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Category: space – Page 778

Silicon chips combine light and ultrasound for better signal processing

The continued growth of wireless and cellular data traffic relies heavily on light waves. Microwave photonics is the field of technology that is dedicated to the distribution and processing of electrical information signals using optical means. Compared with traditional solutions based on electronics alone, microwave photonic systems can handle massive amounts of data. Therefore, microwave photonics has become increasingly important as part of 5G cellular networks and beyond. A primary task of microwave photonics is the realization of narrowband filters: The selection of specific data, at specific frequencies, out of immense volumes that are carried over light.

Many photonic systems are built of discrete, separate components and long optical fiber paths. However, the cost, size, and production volume requirements of advanced networks call for a new generation of microwave photonic systems that are realized on a chip. Integrated microwave photonic filters, particularly in silicon, are highly sought after. There is, however, a fundamental challenge: Narrowband filters require that signals are delayed for comparatively long durations as part of their processing.

“Since the is so fast,” says Prof. Avi Zadok from Bar-Ilan University, Israel, “we run out of chip space before the necessary delays are accommodated. The required delays may reach over 100 nanoseconds. Such delays may appear to be short considering daily experience; however, the optical paths that support them are over ten meters long. We cannot possibly fit such long paths as part of a silicon chip. Even if we could somehow fold over that many meters in a certain layout, the extent of optical power losses to go along with it would be prohibitive.”

Astronomers found a giant “wall” of galaxies hiding in plain sight

Circa 2020

Astronomers have found one of the largest structures in the known universe—a “wall” of galaxies that’s at least 1.4 billion light-years long. And given how close it is to us, it’s remarkable that we haven’t seen it before now.

What happened: An international team of scientists reported the discovery of the South Pole Wall in a paper published Thursday in the Astrophysical Journal. The structure is basically a curtain that stretches across the southern border of the universe (from the perspective of Earth) and consists of thousands of galaxies, along with huge amounts of gas and dust.

What do you mean by “wall”? Galaxies aren’t just strewn randomly throughout the universe. Along huge strands of hydrogen, galaxies collect into larger groupings of massive filaments, separated by giant voids of nearly empty space. Each filament is basically a wall of galaxies, stretching for hundreds of millions of light-years. They’re the biggest structures in the known universe. Other identified structures include the Great Wall, the Sloan Great Wall, the Hercules-Corona Borealis Great Wall, and the Bootes Void.

Video of NASA Probe Landing on Asteroid Is Otherworldly

NASA Goddard

The most striking aspect of the approach—for our money, anyway—is the way Bennu feels like a small world; rather than just a 1600-foot-wide hunk of rock. There’s plenty of space on Bennu’s surface to jump around. And one could even leap off the surface, enter into orbit around the asteroid, and then touch back down. The space probe, in fact, captured rocks doing just that.