August 2, 2013
There are millions out there who’d love to naturally be cheery morning people. Most of these night owls blame genetics or bad luck for their groggy, irritable morning selves.
The true culprit, a growing number of sleep scientists believe, is something much more mundane: the ambient glow of artificial illumination emitted from our light fixtures, computer screens,and primetime TV shows.
The theory goes like this: We evolved to operate on a 24-hour cycle, based off of the reliable rise and set of the Sun everyday. Historically, our bodies were stimulated by these events occurring at roughly the same time daily, so they knew to do things like secrete the hormone melatonin (which aids in sleep) just before sunset, and reduce production of it just before sunrise. This and other biological patterns—known as our internal circadian rhythm—ensured a solid night of sleep and a wakeful morning, day in and day out.
Until the advent of electricity and other elements modern technology, that is, which brought artificial light into all hours of our nights. Our technology—and the increasing reliance on it for our jobs and studies in our labor- and service-based economy—also means that we spend most of our daytime inside, with less exposure to the sunlight needed to set our circadian clocks. As a result, many of us can’t fall asleep when we want to, have trouble sleeping through the night, and feel the opposite of refreshed when our alarm starts buzzing in the morning.
A new study, published yesterday in Current Biology, shows just how detrimental artificial light is to a healthy sleep cycle by testing the hypothesis in a new way. In the study,eight people spent a week camping in the Colorado Rockies without any source of artificial light. To a person, the time spent outdoors during day and night restored a natural sleep cycle, turning even night owls into early risers.
The research team, led by Kenneth Wright, the director of the Sleep and Chronobiology Laboratory at the University of Colorado at Boulder, first closely tracked the sleep habits of the participants, who had an average age of 30, for a week’s time as they went about their normal lives. Each participant wore a watch with sensors that measured their light exposure and when they moved, to indicate when they were sleeping. For one of the days, they also submitted frequent saliva samples, so the scientists could measure the levels of melatonin in their bodies over the course of the day.
Next, the participants were sent for a week of camping in the Eagle Nest Wilderness, forbidden from bringing any electronics that emit artificial light—even flashlights. They wore the same sensors, so the researchers could see their sleeping habits and natural light exposure during the week away.
When the research team looked at the data, they found that all eight participants steadily shifted towards a sleep schedule that more closely mirrored the setting and rising of the Sun. Those who’d been night owls before the camping period—staying up later and waking later—saw the most dramatic shifts in their sleep cycles. As a whole, the campers slept for roughly the same amount of time each night as before, but fell asleep two hours earlier and awoke–without alarm clocks–two hours earlier as well.
The scientists say two factors are at work. For one, eliminating exposure to artificial light after sunset allowed the participants to naturally increase their melatonin levels at the right time, promoting sleep. Additionally, being exposed to natural light all day—something few office workers or students experience on a regular basis—also helped to set their circadian clocks, and as a result, they naturally cut back melatonin levels just before waking, reducing levels of grogginess. For many people in the modern world, melatonin levels don’t drop until one or two hours after waking up, accounting for the extreme tiredness many of us feel when the alarm clock goes off.
How can you take advantage of the finding to improve your own sleep schedule? The researchers say that any increased level of natural light in your day—whether a walk in the morning, a lunch outside, or an opened windowshade—can help align your circadian rhythms more closely with the Sun. Minimizing exposure to artificial light and electronics once the Sun has gone down (dimming lights, and shutting off phones, TVs and tablets) can also make a huge difference.
Of course, to those for whom the research finding is absolutely no surprise—the solution to your sleep woes is much simpler. If you have the freedom (and if unlike this guy you don’t fear the daystar), get off your computer, leave your house, and go camping.
July 16, 2013
Imagine you’re a scientist and you want to track the population of an endangered frog species in, say, the Puerto Rican rainforest.
In the old days, you’d have to write a proposal, win a grant, put together a team, trek out into the field and spend a few weeks or months manually collecting and cataloging samples. A few years later, if you wanted to know whether the frog population had recovered or gotten even smaller, you’d have to go through the same process all over again.
A new way of collecting this information, presented today by scientists from the University of Puerto Rico in the journal PeerJ, promises to make this process much easier, faster and more comprehensive. Their idea—a network of widely distributed microphones and web-based audio recognition software, which they call ARBIMON (for Automated Remote Biodiversity Monitoring Network)—could someday make it possible for us to eventually have real-time estimates on critical animal population levels in spots all over the world.
The researchers designed the distributed hardware part of the system to be built from relatively inexpensive, widely available components—such and iPods and car batteries—along with waterproof cases and solar panels, which would enable the microphones, once placed, to last several years. The idea is that a network of such microphones, with one placed roughly 50 square meters, could act as remote ears listening in on the ecosystem: Every ten minutes, each microphone will record one minute of the local ecosystem’s sounds (amounting to 144 recordings per day) and send it via a radio antenna to a nearby base station.
Each base station will then send the recordings on to a centralized server in Puerto Rico, from where they’ll be made public in near-real time at Arbimon.com. Simultaneously, software will analyze sounds from the recording to pick out the different noises made by different species. Using an existing bank of identified species calls, the software will assign particular sounds to particular birds, frogs and other creatures.
Verified users—perhaps a biologist working on research on a particular species, or a member of the general public with a background in birding, for example—can contribute to the project by listening to the recordings and verifying whether the software is correctly identifying sounds and matching them to right species. Over time, input by users will train the software to become more accurate.
Eventually, once the software is trained to identify each call, the researchers say it’ll be able to process more than 100,000 minute-long recordings in less than an hour. As a result, a biologist will be able access a constant stream of data on the levels of a specific species in spots around the world, or the fluctuating populations of various species in one ecosystem.
Initially, biologists can index certain frequencies of a species’ calls to known populations of that species in each location—for example, 400 coqui chirps per hour means that 10 coquis are in the area. Later on, when the frequency of calls changes, this data can be extrapolated to infer fluctuations in the population present.
In the published paper, the system’s capability was demonstrated by tracking populations of a number of birds, frog, insect and mammals species in Puerto Rico and Costa Rica over the past few years. At the Puerto Rico research site in the Sabana Seca wetland, the researchers focused on tracking populations of the Plains coqui frog, an endangered amphibian discovered in 2005 with a high-pitched, distinctive chirp. Listen to a clip of the Sabana Seca filled with coqui chirps:
Microphones were first installed there in 2008, and over the subsequent few years, the researchers trained the software to become increasingly accurate at analyzing the various sounds picked up and determining which were the plains coqui’s chirp. Eventually, scientists charted variations in the chirp’s frequency on both daily and seasonal timescales and were able to match these with surveyed data on changes in the c
One of the reasons these researchers are most excited about the new system is the way it’ll standardize and permanently store the audio samples indefinitely. 50 years from now, they say, if a conservation biologist wants to look back at the way populations of a species have fluctuated over time, he or she can simply access the recordings and have them analyzed. Not only will this help to track endangered populations, but could also pinpoint when invasive species began to dominate certain ecological niches.
The next step, according to the researchers, is installing these microphone setups in all sorts of ecosystems—every place where there’s a species that merits attention.
July 10, 2013
Every time you switch on a light, charge your electronics or heat your home in the winter, you’re relying upon a tremendous network of energy infrastructure that literally stretches across the country: power plants, pipelines, transmission wires and storage facilities.
It can be hard to visualize all this infrastructure and understand how it makes abundant energy available throughout the country. A map, though, can be a beautiful way of seeing a bigger picture—and a new map, released yesterday by the U.S. Energy Information Administration, combines a wide range of data (the locations of different types of power plants, electricity lines, natural gas pipelines, refineries, storage facilities and more) into an elegant, interactive interface that helps you understand how it all fits together. You can also zoom in on your own city or region to see the types of power plants generating electricity nearby.
The map also includes layers of real-time information on storm movement and risks, and the main intention of making all this data public is to allow utility officials and energy analysts to better understand the potential impact of storms, with hurricane season set to start. But simply playing around with the map can provide interesting insights about the state of our energy infrastructure today.
Here are a few of them, along with the percentage of U.S. electricity generation each power source currently provides:
Fossil Fuels Still Rule (Coal, 37%; Natural Gas, 30%; Petroleum, 1%)
Our capacity to generate renewable energy has certainly grown in recent years, but looking at the map (and the data), one thing is clear: coal (black), natural gas (light blue) and oil-burning (tan) power plants are still the most plentiful forms of electricity generation we have. Coal plants are especially common east of the Mississippi—a relic of the fact that most U.S. coal was once mined in West Virginia, Pennsylvania and Kentucky (PDF), even though the majority now comes from Wyoming’s Powder River Basin. Oil and natural gas plants, meanwhile, are distributed pretty evenly among population centers across the country, with the former slightly more common in the North and East, and the latter a bit more common across the South.
Nuclear Power Could be in Your Backyard (19%)
Although no new nuclear power reactors have been built since 1997, there are still 65 in operation nationally, and most are relatively close to large population centers. More than 16 million people live within 18 miles of one of these plants, the radius that Japanese officials evacuated after the 2011 Fukushima disaster. Despite the potential danger they might pose, though, nuclear plants provide far more electricity than any other non-fossil fuel option—and as a result, they reduce the amount of carbon dioxide emitted by our country as a whole.
Hydroelectric is Crucial (7%)
Hydropower was among the first electricity technologies to be implemented on a wide scale—a power station situated on Niagara Falls began supplying electricity way back in 1881—and it’s still way ahead of the other renewable options. Hydroelectric plants are largely clustered in three areas: New England, the Middle South (partly as a result of the Depression-era Tennessee Valley Authority Project) and the West.
Of all new electricity capacity built from 2008 to 2012, 36.5 percent came from wind, and it shows: Turbines can now be found in most regions of the country with sufficient wind speeds. They’re especially prevalent in the Midwest, where consistent and strong winds blow across the plains year-round. In total, large-scale wind projects have been built in 39 states, with many more in the works. The map above shows turbines (grey) against a background displaying real-time wind speeds, with green arrows indicating slowest winds, then orange showing middle speeds and red showing fastest.
Compared to wind, another main source of renewable energy—solar power—has grown at a considerably slower rate, mostly because it’s much more expensive. Still, though, several major projects have been built, including the Agua Caliente Solar Project in Arizona, which produces more photovoltaic energy than any other plant globally, and the Solar Energy Generating Systems in California’s Mojave Desert, which is the largest solar thermal energy project (generating electricity by harnessing solar power to produce heat) in the world.
It’s hard to truly appreciate how much natural gas pipeline has been laid in this country until you look at the map and see for yourself. To put it in perspective, there are more than 305,000 miles of pipeline nationally, as compared to about 47,000 miles of interstate highway.
When it’s discussed in the news, the Strategic Petroleum Reserve is mainly discussed in the abstract, an emergency supply of oil that we can use if our supply were to be disrupted. As a result, many people imagine it as a distributed, perhaps even hypothetical entity. Not true: This supply of nearly 700 million barrels of petroleum is held in four particular storage locations in Louisiana and Texas, near many of the refineries where it’s made from crude oil.
Of course, these are far from the only insights to be gained from tinkering with the map, packed with more than 20 layers of data on everything from geothermal power to offshore oil platforms to electricity transmission lines. Play around with the map yourself, turning on and off layers of data, and drop us a comment with your most interesting insights below.
July 9, 2013
In extreme Northern Scotland, between the mainland and the Orkney Islands, lies the Pentland Firth, a roughly ten-mile-wide seaway between the North Sea and the Atlantic. Along with seals, porpoises and the occasional killer whale, the Firth is known for its uncommonly strong and fast tides—they’ve been recorded at speeds as high as 18 miles per hour, among the fastest in the world—the result of an enormous quantity of water rushing back and forth through a narrow passage roughly every six hours.
For centuries, these tides have been considered a hazard to sailors and fishing vessels. More recently, though, Scottish officials have pointed out that the Pentland Firth’s powerful tides could present an unexpected benefit: As countries search for new sources of renewable energy, these tides could make Scotland the “Saudi Arabia” of tidal power.
Observers have long speculated about the potential for electricity generation using tidal energy, and though there are still only a handful of tidal power plants completed worldwide, many other projects are nearing construction or have been proposed. Of these, none equals the Pentland Firth in terms of estimated power generation capacity—Scotland has suggested it could provide as much as 10 gigawatts of electricity on average over the course of a day, enough to supply a quarter of the European Union’s daily needs—and as a result, a number of energy companies have recently acquired leases to install turbines in the waterway.
Until now, though, despite the lofty predictions, no scientists had conducted a systematic study to figure out exactly how much energy the Firth might supply. Today, a group from the University of Oxford and elsewhere released the results of their review of the waterway’s total capacity.
Though their numbers might not justify comparing Scotland with the Persian Gulf in terms of overall energy potential, they do suggest that it could certainly be a Saudi Arabia for tidal power, and that the Pentland Firth could play a major role in powering the U.K. Their analysis shows that the seaway could potentially provide an average of 1.9 gigawatts of electricity at any given time, a number that equals about half of Scotland’s electrical consumption.
The analysis, published in the Proceedings of the Royal Society A, modeled the maximum potential electricity generation of a scheme that would involve three rows of underwater tidal turbines, each consisting of hundreds of posts that stretch across the entire passage. These turbines harness the energy in the passing tides in essentially the same way that wind turbines capture the energy in passing gusts of wind—by using the flow of water to spin the turbine, which turns a magnet located in the center, thereby generating an electrical field. Because water is much denser than air, though, tidal turbines will spin faster and can potentially generate much more power than wind turbines of the same size.
The researchers looked at the construction of multiple rows of these sorts of turbines, placed in a variety of locations within the Firth. Their models took into account the depth of the water at each given location, observed tidal speeds and heights over the course of each month, and a number of other variables.
Ultimately, the team found that the maximum practical capacity of 1.9 gigawatts would be possible with three rows of turbines, built in the locations mapped below (B, C, and D on the map). Because each row slows down the movement of the tides that pass through it, building more then three would only marginally improve the power capacity, while increasing the overall cost of the project at a constant rate. (A, on the map, is a proposed alternate scheme that would produce a similar level of energy but at a higher cost.)
Of course, there are numerous impediments to constructing tidal turbines on such a huge scale, which would dwarf any current tidal energy project in existence. Some are concerned that tidal turbines could have negative ecological effects, disrupting fish and other wildlife communities. Research into just how these sorts turbines would affect local ecosystems is in its beginning stages. Additionally, in areas like the Pentland Firth, turbines would have to be constructed with large enough gaps for ships to pass through, since the channel is a crucial shipping waterway, but the authors of this paper took this sort of spacing into account when making their calculations.
As of now, the biggest hurdle is price: without any carbon pollution regulation schemes in place, most renewable sources of energy, including tidal power, just aren’t as cheap as burning coal or other fossil fuels. But many energy companies have already recognized that, long-term, the cost of fossil fuel production will increase—both because of eventual regulations of the emissions of greenhouse gases and because of fossil fuels are becoming increasingly costly to extract—and harnessing the power of the tides could provide a reliable way to meet a portion of our energy demands.
July 8, 2013
The autoclave—a device that generates steam to kill bacteria and sterilize medical equipment—was invented way back in 1879. But 134 years later, infections that develop as a result of improperly sterilized medical equipment are still estimated to affect hundreds of millions of people each year, mostly in the developing world. In places with limited access to autoclave technology, along with an inconsistent power supply, many people still undergo surgery with equipment teeming with bacteria, viruses and other pathogens.
The good news, though, is that this problem could be solved soon, thanks to a device called a solarclave, developed by a group of engineers led by Oara Neumann and Naomi Halas of Rice University. Their device, described in an article published today in Proceedings of the National Academy of Sciences, harnesses the power of the Sun—along with the unique characteristics of specific nanoparticles—to sanitize medical equipment and other instruments without any need for an external electricity source.
The researchers weren’t the first team to have the idea of using solar power to sterilize equipment, but this is the first functioning prototype that has passed standard FDA-level sterilization tests. Conventional autoclaves use electricity to produce steam, but this device does so by relying on metal and carbon nanoparticles (tiny particles that as small as one ten-thousandth of a centimeter in diameter) that are scattered in an aqueous solution.
The nanoparticles’ thermodynamic characteristics cause them to absorb energy much faster than the surrounding liquid, generating a large temperature difference as sunlight is collected by mirrored dish and its heat is funneled into the solution. The heat is then transferred to the water molecules that are adjacent to the nanoparticles and converts them directly into steam. This design allows the conversion of solar power into steam in an extremely efficient manner—only 20 percent of the energy is used to raise the temperature of the liquid, and the remaining 80 percent helps to produce and sustain the steam bath.
Unlike when water is normally boiled and turned into steam, the nanoparticles are able to generate substantial amounts of steam at 70 degrees Celsius, when the solution is still far below its boiling point (some steam was even generated when the researchers put the fluid capsule in an ice bath, keeping it just above zero degrees Celsius). As a result, the solarclave can perform what is normally an extremely energy-intensive process—sterilizing medical equipment—using the limited intensity of solar power alone.
The researchers used this technology to produce two related prototypes that can both operate off the grid. One is a closed-loop system designed to sterilize medical equipment and other relatively small objects; the other allows for inputs and is designed to sterilize human and animal waste to reduce the spread of disease, an ongoing problem in developing countries. If operated three times a week, the researchers estimate that it can process the urine and feces produced by a family of four adults.
The prototypes were tested by their efficacy in killing Geobacillus stearothermophilus, a type of bacteria that grows in hot springs and other warm environments, and thus is more difficult to remove via heating than most other types of microbes. Both of the solarclaves passed the test, killing all the bacteria in the sample over the course of 30 minutes.
If this sort of technology can be produced on a mass scale, it has the potential to help greatly reduce the amount of infections worldwide. The nanoparticles aren’t consumed during the sterilization process, so they can be reused indefinitely, and relatively small amounts of water are used during each cycle. The researchers also sought to use low-cost components whenever possible, but because the device is still in the prototype stage, it’s hard to say what the final price tag would be.
Barring issues of cost, the solarclave can potentially be used in all sorts of circumstances where access to electricity is the main limitation. The most immediate applications are sterilizing medical equipment and human waste, but the researchers speculate that the same sort of technology could eventually be used to purify water and limit the spread of bacteria in food products. The design’s remarkable efficiency in producing steam, they say, could someday even be used in the generation of electricity.