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Whether you found the food pyramid created by the U.S. Department of Agriculture in 1992 beneficial or not, it was at least simple to use. The familiar triangular nutrition guide suggested how much of each food category—grains, dairy products, fruits and vegetables, meats and fats, oils and sweets—one should eat every day. But in my opinion, the USDA’s 2005 replacement, MyPyramid, is a disaster. The process the agriculture agency employed to replace the 1992 food pyramid (left) has been kept secret....

Every now and then the public rises up to make an industry clean up its environmental act. As a result, car companies now offer hybrids, electrics and alternative-fuel cars. Beverage companies are making their bottles with a lot less plastic. New laws have reduced the chemicals that cause acid rain by 76 percent since 1980. And so on. One industry in particular, however, continues to leave a disastrous eco-wake, because no such public pressure exists: consumer electronics....

For about 165,000 people in the United States1, staying awake during the day is a tall order. Individuals with narcolepsy often fall asleep with little warning. But the condition involves far more than just tiredness. It can affect every aspect of life. Around 70 per cent of people with narcolepsy suffer with cataplexy (brief episodes of sudden loss of muscle strength or tone, often brought on by strong emotions)2, and some people with narcolepsy experience hallucinations (vivid dream-like experiences while falling asleep or waking up), and sleep paralysis (the temporary inability to move or speak during sleep-wake transitions)....

At first glance identical twins seem, well, identical. In fact many of these sibling pairs show minor physical variations and differences in characteristics such as susceptibility to disease. Just what causes these dissimilarities is unclear. But a new report further suggests that epigenetic factors–that is, differences in how the genome is expressed–could be responsible. Mario F. Fraga of the Spanish National Cancer Center and his colleagues studied 160 monozygous twins ranging from three to 74 years of age....

For many sea creatures, regrowing a lost limb is routine. But when a young jellyfish loses a tentacle or two to the jaws of a sea turtle, for example, it rearranges its remaining limbs to ensure it can still eat and swim properly, according to a new study published June 15 in Proceedings of the National Academy of Sciences. The discovery should excite marine enthusiasts and roboteers alike, the authors say, because the jellyfish’s strategy for self-repair may teach investigators how to build robots that can heal themselves....

Rising from the floor of Gale Crater on Mars, a stack of sedimentary rock called Mount Sharp towers 5.5 kilometers above the ground. The mountain is only a little shorter than North America’s tallest peak, Alaska’s Mount Denali (nearly 6.2 kilometers high). Monstrous mountains on Earth are usually created by colliding plates of the planet’s outer shell or by erupting volcanoes. But Mars does not have this kind of plate activity and its volcanoes have probably not been active for at least 500 million years....

Brain New World: The Brain Supremacy: Notes from the Frontiers of Neuroscience by Kathleen Taylor Oxford University Press, 2012 ($29.95) What if our thoughts could be plumbed by a brain scanner and memories manipulated with the flip of a genetic switch? Neuroscientist Taylor believes these science fiction–like scenarios could become reality because new technologies may soon allow unprecedented access to our brains. Taylor begins The Brain Supremacy by contemplating a future in which we can decipher others’ private emotions and ideas as well as sculpt designer minds....

News reports in the past two weeks have noted that 2012 was the warmest year ever recorded in the U.S. Today we learn that 3,527 monthly weather records were broken in 2012, according to the Natural Resources Defense Council (NRDC). The tally exceeds the 3,251 records set in 2011, the previous high. NRDC has just released an interactive map equipped with a slider that can be moved from January to December to reveal where record temperatures, rainfall, snowfall, floods, droughts and wildfires were occurring on any given day....

The big bang is often thought of as the beginning of everything, including time, making any questions about what happened beforehand nonsensical. Now exotic theories that suggest the existence of an era before the big bang are growing in number. They indicate that imprints of this era might exist and that an upcoming generation of telescopes could detect them. According to conventional big bang thinking, the universe emerged from a point of infinite energy and density, a singularity where the laws of physics break down....

Man-made deluge scours Grand Canyon in the name of endangered fish To survive, the humpback chub—an endangered fish with a prominent hump of flesh immediately behind its long-snouted head—needs sandbars in the Colorado River. These silt deposits create calm waters where the fish can spawn and also cloud the river creating conditions in which the chub can thrive. But the building of the Glen Canyon Dam in the 1960s ended the natural ebb and flow of the river that courses through the Grand Canyon, which severely altered the natural conditions in which the chub evolved, pushing the silvery-green fish onto the path of extinction....

Solution to warm-up 2: In the frame of reference of the disk, the shortest distances are straight lines. That is, the shortest path from one point on a circle to another is a straight-line segment. In general, the car will therefore traverse a chord through the disk such that the end of the chord is precisely the point where the car wants to exit given the disk’s rotation. See this illustration: http://cs....

KUALA LUMPUR, Malaysia—There are macaques everywhere—climbing on the rocks, grooming one another as they sit on the forest floor. Others have babies on their backs as they trot along at a fair clip. The air is thick with humidity and it must be 35 degrees Celsius or more—the heavy gray clouds above look ready to crack into a noisy tropical thunderstorm at any moment. I’m making my way along a dense rainforest path with the noisy thrum of insects all around me....

A nickel for your bottle works better than a pat on the back for good citizenry. There’s nothing new about reusing and recycling. Archeological digs (see here and here)reveal evidence of people recycling stuff as far back as 400 BC; some scientific evidence suggestsrecycling goes back to the Neanderthalsand possibly beyond. Perhaps that is surprising on its face, but when you think about it, making tools and containers by hand is pretty tough stuff, so reusing from source material in hand makes more than a lot of sense....

How often do you buy a new car? A new house? A new couch? A new raincoat, fridge, or washer and dryer? And now: How often do you get a new cell phone? Clearly, the upgrade cycle plays a much bigger role in the tech industry than in any other realm of consumer goods. Most people wouldn’t be embarrassed to drive a 2009 Toyota Camry or to put their food in a 2002 refrigerator (or even a 1992 fridge)....

Key Concepts Images Virtual images Transmission Reflection Optical illusions Introduction Ever wonder why mirrors can make a room feel so much larger than it really is? Mirrors are so common that we rarely think of how intriguing they really are. They somehow take the three-dimensional world we live in and reproduce it so perfectly that we are subconsciously fooled into perceiving that another 3-D space exists beyond the mirror’s surface. We know, of course, that this is just an illusion....

Researchers hope to send an experiment to the International Space Station (ISS) by the middle of the next decade that would pave the way for transcontinental transmission of secret messages encoded using the mysterious quantum property of entanglement. When two particles such as photons are born from the same event, they emerge entangled, meaning they can communicate instantaneously no matter how far apart they are. Transmitting entangled pairs of photons reliably is the backbone of so-called quantum key distribution—procedures for converting those pairs into potentially unbreakable codes....

Editor’s Note: This is an extended version of the story that original ran in the June 2008 issue of Scientific American. The recent surge in world food prices is already creating havoc in poor countries, and worse is to come. Food riots are spreading across Africa, though many are unreported in the international press. Moreover, the surge in wheat, maize and rice prices seen on commodities markets have not yet fully percolated into the shops and stalls of the poor countries or the budgets of relief organizations....

Natural climate variability is extremely unlikely to have contributed more than about one-quarter of the temperature rise observed in the past 60 years, reports a pair of Swiss climate modelers in a paper published online December 4. Most of the observed warming—at least 74 percent—is almost certainly due to human activity, they write in Nature Geoscience. Since 1950, the average global surface air temperature has increased by more than 0.5 degree Celsius....

On 6 July, if all goes to plan, a pack of about 100 sticky-note-sized ‘chipsats’ will be launched up to the International Space Station for a landmark deployment. During a brief few days of testing, the minuscule satellites will transmit data on their energy load and orientation before they drift out of orbit and burn up in Earth’s atmosphere. The chipsats, flat squares that measure just 3.2 centimetres to a side and weigh about 5 grams apiece, were designed for a PhD project....

From Simons Science News (find original story here). With just 121 protein-coding genes, the diminutive Tremblaya princeps, a symbiotic bacterium that lives inside specialized cells of the sap-eating mealybug, has the smallest known genome of any cellular organism on the planet. Tremblaya helps to supply the mealybug with essential amino acids and likely receives nutrients and other life-sustaining molecules in return. And even as it tests the lower limits of genome size, the Tremblaya genome may still be shedding genes....