Just a few tens of nanometres across, they are among a growing array of 'nanolights' that researchers are tailoring to specific types of fluorescence: the ability to absorb light at one wavelength and re-emit it at another. ... Many naturally occurring compounds can do this, from jellyfish proteins to some rare-earth compounds. But nanolights tend to be much more stable, versatile and easier to prepare — which makes them attractive for users in both industry and academia. ... Nanolights have already begun to find application in areas ranging from flat-screen displays to biochemical tests. And researchers are working towards even more ambitious uses in fields such as solar energy, DNA mapping, motion sensing and even surgery. ... Light is emitted when electrons are kicked up to higher energy levels by some outside source, such as ultraviolet light, then fall back down to lower levels.
According to scientists I spoke with, the quality of your slumber has more repercussions on your happiness, intelligence, and health than what you eat, where you live, or how much money you make. Not to be a downer, but chronic sleep deprivation, which Amnesty International designates a form of torture, has been linked to diabetes, cancer, high blood pressure, heart disease, stroke, learning difficulties, colds, gastrointestinal problems, depression, execution (the sleep-starved defense minister of North Korea is rumored to have been shot after dozing in the presence of Kim Jong-un), world disasters (the Challenger explosion, the Three Mile Island meltdown), and non-disasters ... Many scientists have come to believe that while we sleep the space between our neurons expands, allowing a cranial sewage network—the glymphatic system—to flush the brain of waste products that might otherwise not only prevent memory formation but muck up our mental machinery and perhaps eventually lead to Alzheimer’s. Failing to get enough sleep is like throwing a party and then firing the cleanup crew. ... A National Institutes of Health study showed that twenty-five to thirty per cent of American adults have periodic episodes of sleeplessness and twenty per cent suffer from chronic insomnia. On the advice of sleep doctors, fatigue-management specialists, and know-it-alls on wellness blogs, these tossers and turners drink cherry juice, eat Atlantic perch, set the bedroom thermostat between sixty-seven and seventy degrees, put magnets under the pillow, curl their toes, uncurl their toes, and kick their partners out of bed, usually to little avail. ... The ancient Romans smeared mouse fat onto the soles of their feet, and the Lunesta of the Dark Ages was a smoothie made from the gall of castrated boars.
Is there a workable business model for products that are built to last, rather than to fall apart? This is an idea that I explored here in July, in a story about the L.E.D. quandary. That quandary, in short: companies are making a good thing—light-emitting-diode bulbs that conserve energy and last for years—but they can’t make money in the long run from products that rarely need replacing. As global light sockets fill with L.E.D.s, century-old corporate titans are getting out of the bulb business even before “socket saturation” tips sales into a decline. The question remains whether any company has an incentive to make a product that is not designed to fall apart or become obsolete.
Like many astrophysicists, Sara Seager sometimes has a problem with her perception of scale. Knowing that there are hundreds of billions of galaxies, and that each might contain hundreds of billions of stars, can make the lives of astrophysicists and even those closest to them seem insignificant. Their work can also, paradoxically, bolster their sense of themselves. Believing that you alone might answer the question “Are we alone?” requires considerable ego. Astrophysicists are forever toggling between feelings of bigness and smallness, of hubris and humility, depending on whether they’re looking out or within. ... Her area of expertise is the relatively new field of exoplanets: planets that orbit stars other than our sun. More particular, she wants to find an Earthlike exoplanet — a rocky planet of reasonable mass that orbits its star within a temperate “Goldilocks zone” that is not too hot or too cold, which would allow water to remain liquid — and determine that there is life on it. That is as simple as her math gets. ... The vastness of space almost defies conventional measures of distance. Driving the speed limit to Alpha Centauri, the nearest star grouping to the sun, would take 50 million years or so; our fastest current spacecraft would make the trip in a relatively brisk 73,000 years. The next-nearest star is six light-years away. To rocket across our galaxy would take about 23,000 times as long as a trip to Alpha Centauri, or 1.7 billion years, and the Milky Way is just one of hundreds of billions of galaxies. ... Light or its absence is also the root of something called the transit technique, a newer, more efficient way than radial velocity of finding exoplanets by looking at their stars.
Then, last June, the renovation team discovered Ketra, an LED lighting startup from Austin that promised some pretty big things. ... The first was what Ketra calls “natural light”: white light sources that imperceptibly change their color and intensity throughout the day to mimic the lighting conditions outside. The second was an extreme degree of control. Ketra lights could be wirelessly grouped into zones of any number of lights that could all be separately adjusted via custom software on a wall panel, computer, or phone. The third was precision. Each Ketra bulb contained a patented sensor that measured its own color 360 times a minute to make sure the light being produced was the light being requested. Ketra was selling precisely measured, nature-approximating light, accessible throughout the massive office at the press of a button. ... who really needs them? Being all things to all people doesn’t come cheap. A single Ketra bulb costs about $100. ... before you can sell millions of dollars of high-tech lighting to some of the world’s biggest companies, you have to convince them that there is a very big problem with their light. ... At the heart of Ketra’s tech is an LED chip capable of temperature-optical feedback, which senses heat and color output in real time and adjusts itself according to that data.