though. They push and pull each other in a motion that keeps the two exoplanets close to arithmetic celestial perfection. Kepler-9B, the larger, orbits the star in 19.24 days on average, the astronomers saw. Kepler-9c, the smaller, completes a revolution in an average of 38.91 days. But every time the scientists checked, 9b’s orbit was getting 4 minutes longer, while 9c’s shrank by 39 minutes.
Breaking free of the the Earth’s gravity and floating in zero-G: It’s certainly a thrill for those who get to experience it, either through traveling to space or simulating the journey. All good things, though, must come in moderation. Too much time free from the grip of gravity and we turn into weak-muscled wimps, which is a huge hurdle for hopes to travel to Mars or deep into space.
Robert Fitts wanted to know just how quickly the lack of resistance on one’s muscles makes them out-of-shape and atrophied. So his team tested nine astronauts before and then just after their six-months stays aboard the International Space Station. The study appears this week in the Journal of Physiology.
Attention lovers of old-timey science: the good stuff keeps on coming. Last month, when Britain’s Royal Society released digital versions of some of its greatest scientific papers to celebrate its 350th anniversary, we brought you delightfully odd and gruesome samples from the library. Now the society has uploaded another batch of classic manuscripts, including a book containing an early account of Isaac Newton’s apple story, one of science’s most famous anecdotes.
A biography written by William Stukeley, one of Newton’s contemporaries, relates the apple story as Newton himself told it to Stukeley. The text of Stukeley’s Memoirs of Sir Isaac Newton’s Life has long been available online, but the Royal Society opened up digital access to the handwritten manuscript itself Sunday [Scientific American]. In his 1752 book on Newton, Stukeley writes:
A sophisticated satellite has been carefully placed into orbit just beyond the Earth’s atmosphere, and this week engineers switched on the super-sensitive instrument that will make ultra-fine measurements of Earth’s gravity. The sophisticated gradiometer will feel the subtle variations in Earth’s tug as it sweeps around the globe [BBC News].
The GOCE satellite, built by the European Space Agency (ESA), was launched on March 17, and mission controllers are now busy testing instruments and its cutting-edge propulsion system. In August or September, they will begin the scientific mission. Because the Earth’s mass is not distributed evenly around the planet (think of the mountains and the oceanic rifts), its gravity is not uniform. Mapping these variations has many applications but perhaps the biggest knowledge gains will come in the study of ocean behaviour. Understanding better how gravity pulls water – and therefore heat – around the globe will improve computer models that try to forecast climate change [BBC News].