The meandering instability of a viscous thread
A viscous thread falling from a nozzle onto a surface exhibits the famous rope-coiling effect, in which the thread buckles to form loops. If the surface is replaced by a belt moving with speed U, the rotational symmetry of the buckling instability is broken and a wealth of interesting states are observed
You can do more than roll them down an inclined plane.
Soft-drink cans beat the diffraction limit
The group generated audible sound from a ring of computer speakers surrounding the acoustic ‘lens’: a seven-by-seven array of empty soft-drink cans. Because air is free to move inside and around the cans, they oscillate together like joined-up organ pipes, generating a cacophony of resonance patterns. Crucially, many of the resonances emanate from the can openings, which are much smaller than the wavelength of the sound wave, and so have a similar nature to evanescent waves.
To focus the sound, the trick is to capture these waves at any point on the array.
The best intro book for any topic
Of course I checked out physics and in addition to Larry Gonick’s The Cartoon Guide to Physics, it gave a bunch of books on various topics within physics. I have read none of these books, so I have no basis for endorsing or disputing the choices; I don’t know if “Best Intro” means they were going for pop-sci books for a general audience or intro textbooks for the student or serious amateur. The Cartoon Guide might indicate one way — I’m not sure — but the other titles are or seem more like textbooks. The closest I can come to a recommendation is noting that the QM book is by David J Griffiths, I’ve heard good things about it, and his Electrodynamics textbook is very good.
EIA Report: Renewables Surpass Nuclear Output
Let’s start out with the bad and misleading.
Looking at all energy sectors (e.g., electricity, transportation, thermal), production of renewable energy, including hydropower, has increased by 15.07 percent compared to the first quarter of 2010, and by 25.07 percent when compared to the first quarter of 2009. Among the renewable energy sources, biomass/biofuels accounted for 48.06 percent, hydropower for 35.41 percent, wind for 12.87 percent, geothermal for 2.45 percent, and solar for 1.16 percent.
Biofuels, unfortunately, includes ethanol. In fact, it’s probably mostly ethanol and if ethanol production represents a net gain in energy over the energy used to make it, it’s by a very slim margin. Not only do we mandate its production and inclusion in gasoline in the US, it’s also subsidized (the good news is that the subsidy is scheduled to end, and there’s a chance it won’t be renewed) and diverting land use to corn for ethanol has driven food prices up. Touting a huge increase in the production of ethanol is not good, and it really shouldn’t count as energy production.
I’m not sure where all the additional hydro power is coming from, though. If it’s a rebound in areas that were previously seeing droughts and production is just a return to the norm (or a spike from e.g. above-average snowmelt) then it’s a little misleading as well.
But there is good news:
In terms of actual production, renewable electrical output increased by 25.82 percent in the first three months of 2011 compared to the first quarter of 2010. Solar-generated electricity increased by 104.8 percent, wind-generated electricity rose by 40.3 percent, hydropower output expanded by 28.7 percent, and geothermal electrical generation rose by 5.8 percent. Only electricity from biomass sources dropped — by 4.8 percent. By comparison, natural gas electrical output rose by 1.8 percent and nuclear-generated electricity increased by only 0.4 percent while coal-generated electricity dropped by 5.7 percent.
We are installing solar and wind, and coal use went down. Yay!
Rotating cylinder puts a new spin on slow light
In 1859 the French physicist Hippolyte Fizeau demonstrated this “photon drag” in the longitudinal direction by shining light through flowing water. More than 100 years later, in 1976, the British physicist Reginald Jones demonstrated it similarly in the transverse direction, by shining light near the edge of a spinning glass disc. But until now, it seems, no-one has ever shown that an image formed by light can be rotated. The problem is that the atoms are so quick to re-emit absorbed photons that the change in an image’s rotation is barely perceptible.
via Zapperz
Could a Tyrannosaurus Rex bite through a modern day tank?
Per Glasstone and Sesonske’s Nuclear Reactor Engineering, “Alpha phase uranium is “soft and ductile, Beta phase is hard and brittle and Gamma phase is very soft”. Therefore I don’t believe the depleted uranium would help with a T-Rex on the battlefield.
via @rands
Bend LEGO Bricks, Learn Some Non-Euclidean Geometry
The slight bendability of the small 1×2 and 1×3 bricks, combined with mathematical principles has allowed Sanders to keep building up and out with his designs. Right now, the largest, a “sunflower,” [picture at link] is made of more than 1,800 bricks.
Calamities of Nature’s fill-in-the-Blank form to make you sound like Deepak Chopra. If, for some unfathomable reason, you wanted to sound like Deepak Chopra.
Chocolate printer crafts sculptures from cocoa
Using new digital technology, a printer designed by researchers in England allows you to create your own designs on a computer and reproduce them physically in three dimensional form in chocolate.