For most people, the great mystery of time is that there never seems to be enough of it. If it is any consolation, physicists are having much the same problem. The laws of physics contain a time variable, but it fails to capture key aspects of time as we live it—notably, the distinction between past and future. And as researchers try to formulate more fundamental laws, the little t evaporates altogether....
Chemicals from munitions have permeated soil across an estimated 10 million hectares of land used for firing ranges across the U.S. One such chemical, an explosive called RDX, can leach into groundwater and cause seizures and possibly cancer. Now a study in Nature Biotechnology shows that genetically modified switchgrass—a plant common in North American prairies—can absorb and break down RDX. University of York biologists Neil Bruce and Liz Rylott and their colleagues altered a switchgrass variety to carry two genes from a bacterium that produces enzymes capable of reducing RDX into harmless components....
The World Health Organization this morning released a relatively reassuring report suggesting few health impacts from the 2011 disaster at the Fukushima Daiichi nuclear power plant in Japan. But the accident is likely to cause small, but significant, increases in cancers in populations in a few hotspots exposed to higher radioactive doses. These conclusions regarding the worst nuclear accident since Chernobyl in 1986 could be less comforting than they sound: In fact, Japan dodged a bullet thanks to the weather....
After his 1902 trip to Yemen, scholar and naturalist Wilhelm Hein returned with a variety of plants and animals, which he donated to the Vienna Museum. One of these specimens, a shark, sat unnoticed for more than 80 years. In 1985 it was identified as the first (and only known) specimen of Carcharhinus leiodon, the smoothtooth blacktip shark. Because no others had ever been found by scientists, Alec Moore, regional vice chair of the International Union for Conservation of Nature (IUCN) Shark Specialist Group’s Indian Ocean group, says that “some suspected it might be extinct or not a valid species....
Gas likes to escape. That’s bad news for the atmosphere when the gas in question is methane, the primary component in natural gas that is a much stronger greenhouse gas than carbon dioxide. But burning natural gas results in half the greenhouse gas pollution than coal, making it appealing as fuel in an era of combating climate change. Thanks to a bonanza of natural gas liberated from deep shales by new techniques, the U....
The Federal Reserve Bank of Chicago is investigating how the Volkswagen AG emissions cheating scandal affected health outcomes in the United States. And the findings are grim: A new working paper from the bank found that the addition of just one cheating diesel car per 1,000 cars increased rates of low birth weight and acute asthma attacks among children by 1.9% and 8.0%, respectively. “People tend to avoid pollution. So if they know about the pollution, they will not go out and experience it,” said Chicago Fed economist Diane Alexander....
After an unsuccessful campaign to demonstrate the principles of a futuristic fusion power plant, the world’s most powerful laser facility is set to change course and emphasize its nuclear weapons research. For the past six years, scientists and engineers at the US National Ignition Facility (NIF) have been working flat out to focus 192 laser beams on a gold-lined ‘hohlraum’ capsule, just a few millimeters long, containing a pellet of hydrogen isotopes....
In 2003 a patient known as TN lost his sight after suffering two successive strokes; the visual cortex in his brain was damaged and his vision was totally gone, although the eyes themselves were still healthy. During one examination years after he lost his sight, researchers were flabbergasted to see TN carefully navigate a hallway full of overturned chairs, scattered boxes and other obstacles without colliding with a single thing. How was this possible for a person who was completely blind?...
Did you like this article? Editorial Review This article has been reviewed for accuracy, reliability and adherence to academic standards prior to publication. Mesopotamia is the ancient Greek name (meaning “the land between two rivers”, the Tigris and Euphrates) for the region corresponding to modern-day Iraq and parts of Iran, Syria, and Turkey. It is considered the “cradle of civilization” for the many inventions and innovations which first appeared there c....
Did you like this article? Editorial Review This article has been reviewed for accuracy, reliability and adherence to academic standards prior to publication. This text is part of an article series on the Delian League. The fifth phase of the Delian League begins with the Peace of Nicias – a settlement that settled nothing – and ends with the start of the Decelean War (also referred to as the Ionian War)....
Ishmael Tirado watches as his fellow construction workers rebuild the Steeplechase Pier, a central feature of New York’s iconic Coney Island boardwalk. Planks of tropical ipê wood that were torn asunder by last year’s Hurricane Sandy lie in grey stacks behind him, ready to be scrapped or recycled, but fresh boards are tellingly absent. When the pier reopens this summer, visitors will encounter a shiny expanse of recycled plastic jutting out to sea on a platform of steel-reinforced concrete....
Editor’s Note (5/27/20): Because of unfavorable weather conditions, the historic launch of two NASA astronauts on a SpaceX crew module and rocket has been postponed until Saturday, May 30, at 3:22 P.M. Eastern time. Barring poor weather or last-minute technical glitches, shortly after 4:30 P.M. Eastern time today, a spaceship carrying two crew members will blast off on a rocket from the Kennedy Space Center in Florida. The flight will be bound for the International Space Station (ISS), but its true destination is the annals of space history: it will be the first time that U....
High-speed camera snapshots may have pinpointed a spot in the brain that serves as a marker for depression. Investigators have observed that electrical chatter in the dentate gyrus—a C-shaped region of the hippocampus—contracts in depressed rats but expands again after the animals receive antidepressants. The region may represent a common pathway or intersection for brain activity in those suffering from depression, offering a springboard from which to map that activity and better understand the condition, says Karl Deisseroth, a Stanford University neuroengineer and psychiatrist, who led the study published online this week by Science....
Key concepts Physics Engineering Potential energy Kinetic energy Conservation of energy Introduction You probably know what a catapult is. In the Middle Ages armies would use them to hurl stones at castle walls. But did you know about an even bigger type of medieval siege weapon called a trebuchet? Try this project to build a miniature version! Background The Bring Science Home activity Build a Catapult showed you how to build a miniature catapult out of popsicle sticks and rubber bands....
Urgent efforts to avert a government shutdown at midnight faltered yesterday over Republican initiatives to freeze climate rules, a challenge to the president’s environmental priorities at the outset of his re-election bid. Controversial policy provisions meant to defund U.S. EPA’s rulemaking for greenhouse gas emissions and abortion programs are the key obstacles to negotiating a government funding package through September, Senate Democrats and administration officials said yesterday. “The numbers are basically there,” Senate Majority Leader Harry Reid (D-Nev....
The dwarf planet Makemake has some company out in the cold, dark depths of the outer solar system. Astronomers using NASA’s Hubble Space Telescope have discovered a moon orbiting Makemake, which is the second-brightest object in the distant Kuiper Belt beyond Neptune. (Pluto is the brightest of these bodies.) The newfound satellite—the first ever spotted around Makemake—is 1,300 times fainter than the dwarf planet and is thought to be about 100 miles (160 kilometers) in diameter, researchers said....
The electric grid was designed as a one-way highway, with power cascading out from big power plants to cities and towns at the end of the line. But because of changes to how we consume and generate electricity, managing power flows on the grid is becoming more complex—and will be more so in the future. As more variable renewable energy comes online, grid operators need new ways to maintain the steady balance between supply and demand to ensure reliable service....
By Ari Rabinovitch NEGEV DESERT Israel (Reuters) - An Israeli solar power company, Brenmiller Energy, says it has developed a new, more efficient way to store heat from the sun that could give a boost to the thermal solar power industry by enabling plants to run at full capacity night and day. By next year company founder Avi Brenmiller said he will have a 1.5 megawatt (MW), 15-acre (6-hectare) site in the Negev desert connected to Israel’s national grid, and a number of 10 to 20-MW pilots abroad are expected to follow, which will produce electricity at a price which competes with power from fossil-fuelled plants....
The city of Boulder wants to block fracking in the Rocky Mountain state. The liberal enclave has banned the combination of directional drilling and cracking subterranean rock with high-pressure fluids known as fracking within its city limits. And local Democratic U.S. Rep. Jared Polis wanted to enable other communities in Colorado to follow suit. He began collecting signatures for a ballot measure that would have vested authority in municipalities to enact their own fracking regulations, no matter what the state as a whole decides, to control the controversial practice that frees more oil and gas....
By peering into the distance with the biggest and best telescopes in the world, astronomers have managed to glimpse exploding stars, galaxies and other glowing cosmic beacons as they appeared just hundreds of millions of years after the big bang. They are so far away that their light is only now reaching Earth, even though it was emitted more than 13 billion years ago. Astronomers have been able to identify those objects in the early universe because their bright glow has remained visible even after a long, universe-spanning journey....
