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How Many “Friends” Can You Really Have?

Can social networks expand the evolutionary limit on how many people anyone can truly be close to?

5 min read
How Many “Friends” Can You Really Have?

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Caltech Team Launches Experimental Space-Based Solar Array

The satellite will test some of the tech needed to wirelessly beam power from orbit

4 min read
A lightweight gold-colored square frame for a solar power array, seen flying in space with Earth in background.

Artist's conception of Caltech's Space Solar Power Demonstrator in Earth orbit.

Caltech

For about as long as engineers have talked about beaming solar power to Earth from space, they’ve had to caution that it was an idea unlikely to become real anytime soon. Elaborate designs for orbiting solar farms have circulated for decades—but since photovoltaic cells were inefficient, any arrays would need to be the size of cities. The plans got no closer to space than the upper shelves of libraries.

That’s beginning to change. Right now, in a sun-synchronous orbit about 525 kilometers overhead, there is a small experimental satellite called the Space Solar Power Demonstrator One (SSPD-1 for short). It was designed and built by a team at the California Institute of Technology, funded by donations from the California real estate developer Donald Bren, and launched on 3 January—among 113 other small payloads—on a SpaceX Falcon 9 rocket.

“To the best of our knowledge, this would be the first demonstration of actual power transfer in space, of wireless power transfer,” says Ali Hajimiri, a professor of electrical engineering at Caltech and a codirector of the program behind SSPD-1, the Space Solar Power Project.

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Designing a Silicon Photonic MEMS Phase Shifter With Simulation

Engineers at EPFL used simulation to design photonic devices for enhanced optical network speed, capacity, and reliability

4 min read
Designing a Silicon Photonic MEMS Phase Shifter With Simulation
EPFL

This sponsored article is brought to you by COMSOL.

The modern internet-connected world is often described as wired, but most core network data traffic is actually carried by optical fiber — not electric wires. Despite this, existing infrastructure still relies on many electrical signal processing components embedded inside fiber optic networks. Replacing these components with photonic devices could boost network speed, capacity, and reliability. To help realize the potential of this emerging technology, a multinational team at the Swiss Federal Institute of Technology Lausanne (EPFL) has developed a prototype of a silicon photonic phase shifter, a device that could become an essential building block for the next generation of optical fiber data networks.

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