Month: August 2016

From produce that rots in delivery trucks to oversized portions on restaurant plates, we waste vast amounts of food. In fact, researchers at the Potsdam Institute for Climate Impact Research in Germany recently found that the average amount of food wasted per person per day has increased from 310 kilocalories in 1965 to 510 kilocalories in 2010. That is roughly the equivalent of going from dumping six apples in the trash to tossing 10 of them—every single day. By 2050 that number could go as high as 850 kilocalories, the researchers predict.

An exact tally of food waste is impossible, so to calculate these numbers the Potsdam team used a proxy: food surplus, or the difference between the amount of food a country produces or imports for consumption and the total calories its populace requires. They ran the numbers for 169 countries (98 percent of the world’s population) and calculated that in 2010—the year with the most recent data available—20 percent more food was available globally than what the human population needed. Overall, the higher a country’s standard of living, the more food it wasted. The results were published in Environmental Science & Technology.

Is all that extra food literally going into the garbage? Not necessarily, says co-author and geoecologist Prajal Pradhan. People often eat more than they require (a complex and subjective calculation in its own right), and some leftovers also become livestock feed. That means the study probably overestimated food waste, although Pradhan says the study incorporated fluctuating body weight data that should at least partly compensate for many of the people who simply overeat.

This overestimation does not weaken Pradhan’s findings, however, says Matti Kummu, a civil and environmental engineering professor at Aalto University in Finland who was not involved in the study. “Food surplus might be a simplistic estimate of food waste, but it’s a good one.”

There is also a silver lining to this surplus situation: if we could slash food waste, we could feed the world’s projected population of at least nine billion people in 2050 without heroic increases in agricultural productivity.

Source: “Food Surplus and Its Climate Burdens,” by Ceren Hiç, et al., in Environmental Science & Technology, Vol. 50, No. 8; April 19, 2016. Graphic by Amanda Montañez

While SpaceX is making news with its recoverable rockets, China announced that it is working on the next big thing in spaceflight: a hypersonic spaceplane.

The China Aerospace Science and Technology Corporation is beginning advanced research of such a spaceplane, which would be a high tech, more efficient successor to the retired Space Shuttle, with hybrid combined cycle engines that can takeoff from an airport’s landing strip and fly straight into orbit. The hybrid space plane’s combined cycle engines would use turbofan or turbojet engines to takeoff horizontally from a landing strip. Once airborne, the engine then shifts to ramjet propulsion and, as speed increases, it adjusts into a scramjet engine with supersonic airflow. At the scramjet stage, the hybrid spaceplane would enter hypersonic flight in ‘near space’, the part of the atmosphere between 20km to 100km above sea level. Finally, the hybrid spaceplane would use its rocket motors to push out of nearspace and into orbit. Broadcasts by both state television broadcaster CCTV, and its English service, note that the CASTC spaceplane’s easy reusability would exponentially bring down space launch costs.

Zhang Yong, a CASTC engineer, claimed that China will master the spaceplane’s technologies in the next three to five years, and a full scale spaceplane would then enter service by 2030. Interestingly, another CASTC engineer, Yang Yang, mentioned that the spaceplane would improve "ease of access to space for untrained persons" as the space plane would have more gradual acceleration than a space launch rocket (reducing the physical strain on astronauts during takeoff), suggesting a vision of a large, manned version of the spaceplane which could be used for space tourism.

Getting the complex technologies, like the combined cycle ramjet/turbo engine, the reported timeline is an extremely ambitious target. Yet, China is actually a world leader in a number of the key technologies for the project. In 2015, Professor Wang Zhengou was awarded the Feng Ru prize (China’s top aeronautical medal) for his work in successfully developing and flying a scramjet engine (making China the second nation in the world after the United States to master scramjet technology). CASTC’s rapid research timeline also suggests that the reports in 2015 of a Mach 4 test flight for a recoverable drone testbed for a combined cycle ramjet/turbofan engine were accurate. And China also has the world’s largest hypersonic wind tunnel, the Mach 9 JF-12, which could be used to easily test hypersonic scramjets without costly and potentially dangerous flight testing at altitude. China already has a variety of advanced solid and liquid fuelled space rockets and even China’s historical weakness in turbine engines may not be a problem (the proven WS-10 turbofan is likely to provide enough thrust for the combined cycle engine’s ramjet to take over). For CASTC, the biggest challenge may be in integrating all these components into a single propulsion package, as well as building an airframe light and strong enough to resist the rigors of hypersonic flight and atmospheric reentry

Whether the project meets with success within the targeted timeframe or it slips by several years, the results would be significant, and not just on the civilian side of any space race. In addition to increasing the rate of access and lowered costs for space launches, the Chinese military could draw direct military benefits from the combined cycle engine technology. Without the rocket motor component, the combined cycle engine would be a good fit to power hypersonic UAVs and manned aircraft. Flying in nearspace at speeds above Mach 5, such aircraft could have global reach, while their speed and high altitude would make them effectively immune to all existing air defense systems (though the turbine part of the engine would need to emphasis fuel efficiency and high thrust to weight).

Coming on the heels of other Chinese space advances, including the successful tests of a 3 meter diameter solid rocket booster, and the fuel turbopump for the LM-9 superheavy rocket, the present attention given to such a longterm project is notable. The high profile broadcast of Chinese breakthroughs in space technologies suggests that, in addition to boosting Chinese prestige, the Chinese leadership is looking to raise public awareness and support to justify costly investments in next generation space technology like hybrid spaceplanes and super heavy "Moon" rockets. Getting the first mover advantage in these aerospace milestones would definitely give China superpower status in both Earth and space.

You may also be interested in:

Chinese Hypersonic Engine Wins Award, Reshapes Space Race?

China Aims for Humanity’s Return to the Moon in the 2030s

China’s Largest Ever Space Rocket Takes Another Big Step Forward

China Showcases Plan to Become the Leading Space Power

China’s Space Station Plans in Powerpoint: A Closer Look at Tiangong 3

If you like the outdoors, a road trip between several national parks is perfect for a long weekend or vacation. This map plots the best route between nearby national parks so you spend less time planning and more time exploring.

http://ift.tt/1nyJJP0

While you probably won’t drive to all 47 national parks featured on the map at once, you can still create your own road trip route using parts of it. For example, you could start in L.A., hit Joshua Tree and Death Valley, cut over to Kings Canyon, Sequoia, and Yosemite before looping back towards L.A. through Pinnacles and the Channel Islands. The only route planning you would have to do is between Death Valley and Kings Canyon. In the interactive map at the link below, you can see which national parks are close to each other and the roads you would drive to get to each of them.

The Optimal U.S. National Parks Centennial Road Trip | Randal Olsen