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Wednesday, October 30, 2013

On 7:31 AM by Zufar M Ihsan in ,    No comments

-Dinosaurus memang masih kalah dari paus. Namun, jika dibandingkan dengan sesama mamalia darat, tidak ada yang bisa menyamai dinosaurus.

Dinosaurus bisa tumbuh begitu mega lantaran memiliki sendi yang lebih licin dibanding mamalia darat lainnya. Adanya tambahan lapisan tulang rawan yang menghubungkan tulang-belulang pada dinosaurus membuat tulang tersebut mampu menahan bobot lebih besar.

Demikian hasil penelitian dari sekelompok peneliti di Richard Stockton College of New Jersey, Amerika Serikat. Memang dari ukuran, dinosaurus masih kalah dari paus sebagai mamalia laut. Namun, jika dibandingkan dengan sesama mamalia darat, tidak ada yang bisa menyamai tinggi dan besarnya dinosaurus. Manusia, misalnya, tulang yang kita miliki bisa rontok ketika bobot tubuh terlalu berat.

Untuk bisa mencapai kesimpulan tersebut, tim peneliti ini memeriksa tulang dari beragam mamalia dan membandingkannya dengan tulang dinosaurus. Mereka juga meriset tulang milik burung dan reptil yang memiliki garis keturunan dinosaurus.

Ditemukan bahwa tulang mamalia secara progresif menjadi lebih bulat di bagian ujung untuk menopang berat tubuh agar tidak membebani tekanan pada tulang rangka. Saat tulang menjadi lebih lebar, tulang rawan tertarik oleh lapisan tipis dan kencang di bawah tulang. Keketatannya memungkinkan distribusi berat yang merata.

Namun, tulang dari reptil dan dinosaurus tumbuh lebih lebar dan lebih rata saat hewan tersebut tumbuh membesar dengan bobot yang juga berat. Dibanding mamalia yang memiliki hanya memiliki lapisan tipis, dinosaurus mempunyai lapisan lebih banyak sehingga sendi mereka lebih licin.

Sendi ini tidak hanya melakukan distribusi berat yang lebih merata, tapi juga bisa menahan tekanan lebih besar. Dikatakan oleh Matthew Bonnan sebagai pemimpin penelitian, "Awalnya saya mengharap pola yang sama di kedua grup [mamalia dan dinosaurus], tapi yang Anda lihat ternyata pola yang bertolak belakang."

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-Moss and other indicators suggest the current Arctic meltdown is unique in recent geologic history

Scientists have long known that the Arctic is warming faster than the rest of the globe, even as they had less of a grasp of how recent trends compare to thousands of years ago.

Now, a new study aims to fill the knowledge gap by concluding that recent summer warming in the eastern Canadian Arctic is unprecedented in more than 44,000 years. Prior research documented melt and temperature dynamics going back about 2,000 to 4,000 years in comparison, said study lead author Gifford Miller, associate director of the Institute of Arctic and Alpine Research at the University of Colorado, Boulder.

The findings, published online in Geophysical Research Letters this week, counter the conclusions of some prior studies suggesting that natural forces -- along with greenhouse gases -- may be contributing to some of the extensive Arctic warming. The study also suggests that climate models are underestimating Arctic changes, as their past predictions were off by more than 2 degrees Celsius.

"Our study pushes the clock way back," said Scott Lehman, a research professor at the institute and co-author of the paper.

The scientists concluded that the level of warming now matches or goes beyond what occurred during a natural warm period about 5,000 to 10,000 years ago, known as the Holocene Thermal Maximum. The study provides the first "direct" evidence that Canadian Arctic temperatures in the last century exceeded the peak warmth of that earlier thermal maximum, the scientists said.

Discovery linked to ancient vegetation

The fact that certain ice caps did not melt during the Holocene Thermal Maximum, despite the extreme warmth at the time, suggests that today's unusual warming period can only be caused by greenhouse gases, Miller said.

"Nothing else out there can explain it," Miller said. Based on the Earth's current position in relation to the sun, the region should be cooling in the summer, not warming, he said.

The scientists benefited from a discovery of vegetation on Baffin Island in the Canadian territory of Nunavut. When ice caps receded on the island in recent decades, they revealed mosses long entombed in the ice.

The mosses became exposed recently, in the past year or so. A longer period would have eroded or blown them away, according to the study. Therefore, the scientists determined that the last time the vegetation appeared was during melting of the ice caps.

Via radiocarbon dating of 365 vegetation samples, they determined that some of the newly exposed mosses from four of the ice caps were at least 40,000 years old. "We never expected to find plants that old," Miller said.

Their old age means that the ice caps entombing them had not melted for at least that long, staying colder than the present day through the peak warmth of the Holocene thermal maximum.

During that time, about 5,000 to 10,000 years ago, the eastern Canadian Arctic was closer to the sun in the summer than now, because of natural variabilities in Earth's orbit. The amount of solar radiation hitting the area was about 9 percent higher than now.

Some of the tested vegetation samples were younger, indicating that their ice cap resting places on Baffin Island melted during the peak Holocene warmth 5,000 to 10,000 years ago. However, the melted caps were very close to the ones that remained intact for at least 44,000 years, Miller said.

Are models underestimating warming?

"Those ice caps that didn't melt, you can throw a stone at a slightly lower ice cap that did melt. They are all mixed in together," Miller said. That means that average summer temperatures now are unprecedented in the region in comparison to the past 44,000 years, the study said. The scientists studied 110 ice caps on Baffin Island in total.

Via analysis of the snow-line elevation in the region -- a measure strongly tied to temperature -- the scientists also concluded that summer cooling occurring in Arctic Canada after the peak heat of the Holocene was much greater than predicted by climate models.

As natural variations in Earth's orbit cooled the region between 5,000 years ago and 100 years ago, summer temperatures declined by about 2.7 degrees Celsius, about twice the level predicted by global climate models known as Coupled Model Intercomparison Project Phase 5 (CMIP5).

The discrepancy between the data and the models indicates that scientists also may be underestimating how much the region will warm in the future, Miller said. Many models suggest that the Arctic Ocean will be ice-free by the end of the century, for example, while some scientists say that the ice-free threshold could be reached much sooner (ClimateWire, July 16).

Early results from additional vegetation samples gathered from sites in Greenland and Norway indicate a similar warming trend, Lehman said.

The findings are a "big deal" for showing that current temperatures are higher than the Holocene maximum, even though solar forcing was greater back then, said James Overland, an oceanographer at the National Oceanic and Atmospheric Administration who did not participate in the study.

David Pompeani, a paleoclimateologist and doctorate candidate at the University of Pittsburgh, added that the study's strength was the number of samples and the extensiveness of the radiocarbon dating.

"That is the real big kicker for me," he said.

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-More and more coal, oil and natural gas get burned, leading to growing greenhouse gas pollution

Despite concerted global efforts to reduce carbon emissions through the expansion of clean and renewable energy resources, fossil fuels continued to dominate the global energy sector in 2012, according to new figures released yesterday by the Worldwatch Institute.

Coal, natural gas and oil accounted for 87 percent of the world's primary energy consumption last year, the group reported in a new "Vital Signs Online" report.

"The relative weight of these energy sources keeps shifting, although only slightly," states the report by researchers Milena Gonzalez and Matt Lucky, members of the Worldwatch Institute's climate and energy team.

While the U.S. boom in shale gas helped push the fossil fuel's share of total global energy consumption from 23.8 to 23.9 percent, coal also increased its share, from 29.7 to 29.9 percent, as demand for coal-fired electricity remained strong across much of the developing world, including China and India, and parts of Europe.

As such, coal is expected to surpass oil as the most consumed primary energy source in the world, the report said. In 2012, China alone accounted for more than half the world's total coal consumption, mostly for electric power generation.

But natural gas is also seeing significant gains, both in the United States and in countries like Japan, which are shifting their energy portfolios away from nuclear power. "With increasing shale gas fracking and many countries' interest in displacing coal generation with natural gas due to the lower greenhouse gas emissions, natural gas use seems well poised to grow," the report states.

U.S. will dominate in oil and gas

For the first time in 2012, global gas production exceeded 3 billion metric tons, marking the third consecutive year of both rising production and consumption, according to the report. With the exception of 2009, when the Great Recession resulted in lower energy demand for all fuels, natural gas use has been steadily rising since 1970, according to the report.

Oil, too, has seen a surge in production in the United States, according to Worldwatch, even though globally, oil use accounted for a slightly smaller share of total energy consumption, from 33.4 to 33.1 percent. In 2012, the United States produced oil at record levels and is expected to overtake Russia this year as the world's largest producer of oil and natural gas combined, according to the report.

"Consequently, the [United States] is importing decreasing amounts of these two fossil fuels, while using rising levels of its natural gas for power generation," the report states.

In an email, co-author Lucky noted that although oil may be losing some share of the world's total primary energy consumption, it is still expected to be the dominant fuel for transportation globally and will continue to grow in absolute numbers going forward. The United States, for example, increased oil production by 13.9 percent last year, its highest recorded increase ever, according to the Worldwatch Institute.

"And even though natural gas, biofuels and electric vehicles are growing in popularity in many isolated parts around the world, the world's growing appetite for transportation fuels will likely keep oil as a dominant primary energy resource for the foreseeable future," he said.

U.S. coal production drops as world's rises

While the price of natural gas dropped to near record lows last year in the United States, driving much of the fuel switching by electric utilities, the fossil fuel was significantly more expensive in other parts of the world. In Japan, for example, which relies on imported liquefied natural gas, prices exceeded $16 per million British thermal units, six times higher that what U.S. consumers paid.

Global natural gas consumption grew by 2.2 percent to 2,987 million tons of oil equivalent (mtoe) in 2012 -- more than triple the consumption recording in 1970, according to the report. The largest increases took place in the United States (27.6 mtoe), China (12.0 mtoe) and Japan (10.1 mtoe).

Coal consumption, meanwhile, grew 2.5 percent in 2012, driven by rising demand in China (6.1 percent), India (9.9 percent), Japan (5.4 percent) and the European Union (3.4 percent) and generally falling prices across all markets. But that single-year growth paled in comparison with the 4.4 percent average annual increase in global coal consumption recorded in the last decade as the United States cut its coal consumption by nearly 12 percent, according to the report.

Meanwhile, coal production grew by 2 percent in 2012 despite a 7.5 percent reduction in output from U.S. mines. China, which increased its domestic coal production by 3.5 percent last year, now accounts for 47.5 percent of global coal production, followed by the United States (13.4 percent) and India (6 percent). But the United States still holds the largest share of proved coal reserves at 27.6 percent, followed by Russia, China, Australia and India.

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-Scientists suggest that the highest possible pollution rates are unlikely

Even as governments worldwide have largely failed to limit emissions of global warming gases, the decline of fossil fuel production may reduce those emissions significantly, experts said yesterday during a panel discussion at the Geological Society of America meeting.

Conventional production of oil has been on a plateau since 2005, said James Murray, a professor of oceanography at the University of Washington, who chaired the panel.

As production of conventional oil, which is far easier to get out of the ground, decreases, companies have turned to unconventional sources, such as those in deep water, tar sands or tight oil reserves, which have to be released by hydraulic fracturing.

But those techniques tend to lead to production peaks that tail off quickly, Murray said.

The panelists said these trends belie the high-end emission scenario from the Intergovernmental Panel on Climate Change (IPCC). That scenario, known as RCP 8.5, and often referred to as the "business as usual" scenario, has carbon dioxide emissions increasing through 2100.

"I just think it's going to be really hard to achieve some of these really high CO2 scenarios," Murray said.

David Rutledge, an engineering professor at the California Institute of Technology who studies world coal production, said the IPCC's "business as usual" scenario is unrealistic because it essentially assumes that growth of fossil fuels like coal will continue apace, which is unlikely.

Recovery estimates may be too high

In reality, governments tend to overestimate their coal reserves, and much of these reserves will never be accessed, Rutledge said.

"There is little relationship between the RCPs and the actual historical experience of oil, gas and coal production," Rutledge said.

Rutledge said of the four IPCC scenarios, he found the second RCP scenario, RCP 4.5, where carbon dioxide emissions flatten out around 2080, to be more plausible under a business-as-usual scenario for coal exploitation.

"4.5 would be the closest one if you look at the mining history," Rutledge said. "My own opinion is that no one should use RCP 8.5 for any purpose at all."

David Hughes, of Global Sustainability Research Inc., pointed out that production from tight oil fields like North Dakota's Bakken and Texas' Eagle Ford plays quickly reach what he called "middle age," when production begins to fall off.

He said it is likely that the Bakken Shale oil play will peak in 2015 or 2016 and that the Eagle Ford Shale play, another significant U.S. oil production area, will peak soon after.

"Long-term [production] sustainability is highly questionable, and environmental impacts are a major concern," Hughes said.

The United States should see the temporary bounty of oil from these sources as an opportunity to develop alternative energy sources, Hughes added.

Charles Hall, a professor at the State University of New York who researches energy and wealth, in graph after graph showed that almost every oil-producing country has reached its peak of oil production.

This is even with a tripling of oil prices over the analysis period, Hall said.

Pieter Tans, a climate scientist at the National Oceanic and Atmospheric Administration who wrapped up the panel, said that while governments and policymakers should still aggressively pursue the goal of reducing greenhouse gas emissions, he did not believe that the most severe IPCC scenario, RCP 8.5, was likely.

From a climate perspective, there is some good news about the likely decline in the growth of fossil fuel production discussed by others at the panel, Tans said.

"It does decrease the chances of catastrophic climate change," he said.

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Friday, October 25, 2013

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Considering there's so many interesting articles wrote in Bahasa Indonesia (and the traffic too), We'll start posting articles with Bahasa Indonesia and English.

Mengingat banyaknya artikel menarik berbahasa Indonesia (dan trafficnya juga), kami akan mulai posting artikel berbahasa Indonesia maupun English.

Saturday, October 12, 2013

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The world has followed news of from British Petroleum’s (BP) Deepwater Horizon’s blowout and oil spill in the Gulf of Mexico since the oil rig exploded April 22, 2010. By the time engineers temporarily capped the well July 15, it had poured an estimated 3.0 million to 8.7 million barrels of oil into Gulf waters. How does the magnitude of this spill compare with past oil spills?

This article only compares the magnitude of the world’s largest oil spills and does not compare damages. No oil spill is without environmental consequences. Those in ecologically sensitive areas, however, may carry particularly long-lasting environmental and economic impacts.

Although there are some differences in estimates of individual oil spills, since 1910, there have been at least 17 oil spills around the world exceeding 30 million U.S. gallons or 715,000 barrels. One barrel of oil equals 42 U.S. gallons.

Deepwater Horizon

Unless it derives from a ship disaster, oil spill magnitude is usually difficult to estimate. The volume of oil carried by a ship is always known. Most spills on land are easier to estimate than those that occur underwater from oil well blowouts.

The Deepwater Horizon’s spill in the Gulf of Mexico was apparently the second largest ever to occur. California’s legendary oil spill from a well blowout in Kern County in 1911 may have dumped an incredible 9 million barrels, according to the Los Angeles Times (June 13, 2010), making it the largest spill ever. The purposeful release of oil by the Iraqi army during Desert Storm in 1991 may have dumped two million to six million barrels into the Persian Gulf, probably making it the third largest.

Kern County 1911
Of the 17 largest spills ever, 10 were from ship groundings, collisions or explosions, four were from oil derrick or platform disasters, two were from pipeline leaks, and one was the purposeful release in Iraq.

The 104 worst spills in the world tend to concentrate in two types of locations. Petroleum source areas tend to have a high incidence of spills, generally associated with blowouts, explosions and trans-shipping accidents. These regions of the world include the Persian Gulf and the Gulf of Mexico, where well drilling is prevalent.

The other common spill location is along international oil trade routes, particularly in the North Atlantic, around Europe, East Asia and around Africa’s Cape of Good Hope. These areas are particularly susceptible to ship collisions and breakups. Furthermore, storms often contribute to these shipping disasters.

The remaining spills are more random and are usually linked to aging or failed equipment (pipeline breaks), natural hazards (hurricanes and floods) or human error (Exxon Valdez).

Of the spill disasters on or near U.S. territory, the most significant are the 1911California spill, the BP Deepwater spill and the Greenpoint oil spill in Brooklyn that occurred from the 1940s to 1950s (400,000 to 700,000 barrels) from a crude oil processing plant. The 1989 Exxon Valdez ship spilled approximately 260,000 barrels of oil in Prince William Sound in Alaska, ranking it the fourth largest in the United States and the 36th largest in the world. Despite the intense damage done to the ecosystem around Prince William Sound, the size of the spill does not compare with the world’s 17 largest.

The United States has sustained 47 documented oil spills, the largest number of any country in the world. The high incidence of spills is linked to the country’s high oil consumption.  The U.S. uses nearly one-quarter of the world’s oil. This high rate of consumption requires the handling and transfer of huge amounts of oil daily, making the chances of spills more probable.

Louisiana has sustained 14 significant oil spills, the largest of any state, followed by California (8), Pennsylvania (4), Texas (3) and Alaska (3). These are states with large transfers of petroleum between pipelines and ships.

Drilling and transporting technologies have made major advances in the past 40 years, but improvements in spillage and cleanup technologies apparently have not.

The Deepwater disaster in the Gulf of Mexico was a wake-up call for both the petroleum industry and government agencies that oversee the industry. Lessons learned from this oil spill are yielding more safeguards and new technologies for the future. The environmental, human and monetary costs of the spill remain high and long lasting to the Gulf Coast.

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In the early 1980s, two pediatricians in Bogota, Colombia, made waves around the world for a new method of caring for premature babies. The method, called Kangaroo Care, was so named because of how it resembles marsupial caregiving: A mother snuggles her baby, upright, against her bare chest for long periods of time.

The doctors developed the program in 1979 at the Instituto Materno Infantil at San Juan de Dios Hospital in Bogota. This large maternity hospital was overcrowded and understaffed and underfunded: In the special baby care unit, several babies would often share the same incubator. Infection rates were sky-high, as were abandonment rates and death rates.

To improve this dire situation, doctors Edgar Rey and Hector Martinez launched a program to get babies out of the hospital — and its germs — as soon as they were physically stable, even if they were still very small. They advised mothers to keep their baby on their chest for warmth, and to exclusively breast feed.

Rey and Martinez reported mortality rates of the 539 babies who went through this home care between 1979 and 1981. The smallest babies — those weighing between 501 and 1,000 grams — showed 72 percent survival rates, compared with 0 percent survival with the hospital’s conventional care. Nearly 90 percent of babies between 1,001 and 1,500 grams survived at home, compared with 27 percent in the hospital. And the number of babies abandoned dropped by two-thirds.

These results never appeared in a medical journal, and they are somewhat inflated because they didn’t include deaths of babies who died in the first few days of life. Nevertheless, this very appealing idea — that a mother’s touch could save her child’s life — made headlines all over the world, and UNICEF endorsed the program whole-heartedly.

People in developed countries were eager to try the new method, too, even though they didn’t have any of the problems of a strapped hospital in Colombia. Many doctors were skeptical that Kangarooing would provide much benefit in rich countries, beyond making moms and dads feel better about the experience. As two British doctors wrote in a Lancet paper — titled “Myth of the Marsupial Mother” — in 1985: “Colombia has nothing to teach developed countries about improving survival of [premature] babies but may yet help us to heal some of the psychological problems incurred by modern neonatal care.”

In the three decades since, those Colombian researchers and many other groups have published randomized, rigorous studies of Kangaroo Care, and experts continue to debate whether, and under what circumstances, it does any good. In 2011, the prestigious Cochrane Collaboration published a comprehensive review of all of the major studies to date, and seemed to confirm what Rey and Martinez had originally claimed: In resource-limited settings, Kangaroo Care significantly lowers the risk of infection, hypothermia, and death. It also increases a baby’s weight and head circumference, and the strength of the maternal bond. It’s unclear, though, whether the method’s positive effects last through a baby’s adolescence, nor whether it offers much for premature babies in developed countries.

I write this protracted introduction as a caveat to two new papers reporting that, in Colombia and Israel, respectively, the positive effects of Kangaroo Care can last for more than a decade after a baby’s birth. The studies are fascinating to me because they’re suggesting that a mother’s touch can exert a powerful influence on her child’s brain development (wow! how?). But it’s also possible, given the spotty data, that the positive effects aren’t coming from her touch, per se. So, with caveat said, on to the new studies.

The first was done by a group of Colombian and Canadian researchers who have been advocating for Kangaroo Care since the beginning. They measured brain activity of 48 teenagers in Colombia: 39 born very prematurely and 9 born at term. Of the premature group, 21 had received Kangaroo Care and 18 had received standard hospital care.

The researchers used transcranial magnetic stimulation, or TMS, in which researchers place a wand on the participant’s head. The wand contains a magnetic coil, which produces an electromagnetic pulse that passes through the person’s skull and tickles the neurons underneath. The neurons respond to that pulse, and the researchers then measure that neuronal response via EEG electrodes placed all over the scalp.

In this case, the researchers placed the wand over participants’ motor cortex, on the center of the top of the head, which is involved in motor planning. Teenagers who were born prematurely and received Kangaroo Care showed brain-wave patterns that were similar to the kids born to term, according to the study, published last year in Acta Paediatrica. In contrast, the kids born prematurely who had had standard hospital care showed a slower synchronization of brain activity.

The second study, based at a hospital in Israel, also looked at adolescents who had been born too early: 73 who had received Kangaroo Care and 73 who had been given standard incubator care. As published last week in Biological Psychiatry, the researchers found that by 10 years old, the Kangaroo babies had better responses to stress, more regular sleeping patterns, and scored higher on tests of cognitive development compared with the kids who had received standard preemie treatment.

If we assume (and, again, see caveat above) that these benefits are the direct result of skin-to-skin contact between a baby and her mother, then what could explain that?

Nobody knows for sure, but scientists have learned a lot by studying the interactions between baby rodents and their mothers. For example, early physical contact with mom affects the expression of genes related to stress hormones and social behavior in the baby animal’s brain. Conversely, depriving an infant rodent (or infant human, for that matter) of its mother leads to all sorts of behavioral and medical problems for the rest of the animal’s life. “Being a mammal therefore implies that the brain is not fully formed at birth, and maturation of systems that enable adaptive functioning in the world are gradually acquired through close contact with an alert, responsive mother,” write the authors of the new Biological Psychiatry study.

These studies of mother-baby interactions — and the descriptions of these studies in the popular press — tend to focus on these chemical mechanisms of how a mother’s touch and attention help her baby thrive. (There’s this thing called oxytocin…) What sometimes gets overlooked, though, is that this is not a one-way phenomenon. As a mother touches and influences her baby, so too does the baby touch and influence her mother. It’s the constant, back-and-forth interaction that creates the bond, and the bond that keeps a mother invested in her child’s success for many years to come.

Friday, October 11, 2013

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Space-time. With (Right) and Without Matter (Left)

In 1905, Albert Einstein published the theory of special relativity, which explains how to interpret motion between different inertial frames of reference — that is, places that are moving at constant speeds relative to each other.

Einstein explained that when two objects are moving at a constant speed as the relative motion between the two objects, instead of appealing to the ether as an absolute frame of reference that defined what was going on. If you and some astronaut, Amber, are moving in different spaceships and want to compare your observations, all that matters is how fast you and Amber are moving with respect to each other.

Special relativity includes only the special case (hence the name) where the motion is uniform. The motion it explains is only if you’re traveling in a straight line at a constant speed. As soon as you accelerate or curve — or do anything that changes the nature of the motion in any way — special relativity ceases to apply. That’s where Einstein’s general theory of relativity comes in, because it can explain the general case of any sort of motion.

Einstein’s theory was based on two key principles:

The principle of relativity: The laws of physics don’t change, even for objects moving in inertial (constant speed) frames of reference.

The principle of the speed of light: The speed of light is the same for all observers, regardless of their motion relative to the light source. (Physicists write this speed using the symbol c.)

The genius of Einstein’s discoveries is that he looked at the experiments and assumed the findings were true. This was the exact opposite of what other physicists seemed to be doing. Instead of assuming the theory was correct and that the experiments failed, he assumed that the experiments were correct and the theory had failed.

In the latter part of the 19th century, physicists were searching for the mysterious thing called ether — the medium they believed existed for light waves to wave through. The belief in ether had caused a mess of things, in Einstein’s view, by introducing a medium that caused certain laws of physics to work differently depending on how the observer moved relative to the ether. Einstein just removed the ether entirely and assumed that the laws of physics, including the speed of light, worked the same regardless of how you were moving — exactly as experiments and mathematics showed them to be!

Unifying space and time

Einstein’s theory of special relativity created a fundamental link between space and time. The universe can be viewed as having three space dimensions — up/down, left/right, forward/backward — and one time dimension. This 4-dimensional space is referred to as the space-time continuum.

If you move fast enough through space, the observations that you make about space and time differ somewhat from the observations of other people, who are moving at different speeds.

You can picture this for yourself by understanding the thought experiment depicted in this figure. Imagine that you’re on a spaceship and holding a laser so it shoots a beam of light directly up, striking a mirror you’ve placed on the ceiling. The light beam then comes back down and strikes a detector.

(Top) You see a beam of light go up, bounce off the mirror, and come straight down.
(Bottom) Amber sees the beam travel along a diagonal path.

However, the spaceship is traveling at a constant speed of half the speed of light (0.5c, as physicists would write it). According to Einstein, this makes no difference to you — you can’t even tell that you’re moving. However, if astronaut Amber were spying on you, as in the bottom of the figure, it would be a different story.

Amber would see your beam of light travel upward along a diagonal path, strike the mirror, and then travel downward along a diagonal path before striking the detector. In other words, you and Amber would see different paths for the light and, more importantly, those paths aren’t even the same length. This means that the time the beam takes to go from the laser to the mirror to the detector must also be different for you and Amber so that you both agree on the speed of light.

This phenomenon is known as time dilation, where the time on a ship moving very quickly appears to pass slower than on Earth.

As strange as it seems, this example (and many others) demonstrates that in Einstein’s theory of relativity, space and time are intimately linked together. If you apply Lorentz transformation equations, they work out so that the speed of light is perfectly consistent for both observers.

This strange behavior of space and time is only evident when you’re traveling close to the speed of light, so no one had ever observed it before. Experiments carried out since Einstein’s discovery have confirmed that it’s true — time and space are perceived differently, in precisely the way Einstein described, for objects moving near the speed of light.

Unifying mass and energy

The most famous work of Einstein’s life also dates from 1905 (a busy year for him), when he applied the ideas of his relativity paper to come up with the equation E=mc2 that represents the relationship between mass (m) and energy (E).

In a nutshell, Einstein found that as an object approached the speed of light, c, the mass of the object increased. The object goes faster, but it also gets heavier. If it were actually able to move at c, the object’s mass and energy would both be infinite. A heavier object is harder to speed up, so it’s impossible to ever actually get the particle up to a speed of c.

Until Einstein, the concepts of mass and energy were viewed as completely separate. He proved that the principles of conservation of mass and conservation of energy are part of the same larger, unified principle, conservation of mass-energy. Matter can be turned into energy and energy can be turned into matter because a fundamental connection exists between the two types of substance.

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Thursday, October 10, 2013

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The Sun’s Staggering Strength

Despite its serene appearance when viewed from Earth, the energy produced from the Sun is so strong that every second its core releases the equivalent of 100 billion nuclear bombs.

The Skies: A Visual History Textbook

The next time you’re cloud watching, ponder this: by studying the skies, you are essentially staring into history. Why? The light you presently enjoy travels from distant stars and galaxies takes hundreds, thousands and sometimes millions of years to reach us.

Extraordinary Weather On Mercury

While Mercury is the closest planet to the Sun, its temperatures can reach a biting -280 degrees Fahrenheit as Mercury lacks the atmospheric pressure necessary to trap heat. Venus, on the other hand, has a thick atmosphere to trap heat and is markedly hotter than Mercury, despite being farther away from the Sun.

A Permanent Foot On The Moon

If you are ever lucky or wealthy enough to gallivant to the moon, you can expect your presence to remain much longer than anticipated. As there is no air or wind on the moon, your footprints are likely to last forever (barring a meteoric collision, of course).

Grow By Leaving The Planet

If you consider yourself “vertically challenged,” you should consider becoming an astronaut. The path toward realizing said career is a long one, but since the lack of gravity in space allows for the elongation of the spine, you would grow two inches while floating in the Milky Way.

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The sight of a cockroach scuttling across the floor makes most of us shudder, but in a disaster, roaches might prove to be our new best friends.

Cockroaches that are surgically transformed into remote-controlled "biobots" could help locate earthquake survivors in hard-to-access areas. 

To learn more, Amanda Fiegl spoke to assistant professor of engineering Alper Bozkurt, who led the roach biobot project.

What exactly is a biobot? Is it like a cyborg, a combination of a living organism and a robot?

"Biobot" is short for "biological robot." It is the first stage of creating what we would call an insect cyborg.

Currently, we can steer these roaches remotely and make them stop, go, and turn. If we can have them interact independently with the technologies we've surgically implanted in them, then they will become true cyborgs.

Is it hard to perform surgery on a cockroach?

No, it's quite simple. Insects can be anesthetized by putting them in the fridge for a few hours—the cold basically makes them hibernate, so they don't move. Then you just need tweezers and a microscope.

We do a simple surgery to insert the electrodes in the roaches' antennae and cerci [rear sensors]. We also use medical-grade epoxy to glue tiny magnets to their backs, so that we can just snap on the backpack containing the wireless control system.

Your paper mentions that these biobots could help rescue earthquake survivors. How, exactly?

Their backpacks can carry a locator beacon and a tiny microphone to pick up cries for help. Of course, a human operator or computer still has to be listening and steering them. Our biobots are basically just beasts of burden. They could also carry a camera or any other kind of miniaturized sensor one can imagine.

These experiments were done in a very controlled laboratory environment, on a flat surface, so we are now in the process of building test-beds that mimic some real-life scenarios. I don't think it will be very long before we can deploy them to actually help rescue people.

Why use real cockroaches, instead of synthetic robots made from some tougher material?

They come with a self-powered locomotion system. And they have biological autonomy to help them survive—they will run away when they sense danger, which makes them hard to trap or squash. That's really useful in uncertain, dynamic environments.

How many roach biobots have you created so far? Are most of them male or female?

More than ten. We paint them with different colors of nail polish to tell them apart. We prefer to work with females, because they can carry eggs inside, so they are theoretically better at carrying payloads. But it works on males as well.

Can you explain exactly how you are able to steer the biobots?

We use electric pulses to stimulate their antenna sensor cells, making them think there is an obstacle to navigate around.

Cockroaches use their antennae as touch sensors, similar to the way a blind person might use their hands to recognize the environment. So when we stimulate the antennal sensor on the roach's right side, it makes a left turn, and vice versa. We also stimulate their cerci to make them go forward. Cerci are the sensors at the very back of the insect that sense any predator behind.

Do the electrical pulses hurt the roaches?

No, there are a lot of scientific papers and evidence that show that invertebrates don't have the sense of pain as we, humans, perceive it. So it was not like we were zapping them and they were reacting to pain. Their reflexes were simply navigating them around perceived obstacles.

We don't want to torture cockroaches. Actually, we hope that our research will help the public to appreciate the importance and complexity of these little folks that we share an ecosystem with. Personally, I can't even kill pest insects at home since I appreciate them so much!

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This beetle is named after Arnold Schwarzenegger 
When you have to name 65 new species at once, it pays to get creative. That's how the Darth Vader beetle, or Agathidium vaderi, came to grace a scientific publication in 2005.

"We had exhausted the useful descriptive names," said Quentin Wheeler, a researcher at Arizona State University (ASU) in Phoenix who helped describe the beetles. "[So] that gives you license to get a little more inventive."

Participants in an ongoing contest—sponsored by the National Geographic Society—to name a mystery fish discovered earlier this year by marine ecologist Enric Sala only have to come up with one name.

But once named, this unidentified fish could bear its new moniker far into the future.

The contest runs until August 26, 2013, but there are already over 4,500 suggestions. Since participants can only enter once—and there is a ten-day trip to the Galápagos on the line—it wouldn't hurt to start thinking outside the box. 

While taxonomists—scientists who describe and name species—try to bestow names descriptive of the new organism, there is also ample evidence that they like to have fun with their task. 

Wheeler and colleague Kelly Miller are responsible for a genus of slime-mold beetles that include Gelae donut, Gelae baen, Gelae belae, Gelae fish, and Gelae rol.

"Kelly deserves the blame, or credit, as you choose," said Wheeler with a laugh. "It's kind of a tongue-in-cheek reference to [their] food source." The beetles in the Gelae genus feed on the immature, jelly-like stage of slime molds.

Wheeler chose to name the Darth Vader beetle after the Star Wars villain because the insect's shiny black head and slit-like eyes reminded him of the movie character.

Darth Vader Beetle


Terry Erwin, an insect researcher who specializes in beetles at the Smithsonian National Museum of Natural History, has named almost 300 species in a genus of beetles called Agra.

Erwin noted that he's got about 1,500 species in the Agra genus still awaiting names in a cabinet right outside his office door. And every time he goes collecting, he finds more new beetles. "This is a genus with endless species," he said.

The group includes species like Agra sasquatch—named for its big feet. Erwin named its sister species Agra yeti.

Two others bear the names Agra vation and Agra vate. Erwin insists he wasn't particularly annoyed when he named the two sister species. "It was just to use aggravation because it went with Agra," he said.

Yet another beetle is named Agra ichabod for Ichabod Crane, the main character in The Legend of Sleepy Hollow, because the beetle Erwin used in his description of the species was missing its head.

"All the old guys who were strict Latin namers, I've outlived them all," Erwin said. Since he's the only one left working to describe all the new Agra species, no one criticizes his name choices anymore, he said.


Since all new species descriptions must be published in a peer-reviewed scientific journal, getting unusual names past colleagues is crucial. Luckily, those reviewers also seem to have a sense of humor.

Some of the more whimsical names researchers have come up with include a mushroom named for the cartoon character SpongeBob SquarePants—Spongiforma squarepantsii. 

There is a striped octopus species found around the Indonesian archipelago named Wunderpus photogenicus, and a genus of tiny marine snail called Ittibittium.

And then there are all the species named for celebrities and politicians. There is a lichen species—a symbiotic pairing of fungus and algae—called Caloplaca obamae, named for President Barack Obama.

Singers Lady Gaga and Beyoncé have a genus of fern (Gaga) and a fly with a golden rump (Scaptia [Plinthina] beyonceae) named for them.

The Smithsonian's Erwin names some of his beetles for actors and actresses that star in disaster movies. "An actor or starlet doesn't get a name unless they've been in a film that I can use to compare to the destruction of the rain forest," he said.

There is Agra katewinsletae, named for the actress in the movie Titanic. And Agra liv, named in honor of Liv Tyler for her part in the movie Armageddon.


And finally, there are the rude and risqué names that have somehow made it into the pantheon of scientific literature.

A goby native to the ocean around Indonesia bears the unfortunate name Stupidogobius flavipinnis, while a species of rhinoceros beetle must suffer under the scientific name Enema pan.

A species of fish found in the Gulf of Mexico is burdened with the embarrassing moniker Gunterichthys longipenis.

The story goes that a fish specialist, or ichthyologist, in the '60s named Gunter had a drinking buddy—also a fish researcher—who named the fish after him as a joke.

Gunterichthys longipenis

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Move over, Sharks and Jets. New Yawk's next turf rumble could pit roach against roach.

According to an ongoing study called the National Cockroach Project, the roaches of three NYC neighborhoods—the Upper West Side, the Upper East Side, and Roosevelt Island—are genetically distinct. Like many of the city's humans, each group tends to stay in its own neighborhood. And, since American cockroaches originated overseas, these urban insects can also claim immigrants as ancestors.

To find out more about what's bugging the Big Apple, we sat down with the project's lead scientist: Mark Stoeckle, an infectious-disease specialist and senior research associate at the Rockefeller University's Program for the Human Environment.

How did the National Cockroach Project come about?

We'd been working with high-school students using bar coding, which is a simple way of identifying species by DNA. And one of the projects a couple of years ago was a sort of CSI for the home—students went around and collected everything they could find that might have DNA in it. When we had that tested, one of the things that turned up was a cockroach that looked genetically distinct.

We thought we might have a new species, but when we had it looked at in the American Museum of Natural History, they said, "No, that's a regular American cockroach." So [to understand why it seemed genetically distinct] we needed a lot more specimens.

The idea became to involve students and other citizen scientists to help us collect cockroaches. There hadn't been a lot of work done on them, because they're pests. So this [is an opportunity] to learn about something that lives in cities, where most of us live.

So how does it work—students and other citizen scientists collect cockroaches and send them to you?

Yes. At first we weren't sure if anyone would actually send in a cockroach—it's certainly an unusual request—and we weren't sure what condition it would arrive in. Cockroaches are icky, but they're not dangerous like, say, ticks, which can actually carry blood-borne diseases.

You're saying roaches don't deserve the bad rap they get?

I mean, I don't like seeing them crawling across my floor. They can track things in—they're sort of like houseflies in that way. And they may contribute to allergies, particularly asthma; the dust from cockroach shells may be an issue. But they don't carry specific diseases.

How many samples have you received so far, and from where?

We've gotten about 200 specimens, either mailed in or [hand-delivered]. Most are from the U.S., from New York City. We've had better luck getting New Yorkers to pick up cockroaches than we've had elsewhere.

But we also have specimens from Australia and Spain. Two high-school students in Spain saw our project on the Web and sent them in. It's really wonderful that people we have no direct connection to are interested and willing to contribute.

How many species of roaches are there in the world?

More than 4,000. Most live out in the wild. A few of them have adapted—or already were adapted—to a human environment. The common ones that are considered pests in the United States are the American cockroach (the large, water-bug type) and the German cockroach (the smaller one more common in apartments or households). Those are the two main ones. There's also the smokybrown cockroach and the brown-banded cockroach.

So how are roaches like New Yorkers?

Well, they're definitely immigrants. We know these are tropical species that are thought to have come from Africa, though there's no definite proof of that. They require a very warm, moist environment. And we've made a nice home for them in cities, because we have underground tunnels and sewers where they can live year-round. In the summer they come up above ground, and that's when we usually see them. But they've only been here as long as we've had an underground environment that's congenial for them.

So they're all immigrants and like New Yorkers in that way. The other way—the biggest finding of the study—is that there are four distinct genetic types of cockroaches within this species [the American cockroach]. Evolutionarily these genetic types are separated by a million or two million years. So they were probably living in different parts of the world. We brought them here.

They do interbreed, so we don't think they're separate species. But on the other hand, in the New York City neighborhoods where we've looked in detail—the Upper West Side, the Upper East Side, and Roosevelt Island—the genetic types are quite different. So they must be staying close to home.

The diversity was a surprise to us, and the fact that they're not just all mixed together—it's not a random assortment. So they must be staying close to home, and they have their own neighborhoods.

Do the genetic differences in neighborhood roaches manifest themselves in terms of behavior, appearance, longevity? What about vulnerability to pesticides?

It's possible. We just haven't looked at that. Cockroaches look all the same to us, but presumably they can tell each other apart. They are social insects, like ants. They don't have as elaborate a society as ants. But they do definitely live in groups.

For our citizen-science project we're probably not going to be studying pesticide resistance. But [we've created an] opening for someone to look at that.

What would happen if you took an Upper West Side roach and relocated it to, say, the Lower East Side?

Ha, I don't know. Maybe we can do some tracking experiments—put tiny radio collars, very little cameras on them. It's a fun question to think about and guess what might happen.

What can we learn from this project?

There's a lot more diversity going on around us than we might realize. We think of an urban environment as a boring environment for wildlife. But in fact, at least with this one species, there's a lot going on there. That's one part of it.

The other part is that they're all immigrants, like all New Yorkers—they've come here from different parts of the world.

So what do you do if you see a roach in your apartment?

I step on it. And I carry a plastic bag with me so I can pick it up and stick it in the freezer. I have a freezer in my apartment with a lot of cockroaches in it.
On 5:35 AM by Zufar M Ihsan in ,    No comments
Giant Hornet

The world's biggest hornet is wreaking havoc in northwestern China, where 42 people have died after being swarmed and stung in Shaanxi Province, according to the Chinese news agency Xinhua.

Some 1,600 others have been injured since the outbreak of the Asian giant hornet (Vespa mandarinia) began in July, the regional health authority reported, and attacks continue even as local authorities take action, including destroying hundreds of hives and improving medical treatment for victims. 

"The problem with this particular hornet is that it's big, sort of thumb-sized, and it packs a lot of venom," said entomologist Lynn Kimsey, director of the Bohart Museum of Entomology at the University of California, Davis.

"And its nests get fairly large, including maybe several hundred individuals. They are aggressive, they are predatory, and they have been known to kill and eat an entire colony of honeybees," she said.

At 1.5 to 2 inches (4 to 5 centimeters) long, the giant hornets are found across many parts of East and Southeast Asia and are especially well known in Japan. They're among the more dangerous venomous insects of their type, Kimsey said, though others, like Africanized bees and yellow jackets, can cause similar problems.

Bee-Loving Hornets

While the hornets don't typically swarm humans in such numbers, they're well known for their ability to quickly decimate a hive of thousands of honeybees, leaving behind a trail of severed heads and limbs.

The hornets routinely fly miles from their nests and employ scouts to locate a bee colony and then mark it with a special pheromone that attracts their allies to attack, destroy, and occupy the hive.

With their huge size advantage, the hornets typically make short work of the bees, unless the victims are able to eliminate the advance scout before it can summon others. They sometimes do so with an incredible defense—swarming the hornet in a ball and literally cooking it to death.

Often, however, the bees and other insect victims become fodder for the growth of the hornet hive. Adult workers chew their victims' flesh into a nutritious paste that feeds larvae, which in turn produces saliva that serves as a powerful "energy drink" to be consumed by adults who cannot digest solid protein.

Why Are Hornets Attacking People?

It's unclear exactly what factor or factors has led to the hornets' deadly season of human attacks.

Huang Rongyao, an insect expert with the Forestry Bureau of Ankang City, told Xinhua that local vegetation growth has increased hornet habitat, and that two months of hot weather have made the insects much more active. Ankang is one of the cities most affected by hornet attacks, along with Hanzhong and Shangluo.

Hua Baozhen, an entomologist at China's Northwest Agriculture and Forestry University, pinpointed a decrease in populations of the insect's natural enemies like spiders and birds, while other experts speculate that urban sprawl simply means more people are living in what was formerly hornet country.

Kimsey noted that this type of behavior is often seen with invasive species, though she's not sure if the hornet is native to the region or how long it may have been there.

"What we see happen when you get a newly introduced species is that it may sort of go along relatively unnoticed for years, but then eventually you see a huge outbreak. We have that happening in California, where the European paper wasp was introduced 20 years ago, and now suddenly it's an outbreak and they are everywhere."

If the hornets are in fact natives, Kimsey added, this year's weather probably does play a major part in the outbreak. "In that case I'd suspect that they had a very mild winter and spring, so that a lot of queens survived and consequently they now have many more nests than they normally would have."

That scenario also has parallels in the U.S. she added, like the western yellow jacket, whose numbers have risen to "spectacular" levels in California due to recent milder weather. 

Mating Season

In addition, autumn is mating season for hornets, which can make them more aggressive, particularly toward the end of the process, UC-Davis's Kimsey said.

"Right now if it's getting towards the end of the season, they are irritable. They are not producing a new brood, and there are a lot of workers not doing much of anything."

Once a queen has been fertilized, a typical hive begins to shut down with the approach of cool weather; the workers will die off while the queen finds a place to overwinter.

Xinhua reported that hives in the region typically go dormant by December, though attacks are expected to taper off sooner, perhaps by the end of the month. In the spring, hornet queens will begin new nesting colonies with offspring numbering in the thousands.

Deadly Attacks

In the meantime, staying well clear of the hornets is the best route to safety, experts advise, but that's often easier said than done.

The insect often locates nests underground or even on buildings, which puts them directly in human territory. Disturbing them or merely passing too close for the hornets' comfort can unleash a fierce retaliation. Some attacks seem especially unprovoked. In September, Xinhua reported that a swarm attacked a school in southern China, injuring 30 people—all but one of whom had to be hospitalized with multiple stings.

"If you inadvertently disturb a nest, they will come out en masse and you could get lots and lots of stings," Kimsey said, noting that the insect is proving deadly in much the same way a swarm of Africanized honeybees might. 

"Even if you're not allergic, the amount of foreign protein that circulates in your blood after so many stings can cause kidney failure. It's like sepsis, and if you don't get on dialysis you can die.

"People are probably dying because they aren't receiving the appropriate treatment in time," she added.

"And many Chinese doctors probably don't know exactly how to treat this problem, just as many doctors wouldn't in this country."

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