Tag: scientific method

The British ‘Atlantis’ is mapped in detail

Dunwich Beach Sutterstock A professor of physical geography has put together the most detailed map yet of the sunken medieval town of Dunwich using underwater acoustic imagining. The port town, often referred to as “the British Atlantis,” was a hub of activity up until its collapse in the 1400s. This was brought about after a series of epic storms battered the coastline in the 1200s and 1300s, causing repeated flooding, submerging parts of the town, and flooding the harbor and river with silt. Today it stands as a small village, but up until its demise it was around the same size as medieval London. Despite still existing at depths of just three to 10 meters (or, 9.8 ft to 32.8 ft) below sea level, the murky conditions have made investigating what lies beneath particularly tricky. Since 2010, however, Southampton’s David Sear—along with the GeoData Institute, the National Oceanography Center, Wessex Archaeology, and local divers from North Sea Recovery and Learn Scuba—has been exploring the muddy depths using dual-frequency identification sonar (DIDSON) acoustic imaging. Read 8 remaining paragraphs | Comments

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The British ‘Atlantis’ is mapped in detail

New F-1B rocket engine upgrades Apollo-era design with 1.8M lbs of thrust

NASA has spent a lot of time and money resurrecting the F-1 rocket engine that powered the Saturn V back in the 1960s and 1970s, and Ars recently spent a week at the Marshall Space Flight Center in Huntsville, Alabama, to get the inside scoop on how the effort came to be . But there’s a very practical reason why NASA is putting old rocket parts up on a test stand and firing them off: its latest launch vehicle might be powered by engines that look, sound, and work a whole lot like the legendary F-1. This new launch vehicle, known as the Space Launch System , or SLS, is currently taking shape on NASA drawing boards. However, as is its mandate, NASA won’t be building the rocket itself—it will allow private industry to bid for the rights to build various components. One potential design wrinkle in SLS is that instead of using Space Shuttle-style solid rocket boosters, SLS could instead use liquid-fueled rocket motors, which would make it the United States’ first human-rated rocket in more than 30 years not to use solid-fuel boosters. The contest to suss this out is the Advanced Booster Competition , and one of the companies that has been down-selected as a final competitor is Huntsville-based Dynetics . Dynetics has partnered with Pratt Whitney Rocketdyne (designers of the Saturn V’s F-1 engine, among others) to propose a liquid-fueled booster featuring an engine based heavily on the design of the famous F-1. The booster is tentatively named Pyrios , after one of the fiery horses that pulled the god Apollo’s chariot; the engine is being called the F-1B. Read 34 remaining paragraphs | Comments

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New F-1B rocket engine upgrades Apollo-era design with 1.8M lbs of thrust

Newly spotted miles-wide comet bearing down on Mars

A comet spotted earlier this year may pass close enough for Mars to feel the rock’s hot breath down its neck, according to new reports that surfaced Monday and Tuesday. The comet, named C/2013 A1, may pass within a few tens of thousands of miles of Mars’ center, with a remote chance that the miles-wide comet will collide with the planet. C/2013 A1 “Siding Spring,” a comet between 5 and 30 miles wide, was spotted January 3 by astronomer Robert H. McNaught. Researchers were able to look back in the image history of the Catalina Sky Survey in Arizona and spot signs of the comet as early as December 8, 2012. NASA states that other archives have traced sightings back to October 4, 2012. According to scientists at NASA’s Near-Earth Object Program Office , Siding Spring originates from the Oort Cloud of our Solar System and has been journeying to this point for more than a million years. In less than two years, around October 19, 2014, the comet will pass very close to Mars. Read 2 remaining paragraphs | Comments

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Newly spotted miles-wide comet bearing down on Mars

Starved brains kill memory-making to survive

“Thanks for the memories, but I’d prefer a bite to eat.” UFL.edu As the organ responsible for maintaining equilibrium in the body and the most energy-demanding of all the organs, the brain takes a lot of the body’s energy allocation. So when food is in short supply, the brain is the organ that is fed first. But what happens when there isn’t enough food to fulfill the high-energy needs of the brain and survival is threatened? The brain does not simply self-allocate available resources on the fly; instead it “trims the fat” by turning off entire processes that are too costly. Researchers from CNRS in Paris created a true case of do-or-die, starving flies to the point where they must choose between switching off costly memory formation or dying. When flies are starved, their brains will block the formation of aversive long-term memories, which depend on costly protein synthesis and require repetitive learning. But that doesn’t mean all long-term memories are shut down. Appetitive long-term memories, which can be formed after a single training, are enhanced during a food shortage. Read 3 remaining paragraphs | Comments

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Starved brains kill memory-making to survive

MP3 files written as DNA with storage density of 2.2 petabytes per gram

The general approach to storing a binary file as DNA, described in detail below. Goldman et al., Nature It’s easy to get excited about the idea of encoding information in single molecules, which seems to be the ultimate end of the miniaturization that has been driving the electronics industry. But it’s also easy to forget that we’ve been beaten there—by a few billion years. The chemical information present in biomolecules was critical to the origin of life and probably dates back to whatever interesting chemical reactions preceded it. It’s only within the past few decades, however, that humans have learned to speak DNA. Even then, it took a while to develop the technology needed to synthesize and determine the sequence of large populations of molecules. But we’re there now, and people have started experimenting with putting binary data in biological form. Now, a new study has confirmed the flexibility of the approach by encoding everything from an MP3 to the decoding algorithm into fragments of DNA. The cost analysis done by the authors suggest that the technology may soon be suitable for decade-scale storage, provided current trends continue. Trinary encoding Computer data is in binary, while each location in a DNA molecule can hold any one of four bases (A, T, C, and G). Rather than using all that extra information capacity, however, the authors used it to avoid a technical problem. Stretches of a single type of base (say, TTTTT) are often not sequenced properly by current techniques—in fact, this was the biggest source of errors in the previous DNA data storage effort. So for this new encoding, they used one of the bases to break up long runs of any of the other three. Read 9 remaining paragraphs | Comments

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MP3 files written as DNA with storage density of 2.2 petabytes per gram

Wires smaller in diameter than light waves boost solar cell efficiency

Electron micrograph of indium phosphide (InP) nanowires. Each is 180 nanometers in diameter; this diameter allows them to capture more light, making them effective in a photovoltaic solar cell. Wallentin et al. In the continuing quest to create solar cells, researchers seek new materials, use clever techniques, and look for novel physical phenomena to extract the maximum electricity out of sunlight for the lowest cost. One method of extracting more power at a lower cost relies on creating arrays of nanowires that stand vertically on inexpensive substrates. In contrast to the material in ordinary solar cells, nanowires use less material, can potentially be built with less costly materials, and in principle trap more light thanks to the geometry of the arrays. However, most nanowire solar cells are currently outperformed by their conventional counterparts. A new effort used indium phosphide (InP) nanowires with diameters smaller than the wavelength of the light they were trapping. That trick enabled Jesper Wallentin and colleagues to reach comparable efficiencies and slightly higher voltage than a conventional InP solar cell. While the wires only covered 12 percent of the surface area, they exploited a principle known as resonant trapping to extract over half as much current as a full planar cell of InP. This approach could lead to even greater efficiency at lower cost for solar cells. Many candidates for the next generation of photovoltaic (PV) solar cells are being investigated. Research in this area has two goals that don’t always overlap: maximizing the efficiency of converting sunlight into electric current, and reducing cost per unit of electricity. The advantage of nanowire-based cells lies in using a lot less material, since the entire surface need not be covered in PV material. Additionally, the wires themselves can be fabricated from relatively inexpensive semiconductor materials. Read 7 remaining paragraphs | Comments

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Wires smaller in diameter than light waves boost solar cell efficiency

SpaceX gets its first military contract

The iconic “blue marble” picture of Earth, taken during the Apollo missions, will be a regular feature of the DSCOVR hardware NASA SpaceX announced that it had won two big US Air Force launch contracts Wednesday. If successful, the two demonstrations would help them qualify to compete for Air Force business against launch provider ULA (United Launch Alliance), which currently has a stranglehold on the largest Air Force launches. The first launch, planned for a Falcon 9, will send up the long-awaited NASA DSCOVR satellite to a distant point between the Sun and the Earth, where it can look at the Earth with the Sun behind it. The second, a Falcon Heavy launch, will put up several satellites and a 5 metric ton ballast, in an effort to demonstrate the Falcon 9 Heavy for the Air Force. Both contracts fall under the Air Force’s OSP-3 (Orbital/Suborbital) program, an Air Force program specifically designed to bringing in new launch companies. “GoreSat” rises from storage DSCOVR, NASA’s Deep Space Climate Observatory , has been in deep storage since 2001, when it was imprisoned by the incoming Bush Administration. DSCOVR is designed to measure the Earth’s albedo by tracking sunlight reflected back from the Earth from a distant vantage point. Former Vice-President Al Gore suggested that a video camera be installed on the satellite, with the hope that the constant video feed of the distant Earth would provide the same kind of ” Blue Marble ” perspective that the first pictures from Apollo did. The original Blue Marble picture is probably the most-circulated picture in human history, and is widely credited with contributing to the start of the modern ecology movement. Read 9 remaining paragraphs | Comments

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SpaceX gets its first military contract

Curiosity’s first chem test: Sands of Mars taste a lot like volcano

NASA/JPL After a few dry runs, the Curiosity rover has now put its chemistry set to use at a site called the Rock Garden. For the first time, we’ve operated an X-ray diffraction system on another planet, telling us something about the structure of the minerals in the Martian soil. The first results tell us the sand the rover has driven through contains some material that wouldn’t be out of place near a volcano on Earth. Curiosity comes equipped with a scoop that lets it pick up loose soil from the Martian surface and drop it into a hatch on the main body. From there, the samples can be directed into a variety of chemistry labs. Yesterday, NASA and the Jet Propulsion Laboratory revealed the first results obtained by the Chemistry and Mineralogy (or CheMin) instrument, the first time anything of this kind has been operated on another planet. We have a lot of ways to look at the composition of the material on Mars’ surface. We can look at the absorption of light by materials (including from orbit), which can tell us a lot about its likely composition. The rover itself has a number of spectrometers, which can also tell us about the chemical composition of rocks, as well as wet and dry chemistry labs. Read 5 remaining paragraphs | Comments

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Curiosity’s first chem test: Sands of Mars taste a lot like volcano