miércoles, 31 de julio de 2013

martes, 30 de julio de 2013

lunes, 29 de julio de 2013

domingo, 28 de julio de 2013

sábado, 27 de julio de 2013

viernes, 26 de julio de 2013

What If You Could See WiFi?

Wifi is an energy field that is transmitted as waves. The waves have a certain height, distance between them and travel at a certain speed. The distance between wifi waves is shorter than that of radio waves and longer than that of microwaves, giving wifi a unique transmission band that can't be interrupted by other signals. These images show an “idealized” wifi data transmitted over a band that is divided into different sub-channels, which are shown in red, yellow, green and other colors. 

The wifi pulses are shown here as multicolored spheres radiating out from the source, near the right of the image. Wifi transmitters are basically an antenna equipped with a transmission protocol that splits the frequency band into several segments, referred to as channels. Data can be transmitted over each channel or in order to send and receive greater quantities of data at faster rates. Although color represents its own unique, visible segment of the electromagnetic spectrum, we use red, orange, yellow and other colors to show the invisible wifi channels that make up the overall wifi signal. Wifi fields are usually spherical (like the one here) or ellipsoidal and extend about 20-30 meters, assuming a typical off the shelf wifi box.

The illustrations were produced with the help of M. Browning Vogel. She has a Ph.D. in Astrobiology, worked at NASA Ames for five years, and now teaches science at the University level. 
Nickolay Lamm

jueves, 25 de julio de 2013

jueves, 18 de julio de 2013

'Invisibility wetsuit' to protect against sharks launched in Western Australia

Suits are designed to mimic nature, some camouflaging swimmers, others warning sharks to stay away

An “invisibility cloak” to protect surfers from sharks has been launched in Western Australia, the scene of five fatal shark attacks in recent years.
Scientists from the University of Western Australia, with designers Shark Attack Mitigation Systems (SAMS), have unveiled two new wetsuits that they say could save lives in the water.
Based on a breakthrough discovery that sharks are colour-blind, one wetsuit, labelled the “Elude”, is designed to camouflage a swimmer or diver in the sea.
At the other extreme, the “Diverter” sports bold white and dark-blue stripes, and is intended to mirror nature's warning signs to ward off any potential shark attack.
More than two years in development, the suits, which retail at $495, went on sale via online distributor Radiator on Wednesday.
Prof Shaun Collin, from UWA's Ocean Institute, said a mix of scientific discoveries and observations about nature were used to come up with warning suit designs aimed at reducing the risk to swimmers, surfers and divers.
“The idea is to reduce the risk of the wearer in certain conditions,” Collin said.
“Many animals in biology are repelled by noxious animals – prey that provide a signal that somehow says ‘Don't eat me’ – and that has been manifest in a striped pattern.
“We are using a lot of nature's technology, based on high-contrast-based banding patterns.
The wearer will be obvious, and the idea is the shark will see that as an unpalatable food item and swim right by.”
The five fatal attacks in WA waters in just under 12 months, which earned the state the unwelcome tag of shark attack capital of the world, prompted the research into the suits more than two years ago.
The designs have been tested in the water with tiger sharks – but not on humans – mainly in waters off the northern WA coast near Ningaloo Reef.
Testing will continue this summer with great white sharks in the waters off South Australia and South Africa.
Hamish Jolly, from SAMS, said the results so far warranted the suits going on sale immediately.
"We now know what these big predatory sharks can see, and what we have done is convert that science into a marketable technology," Jolly said.
"We have converted that into patents that we know will hide [wearers] or present wearers as not shark food."

miércoles, 17 de julio de 2013

martes, 16 de julio de 2013

lunes, 15 de julio de 2013

domingo, 14 de julio de 2013

sábado, 13 de julio de 2013