Quantcast

Latest Steven Cummer Stories

A 3D Acoustic Cloak That Hides Objects From Sound
2014-03-12 12:14:17

Lee Rannals for redOrbit.com - Your Universe Online Engineers at Duke University have demonstrated the world’s first three-dimensional acoustic cloaking device. The scientists reported in the journal Nature Materials that they have created a new device that reroutes sound waves to create the impression that the cloak and whatever it covers is not there. This technology could one day be used by the US Navy as a way to avoid sonar detection. According to the researchers, the acoustic...

365cd3aa041c23696704d122b8533263
2011-06-25 07:39:27

Scientists have developed a new device that makes objects invisible to sound waves. The approach borrows ideas from attempts to "cloak" objects from light. The scientists said it uses simple plastic sheets with arrays of holes, and could be put to use in making ships invisible to sonar or in an acoustic design for concert halls. Researchers have put forth effort to try and create "invisibility cloaks" since the feasibility of the idea was theorized in 2006. Those approaches are based on...

4e72222ac8c0bdfb905e5720de86f9281
2009-08-24 12:45:00

Duke University researchers have captured images of lightning bolts shooting upwards. The rare phenomenon, known as "gigantic jets," was photographed during tropical storm Cristobal last year. The gigantic jets shot more than 40 miles high, Duke Professor Steven Cummer and colleagues wrote in the journal Nature Geoscience. "Despite poor viewing conditions as a result of a full moon and a hazy atmosphere, we were able to clearly capture the gigantic jet," said Cummer. "What we were able to...

44acbb37699048aafe8d4188694484631
2008-01-09 15:05:24

DURHAM, N.C. -- Contrary to earlier predictions, Duke University engineers have found that a three-dimensional sound cloak is possible, at least in theory. Such an acoustic veil would do for sound what the "invisibility cloak" previously demonstrated by the research team does for microwaves--allowing sound waves to travel seamlessly around it and emerge on the other side without distortion (http://www.pratt.duke.edu/news/?id=792). "We've devised a recipe for an acoustic material that would...

b115403d2cbc85f1e4d6254d38e25db51
2005-06-07 12:35:00

NASA -- Giant red blobs, picket fences, upward branching carrots, and tentacled octopi -- these are just a few of the phrases used to describe sprites -- spectacular, eerie flashes of colored light high above the tops of powerful thunderstorms that can travel up to 50 miles high in the atmosphere. Sprites, so-named by a University of Alaska scientist inspired by the creatures in Shakespeare's "The Tempest," have been observed since the 1800s, though rarely visible from the ground. Aircraft...


Word of the Day
tesla
  • The unit of magnetic flux density in the International System of Units, equal to the magnitude of the magnetic field vector necessary to produce a force of one newton on a charge of one coulomb moving perpendicular to the direction of the magnetic field vector with a velocity of one meter per second. It is equivalent to one weber per square meter.
This word is named for Nikola Tesla, the inventor, engineer, and futurist.