Molecules/Matter & Energy

Toy warp drive proposed
A physicist who previously created a toy universe out of metamaterials that bend light in unusual ways has now dreamed up a way to use those materials to build a warp drive. Simulations by Igor Smolyaninov at the University of Maryland in College Park show that moving faster than light is still impossible in toy universes, just as it is in the real one. But the right material should allow superspeed travel at up to one-quarter light speed — by riding in a moving spacetime bubble, he reports in an upcoming issue of Physical Review B. —Devin Powell.

Butterflies sip like sponges
To sip nectar, a butterfly uses a proboscis that looks like straw but also works like a sponge. At the small scales of butterfly existence, liquid is just too thick to be slurped, a team led by researchers at Clemson University in South Carolina reports. X-ray images of butterfly feeding tubes reveal pores that draw fluid upward by capillary action, the same process that pulls water through a paper towel. This anatomy may help butterflies dine on a greater variety of foods, and its principle could be borrowed to design probes that sample the liquid inside cells, the researchers report online August 17 in the Journal of the Royal Society Interface. —Devin Powell.

Coffee ring regulation
Starbucks tables everywhere rejoice: There’s a way to prevent the coffee ring effect. The quiet drying of spilled coffee on a countertop produces a crusty edge because round particles flee in a frenzy from the center of the spill. But oblong particles in the liquid can’t flee that well and end up spreading out uniformly, University of Pennsylvania scientists report in the Aug. 18 Nature. Upping the number of elongated particles compared to spherical ones can prevent ring formation, suggesting that particle shape influences fluid interactions. The finding could help in designing better inks, paints and even foams and lotions.—Rachel Ehrenberg