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Day July 2, 2010

Blue Nebula

Via Wired, by Lisa Grossman; image from ESO:

This wispy blue cloud of gas and dust is a star-forming region surrounding the star R Coronae Australis, which is about 420 light-years away. The new portrait was taken with the Wide Field Imager at the La Silla Observatory in Chile. The image, a combination of 12 separate snapshots in three different colors, depicts a young family of stars still embedded in and interacting with the cloud of dust and gas from which they formed.

The image spans about 4 light-years, and focuses on a nascent star-forming region located in the small, tiara-shaped constellation Coronae Australis, the Southern Crown. The infant stars there give off hot, intense radiation, and the surrounding gas and dust either reflects or absorbs this radiation and re-emits it at a different wavelength.

While most nebulae glow with a characteristic red tint, the R Coronae Australis region takes an unusual blue hue. The stars are about the mass of the sun, and don’t emit enough ultraviolet light to strip the surrounding hydrogen gas of its electrons, which would produce the familiar red glow. The blue fog is mostly due to starlight reflecting off small dust particles.

In some regions, like the dark band that crosses the image from the bottom left, the starlight is completely absorbed by dust. Any stars hiding in this region would only be visible with an infrared telescope that can detect their heat.

Researchers Shed Light on Birth of the First Stars

Via PhysOrg

In the beginning, there were hydrogen and helium. Created in the first three minutes after the Big Bang, these elements gave rise to all other elements in the universe. The factories that made this possible were stars. Through nuclear fusion, stars generated elements such as carbon, oxygen, magnesium, silicon and the other raw materials necessary for making planets and ultimately life.

But how did the first stars come to be? New research from Columbia University shows that it all boils down to this simple reaction:

H- + H –> H2 + electron

“In order for us to follow the chain of events responsible for how we got here, we need to understand the beginning,” said Daniel Wolf Savin, a senior research scientist in Columbia University’s Astrophysics Laboratory. The work of Savin and his collaborators, who include lead author and former group member Holger Kreckel, now at the University of Illinois, will be published July 2 in the journal Science.

Savin’s research details a key chemical reaction that took place in the universe about a million years after the Big Bang. That reaction, called associative detachment, allowed clouds in the universe to cool, condense and form the first stars.

“In order to understand how the first stars formed, we need to know how the clouds that gave birth to them cooled. Molecular hydrogen (H2) radiated the heat out of the clouds, so we need to know how much H2 was in the cloud. This in turn requires understanding the chemical process by which the H2 formed. That’s what we’ve measured,” said Savin.

H2 is formed when two hydrogen atoms come together and bind to one another to make a molecule. Savin’s group measured this probability. His results show that the likelihood for this is higher than previous theoretical calculations and experiments have shown.

“The previous uncertainty in this reaction limited our ability to predict if a cloud of gas would form a star or not, and if it did, then what the mass of that star would be,” said Savin. “That’s an important thing to quantify, because the mass of a star determines the elements it will synthesize.”

The predicted masses for the first stars depend on the initial conditions of the primordial clouds from which they formed. These conditions are highly uncertain and still an active area of research. By comparing model predictions to observations of the universe astronomers can approximate what these initial conditions must have been. But the accuracy of these estimates depends critically on our understanding of the underlying chemical reactions, particularly those measured by Savin and his group. With the new data in hand, cosmologists will be better able to determine what the initial conditions were in the early universe leading to the formation of the first stars.

Morality: Rose-Colored Spectacles?

From The Economist

Cheats may or may not prosper, but they despise themselves for cheating

Those who buy counterfeit designer goods project a fashionable image at a fraction of the price of the real thing. You might think that would make them feel rather smug about themselves. But an intriguing piece of research published in Psychological Science by Francesca Gino of the University of North Carolina, Chapel Hill, suggests the opposite: wearing fake goods makes you feel a fake yourself, and causes you to be more dishonest in other matters than you would otherwise be.

Dr Gino and her colleagues provided a group of female volunteers with Chloé sunglasses that cost about $300 a pair, supposedly as part of a marketing study. They told some of the volunteers that the sunglasses were real, and others that they were counterfeit. They then asked the volunteers to perform pencil-and-paper mathematical quizzes for which they could earn up to $10, depending on how many questions they got right. The participants were spun a yarn about how doing these quizzes would allow them to judge the comfort and quality of the glasses.

Crucially, the quizzes were presented as “honour tests” that participants would mark themselves, reporting their own scores to the study’s organisers. The quiz papers were unnumbered and thus appeared to be untraceable, and were thrown away at the end of the study. In fact, though, each had one unique question on it, meaning that it could be identified—and the papers were recovered and marked again by the researchers after they had been discarded.

Of participants told that they were wearing authentic designer sunglasses, 30% were found to have cheated, reporting that they had solved more problems than was actually the case. Of those who thought they were wearing fake sunglasses, by contrast, about 70% cheated.

The results were similar when the women completed a computer-based task that involved counting dots on a screen. In this case, the location of the dots determined the financial reward. The women who thought they were wearing counterfeits lied about those locations more often than those who did not.

In a third part of the study, the participants were asked questions about the honesty and ethics of people they knew and people in general. Those who thought they had knock-offs were more likely to say that people were dishonest and unethical.

It looked, then, as if believing they were wearing fakes made people feel like fakes. To test that hypothesis, Dr Gino and her colleagues ran the experiment again, this time including a test meant to detect self-alienation. They asked the participants if they agreed with statements like, “right now, I feel as if I don’t know myself very well”. Those who thought they were wearing fakes did indeed feel more alienated from themselves than those who knew they were wearing the real things.

It remained possible, however, that it was the sense of self-alienation which was normal, and that believing you were wearing designer glasses made you more at ease with yourself. To test that, the team ran one final set of experiments, in which some people were given sunglasses to wear without any indication of their provenance. Volunteers in this control group behaved like those who believed the glasses were authentic.

The moral, then, is that people’s sense of right and wrong influences the way they feel and behave. Even when it is someone else who has made them behave badly, it can affect their subsequent behaviour. Next time you are offered fake accessories, beware: wearing them can make you feel like a bad person, not a better one.

City Monologues

From Acne Paper

illmantra_1 & Trusss

illmantra_1

Trusss

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