Rare blue galaxy may shed new light on Big Bang

Astronomers have discovered a faint blue galaxy about 30 million light-years from Earth that could shed new light on conditions at the birth of the universe.

The galaxy nicknamed Leoncino, or "little lion," located in the constellation Leo Minor, contains the lowest level of heavy chemical elements, or "metals" ever observed in a gravitationally bound system of stars. "Finding the most metal-poor galaxy ever is exciting since it could help contribute to a quantitative test of the Big Bang," said John J Salzer, a professor at Indiana University in the US.  "There are relatively few ways to explore conditions at the birth of the universe, but low-metal galaxies are among the most promising," Salzer said.  This is because the current accepted model of the start of the universe makes clear predictions about the amount of helium and hydrogen present during the Big Bang, and the ratio of these atoms in metal-poor galaxies provides a direct test of the model.  In astronomy, any element other than hydrogen or helium is referred to as a metal.  The elemental make-up of metal-poor galaxies is very close to that of the early universe.  "Low metal abundance is essentially a sign that very little stellar activity has taken place compared to most galaxies," said lead author Alec S Hirschauer, a graduate student at Indiana University.  Leoncino is considered a member of the "local universe," a region of space within about 1 billion light years from Earth and estimated to contain several million galaxies, of which only a small portion have been catalogued.  A galaxy previously recognised to possess the lowest metal abundance was identified in 2005; however, Leoncino has an estimated 29 per cent lower metal abundance. The abundance of elements in a galaxy is estimated based upon spectroscopic observations, which capture the light waves emitted by these systems.  Regions of space that form stars, for example, emit light that contains specific types of bright lines, each indicating the atoms from various gases: hydrogen, helium, oxygen, nitrogen and more.  In the light of the star-forming region in Leoncino, scientists detected lines from these elements, after which they used the laws of atomic physics to calculate the abundance of specific elements.  Aside from low levels of heavier elements, Leoncino is unique in several other ways.  A so-called "dwarf galaxy," it is only about 1,000 light years in diameter and composed of several million stars.  The Milky Way, by comparison, contains an estimated 200 billion to 400 billion stars. Leoncino is also blue in colour, due to the presence of recently formed hot stars, but surprisingly dim, with the lowest luminosity level ever observed in a system of its type.

No, Mercury Retrograde Will Not Mess Up Your Life

For people of the astrological persuasion, few planetary trends are as noteworthy as Mercury in retrograde. As the solar system's smallest planet appears to reverse through the sky, you'll hear it blamed for a wealth of frustrating situations, including overspending on new purchases, poorly planned work pitches and unimpressive first dates.

The common astrological advice for people during Mercury retrograde is to avoid starting anything new and to focus instead on reassessment, mimicking the way the planet appears to be retracing its own movements. In 2016, Mercury retrograde will occur four times, totaling about 80 days. That is a lot of time for reassessment.

Astronomers tend to disagree with these associations. "The idea that the gravity from these very distant bodies affects our lives in some way just doesn't work in the framework of physics," said Jean-Luc Margot, a planetary astronomer and professor at UCLA.

Finding the facts about Mercury's retrograde motion is complicated because it's both a real and imagined phenomenon. "All the planets rotate around the sun in the same direction, and that never changes," Margot said. However, if a person were able to trace Mercury's position during retrograde — which is a challenge, because the sun blocks our view — they'd end up with a line that changes direction. This is because Mercury retrograde is an optical illusion resulting from our position (on Earth) relative to Mercury.

The term "retrograde" in this instance refers to a perceived reversal in the standard west-to-east movement of Mercury through the stars. While some objects in space do experience true retrograde motion — Venus spins about its axis in the opposite direction than the other planets, a situation called retrograde spin — Mercury's backtracking is an issue of perspective. Its orbit is smaller and faster than Earth's. When its orbit catches up to and passes Earth, it creates the illusion that Mercury is backtracking, astronomers say.

Put more plainly, pretend you're Earth, watching Mercury run around a track. As it runs its loop, it will start out moving from the left side of your field of vision to your right. Then, it rounds the corner and, although not moving backward, is now running from right to left. This analogy is oversimplified because it doesn't take into account the fact that Earth is also moving, but it gives a good idea of how this optical illusion plays out.

All of the planets exhibit apparent retrograde motion, although it plays out slightly differently for planets farther from the sun than Earth versus those, like Mercury, that are closer to the sun than Earth.
Pseudo planetary effects

As for the potential influence of this seemingly odd movement on our daily lives, science doesn't back it up. In his 1974 book "The Jupiter Effect" (Walker Books), writer John R. Gribbinpredicted that the alignment of all of the planets and the sun on the same side of the Earth would have catastrophic effects.

James Zimbelman, a geologist at the Center for Earth and Planetary Studies at the Smithsonian's National Air and Space Museum, said this prediction actually prompted some scientists to look into the magnitude of the gravitational effects of planetary objects on Earth. "The net result of all of that was, the force is so small compared to either the sun or the moon, that any kind of planetary effect would just be swamped by the things the Earth is always feeling by either the sun or the moon," Zimbelman told Live Science.

(For reference, Margot said the gravitational effects a person experiences when standing next to another person are thousands to tens of thousands of times greater than the gravitational forces exerted on them by the moon.)

The vast number of internet sources mentioning Mercury's retrograde are astrological sites, which then go on to offer advice on how to combat its influence. Mars' apparent retrograde motion is the most obvious of the retrogrades because people can easily view Mars in the night sky as it is the closest planet and, unlike Mercury and Venus, doesn't require a person to look at the sun in order to observe it. This apparent retrograde motion garners much more notice from educational sources. Of the three experts contacted by Live Science, all three considered Mercury retrograde fairly unworthy of discussion.

"All planets appear to go through a period of retrograde (east-to-west) motion against the stars as seen from the Earth," Geoff Chester, a spokesman for the U.S. Naval Observatory, wrote in an email to Live Science. "There is nothing unusual in this. Mercury is no exception. There is no story here."
The Mercury transit

Even if retrograde isn't worthy of much scientific thought, it does overlap with a more exciting astronomical event. About once every 10 years, while Mercury is passing Earth, everything lines up just right, and Mercury crosses in front of the sun from our point of view on Earth. This is called the transit of Mercury and will occur on May 9

Enjoying the transit may be perhaps the greatest, clearest effect Mercury retrograde can have on your life.

New Print-Out Lasers Are So Cheap They're Disposable

Everyone's heard of disposable razors, but what about disposable lasers? Using inkjet printers, scientists have made laser devices cheap enough to be thrown out after a single use.

Lasers create their high-energy beams using a so-called gain medium, which takes advantage of the interactions between the electrons of its atoms and incoming photons to amplify light to high intensities. Typically, the gain medium is made from inorganic materials such as glasses, crystals or gallium-based semiconductors, but in recent years, researchers have investigated using organic carbon-based dyes instead.

Organic lasers hold great promise because they are low-cost and can emit light in a wide range of wavelengths, but they are limited because the dyes degrade rapidly.

Now, researchers from France and Hungary have used inkjet printers to produce the organic laser chips at the heart of these devices for mere cents, making it cost-effective to regularly replace the degraded parts.

"I think that this is an exciting piece of work with great potential for applications," said organic laser expert Graham Turnbull, a professor in the School of Physics and Astronomy at the University of St Andrews in Scotland. "The lasers could have future applications as disposable light sources for chemical analysis such as medical screening or pollution monitoring," Turnbull, who was not involved in the new study, told Live Science.

In a paper published today (May 3) in the Journal of Applied Physics, the researchers said the key to their approach's low cost is its efficiency. The most popular method for creating organic laser chips in the past has been spin coating. In this process, the surface on which the dye solution is to be deposited is spun rapidly so that centrifugal force spreads the liquid evenly to form a uniform thin film.

Inkjet printed "lasing capsules" serve as the core of an organic laser. Figure (a) shows a schematic of the laser setup, while figure (b) shows actual lasing capsules, which would cost only a few cents to produce. OC stands for "Output Coupler" and FP stands for Febry-Perot etalon.Credit: Sanaur, et al/JAP

But with typical spin-coating techniques, the vast majority of the dye solution spins off the surface and thus is wasted; as little as 2 percent is actually deposited usefully, the researchers said. In contrast, inkjet printers can accurately squirt small jets of fluid onto the underlying material, they added.

"You print 'where you want, when you want,' without wasting raw materials," study lead researcher Sébastien Sanaur, an associate professor of microelectronics at the Ecole Nationale Supérieure des Mines de Saint-Étienne in France, said in a statement.

For the laser dyes to be printed, they first needed to be mixed with an ink. Although the researchers experimented with inks specifically designed for optical applications, they eventually settled on a commercial variety called EMD6415 that exhibited excellent printing and optical properties.

Then, the solution was printed onto a slide made of quartz in 0.08-square-inch (50 square millimeter) pixels to make the laser chip. The chip was placed between two mirrors that reflected light back and forth through the gain medium during amplification. Another laser, known as the pump, was used to provide the light energy input, the researchers said.

Importantly, the scientists said the laser chip can be switched out easily when it deteriorates. They also demonstrated that they could use two different dyes to produce laser emissions ranging in color from yellow to deep red.

"The major advance here is the perfection of the inkjet printing process for the fabrication of organic 'gain' chips," said Stéphane Kéna-Cohen, an assistant professor in the Department of Engineering Physics at Polytechnique Montréal in Canada. "When used in a laser cavity, these can be used to fabricate broadly tunable lasers, and several dyes exist that together can span the entire visible spectrum," Kéna-Cohen, who was not involved with the new study, told Live Science.

Both Kéna-Cohen and Turnbull said one of the most promising aspects of the research is the possibility of printing several dyes onto the same chip to generate a spectrum of colors with the same device.

"The major obstacle, however, is that these organic lasers still need to be pumped by an external, relatively high-energy laser," Kéna-Cohen said. "Finding a way to pump these electrically or with a low-cost LED would be a major breakthrough for many practical purposes."- See more at: http://www.livescience.com/54632-disposable-lasers-made-from-inkjet-printers.html#sthash.wpz9uo7h.dpuf

SpaceX successfully launches Japanese JCSAT-14 Satellite

US based private space transport service company, SpaceX has successfully launched Japanese JCSAT-14 communication satellite into the space. The satellite was place into its intended preliminary geostationary transfer orbit by SpaceX Falcon 9 rocket which was launched from Cape Canaveral Air Force Station in Florida, US. After meeting its primary goal of the mission, the SpaceX Falcon 9 rocket successfully landed on an ocean (floating) platform, known as a drone ship, off the coast of Florida. This is for the second time in row the reusable main stage booster of Falcon 9 rocket successfully landed on offshore floating platform after the April 8, 2016 landing.
About JCSAT-14 Satellite
JCSAT-14 Satellite is owned by Sky Perfect JSAT Corporation. The satellite will boost the company’s fleet of relay stations to 17. The satellite is built by Space Systems/Loral and is equipped with 26 C-band and 18 Ku-band transponders. It has design life of 15 years and replaces the aging JCSAT-2A which is now stationed at 154 degrees East longitude. Sky Perfect JSAT Corporation is the only non-governmental provider of multi-channel pay television and satellite communications in Japan and a major communications provider across Asia and Oceania.

Dinosaurs fled Europe over 100 million years ago: study

Dinosaurs fled Europe over 100 million years ago: study Dinosaurs migrated out of Europe between 125 and 100 million years ago after the original super continent broke up, according to a new study that used 'network theory' for the first time to visually depict the movement of dinosaurs around the world.

The research also reaffirms previous studies that have found that dinosaurs continued to migrate to all parts of the world after the 'super-continent' Pangaea split into land masses that are separated by oceans. "We presume that temporary land bridges formed due to changes in sea levels, temporarily reconnecting the continents," said Alex Dunhill, from the University of Leeds in the UK, who led the study. "Such massive structures - spanning, for example, from Indo-Madagascar to Australia - may be hard to imagine," Dunhill said. "But over the timescales that we are talking about, which is in the order of tens of millions of years, it is perfectly feasible that plate tectonic activity gave rise to the right conditions for such land bridges to form," he said. The researchers used the Paleobiology Database that contains every documented and accessible dinosaur fossil from around the world. Fossil records for the same dinosaur families from different continents were then cross-mapped for different periods of time, showing connections that show how they have migrated. Some regions of the world, such as Europe, have extensive fossil records from a long history of palaeontology digs, while other parts of the world have been largely unexplored. To help account for this disparity in fossil records, which could otherwise skew the findings, the researchers applied a filter to the database records to only count the first time that a dinosaur family connection occurred between two continents. The findings support the idea that, although continental splitting undoubtedly reduced intercontinental migration of dinosaurs, it did not completely inhibit it. The research also showed that all connections between Europe and other continents during the Early Cretaceous period (125-100 million years ago) were out-going. While dinosaur families were leaving Europe, no new families were migrating into Europe, researchers said. While network theory is commonly used in computer science for quantifying internet data, such as friend connections on Facebook, it has only recently been applied to biology research and this is the first study to use it to on dinosaur research.

Comet craters helped create 'seeds of life' on Earth

Large meteorite and comet impacts into the sea may have formed the nurseries from which life on Earth first sparked, a new study has found.

Researchers from the Trinity College Dublin propose that meteorite and comet impacts created structures that provided conditions favourable for life. Water then interacted with impact-heated rock to enable synthesis of complex organic molecules, and the enclosed crater itself was a micro-habitat within which life could flourish.  It has long been suggested that the meteoritic and cometary material that bombarded the early Earth delivered the raw materials - complex organic molecules, such as glycine, beta-alanine, gamma-amino-n-butyric acid, and water - and the energy that was required for synthesis. "Previous studies investigating the origin of life have focused on synthesis in hydrothermal environments," said Edel O'Sullivan, postgraduate researcher at Trinity College Dublin. "Today these are found at mid-ocean ridges - hallmark features of plate tectonics, which likely did not exist on the early Earth," said O'Sullivan.  "By contrast, the findings of this new study suggest that extensive hydrothermal systems operated in an enclosed impact crater at Sudbury, Ontario, Canada," she said. Although no very ancient terrestrial impact structures are preserved, the Sudbury basin provides a unique opportunity to study the sediment that filled the basin as a guide to what the earlier impact craters would have looked like.  The Sudbury has an unusually thick (nearly 2.5 km) basin fill, and much of this is almost black in colour (due to carbon) containing also hydrothermal metal deposits. Representative samples across the basin fill were analysed for their chemistry and for carbon isotopes.  Researchers found that the crater was filled with seawater at an early stage, and remained sub-marine throughout deposition. The water in the basin was isolated from the open ocean for long enough to deposit more than 1.5 km of volcanic rock and sediment.  The lower fill is made up of rocks that formed when the water entered the crater whose floor was covered by hot impact melt. Fuel-coolant reactions deposited volcanic rocks and promoted hydrothermal activity. Above these deposits, reduced carbon starts and the volcanic products become more basaltic. Microbial life within the crater basin was responsible for the build-up of carbon and also for the depletion in vital nutrients, such as sulphate, researchers said. Only after the crater walls collapsed, did the study show replenishment of nutrients from the surrounding sea.  These sub-marine, isolated impact basins, which experienced basaltic volcanism and were equipped with their own hydrothermal systems, thus present a new pathway to synthesis and concentration of the stepping stones to life.

India to witness rare transit of Mercury passing Sun on May 9

India to witness rare transit of Mercury passing Sun on May 9

A rare transit of the smallest planet in the solar system - Mercury over the disc of the Sun will take place on May 9, 2016 in the afternoon.

This transit phenomenon will also be visible from India. A transit occurs when one astronomical body appears to move across the face of another as seen from Earth. In a similar way, the planet Mercury will be seen as a small black dot when it passes between the Sun and the Earth. This happens only when the Sun, the planet Mercury and the Earth are lined up in one plane. This phenomenon occurs rarely 13-14 times in a century in the month of May and November.  The interval between one November transit and next November transit may be 7, 13 or 33 years whereas the interval between one May transit and the next May transit may be 13 or 33 years. The entire transit, from beginning to end, will be visible from eastern North America, northern South America, the Arctic, Greenland, extreme northwestern Africa, Western Europe, and the North Atlantic Ocean. The duration of the entire transit event will be about 7 hour and 30 minutes. However, the observers in India will not be able to see the ending of the event as the same will be in progress after sunset. Depending upon the sunset time of different places in the country, people living in the extreme east of the country will see the event about 1 hour from the beginning and people living in the extreme west of the country will see the event about 2 hours and 45 minutes from the beginning. In Delhi, the event can be seen for a duration of about 2 hours 20 minutes as it will start at 04:41 PM and sunset will take place at 07:01 PM. Similarly, in Kolkata the event will start at 04:41 PM and it can be seen for a duration of about 1 hour 26 minutes. In Mumbai the event will start at 04:41 PM and it can be seen for a duration of about 2 hours 24 minutes and in Chennai the event will start at 04:41 PM and it can be seen for a duration of about 1 hour 45 minutes.

New Earth-Like Planet Discovered by NASA’s Kepler Space Telescope

Astronomers using NASA’s Kepler Space Telescope announced Thursday the discovery of the most Earth-like planet yet orbiting a distant star like our own sun, bringing to a dozen the number of small worlds potentially suitable for life spotted elsewhere in the galaxy.

The newly discovered planet, called Kepler-452b, is the smallest to date found orbiting in the habitable zone of a distant star—the area where the water considered essential for life could exist.

Every 385 days, the planet circles a star slightly brighter than the sun, located about 1,400 light years away in the Constellation Cygnus, the researchers said.

Interactive: From Pluto to the Sun

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Based on available data, the planet is most likely rocky, about 60% larger than Earth and about 1.5 billion years or so older, the researchers said. So far, there is no evidence that it has an atmosphere. The researchers don’t know the planet’s mass, but speculated that its gravity may be twice that on Earth.

“It is a pretty good close cousin to our Earth and our sun,” said John Grunsfeld, associate administrator for science at the National Aeronautics and Space Administration in Washington, D.C. “It is the closest so far.”

The Kepler astronomers, however, have no direct evidence that the newly found planet can actually support life.

The space agency announced the find at a media briefing Thursday. A research paper reporting the conclusions has been accepted for publication in the Astronomical Journal.

The discovery was found by analyzing data on about 150,000 stars collected by the $600 million planet-hunting space telescope before it malfunctioned two years ago.

To help confirm the finding, astronomers also conducted ground-based observations at the University of Texas’ McDonald Observatory in Fort Davis, Texas; the Fred Lawrence Whipple Observatory on Mount Hopkins in Arizona; and the W.M. Keck Observatory on Mauna Kea in Hawaii.

The Kepler scientists said Thursday that they also have identified 521 new possible exoplanets, as worlds around other stars are called.

So far, the Kepler astronomers have confirmed the existence of 12 planets less than twice the size of Earth in the habitable zones of the stars they orbit.

All told, the researchers are analyzing data about 4,696 potential exoplanets and have confirmed the existence of 1,028 exoplanets of all sorts. A dozen of them appear to be between one to two times the size of Earth, and orbit in their star’s habitable zone. Of these, nine orbit stars that are similar to the sun in size and temperature, including the exoplanet announced Thursday.

“We are the breadcrumbs of the universe,” said Kepler research scientist Jeff Coughlin, from the SETI Institute in Mountain View, Calif. “Planets like Earth do appear to be quite common.”

An individual blood cell takes about 60 seconds to make a complete circuit of the body

You have about 5 litres of blood in your body (at least most people do) and the average heart pumps about 70 ml of blood out with each beat. Also, a healthy heart beats around 70 times a minute. So, if you multiply the amount of blood that the heart can pump by the number of beats in a minute, you actually get about 4.9 litres of blood, which is almost your whole body’s worth of blood. In just a minute, the hearts pumps the entire blood volume around your body.

The average person walks the equivalent of five times around the world in a lifetime

The average moderately active person take aound 7,500 step/day.  If you maintain that daily average and live until 80 years of age, you’ll have walked about 216,262,500 steps in your lifetime. Doing the math;  the average person with the average stride living until 80 will walk a distance of around 110,000 miles.  Which is the equivalent of walking about 5 times around the Earth, right on the equator. 

It can take a photon 40,000 years to travel from the core of the sun to its surface, but only 8 minutes to travel the rest of the way to Earth

A photon travels, on average, a particular distance, d, before being briefly absorbed and released by an atom, which scatters it in a new random direction.From the core to the sun’s surface (696,000 kilometers) where it can escape into space, a photon needs to make a huge number of drunken jumps. The calculation is a little tricky, but the conclusion is that a photon takes between many thousands and many millions of years to drunkenly wander to the surface of the Sun. In a way, the light that reaches us today is energy produced maybe millions of years ago. Amazing!

There is enough DNA in an average person’s body to stretch from the sun to Pluto and back. 17 times

The human genome, the genetic code in each human cell, contains 23 DNA molecules each containing from 500 thousand to 2.5 million nucleotide pairs. DNA molecules of this size are 1.7 to 8.5 cm long when uncoiled, or about 5 cm on average. There are about 37 trillion cells in the human body and if you’d uncoil all of the DNA encased in each cell and put them end to end, then these would sum to a total length of 2×1014 meters or enough for 17 Pluto roundtrips (1.2×1013meters/Pluto roundtrip).

Why Do So Many Earthquakes Strike Japan?

A magnitude-7.0 earthquake struck southern Japan today, less than two days after a 6.2-magnitude temblor rocked the same region, triggering tsunami advisories in the area.

The most recent earthquake struck the Kumamoto region on Japan's Kyushu Island early Saturday (April 16) at 1:25 a.m. local time (12:25 p.m. ET on April 15), according to the U.S. Geological Survey (USGS). The smaller 6.2-magnitude quake on Thursday (April 14) killed nine people and injured hundreds more, reported CBS News.

With residents of the Kumamoto region reeling from two sizable earthquakes in as many days, and with memories of the massive 9.0-magnitude earthquake and tsunami that devastated Tohoku, Japan, in 2011 not far from people's minds, what is it about this part of the world that makes it so seismically active? [The 10 Biggest Earthquakes in History]

For starters, Japan is located along the so-called Pacific Ring of Fire, which is the most active earthquake belt in the world. This "ring" is actually an imaginary horseshoe-shaped zone that follows the rim of the Pacific Ocean, where many of the world's earthquakes and volcanic eruptions occur.

Within the Ring of Fire, several tectonic plates — including the Pacific Plate beneath the Pacific Ocean and the Philippine Sea Plate — mash and collide.

"The Earth's surface is broken up into about a dozen or so major chunks that are all moving around. Where they all interact at their edges, interesting things happen," said Douglas Given, a geophysicist with the USGS in Pasadena, California.

Today's earthquake seems to have been caused by the Philippines Sea Plate diving underneath the Eurasia Plate, according to Paul Caruso, a geophysicist with the USGS.

While Japan is no stranger to earthquakes, the 7.0-magnitude temblor is one of the largest ever recorded in this part of southern Japan, Caruso told Live Science.

"The second-largest was probably on March 20, 1939 — there was a magnitude-6.7 in this area. And we've had magnitude-6.5 and magnitude-6.3 earthquakes, but this is the largest quake that has been measured in that vicinity," he said.

A tsunami advisory was issued after today's earthquake, but it was subsequently lifted by the Japan Meteorological Agency, and there are currently no major tsunami warnings or advisories in effect.

Not all earthquakes trigger tsunamis, Caruso said. In general, there are three key ingredients that can produce a dangerous earthquake-tsunami combination, he added. First, the earthquake must be at least a magnitude-7 temblor. Second, the quake's epicenter has to be underneath the ocean, Caruso said. And finally, the earthquake has to be shallow.

"We have quakes around Fiji all the time, but those are sometimes 400 miles [640 kilometers] underground, so they aren't going to generate a tsunami," he said.

Today's earthquake was shallow — about 6 miles (10 km) underground — but the epicenter was on land, meaning there aren't likely to be any dangerous tsunamis as a result, Caruso said.

Given said he hasn't seen many damage reports yet, but Japanese authorities and scientists at the USGS will be monitoring the area for potentially dangerous aftershocks, which are smaller quakes that follow the largest event in a series and that generally decrease in strength.

"This seems to be a pretty energetic sequence, and there are lots of large aftershocks," Given told Live Science. "And of course, after a large earthquake, structures are often weakened as a result. Additional damage can be expected."

Residents of the area should expect more shaking in the coming days, according to Caruso.

"We can say for certain that there are going to be more aftershocks in this area," he said. "Exactly when and how big they're going to be is difficult to say, though. No one can predict that."

Matters of the Brain: Why Men and Women Are So Different

LONDON – A prevalent understanding, particularly in the 1980s, was that boys and girls are born cognitively the same. It was the way parents and society treated them that made them different.

Since then, a preponderance of research has called this belief into question. The majority of today's psychologists agree that some of the differences exhibited by male and female brains are innate.

"We do socialize our boys and girls differently, but the contribution of biology is not zero," said Diane Halpern, a professor of psychology at Claremont McKenna College in California, who has been studying cognitive gender differences for 25 years. Halpern was a keynote speaker at the British Psychological Society Annual Conference here last Thursday (April 19). 

How much, rather than whether, biology contributes is where the unusually heated debate is now focused, she said.

Differences confirmed (so far)

Some of the many gender differences that float in popular consciousness have more support than others.

The ones that have been consistently found across cultures, life spans and even across species are the most likely — but by no means guaranteed — to have some biological underpinning.

Across age groups, species and nations, males tend to be better at various spatial skills. For example, male dominance in rotating an object in their minds, a quite large difference that has been reliably found for the last 35 years, has recently been documented in infants as young as 3 months old. Similarly, on average, males across cultures and species are better at judging angle orientation and navigating by cardinal direction.

Females, on the other hand, tend to have more verbal fluency and greater memory for objects — that is, "they are better at remembering where things are," Halpern said during her talk. Women and females from other species are more likely to navigate by using landmarks than cardinal direction.

"But you can get there using both," Halpern told LiveScience, pointing out that having different skills does not mean that men and women have different levels of intelligence. "There is not a smarter sex," she said.

In general, across a variety of tests, differences seem to fall particularly at the tails of distribution curves, with more males doing very poorly andmore males doing exceedingly well.

Differences that vary

It has been overreported that boys tend to do better at math while girls often excel at reading and writing. In truth, the degree of difference is context-dependent.

In school, girls tend to do better in all subjects, albeit by only about a quarter grade on a four-point scale, Halpern said, citing U.S.-focused research. Boys, on the other hand, tend to excel at tests that focus on areas outside their school's curriculum, she said.

Whether these findings mean schools are biased against boys, standardized tests are biased against girls, or nothing of the sort are among the unanswered questions that rage through psychology, education systems and parenting circles today.

And society does play a big role — just not always with the expected results.

In more gender-equal societies, "the male advantage in math virtually disappears," Halpern said, but other differences grow. When given more equal encouragement and access to education, on average, girls become even better at reading than boys and boys further outstrip girls in visual-spatial tasks.

Economics also matter. "Being poor is not good for anyone's cognitive development," Halpern said.

While the disadvantage may be staggering in the poorest nations, it is true in developed countries as well. Halpern explained that while women outnumber men in college, it is primarily men from lower socio-economic brackets that are not getting degrees. [6 Gender Myths Busted]

Losing talent

So, if neither sex is more intelligent, why are we so stratified by adulthood? Why, for example, are more than 90 percent of CEOs male and more than 90 percent of secretaries female?

As long as women are doing most of the caretaking jobsin society, Halpern told LiveScience, such as taking care of young and elderly loved ones, they are going to occupy wage-earning jobs that require less time. (In addition to being a research psychologist, Halpern was the founding director of the Berger Institute for Work, Family and Children.)

There is also an issue of interest, she said, in that many young women may not realize that being, say, an engineer can also be a "helping" job.

As a society, we are not only losing talented women from the workplace, she added, we are also losing talented men in the domestic front. Men can be excellent caregivers, and numerous studies have shown the importance of fathering for children.

Crocodiles Swallow Stones for Swimming

The stomach of a crocodile is a rocky place to be, for more than one reason. To begin with, a croc's digestive system encounters everything from turtles, fish and birds to giraffes, buffalo, lions and even (when defending territory) other crocodiles. In addition to that bellyful-o'-ecosystem, rocks show up too. The reptiles swallow large stones that stay permanently in their bellies. It's been suggested these are used for ballast in diving.

Since you made it all the way, here are some bonus crocodile facts: The largest croc ever found was 20.24 feet (6.17m) long. These reptiles are cold-blooded, so in winter they hibernate. A croc can lay up to 60 eggs at a time!

Birds Use Landmarks to Navigate Long Journeys

We humans have detailed maps, GPS navigation systems and even Siri to guide us wherever we'd like to go. Birds, smart as they are, haven't learned to use any of this technology. Yet pigeons can fly thousands of miles to find the same roosting spot with no navigational difficulties. Some species of birds, like the Arctic tern, make a 25,000 mile round-trip journey every year. Many species use built-in ferromagnets to detect their orientation with respect to the Earth's magnetic field. A November 2006 study published in Animal Behaviour suggests that pigeons also use familiar landmarks on the ground below to help find their way home. Still, much about bird navigation remains a mystery, according to this 2014 this perspective piece by University of Oxford researcher Tim Guilford.

Mole-Rats aren't Blind

With their puny eyes and underground lifestyle, African mole-rats have long been considered the Mr. Magoos of rodents, detecting little light and, it has been suggested, using their eyes more for sensing changes in air currents than for actual vision. But findings of the past few years have shown that African mole-rats have a keen, if limited, sense of sight. And they don't like what they see, according to a report in the November 2006 Animal Behaviour. Light may suggest that a predator has broken into a tunnel, which could explain why subterranean diggers developed sight in the first place. 

Baby Chicks and Brotherhood

It's a mistake to think of evolution as producing selfish animals concerned only with their own survival. Altruism abounds in cases where a helping hand will encourage the survival of genetic material similar to one's own. Baby chicks practice this "kin selection" by making a special chirp while feeding. This call announces the food find to nearby chicks, who are probably close relations and so share many of the chick's genes. The key to natural selection isn't survival of the fittest animal. It's survival of the fittest genetic material, and so brotherly behavior that favors close relations will thrive. Chimps are also known to be selfless on occasion.

Many Fish Swap Sex Organs

With so many land creatures to wonder at, it's easy to forget that some of the weirdest activities take place deep in the ocean. The strange practice of hermaphroditism is more common among species of fish than within any other group of vertebrates. Some fish change sex in response to hormonal cycle or environmental changes. Others simultaneously possess both male and female sex organs. Scrawny male molly fish flaunt their bisexuality to improve their mating odds, according to research reported in the journal Biology Letters.

Giraffes Compensate for Height with Unique Blood Flow

The stately giraffe, whose head sits some 16 feet up atop an unlikely pedestal, adapted his long neck to compete for foliage with other grazers. The long necks of giraffes date back to ancestors that lived 16 million years ago, according to a study reported October 7, 2015 in the journal Royal Society Open Science. While the advantage of reach is obvious, some difficulties arise at such a height. The heart must pump twice as hard as a cow's to get blood up to the brain, and a complex blood vessel system is needed to ensure that blood doesn't rush to the head when bent over. Six feet below the heart, the skin of the legs must then be extremely tight to prevent blood from pooling at the hooves.