In order for the math of general relativity to work, this fabric of space-time has to be absolutely smooth at the tiniest of scales. No matter how far you zoom in, space-time will always be as wrinkle-free as a recently ironed shirt. No holes, no tears, no tangles. Just pure, clean smoothness. Without this smoothness, the mathematics of gravity simply break down. But general relativity isn't the only thing telling us about space-time. We also have quantum mechanics (and its successor, quantum field theory). In the quantum world, everything microscopic is ruled by random chance and probabilities. Particles can appear and disappear at a moment's notice (and usually even less time than that). Fields can wiggle and vibrate with a will all their own. And nothing can ever be known for certain.

That's exactly what a team of astronomers did, submitting their results for publication in the Monthly Notices of the Royal Astronomical Society, and also posting their work to the online preprint site arXiv. And in a perfect coincidence, they searched for the frothiness of space-time using espresso. No, not the drink. ESPRESSO, the Echelle Spectrograph for Rocky Exoplanet and Stable Spectroscopic Observations, an instrument based at the European Southern Observatory's Very Large Telescope. As its name suggests, ESPRESSO was not designed to search for space-time frothiness, but it turned out to be the best tool for the job. And the astronomers pointed it at a perfect source: a run-of-the-mill gas cloud sitting over 18 billion light-years away. What makes this particular gas cloud especially useful is two facts. One, there is a bright source sitting just behind it, illuminating it. And two, there's iron in the cloud, which absorbs the background light at a very specific wavelength.

What is missing in such mandatory “stick” approaches is the more active use of “carrot” incentives that could both encourage self-isolation and help prepare a workforce to bounce back in the recovery phase. Noncompliance during a quarantine has large social costs, not least a faster spread of the pandemic and higher death rates. But governments could subsidize activities that help to better align private incentives with social objectives, and, in so doing, provide new forms of social protection that also make social distancing more bearable. What are some activities that could be performed by many citizens without leaving their homes?

Another high-potential area is document digitization: Only 10 percent of the world’s books are digitized. Even with the current level of optical character recognition (OCR) technology, for a book to be digitized, an independent person needs to check it for errors, problems with tables and images, tagging, and oversee the look of the resulting text. Handwritten documents, images, and tables, even in printed books, require manual processing, proofreading, careful checking, and quality control. A person would receive scanned images of, let’s say, old letters to decipher and type into the electronic document. Comparing the results of several independent people working on the same document would assure the quality of transcription. The Rainfall Rescue Project of the U.K.’s Met Office aims to digitize 65,000 pieces of paper that contain monthly and decadal rainfall totals at thousands of weather stations across the U.K. from 1950 back to 1820. Because of their public-good nature, such projects are underfinanced. The global research community and libraries around the world would benefit from government support of these efforts. And many people could earn income and be kept occupied at home, inputting historical climatic data in spreadsheets.