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Huzzah! Another scientific mystery bites the dust! Scientists have finally cracked a problem that has "perplexed humanity since Leonardo da Vinci pondered it 500 years ago."
Learn all about the Rapunzel Number, which provides a key ratio needed to calculate the effect of gravity on hair relative to its length. In the right hands, this dangerous number can predict the shape of any ponytail:
Cambridge Professor Raymond Goldstein told Reuters that he and his colleagues took account of the stiffness of individual hairs, the effects of gravity and the average waviness of human hair to come up with their formula. [...]
"That determines whether the ponytail looks like a fan or whether it arcs over and becomes nearly vertical at the bottom," Goldstein said in a telephone interview.
The research also took into account how a bundle of hair is swelled by the outward pressure that arises from collisions between the component hairs.
Oh, he also mentioned how the Rapunzel Number would also help scientists deepend their understanding of fibers, as well as be useful in computer graphics and animation, but we all know that the real reason for the study is to break the stronghold of the hair stylist mafia on ponytail-wearing populace.
Artist Scott Garner gives us a depiction of a bowl of fruit on a table, named “Still Life.” But this interactive artwork is anything but still! Link -via The Daily What Geek
While some scientists are working on an invisibility cloak to hide things, Cornell postdoctoral researcher Moti Fridman and his colleagues have been working on a “temporal cloak,” to hide events in time.
A physical object or even another beam of light in the laser beam’s path could create a change in the laser light that the detector would register. But with some clever optics, Fridman and his colleagues were able to open up a brief time gap in the beam and then close it back up as if the beam had gone undisturbed, and such that the detector did not register the interruption. The gap allows anything that would have otherwise affected the beam to instead slip right through [see animation below], leaving no trace for the detector to pick up.
The events that can slip through the cloak have to be very fast: the gap is only 50 trillionths of a second. The video at the link explains the process much more clearly. Link -via Monkeyfilter
Here’s a simple physics game in which you release a little red block by rotating the fence holding it. Or multiple fences. And please avoid the force field! Oh yes, it starts out easy, but gets more challenging. The level you see here gave me fits, but I breezed through the next couple easily -go figure. Link
Sascha Mehlhase built a model of the ATLAS experiment at the CERN Large Hadron Collider out of LEGO bricks! It contains around 9,500 bricks and took 33 hours to assemble, in addition to 48 total hours of work just designing it. Read more about and see more pictures at his site. Link -via reddit
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No, not from a pint of Guinness - though the perfect foam does hail from Trinity College in Dublin, Ireland:
‘Perfect’ here means the lowest-energy configuration of packed bubbles of equal size. This is a compromise between the surface area of the bubbles and the stability of the many interlocking faces of the polyhedral bubbles in the foam.
Read all about it over at Nature's newsblog: Link
Comments Off The International Space Station (ISS) occasionally has to boost itself into a higher altitude to counteract the effects of microgravity drag. Recently, the ISS boosted itself about two miles up, and video cameras caught what happened inside to Commander Mike Fossum and Flight Engineers Satoshi Furukawa and Sergei Volkov. The physics of the process are explained at Bad Astronomy Blog. Link -Thanks, Phil!
One-Minute Physics explains how to break the speed of light by pointing a laser at the moon. I think this boils down to appearance vs. reality, but I may be mistaken. Anyway, it sounds fun to try! -via The Daily What Geek
When you heard the name Clifford A. Pickover, you might think of the website Clifford Pickover’s Reality Carnival. Or you might think of the book The Math Book: Milestones in the History of Math, which we featured here a couple of years ago. Pickover has done it again, with a new book called The Physics Book: From the Big Bang to Quantum Resurrection, 250 Milestones in the History of Physics.
The Physics Book is a large, substantial book, but don’t let that fool you! It’s a treat to read, whether you have a background in physics or not. I don’t, so I was delighted to see how interesting and accessible The Physic Book is. The 500 pages are broken down into 250 subjects, with a one-page explanation plus a gorgeous, full-page illustration for each. This means that each of those 250 physics topics can be consumed in bite-size pieces at your leisure. They are laid out in somewhat chronological order -”somewhat” meaning that the order is either when something happened, when it was discovered, or when it was particularly meaningful. So you can start at the beginning if you like and get a good overview of the timeline of physics or you can browse topics that interest you anywhere in the book. Of course, there’s an alphabetical index so you can easily find any of them.
The topics range from simple everyday subjects to higher concepts you’ve heard of, but don’t (yet) understand. In the simpler subjects, Pickover gives us a short explanation of scientific milestones and basic concepts that make the mundane into something fascinating. For example, for the hourglass, a mundane yet ingenious device, you get both history and science in one page.
Interestingly, the sailing ships of Ferdinand Magellan retained 18 hourglasses per ship as he attempted to circumnavigate the globe. One of the largest hourglasses -39 feet (11.9 meters) in height- was built in 2008 in Moscow. Through history, hourglasses were used in factories and to control the duration of sermons in church.
In 1996, British researchers at the University of Leicester determined that the rate of flow depended only on the few centimeters above the neck and not on the bulk of sand above that. They also found that small glass beads known as ballotini gave the most reproducible results. “For a given volume of ballotini,” the researchers write, “the period is controlled by their size, the size of the orifice, and the shape of the reservoir.”
Read the rest on page 68. My younger children didn’t realize that gears had anything to do with physics until they saw page 57.
Rotating gears, with their intermeshed teeth, have played a crucial role in the history of technology. Not only are gear mechanisms important for increasing the applied twisting force, or torque, but gears are also useful for changing the speed and direction of force. One of the oldest machines is a potter’s wheel, and primitive gears associated with these kinds of wheels probably existed for thousands of years. In the fourth century B.C., Aristotle wrote about wheels using friction between smooth surfaces to convey motions. Built around 125 B.C., the Antikythera Mechanism employed toothed gears for calculating astronomical positions. One of the earliest written references to toothed gears was made by Hero of Alexandria, c 50 A.D. Through time, gears have played a crucial role in mills, clocks, bicycles, cars, washing machines, and drills. Because they are so useful in amplifying forces, early engineers used them for lifting heavy construction loads. The speed-changing properties of gear assemblies were put to use when ancient textile machines were powered by the movement of horses or water. The rotational speed of these power supplies was often insufficient, so a set of wooden gears was used to increase the speed for textile production.
And then Pickover goes on to explain exactly how gears do these things. Other basic concepts covered include the invention of the telescope, the discovery of planets (which is, of course, related), and how things like boomerangs and pulleys and atomic bombs work. But it’s not only simple physics concepts. Interested readers can select puzzlers like the Schrödinger’s Cat thought experiment, proposed by Austrian physicist Erwin Schrödinger in 1935 and explained on page 376.
more …
Question: How do you summarize 10 pages and 1 figure of high energy physics?
Answer: Very well, thank you.
Here's the best abstract of a science paper I've ever read (and, having studied biochemistry in college and grad school, boy have I read a lot of science papers): Link - via reddit
When you drop a slinky, which part of it moves faster? When you get a good look at it in slow-motion, it only raises more questions, which physics professor Rod Cross explains. See the rest of the experiment at The Daily What Geek. Link -via mental_floss
Scientists at the U.S. Department of Energy’s Brookhaven National Laboratory announced today that they have observed a rare property in a special class of metals called multiferroics: they have both magnetic and electric properties, which normally don’t happen in the same material. Ferromagnets are, of course, magnetic metals, and ferroelectrics are materials that have a permanent electric polarization.
Now, scientists have found a new way that electric and magnetic properties can be coupled in a material. The group used extremely bright beams of x-rays at Brookhaven’s National Synchrotron Light Source (NSLS) to examine the electronic structure of a particular metal oxide made of yttrium, manganese, and oxygen. They determined that the magnetic-electric coupling is caused by the outer cloud of electrons surrounding the atom.
“Previously, this mechanism had only been predicted theoretically and its existence was hotly debated,” [Brookhaven physicist Stuart] Wilkins said.
In this particular material, the manganese and oxygen electrons mix atomic orbitals in a process that creates atomic bonds and keeps the material together. The researchers’ measurements show that this process is dependent upon the magnetic structure of the material, which in this case, causes the material to become ferroelectric, i.e. have an electric polarization. In other words, any change in the material’s magnetic structure will result in a change in direction of its ferroelectric state. By definition, that makes the material a multiferroic.
You’ll find more technical information at the Brookhaven National Laboratory site.
When I was in high school we actually built giant sling shots in our physics class. These days though, kids are learning from sling shots in video games. Really though it was only a matter of time before Angry Birds entered the public school system.
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Do you ever drive on roads that feel like you’re driving on a washboard?
When I visit northern Minnesota, I always encounter a road that in midsummer becomes classically “washboard.” The county sends out a road grader to smooth it and give it a new crown, and a few weeks later it’s a washboard again.
Minnesotastan looked up the physics of why this happens. The explanation includes a video that led to the discussion of the word “widdershins” in the comments. Link
(Image credit: David C. Mays)
Although some television shows demonstrate an obvious departure from scientific realism (e.g. Stargate SG-1, Battlestar Galactica), you may be surprised that the highly-rated cartoon My Little Pony: Friendship is Magic is not an accurate presentation of physics — at least as it is currently understood. For a class project, YouTube user beatledude64 explained, in great physical and mathematical detail, how My Little Pony bends good science for the sake of storytelling.
via Boing Boing
“Fano flow” is a term used for some of the strange ways non-Newtonian fluids move. From the YouTube page:
In the so-called ”tubeless” syphon, a fluid can be made to flow up through an unsupported liquid column above the free surface of the liquid. One way to achieve this is by slowly withdrawing and raising a syringe from a pool of the liquid below.
In the so-called ”open channel” syphon, after initially commencing the
flow of an elastic fluid from say a beaker, the fluid will continue to
flow up the side and over the lip of the beaker for sometime despite the level of its free surface having fallen considerably below the top of the beaker. In this way the slightest spill will cause the beaker to partly empty in what is commonly refereed to as a ”self-syphoning” effect.
-via TYWKIWDBI
We know that a piece of toast, if dropped, will fall butter-side down. We also know that a cat, if dropped, will land on its feet. What happens when you strap a piece of buttered toast to a cat’s back and drop them both is called the Buttered Cat Paradox, and there’s an extensive amount of research on the internet devoted to just this conundrum. Find out more about it at mental_floss, including possible uses for the energy produced from such a venture, and ways it could go wrong. Link
Why is a curveball so hard to hit? Some say it presents an optical illusion to the batter. Others say it really does curve. Lyman Briggs of the National Bureau of Standards aimed to settle the matter.
This was a period when the question of whether the curve ball actually curved was hotly debated. Among the true believers was St. Louis Cardinals pitcher Dizzy Dean. “Ball can’t curve?” he famously declared during the 1930s. “Shucks, get behind a tree and I’ll hit you with an optical illusion.” But anecdotes aren’t a substitute for scientific data. So once Briggs officially retired, he decided to do the experiments to settle the matter. And he was well-connected enough to enlist the aid of the pitching staff of the Washington Senators and their manager, Cookie Lavagetto, to do so. It wasn’t just a question of baseball, either: the question related to NIST’s ongoing research into ballistics and projectiles: the rate of spin is related to how much the ball (or projectile) is deflected at different speeds. Apparently the NSB (now NIST) conducted lots of experiments with golf balls and baseballs; one of Briggs’ publications was a 1945 paper entitled, “Methods for Measuring the Coefficient of Restitution and the Spin of the Ball.”
Read how Briggs designed experiments to find out exactly how much of a curve there is to a curveball at Cocktail Physics. Link
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Biology, Chemistry and Physics T-Shirt from the NeatoShop
Which branch of science is the deadliest? Alex "Sandy" Antunes of Science 2.0 compared the three most murderous fields of science: physics, chemistry, and biology.
Pulling out real world statistics, we look to the Center for Disease Control (CDh). In 2007 (their most recent complete survey), we find that the bulk of the 2,423,712 US deaths were due to three causes: heart disease, cancer, and stroke.
Damn, looks like Biology takes an early lead. Those 3 causes alone cover over half of all deaths (54.2%) In fact, of the 15 leading causes, 9 of them are simple biology, causing 68.2% of all deaths. Disease and infection rule the land of the dead.
Einstein’s famous Twin Paradox in which a twin makes a journey into space in a high-speed rocket and returns home to find he has aged less than his identical twin who stayed on Earth is a mind boggling concept at first glance. This clever animation produced by Yuanjian Luo interprets the theory in a way that makes it easier to understand, even for those of us who have never heard of time dilation or nonequivalent reference frames.
In the famous 1971 footage from Apollo 15, astronaut David R. Scott dropped a hammer and a feather at the same time on the surface of the Moon, thus confirming Galileo’s hypothesis that gravity accelerates all objects at the same rate, regardless of mass or composition:
Undoubtedly that has been hammered into your brain since grade school. So, how do you explain this neat little video from the clever folks over at MIT:
Two wood boards are connected by a hinge. A small cup is mounted near one end of the upper board with a tee for a ball on the end. The board is lifted to a certain height, and when released the ball ends up in the plastic cup. This shows that the board has moved farther than the ball in the same period of time.
To see the video, visit the MIT News Multimedia website: Link – via Science2.0
So, the hinged plank has to travel in an arc, which is longer than the straight path that the ball falls through in order for the ball to fall into the cup. Notice that the plank hits the tabletop before the ball. Assuming air resistance doesn’t come into much play (after all, the plank has more surface area than the ball) Does this mean that gravity affects the plank more than the ball? Is Galileo wrong?
The tiny sliver of metal above, measuring as long as the human hair is wide, may be barely visible to the naked eye, but its implication to science is so staggering that it is hailed as the greatest scientific breakthrough of 2010.
Behold, the world’s first quantum machine:
It’s not much to look at. In fact, you can barely see it with the naked eye, and it doesn’t work unless it’s cooled down to just a fraction of a degree above absolute zero. But when researchers at the University of California at Santa Barbara created their tiny vibrating "springboard," that represented "the first time that scientists have demonstrated quantum effects in the motion of a human-made object," said Adrian Cho, a news writer for Science.
"On a conceptual level, that’s cool because it extends quantum mechanics into a whole new realm," he said. "On a practical level, it opens up a variety of possibilities ranging from new experiments that meld quantum control over light, electrical currents and motion to, perhaps someday, tests of the bounds of quantum mechanics and our sense of reality."
One of the more bizarre principles of quantum mechanics is that something can be in two states simultaneously: both on and off, both 1 and 0. Under just the right conditions, UCSB’s aluminum nitride oscillator took on a single quantum of motion, so that it vibrated both a little and a lot at the same time.
UCSB’s Aaron O’Connell, John Martinis and Andrew Cleland reported their results in March in the journal Nature. At the time, Cleland told me that "we were just trying to demonstrate quantum effects in a big thing."
"But a possible application would be if you try to detect these acoustic vibrations at the quantum level," he said. "You could do it with this. You could use it as a quantum microphone, or a quantum loudspeaker." Such devices might also be used to read out the results of a quantum computer’s calculations.
No word on whether Schroedinger’s cat is jumping for joy/already dead, but you can celebrate this achievement with the NeatoShop‘s latest physics T-shirt:
Look Out Schroedinger’s Cat, It’s a Trap! by Mike Jacobsen – $14.95
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University of Washington
Seattle, Washington Illustrations by Marian Parry
I report here the first evidence that domestic cats exhibit quantum tunneling.
Subatomic particles can make seemingly impossible, instantaneous “jumps” from one place to another. This has been known in theory for well over half a century. Numerous examples of it have been observed and meticulously documented. Known as “quantum tunneling,” this strange phenomenon had previously been thought to occur only on very small scales.
In this paper I report instances of the spontaneous relocation of entire cats. Though cats are arguably quantal to the extent that they tend to exist as discrete entities, the appreciable magnitude of some of the cats in question constitutes a novel aspect of the tunneling phenomenon.
The physical literature contains many reports of electrons and similar particles spontaneously jumping or “tunneling” from one place to another via so-called “forbidden” routes. This phenomenon has enjoyed much attention since the advent of scanning tunneling microscopy (STM). In all reports to date, the particles in question have ranged in size from extremely small to very, very small, with rare cases involving particles that are merely quite small. more …
Christoph Neimann illustrated the laws of physics as they apply to our daily lives. I can really relate to this one.
But back to Newton: he discovered that any two objects in the universe attract each other, and that this force is proportional to their mass.
The Earth is heavier than the Moon, and therefore attracts our bodies with a much greater force.
This explains why an empty refrigerator administrates a much smaller gravitational pull than, say, one that’s stacked with 50 pounds of delicious leftovers.
He also explains physics as it relates to waking up, subway crowding, and hair loss. Link -via The Daily What
Some physicists have proposed that the entire universe is not real, but a holographic illusion. Now astrophysicist Craig Hogan is building a machine to test that hypothesis:
Possible evidence for this model appeared last year in the unaccountable “noise” plaguing the GEO600 experiment in Germany, which searches for gravitational waves from black holes. To Hogan, the jitteriness suggested that the experiment had stumbled upon the lower limit of the spacetime pixels’ resolution.
Black hole physics, in which space and time become compressed, provides a basis for math showing that the third dimension may not exist at all. In this two-dimensional cartoon of a universe, what we perceive as a third dimension would actually be a projection of time intertwined with depth. If this is true, the illusion can only be maintained until equipment becomes sensitive enough to find its limits.[...]
“So we want to build a machine which will be the most sensitive measurement ever made of spacetime itself,” says Hogan. “That’s the holometer.”[...]
In the holometer, this loss of sync looks like a shaking or vibrations that represent jitters in spacetime itself, like the fuzziness of radio coming over too little bandwidth.
The holometer’s precision means that it doesn’t have to be large; at 40 meters in length, it is only one hundredth of the size of current interferometers, which measure gravitational waves from black holes and supernovas. Yet because the spacetime frequencies it measures are so rapid, it will be more precise over very short time intervals by seven orders of magnitude than any atomic clock in existence.
Link via The Agitator | Image: Paramount
Shaun the Sheep stars in a cute physics game in which you guide the sheep home. You have obstacles to cross, and three sheep of different mass. While you figure out a strategy, enjoy the artwork and sound effects. Link -via Metafilter
The game Flabby Physics is so simple it will drive you crazy! Just use your space bar to hit the star. That’s it. Good luck! Link -via b3ta
The Nobel Prize committee has announced the 2010 Nobel Prize laureates for Physics. The honor will be shared by Andre Geim and Konstantin Novoselov “for groundbreaking experiments regarding the two-dimensional material graphene“. However, this is not the first physics prize for Andre Geim.
Congratulations to Andre Geim, new Nobel Prize winner in physics. He becomes the first to win, as an individual, both a Nobel Prize (this year, together with Konstantin Novoselov, for experiments with the substance graphene) and an Ig Nobel Prize (in the year 2000, shared with Sir Michael Berry, for using magnets to levitate a frog).
You can see a video of the levitating frog at Improbable Research. Link
Physicists at the National Institute of Standards and Technology (NIST) tested Einstein’s theories about relative time in a physical setting. Time goes faster at higher elevations, and slower for moving objects. The experiments involved a comparison of two identical atomic clocks.
The NIST experiments focused on two scenarios predicted by Einstein’s theories of relativity. First, when two clocks are subjected to unequal gravitational forces due to their different elevations above the surface of the Earth, the higher clock—experiencing a smaller gravitational force—runs faster. Second, when an observer is moving, a stationary clock’s tick appears to last longer, so the clock appears to run slow. Scientists refer to this as the “twin paradox,” in which a twin sibling who travels on a fast-moving rocket ship would return home younger than the other twin. The crucial factor is the acceleration (speeding up and slowing down) of the travelling twin in making the round-trip journey.
NIST scientists observed these effects by making specific changes in one of the two aluminum clocks and measuring the resulting differences in the two ions’ relative ticking rates, or frequencies.
In one set of experiments, scientists raised one of the clocks by jacking up the laser table to a height one-third of a meter (about a foot) above the second clock. Sure enough, the higher clock ran at a slightly faster rate than the lower clock, exactly as predicted.
The second set of experiments examined the effects of altering the physical motion of the ion in one clock. (The ions are almost completely motionless during normal clock operations.) NIST scientists tweaked the one ion so that it gyrated back and forth at speeds equivalent to several meters per second. That clock ticked at a slightly slower rate than the second clock, as predicted by relativity. The moving ion acts like the traveling twin in the twin paradox.
So if you want to age more slowly, you should run as fast as you can on a beach or a valley below sea level. The time you gain would not offset the difference in the time you put in, but you might live longer due to the benefit of the physical exertion. Link -via reddit
(Image credit: Loel Barr)
At a 1997 soccer match, Roberto Carlos scored a goal against the French national team that seemed physically impossible. The ball seemed to curve around the French players. Physicists couldn’t explain the ball’s movement:
A group of French scientists, perhaps desperate to prove that at least the laws of physics weren’t actively rooting against their national team, have been able to figure out the trajectory of the ball and, with it, an equation to describe its unusual path.
It all comes down to the fact that, when a sphere spins, its trajectory is a spiral. Usually, gravity and the relatively short distance the ball travels cover up this spiral trajectory, but Carlos was a mere 115 feet away and kicked the ball hard enough to reveal its true spiral-like path. As you can see in the diagram above, the ball would have kept spiraling if gravity (and the netting) hadn’t gotten in the way.
At the link, you can see a video of the kick.
Link | Image: New Journal of Physics
