Eclipse Sequence Over Africa
Two cameras were used to create this dramatic view of the June 2001 total solar eclipse above Chisamba, Zambia.
One camera captured totality and a thorn acacia tree while the second camera recorded the partial phases at 5 minute intervals through a solar filter. — Fred Espenak
The Variety of Animal Species
An interesting infographic about the amount of species on earth. The total estimate of the this chart puts the number of different species of animals over 6 million. It is also important to remember that this number excludes different plants and single-celled organisms.
Scientists also estimate that out of all of the various species alive today (animals, plants, etc. included) is only 1% of the species that have lived on earth in the past.Image courtesy of National Geographic
Zhangye Danxia - Geology From a Storybook
Long ago, colorful sediments were deposited in western China, layer after layer, century after century. If you were there at the time, you would have seen unremarkable ground, a single hue of dirt no different from a thousand other places on Earth.
But after thousands and thousands of years subject to the forces of pressure and tectonic movement, the total of those layers has been pushed upward, letting us peek at a rainbow-hued slice of Earth’s past perhaps unmatched on this planet. The planet looks more like the cross-section of a jawbreaker candy than layers of rock in these photos, near Zhangye, China.
The Zhangye formation, not to be confused with this danxia, a UNESCO heritage site, reminds us how our crust is heaved and hurled throughout the ages, a slow evolution that will continue into the distant future. It’s yet another story of Earth’s past, written in stone, but perhaps with the same pen as a fantasy storybook.
One year ago the Elwha and Glines Canyon Dams started to be removed as part of the watershed restoration on Washington’s Olympic peninsula. It is the largest dam removal in the history of the USA.
The dam removal will restores ecosystems in the long term, it will open up the river to migrating fish for the first time in 100 years and allow the river to transport sediment throughout its reach, helping to rebuild the natural bed structure and flow of the Elwha all the way to the sea by rebuilding beaches that today are starved for sand and other fine material.
In the short term, excess turbidity remains the biggest concern during the next 3–10 years. About 600 dams have been taken down in the U.S. over the past 50 years, but none involved so much sediment (24 million cubic yards).
In the case of the Elwha, Congress authorized the dam removal 20 years ago, but it took two decades to get the money and logistical details in place.
Classic Children’s Books
“Take some more tea,” the March Hare said to Alice, very earnestly.
“I’ve had nothing yet,” Alice replied in an offended tone, “so I can’t take more.”
“You mean you can’t take less,” said the Hatter: “it’s very easy to take more than nothing.”
“Nobody asked your opinion,” said Alice.”
There could not have been a lovelier sight; but there was none to see it except a little boy who was staring in at the window. He had ecstasies innumerable that other children can never know; but he was looking through the window at the one joy from which he must be for ever barred.
‘That proves you are unusual,’ returned the Scarecrow; ‘and I am convinced that the only people worthy of consideration in this world are the unusual ones. For the common folks are like the leaves of a tree, and live and die unnoticed.’
At first people refuse to believe that a strange new thing can be done, then they begin to hope it can be done, then they see it can be done—then it is done and all the world wonders why it was not done centuries ago.
The proof that the little prince existed is that he was charming, that he laughed, and that he was looking for a sheep. If anybody wants a sheep, that is a proof that he exists.
If you want to find Cherry-Tree Lane all you have to do is ask the Policeman at the cross-roads.
There’s such a lot of different Annes in me. I sometimes think that is why I’m such a troublesome person. If I was just the one Anne it would be ever so much more comfortable, but then it wouldn’t be half so interesting.
Home! That was what they meant, those caressing appeals, Those soft touches wafted through the air, those invisible little hands pulling and tugging, all one way.
Dust Pillar of the Carina Nebula
Inside the head of this interstellar monster is a star that is slowly destroying it. The monster, actually an inanimate pillar of gas and dust, measures over a light year in length.
The star, not itself visible through the opaque dust, is bursting out partly by ejecting energetic beams of particles. Similar epic battles are being waged all over the star-forming Carina Nebula (NGC 3372). The stars will win in the end, destroying their pillars of creation over the next 100,000 years, and resulting in a new open cluster of stars. The pink dots are newly formed stars that have already been freed from their birth monster.
The above image is only a small part of a highly detailed panoramic mosaic of the Carina Nebula taken by the Hubble Space Telescope in 2007. The technical name for the stellar jets are Herbig-Haro objects. How a star creates Herbig-Haro jets is an ongoing topic of research, but it likely involves an accretion disk swirling around a central star. A second impressive Herbig-Haro jet is visible across the bottom of a larger image.
The body: Your curious behaviours and what they reveal
What makes humans so special? The obvious answer is our amazing brains. The body barely gets a mention.
Yet it should. Our bodies are extraordinary: hairless, upright and with many peculiar features related to intelligence, including an oversized head. And that is just the start.
Ever wondered why yawns are contagious, you can’t tickle yourself and we don’t speak from our bottoms?
IT’S your body, and you like to think you’ve got it under control. But underneath the calm exterior lurk unruly instincts and urges that are struggling to escape, putting you at risk of embarrassment or ridicule. These disreputable behaviours – the likes of the fart, hiccup, itch and yawn – are familiar to us all, yet they are also decidedly curious. Although they have been the source of folklore and puzzlement since antiquity, they have largely been overlooked by scientists. After all, where is the scientific grandeur in such ignoble acts? I take a different view. Where others see forbidden areas, I find unexplored territory and new frontiers of research. So I have made a point of studying our curious behaviours. What I have found sheds new light on our body, our mind and our evolution as a social animal.
Whatever the purpose of a spontaneous yawn – and this remains hotly contested – the most extraordinary property of human yawning is its contagiousness. When we see someone yawn, our body is hijacked by a primal neurological process that is hard to resist. Imagine a yawning person with mouth stretched wide open, eyes squinting, taking a long inhalation followed by a shorter outward breath. Are you yawning yet?
Yawns are so catching that almost anything associated with them can stimulate more yawns, including seeing, hearing, reading about, or even thinking about yawning. My colleagues and I have found that silent videos of yawning people trigger contagious yawns in about 55 per cent of observers within five minutes, and almost everyone reports being at least tempted to yawn. Surprisingly, given that a gaping mouth is the most conspicuous element of yawning, videos that had the mouth edited out were just as effective at making viewers yawn. In fact, videos showing just a yawning mouth evoked no more yawns than one of a smiling face. That may be because an open mouth is not exclusively associated with yawning and could be doing something else such as singing or yelling. We respond to the overall configuration of the yawning face, including the squinting eyes.
From the evolutionary perspective, spontaneous yawns are ancient – occurring in most vertebrates – whereas contagious ones are relatively modern, being confined to social mammals including chimpanzees andperhaps dogs. In humans, spontaneous yawning develops while we are still in the womb, but the contagious variety does not appear until a child is 4 or 5. This is also roughly when children start being able to attribute mental states to themselves and others, strengthening the idea that contagious yawning is linked with sociality. Although the neurobiology of this curious behaviour is little understood, it is clear that when it occurs we become mindless beasts of the herd. As a yawn propagates through a group, it drives a ripple of physiological and emotional connection, transforming individuals into a superorganism.
Itching is an exquisite torment that earned a place in Dante’s Inferno, but it has its virtues. The skin is our body’s first line of defence against invasion and we are neurologically primed to maintain its integrity. So, when threatened by insect pests, toxic flora or other irritants, an itch guides us to the problem area and motivates us to scratch, in an attempt to dislodge the invader and quell the discomfort. Only the skin, not internal organs, gets itchy. We also respond to tactile false alarms when we itch in response to skin conditions such as eczema, athlete’s foot and psoriasis and, even more mysteriously, as a result of thyroid disease, diabetes and some neuropathologies. Itching isinhibited by pain, but while vigorous, tissue-damaging scratching can offer blessed relief in the short term, it can produce even more itching, locking us into a self-perpetuating itch-scratch cycle.
Like yawning, itching is contagious. You can “catch” an itch from observing someone scratching, attending a lecture about itching, or viewing slides ofitch-producing pests such as lice. Even reading this may make you itchy. Contagious itching makes evolutionary sense: your neighbour’s pesky flea may jump from its host to you but won’t get far if you are already scratching.
Hiccupping starts with a sudden inhalation produced by a downward jerk of the diaphragm and contraction of the muscles between the ribs, and ends almost immediately by glottal closing to produce the “hic” sound. Although of unknown purpose, this enigmatic act is one of the most common prenatal behaviours, suggesting a developmental role. Hiccupping starts at around 8 weeks of gestation, peaking between 10 and 13 weeks, then declines through the remainder of life. For an unfortunate few, however, hiccups return with a vengeance in later life in the form of persistent bouts lasting 48 hours or longer. Men are nine times more likely to suffer this than women. The record for chronic hiccupping is held by Iowa farmer Charlie Osborne who hiccupped for over 67 years. Fortunately, hiccups usually stop during sleep.
A “hiccup generator” in the brainstem choreographs the widely distributed neurological and muscular components of a hiccup when it receives certain cues. These causes can range from distension of the stomach and irritation of the oesophagus to various thoracic and nervous disorders. Remedies are even more diverse. In his Symposium, Plato listed breath holding, gargling and sneezing. Other purported cures include eating sugar, drinking water upside down, being frightened and putting your fingers in your ears. During the course of my research I have discovered another. The audio recorder cure simply entails my standing expectantly, microphone in hand, next to the hiccupper. It is particularly effective on children and shows the power of social inhibition over an ancient, instinctive act.
If you ingest a toxic substance, your body uses an effective and violent response to try to eject it: vomiting. However, you are also prone to retch at the mere sight, smell or sound of someone else doing it. Why? I became fascinated by this phenomenon as a child on a particularly nauseating family road trip when my cousin Karen was sick in the car, causing the other passengers to vomit. Decades later I got a chance to investigate contagious (or hysterical) vomiting. I found that girls of middle-school and high-school age are especially prone. Bouts usually occur during a group event that provokes anxiety. They tend to involve reports of vague smells such as vehicle exhaust fumes or sewer gas, or odd tasting or smelling food or drink. Symptoms are likely to be vague and the illness will resolve quickly and have no adverse effects.
Although contagious vomiting seems like a prime example of a bodily malfunction, in evolutionary terms it is adaptive, permitting everybody in a group to benefit vicariously from the reaction of the person who takes the first taste of something toxic. Messy false alarms are a small price to pay for a potentially life-saving gut reaction. Indeed, some Central and South American peoples intentionally induce communal vomiting by drinking the ritual emetic ayahuasca, in their quest for purification and bonding. Cheers!
Tickling is exceptional in its philosophical, neurological, psychological and practical significance – impressive credentials for a behaviour that is often relegated to a footnote.
Everything starts with the observation that we cannot tickle ourselves. This is fortunate, otherwise we would go through life in a giant chain reaction of goosiness, confused about whether we touched something or it touched us. The neurological process that inhibits our response to self-touching also computes our discrimination of self and other. Who would have thought that the lowly tickle could offer a solution to the ancient and thorny philosophical problem of personhood?
This amazing insight even has a practical application. If computer scientists could create an algorithm to differentiate touching from being touched, they would increase the fine motor control of robots and be on the way to producing a machine with personhood.
The fact that we cannot tickle ourselves makes tickling inherently social. It is an important means of tactile communication and bonding, and, I would argue, the basis of a baby’s earliest preverbal conversations with carers. Although self-professed tickle-haters abound, my surveys indicate that we usually tickle and are tickled by friends, family and lovers, with the motive of showing affection and getting attention. The capacity for mutual tickling enables the neurologically programmed choreography of tickle battles, physical play and sex play. The laboured breathing this produces is the origin of laughter, with the ancestral “pant-pant” – still produced by chimpanzees when tickled – evolving into the modern human “ha-ha”. I will further suggest that feigned tickle – the basis of the “I’m going to get you” game – is the most ancient joke.
No investigation of our quirky bodily behaviours would be complete without considering flatulence. This uncouth act has attracted interest from scholars and the general public alike since antiquity. A growing appreciation of the importance of our gut microfauna has brought farting to the attention of gastroenterologists. My interest in the subject is more esoteric: given the rich variety of sounds entailed, I wondered why we speak through our mouth rather than our butt.
This is not as frivolous as it first seems, given that no part of the human body evolved specifically for speech. We speak through the same orifice through which we breathe, eat, drink and vomit, and the vocal cords are two flaps of tissue that act as a seal to keep food and drink out of the airway when we swallow. So why did evolution not take the alternative option of using the abdomen and lower bowel as bellows – some people do have such control – and the anal sphincter as the vibrating seal? Well, a major weakness of this idea is that while the oral vocal tract has the mouth, tongue, teeth and throat to shape sounds, the anus lacks such features. That hasn’t stopped herring using farts to communicate, but the fish are an exception, and even then it causes problems. Flatulent herring attract the attention of hungry killer whales that home in on the sound of their breaking wind. Alas, buttspeak turns out to be a weak contender in the speech evolution sweepstakes.
(Image: La Promessa, 2010, Bronze. Matteo Pugliese)
After nearly a decade of careful observations an international team of astronomers has measured the distance to our neighbouring galaxy, the Large Magellanic Cloud, more accurately than ever before. This new measurement also improves our knowledge of the rate of expansion of the Universe — the Hubble Constant — and is a crucial step towards understanding the nature of the mysterious dark energy that is causing the expansion to accelerate. The team used telescopes at ESO’s La Silla Observatory in Chile as well as others around the globe. These results appear in the 7 March 2013 issue of the journal Nature.
Image: This artist’s impression shows an eclipsing binary star system. Credit: ESO/L. Calçada
Astronomers survey the scale of the Universe by first measuring the distances to close-by objects and then using them as standard candles  to pin down distances further and further out into the cosmos. But this chain is only as accurate as its weakest link. Up to now finding an accurate distance to the Large Magellanic Cloud (LMC), one of the nearest galaxies to the Milky Way, has proved elusive. As stars in this galaxy are used to fix the distance scale for more remote galaxies, it is crucially important.
But careful observations of a rare class of double star have now allowed a team of astronomers to deduce a much more precise value for the LMC distance: 163 000 light-years.
“I am very excited because astronomers have been trying for a hundred years to accurately measure the distance to the Large Magellanic Cloud, and it has proved to be extremely difficult,” says Wolfgang Gieren (Universidad de Concepción, Chile) and one of the leaders of the team. “Now we have solved this problem by demonstrably having a result accurate to 2%.”