Downloading the Sky

Astronomers and computer scientists are building the world's best telescope--and it's all online

11 min read

The Year Is 2007, And I'M Sitting At Home, drinking a cup of tea, and observing a galaxy millions of light-years away. No, I don't have a fortune in cutting-edge astronomical instruments, just a personal computer and a reasonably fast Internet connection.

Scattered across the screen is a handful of images, each showing that same galaxy but at a different wavelength. The visible-light image, a five-year-old photo from the twin Keck telescopes on Mauna Kea in Hawaii, shows the classic galactic pinwheel, spiral arms twisting out from a dense, starry center. In the infrared image, captured just a few seconds ago by a mountaintop telescope in Arizona, the galaxy looks more like a series of concentric rings, the telltale signs of dust-filled regions where stars are born. A radio image from a space-based telescope also shows a bright ring, but in this case it signifies the energy thrown off by countless exploding stars. Seen in the X-ray portion of the spectrum, the galaxy's rings are completely lost, replaced by a bright central core--probably a black hole.

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Deep Learning Could Bring the Concert Experience Home

The century-old quest for truly realistic sound production is finally paying off

12 min read
Image containing multiple aspects such as instruments and left and right open hands.
Stuart Bradford

Now that recorded sound has become ubiquitous, we hardly think about it. From our smartphones, smart speakers, TVs, radios, disc players, and car sound systems, it’s an enduring and enjoyable presence in our lives. In 2017, a survey by the polling firm Nielsen suggested that some 90 percent of the U.S. population listens to music regularly and that, on average, they do so 32 hours per week.

Behind this free-flowing pleasure are enormous industries applying technology to the long-standing goal of reproducing sound with the greatest possible realism. From Edison’s phonograph and the horn speakers of the 1880s, successive generations of engineers in pursuit of this ideal invented and exploited countless technologies: triode vacuum tubes, dynamic loudspeakers, magnetic phonograph cartridges, solid-state amplifier circuits in scores of different topologies, electrostatic speakers, optical discs, stereo, and surround sound. And over the past five decades, digital technologies, like audio compression and streaming, have transformed the music industry.

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