Archive for the SCIENCE Category

How Your Birth Month Affects Your Risk of Disease (Infographic)

Posted in SCIENCE with tags on January 25, 2016 by 2eyeswatching

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How Your Birth Month Affects Your Risk of Disease (Infographic)

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US Military Wants Smaller and More Stable Atomic Clocks

Posted in SCIENCE, TECHNOLOGY with tags on January 25, 2016 by 2eyeswatching

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US Military Wants Smaller and More Stable Atomic Clocks

The U.S. military wants you … to design a better atomic clock.

The Defense Advanced Research Projects Agency (DARPA), the branch of the U.S. Department of Defense tasked with developing new technologies for the military, recently announced a new program called Atomic Clocks with Enhanced Stability (ACES). The program aims to design anatomic clock that is 1,000 times more stable than current models, which are so precise that they arecapable of maintaining perfect time for billions of years, neither gaining nor losing 1 second during that time.

Atomic clocks are used to keep track of time in places where a tiny fraction of a second makes a huge difference. For instance, telecommunications towers employ them to synchronize data packets to within microseconds; if their clocks were off, the bits would pile up like cars in a traffic jam, and calls would get dropped. GPS satellites use them to time the signals that bounce between the satellites and the receivers to pinpoint specific locations. [5 of the Most Precise Clocks Ever Made]

“Every nanosecond you’re off, you’re out by 3 feet [0.9 meters],” said John Kitching, a group leader at the National Institute of Standards and Technology and an expert on small atomic clocks. “So, if you’re out [by a] microsecond, you’re off by a mile.”

Ordinarily, atomic clocks resynchronize regularly — for example, cellphone towers will check their clocks against those in GPS satellitesand adjust for any discrepancies. But they can’t do that if the GPS signal gets lost. GPS signals are weak enough that they can be jammed or interfered with, sometimes even inadvertently by a passerby with a cellphone, Kitching said. This could cause a satellite to go offline, either by accident or design. You can even lose a GPS signal by walking into a building or a canyon. (You may have noticed that when you’re inside a building, your phone’s mapping app is usually using the local Wi-Fi.)

This is one reason the military wants to build more stable clocks — they want ones that stay synchronized even if they are out of contact with GPS systems for extended periods of time.

As part of the ACES program, the Department of Defense wants to have atomic clocks that are small enough to fit inside a wallet and that can run on a quarter of a watt. That second parameter will likely be the bigger challenge, Kitching told Live Science.

“The smallest atomic clocks fit into a deck of cards, but they run on about 10 watts,” he said. “That’s not much if you’re plugging it into a wall, but an ordinarylithium-ion battery will run for about 10 minutes.”

Power is such a problem because of the way atomic clocks work, Kitching said. In an atomic clock, the “pendulum” is an atom, usually of an alkali metal like rubidium or cesium. The metal is put into a tiny vacuum chamber, surrounded by a piece of silicon. Then, both are sandwiched between pieces of glass. The metal is warmed up, and some of its atoms separate, forming a vapor.

Then, a laser beam is fired through the metal. Lasers operate at a specific frequency, though they can be tuned up or down a small amount, he added. The laser beam hits the atoms, which vibrate at a specific frequency. Meanwhile, a photodetector picks up the beam as it exits the vacuum chamber. As the laser is tuned, the light starts to match the frequency of the atoms’ vibrations, reaching a state called resonance. When it matches up, the photodetector picks up a stronger signal and turns that into an electrical pulse. The pulse goes to an oscillator that feeds back to the laser to keep it precisely tuned. Kitching said. All this takes power to run. [Video: How to Build the Most Accurate Atomic Clocks]

Even the most precise atomic clocks will drift, and the most sophisticated ones in labs like the NIST are operated at extremely low temperatures and are cooled with room-size laser beams. Both of these factors mean it will be challenging to make atomic clocks wallet-size and less power-hungry, said Kitching.

Robert Lutwak, DARPA’s program manager for the atomic clock project, agreed that fulfilling all the requirements set out by the agency will not be easy. “NIST has a fairly unique mission — to demonstrate the highest possible accuracy in a laboratory setting. As such, they “pull out all of the stops” to achieve the optimum performance without regards for cost, size, weight, or power, and without need for robust continuous operation over time, temperature, vibration, shock, or other real-world environments,” he told Live Science in an email.

The ACES program will have a budget of up to $50 million and will include three phases, according to DARPA. The teams chosen to take part in the first phase of the program will build their clocks in a laboratory and have to show that the parts operate together as an atomic clock with better stability than existing models. The teams chosen to continue the program will be asked to pack their clocks into a space smaller than 2 cubic inches (33 cubic centimeters). The final stage will involve demonstrating that the atomic clock can fit into a space less than 3 cubic inches (49 cubic cm), along with all the associated electronics.

An earlier DARPA program that lasted from 2000 to 2009 managed to shrink atomic clocks by a factor of 100 and create ones that were stable by a factor of 1 in 10 billion each second (meaning they will drift one second every 317 years). “The goals of the ACES program are to advance these by at least an order of magnitude,” Lutwak said.

On Feb. 1, DARPA will host an event to provide additional details about the ACES program.

Follow Live Science on Twitter @livescience. We’re also on Facebook &Google+. Original article on Live Science.

This Dry Patch of Land Used to Be Bolivia’s Second Largest Lake

Posted in INVIRONMENT, SCIENCE with tags on January 22, 2016 by 2eyeswatching

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This Dry Patch of Land Used to Be Bolivia’s Second Largest Lake

Yesterday 5:34pm

 http://gizmodo.com/this-dry-patch-of-land-used-to-be-bolivias-second-large-1754353903

This Dry Patch of Land Used to Be Bolivia's Second Largest Lake

This satellite image shows the outline of where Bolvia’s Lake Poopó used to be. Once the county’s second largest body of fresh water, it’s now dried up because of recurring drought and water diversion projects.

Typically, rainfall during the wet season (which runs from December to March) replenishes the lake. But we’re now well into January and rain remains scarce.

This Dry Patch of Land Used to Be Bolivia's Second Largest Lake

The image above was taken on April 12, 2013, and shows Lake Poopó when it’s filled with water. The one below was taken just six days ago on January 15, 2016. The water is essentially gone, replaced with dusty sand flats. The effect on the environment and ecosystem has been devastating.

This Dry Patch of Land Used to Be Bolivia's Second Largest Lake

This happened before in 1994, and it took several years for the water to return. But this time, scientists say recovery may not be possible. The APreports:

“This is a picture of the future of climate change,” says Dirk Hoffman, a German glaciologist who studies how rising temperatures from the burning of fossil fuels has accelerated glacial melting in Bolivia.

As Andean glaciers disappear so do the sources of Poopo’s water. But other factors are in play in the demise of Bolivia’s second-largest body of water behind Lake Titicaca.

Drought caused by the recurrent El Nino meteorological phenomenon is considered the main driver. Authorities say another factor is the diversion of water from Poopo’s tributaries, mostly for mining but also for agriculture.

[…]

A study by the German consortium Gitec-Cobodes determined that Poopo received 161 billion fewer liters of water in 2013 than required to maintain equilibrium.

“Irreversible changes in ecosystems could occur, causing massive emigration and greater conflicts,” said the study commissioned by Bolivia’s government.

A similar situation is happening in California, where the Salton Sea—a massive man-made lake—is shrinking, releasing dangerous toxins into the environment.

[NASA Earth Observatory | AP]

Top image: Jesse Allen, using Landsat data from the U.S. Geological Survey.

Email the author at george@gizmodo.com and follow him @dvorsky.

Hundreds of Tiny Bugs Are Probably Hiding in Your Home

Posted in INVIRONMENT, SCIENCE with tags on January 21, 2016 by 2eyeswatching

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Hundreds of Tiny Bugs Are Probably Hiding in Your Home

Why Does Soda Fizz?

Posted in SCIENCE with tags on January 21, 2016 by 2eyeswatching

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Why Does Soda Fizz?

Does China’s Cat-Eyed Boy Really Have Night Vision?

Posted in SCIENCE with tags on January 21, 2016 by 2eyeswatching

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Does China’s Cat-Eyed Boy Really Have Night Vision?

The First Flower Grown in Space is an Edible Orange Zinnia

Posted in SCIENCE with tags on January 17, 2016 by 2eyeswatching

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The First Flower Grown in Space is an Edible Orange Zinnia

The First Flower Grown in Space is an Edible Orange Zinnia1

The first flowers to ever grow in space are blooming on the International Space Station today. Despite fears of over-watering, the crew coaxed the zinnias into a burst of colour in their zero-g vegetable garden.

Zinnias are edible blooming plants that are usually on the easy ends in the spectrum to grow. They’re the second plant to be tested in the space station’s hydroponic VEGGIE lab. Astronauts taste-tested their previous crop, lettuce, last last year. Zinnias are most commonly eaten in salads, but also made a tasty accent to tacos.

So, gardeners: How does this flower look different than your terrestrial blooms?

Image credit: NASA/Scott Kelly


Contact the author at mika.mckinnon@io9.com or follow her at @MikaMcKinnon.