Just Passing Through

kateoplis:

American and Israeli researchers have used twisted vortex beams to transmit data at 2.5 terabits per second. As far as we can discern, this is the fastest wireless network ever created — by some margin. This technique is likely to be used in the next few years to vastly increase the throughput of both wireless and fiber-optic networks.

These twisted signals use orbital angular momentum (OAM) to cram much more data into a single stream. In current state-of-the-art transmission protocols (WiFi, LTE, COFDM), we only modulate the spin angular momentum (SAM) of radio waves, not the OAM. If you picture the Earth, SAM is our planet spinning on its axis, while OAM is our movement around the Sun. Basically, the breakthrough here is that researchers have created a wireless network protocol that uses both OAM and SAM. 

In this case, Alan Willner and fellow researchers from the University of Southern California, NASA’s Jet Propulsion Laboratory, and Tel Aviv University, twisted together eight ~300Gbps visible light data streams using OAM. Each of the eight beams has a different level of OAM twist. The beams are bundled into two groups of four, which are passed through different polarization filters. One bundle of four is transmitted as a thin stream, like a screw thread, while the other four are transmitted around the outside, like a sheathe. The beam is then transmitted over open space (just one meter in this case), and untwisted and processed by the receiving end. 2.5 terabits per second is equivalent to 320 gigabytes per second, or around seven full Blu-ray movies per second.

This huge achievement comes just a few months after Bo Thide finally proved that OAM is actually possible.

Read on.

Gorgeous illustration and an interesting single-page format web site

marlonmarcello:

This is a tutorial for beginner and intermediate HTML5 and CSS3 developers who want to create a drop-down menu. The menu we’re creating is animated using only CSS … there’s no JavaScript in sight!

holtthink:

i love this kind of thinking because I immediately think about how this can be translated into education. 

From the site:

“The human brain starts working the moment you are born and never stops until you stand up to speak in public,” George Jessel famously quipped. In 100 Things Every Designer Needs to Know About People (public library), Dr. Susan Weinschenkunpacks the secrets of eliciting response from people — the core purpose of design, it’s been argued — through a combination of behavioral science, psychology, and practical examples to alleviate the misery and mystery of public speaking.

This great short animated teaser offers five of the most essential secrets to a great presentation, whatever your discipline or topic. (Not so great? The dishearteningly blatant RSA-style animation rip-off.)

1. People learn best in 20-minute chunks. There must be a reason for the successful TED-sized talk format.
2. Multiple sensory channels compete. During a talk, you engage both the auditory and visual channels — because we’re visual creatures and the visual channel trumps the auditory, make sure your slides don’t require people to read much or otherwise distract from the talk.

It’s awesome.