Category Physics

Multiple reflections like in a drop of paint

Inside a drop of paint, light is scattered so often that it seems impossible to demonstrate quantum effects. But despite the thousands of possible paths the light can take, researchers of the Uni of Twente now show that there are just 2 exits. Depending on the light pattern that enters the paint, 2 photons always come out through the same exit, or through different ones – as though they avoid each other.

Most of the experiments showing that light sometimes behaves like a wave and sometimes like a particle, are as simple as possible: a physics textbook example is Young’s two slit experiment. The number of possible light paths is limited, but even at this level, the experiments strongly challenge our intuition...

In this example, the speed of the spinning tag on the pinwheel is mapped to onscreen graphics. Credit: Eric Brockmeyer/Disney Research

Researchers have created ways to give a piece of paper sensing capabilities that allows it to respond to gesture commands and connect to the digital world, IoT. The method relies on small radio frequency (RFID) tags that are stuck on, printed or drawn onto the paper to create interactive, lightweight interfaces that can do anything from controlling music using a paper baton, to live polling in a classroom.

The technology – PaperID – leverages inexpensive, off-the-shelf RFID tags, which function without batteries but can be detected through a reader device placed in the same room as the tags...

The wavelike pattern at the top shows the accordion-like structure of a proposed quantum material—an artificial crystal made of light—that can trap atoms in regularly spaced nanoscale pockets. These pockets can be made to hold a large collection of ultracold “host” atoms (green), slowed to a standstill by laser light, and individually planted “probe” atoms (red) that can be made to transmit quantum information in the form of a photon (particle of light). The lower panel shows how the artificial crystal can be reconfigured with light from an open (hyperbolic, in orange) geometry to a closed (elliptical, in green) geometry, which greatly affects the speed at which the probe atom can release a photon. Credit: Pankaj K. Jha/UC Berkeley

Scientists have devised a way to build a “quan...

This five-fingered robot hand developed by University of Washington computer science and engineering researchers can learn how to perform dexterous manipulation — like spinning a tube full of coffee beans — on its own, rather than having humans program its actions. Credit: University of Washington

Computer science experts and engineering researchers have built a robot hand that can not only perform dexterous manipulation but also learn from its own experience. Robots today can perform space missions, solve a Rubik’s cube, sort hospital medication and even make pancakes. But most can’t manage the simple act of grasping a pencil and spinning it around to get a solid grip.

Intricate tasks that require dexterous in-hand manipulation – rolling, pivoting, bending, sensing friction and other thin...