Squeezing light to detect more gravitational waves

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This article appeared in the fall print issue of Popular Science, but I missed that this article had also been published online.

Something called ‘squeezed light’ is about to give us a closer look at cosmic goldmines

Gravitational wave detection is going through an even tighter squeeze.

For Popular Science:

In 2015, scientists caught evidence of a ­cosmic throwdown that took place 1.3 billion light-​years away. They spied this binary black-hole collision by capturing gravitational waves—­ripples in spacetime created when massive objects ­interact—​for the first time. But now physicists want to see even farther. Doing so could help them accurately measure waves cast off by colliding neutron stars, impacts that might be the source of many Earthly elements, including gold. For that, they need the most sensitive gravitational-wave detectors ever.

The devices that nab waves all rely on the same mechanism. The U.S.-based Laser Interferometer Gravitational-Wave Observatory (LIGO) and its European counterpart, Virgo, fire lasers down two mile-plus-long arms with mirrors at their ends. Passing waves wiggle the mirrors less than the width of an atom, and scientists measure the ripples based on when photons in the laser light bounce off them and come back. Ordinarily, photons exit the lasers at random intervals, so the signals are fuzzy.

[Read the rest at Popular Science]

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Why physicists hate time

[ This blog is dedicated to tracking my most recent publications. Subscribe to the feed to keep up with all the science stories I write! ]

Wait a second: What came before the big bang?

Not everyone thinks the universe had a beginning.

This story originally appeared in the print edition of the September issue of Popular Science. This week, it appeared online with enhanced graphics. The text is by PopSci editor Rachel Feltman and me; the art is by Matei Apostolescu.

Cosmologists used to think the universe was totally timeless: no beginning, no end. That might sound mind-melting, but it’s easier on the scientific brain than figuring out what a set starting point would mean, let alone when it would be. So some physicists have cooked up alternative cosmological theories that make time’s role seem a little less important. The concepts are as trippy as those black-light posters you had in college.

[read the rest at Popular Science]