Earthly/Geo/Astro · Science · Technology

How Japan Plans to Build an Orbital Solar Farm

Imagine looking out over Tokyo Bay from high above and seeing a man-made island in the harbor, 3 kilometers long. A massive net is stretched over the island and studded with 5 billion tiny rectifying antennas, which convert microwave energy into DC electricity. Also on the island is a substation that sends that electricity coursing through a submarine cable to Tokyo, to help keep the factories of the Keihin industrial zone humming and the neon lights of Shibuya shining bright.

But you can’t even see the most interesting part. Several giant solar collectors in geosynchronous orbit are beaming microwaves down to the island from 36 000 km above Earth.

It’s been the subject of many previous studies and the stuff of sci-fi for decades, but space-based solar power could at last become a reality—and within 25 years, according to a proposal from researchers at the Japan Aerospace Exploration Agency (JAXA). The agency, which leads the world in research on space-based solar power systems, now has a technology road map that suggests a series of ground and orbital demonstrations leading to the development in the 2030s of a 1-gigawatt commercial system—about the same output as a typical nuclear power plant.”

Text and Images via Spectrum

Performativity · Science · Technology

Choreographing dance of electrons offers promise in pursuit of quantum computers

Electrical engineers Stephen Lyon (left) and Alexei Tyryshkin examine the casing that holds the silicon crystal they used to coordinate the spins of billions of electrons in work toward developing the technology for powerful machines known as quantum computers. (Photo by John Jameson)

The waves pulsed like distant music across the crystal and deep within its heart, billions of electrons started spinning to their beat.

Reaching into the silicon crystal and choreographing the dance of 100 billion infinitesimal particles is an impressive achievement on its own, but it is also a stride toward developing the technology for powerful machines known as quantum computers.

“Standard computers have come to their limit and cannot do some of the things we want,” said Tyryshkin, a research scholar in the Department of Electrical Engineering. “We are trying to find a different way of doing computing, using additional degrees of freedom involving quantum computing and things like spins.”

Using the spins of subatomic particles such as electrons offers a path to developing a machine that would apply the reality-bending rules of quantum mechanics to arrive at new and powerful ways to approach difficult mathematical problems. But maintaining that control for long enough to build a working computer has proven incredibly difficult.

Until recently, the best attempts at such control lasted for only a fraction of a second. But researchers at Princeton led by Stephen Lyon, a professor of electrical engineering, have found a way to extend their control over the spins of billions of electrons for up to 10 seconds.

The researchers, part of an international team, reported their results online Dec. 4 in Nature Materials. The research at Princeton was supported by the National Science Foundation and the National Security Agency.

Lyon said the key to the new results lies in the use of a highly purified sample of silicon. The experiment uses a small silicon chip the size of a pencil lead made almost entirely of a particular isotope of silicon: silicon-28.

“Partly, it is an improvement in our measurements, but it is mainly the material,” Lyon said. “This is the purest sample we have ever used.”

Written by John Sullivan. Continue HERE