Back when BP was still trying the "top kill" method of slowing the flow of oil into the Gulf of Mexico, the news was full of references to "drilling mud."
This stuff is no ordinary mud. It helps a rig drill faster and keeps the equipment cool and lubricated, but it's got some wacky other properties. It's a non-Newtonian fluid. That means its viscosity changes as you apply stress. If you punch or hit a shear thickening non-Newtonian fluid, the atoms in the fluid rearrange themselves in such a way that the liquid acts like a solid. A shear thinning non-Newtonian fluid (like ketchup or toothpaste) behaves the opposite way, getting thinner and drippier under stress.
Still don't quite get it? Check this video:
When they're running--applying a stress whenever their feet strike the surface--the fluid acts like a solid and they can walk on top of it. But when he stands still....
The Mythbusters have played with this phenomenon, too:
So. Drilling mud behaves kind of the same way. Here's Bill Nye explaining it all on CNN. When the drilling mud passes through a narrow opening, under pressure, it locks up and acts more like a solid. The idea was that if BP could pump a water-based drilling mud into the ruined well head and get it to solidify, then they could slow the flow of oil enough that engineers could encase the whole thing in cement. It didn't work. That's because the oil and gas spewing out of the pipe are under tremendous pressure. BP engineers just couldn't pump enough mud in there to stop the oil.
But oobleck isn't. What's oobleck? It's a non-Newtonian fluid you can make and play with at home.
Instructables tells you how.
August Ferdinand Mobius, German astronomer, mathematician, and author, was born on November 17, 1790. He's best known for the discovery in 1858 of the Mobius strip, a two-dimensional surface with only one side. Celebrate his birthday by making a Mobius strip of your own. Here's how.
Storm chasers know that puffy cumulus clouds often cause sudden rainstorms, while storms associated with stratus clouds form more slowly. Now physicists at England’s Open University have finally found an explanation.
They propose that neighboring water droplets in a stable stratus cloud don’t crash into each other because they’re all moving at about the same speed. But fast-forming, turbulent cumulous clouds contain water droplets moving at many different speeds. They crash into each other and form larger drops. As the turbulence grows, the drops grow quickly and fall as rain within a few minutes.
Sun and rain
Ever noticed the bright, moving lines on the bottom of a stream, bathtub, or swimming pool? They’re called caustics, and they’re caused when ripples on the water’s surface focus sunlight. (Caustics form whenever light rays are bent by a curved surface or object and then projected onto another surface.
Caustics have a characteristic shape. Physicists can graph the phenomenon mathematically, and the graph also describes other phenomena, such as particle motion or the movement of raindrops within a cumulus cloud.
Atmosphere to outer space
The researchers say their finding won’t have any impact on weather forecasting. But particle collisions in turbulent gases must have been involved in planet formation. Perhaps the same theory can be applied?
If you're at the museum on Saturday afternoon (11/18), the MakeIt team can help you play with caustics. Does bending mylar in a different direction produce a new pattern? Does using a different color flashlight or a brighter or dimmer light affect the design?
You can also play with caustics at home.
On Wednesday the Make It Team from the museum's Youth Science Center talked about research using animals.
The teens watched four short videos:
After watching the videos, teens used the Democs Game to talk about the pros and cons of animal testing. Democs is a role playing activity where teens are assigned different view points and then asked to debate issues from those view points.
Ever notice that uncooked spaghetti doesn't break neatly in two when you bend it? Instead, it shatters into several pieces of different lengths. Why?
Researchers recently solved the spaghetti mystery and improved scientists' understanding of how things shatter. Because strands of spaghetti are similar in some ways to lots of brittle objects—from industrial cutting tools to body armor—knowing why spaghetti breaks the way it does may help make those things stronger and safer.
The researchers clamped one end of a piece of spaghetti in place, and then bent the rod until it was just about to break. Then they let the unclamped end go, and filmed the results with a digital camera that took 1,000 images per second. The pictures showed that the spaghetti rod didn't spring back to its original position like a diving board would. Instead, the release caused ripples that ran down the rod's length and bounced back from the clamped end. The spaghetti snaps where the curvature is greatest—where the ripples from the free end meet the ripples bouncing back from the clamped end. And it happens again in the remaining piece of spaghetti each time the rod breaks. (See some movies of the breaking spaghetti.)
Just getting started
Now scientists know why spaghetti breaks into more than two pieces, but the new research opens up many more questions about how objects shatter.
MAKE IT at the Museum
The recent spaghetti discovery was made possible by an extremely high-speed camera that captured photos of how the pasta bent and broke. On Saturday, December 10, between 1:30 and 3:30, you can make a zoetrope and watch some spaghetti "filmstrips" for yourself. It's free, it's fun, it only takes a few minutes, and you can take your creation home with you when you're done.
Psychologists at Emory University in Atlanta have been studying how capuchin monkeys see themselves by showing them their own reflections.
The scientists assumed that the monkeys would behave as they would when meeting a stranger. Instead, females react with curiosity and friendly gestures, while males act distressed and fearful. Psychologist Frans B.M. de Waal thinks the monkeys realize that the reflections are special, even if they're not quite sure who they're looking at.
When you look in the mirror, you know the person you're seeing is you. You're "self aware." (Scientists consider an animal self-aware if it touches a painted spot on its own face when it looks in a mirror.) People, apes, and dolphins recognize themselves. Most monkeys, though, don't get it.
In a series of experiments, the Emory scientists put capuchin monkeys into test chambers where they had one of three experiences: they saw a monkey of the same sex that they'd never met before, they saw a familiar monkey of the same sex, or they saw their own reflections. Reactions to the other monkeys were predictable, but the reactions to the mirrors were new. And the Emory scientists think they prove that the capuchins have reached some intermediate level of self-awareness, somewhere between seeing their reflections as other monkeys and recognizing themselves.
Researchers at Washington University in St. Louis have discovered that mice sing.
Scientists already knew that mice make ultrasonic sounds-squeaks that are too high-pitched for us to hear without special equipment. But these scientists used microphones and computer software to study the squeaks of 45 male mice.
The researchers separated the squeaks into types of syllables based on how quickly the pitch rose or fell. The mice "sang" about 10 syllables per second. And almost all of the mice repeated sequences of syllables in clear patterns. None of the mice are Marvin Gaye, exactly, but their noises meet the scientific definition of song. (People, birds, whales, and some insects do the same thing.)
Researchers still have to figure out WHY the mice sing. Because the mice sang in response to pheremones-chemicals that transmit messages between animals of the same species-one guess is that male mice sing to impress females.