ikenbot:

Kilimanjaro Fireball

While an electric-lighted line of mountain climbers snakes toward it, a dazzling fireball (bright meteor) streaks over Tanzania’s Mount Kilimanjaro (the summit of Kibo at 5893 meters). — Kwon, O Chul

Supermoon Rises Behind a Tree — Nikolakakos Panagiotis

knowledgethroughscience:

What were the first stars?

Astronomers now know that the Big Bang occurred 13.7 billion years ago. For the first few hundred million years, the entire Universe was too hot any stars to form. But then the Universe cooled down to the point that gravity could start pulling together the raw hydrogen and helium into the first ever stars.

The first generation of stars, which astronomers call Population III stars, would have lived short violent lives. They probably lasted just a million years or so, and then detonated as supernovae. But in their lives, these Population III stars would have created heavier and heavier elements at their cores, and in their violent deaths, they would have created the even more exotic heavier elements, like gold and uranium. It’s possible that the first stars went through a few quick cycles, pulling in material, detonating and seeing the region with heavier elements. Eventually the first long-term stars would have gotten going, stars with the amount of heavier elements we see today.

Brain Can Be Trained in Compassion, Study Shows

May 22, 2013 — Until now, little was scientifically known about the human potential to cultivate compassion — the emotional state of caring for people who are suffering in a way that motivates altruistic behavior.

A new study by researchers at the Center for Investigating Healthy Minds at the Waisman Center of the University of Wisconsin-Madison shows that adults can be trained to be more compassionate. The report, published Psychological Science, a journal of the Association for Psychological Science, investigates whether training adults in compassion can result in greater altruistic behavior and related changes in neural systems underlying compassion.

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thescienceofreality:

Three Possible Futures for the Universe via Chandra X-ray Observatory (Credit: NASA/CXC/M.Weiss)

“This illustration shows three possible futures for the Universe, depending on the behavior of dark energy, by showing how the scale of the Universe may change with time. If dark energy is constant, as the new Chandra results suggest, the expansion should continue accelerating forever. If dark energy increases, the acceleration may happen so quickly that galaxies, stars, and eventually atoms will be torn apart, in the so-called Big Rip. Dark energy may also lead to a recollapse of the Universe, in the Big Crunch. The illustration also shows the early decelerating expansion of the Universe, followed by the accelerating phase that started about 6 billion years ago.”

Related Link here on dark energy.

Largest Genetic Sequencing Study of Human Disease

May 22, 2013 — Researchers from Queen Mary, University of London have led the largest sequencing study of human disease to date, investigating the genetic basis of six autoimmune diseases.

The exact cause of these diseases — autoimmune thyroid disease, celiac disease, Crohn’s disease, psoriasis, multiple sclerosis and type 1 diabetes- is unknown, but is believed to be a complex combination of genetic and environmental factors. In each disease only a proportion of the heritability is explained by the identified genetic variants. The techniques used to date, have generally identified common (in the population) variants of weak effect.

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Humans With Amplified Intelligence Could Be More Powerful Than AI

With much of our attention focused the rise of advanced artificial intelligence, few consider the potential for radically amplified human intelligence (IA). It’s an open question as to which will come first, but a technologically boosted brain could be just as powerful — and just as dangerous – as AI. We spoke to a leading futurist to learn more.

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Dreaming of Animals and Other Warning Signs of Neurodegeneration

Sleep disturbances may be an early warning sign of Alzheimer’s and other neurodegenerative diseases.

The latest issue of Nature contains an Outlook supplement about the health impacts of poor sleep, including a feature I wrote about the link between sleep disturbances and neurodegenerative diseases, called ‘Amyloid awakenings.’ The title refers to a process called amyloidosis, by which mutated, abnormally folded proteins aggregate to form insoluble clumps in the brain.

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medicalschool:

The human brain in cross section

Humans May Soon Regenerate Damaged Body Parts Like Salamanders

Australian researchers have isolated an immune system cell in salamanders which helps it regenerate missing limbs and damaged organs — and they suspect the same thing could work in humans, too.

Salamanders, or axolotls, are unique among vertebrates in that they’ve got remarkable regenerative powers. Adults can literally regrow and restore function to any part of the body, including the spinal cord and heart — even parts of the brain. Moreover, the regenerated tissue is scar free; once repaired, the new tissue looks almost the same as it was before.

Mammals obviously can’t do this. When we suffer tissue damage, the growth response is severely limited, while also being subject to scarring.

Now, thanks to the work of James Godwin and colleagues at Monash University’s Australian Regenerative Medicine Institute, scientists are one step closer to figuring out how to transfer the salamander’s regenerative powers to humans.

A crucial part of the healing process involves the presence of macrophages — a major immune system cell type that patrols tissues and gobbles-up foreign invaders, like bacteria and fungi. What’s more, they also play an important role in determining the mode of repair and instigating the tissue regeneration process.

Godwin et al. determined this after they got rid of all the macrophages in the salamanders they were experimenting upon. Devoid of these immune cells, the salamanders completely lost their ability to regrow limbs. In a manner of speaking, they suddenly became mammal-like — left with stumps and scarred tissue.

But then, after the macrophages were re-introduced, their regenerative capacities were restored, and the salamanders were able to grow their limbs back.

“Previously, we thought that macrophages were negative for regeneration, and this research shows that that’s not the case — if the macrophages are not present in the early phases of healing, regeneration does not occur,” he said in a press statement. “Now, we need to find out exactly how these macrophages are contributing to regeneration. Down the road, this could lead to therapies that tweak the human immune system down a more regenerative pathway.”

The researchers theorize that chemicals released by the macrophages are crucial for regeneration. And indeed, this is the next phase of their research. Their ultimate goal is to reverse-engineer these techniques into human therapies — a medical breakthrough that could lead to treatments for heart and liver diseases associated with scarring (fibrosis). It could also lead to therapies for the treatment of spinal cord and brain injuries.

Read the entire study at PNAS: “Macrophages are required for adult salamander limb regeneration.”

Image: National Geographic/Stephen Dalton/Animals Animals—Earth Scenes.

(Source: io9.com)

What are Quasars and Blazars?

Blazars and quasars are both subclasses of active galactic nuclei (AGN).

Blazars and quasars are intrinsically the same object — a supermassive black hole with a surrounding accretion disk, producing a jet — but seen at different orientation angles with respect to the jet’s axis.¹

Quasar is short for Quasi Stellar Radio Source.

History

The discovery of Quasars in 1963 provided a final piece of evidence that undermined the Steady State theory of the universe, and supported the Big Bang.  Maarten Schmidt, a Caltech astronomer working at Mt. Palomar Observatory, was credited with discovering the most distant object observed to date—so bright that it was mistaken for a star; but it was billion light years away.  Because of the Doppler shift, the characteristic lines with which we identify stars were not at the expected wavelengths.   

Schmidt’s discovery capped an exciting period in which the distance scale of the universe was expanded nearly tenfold, thanks to the contributions of Walter Baade, Alan Sandage, the new science of radio astronomy, and the magnificent telescopes of Mount Palomar.

Not all radio sources can be seen in visible light.  Many are thought to be distant galaxies.  The Sun emits radio waves that are easily detected because it is so close to us, but most stars are not bright radio sources. In 1963 Maarten Schmidt was studying radio Source 3C 273.  It was unusual because the radio signals appeared to be coming from a star. At first the spectrum of the star was puzzling.   Schmidt could not figure out what elements produced the bight spectral lines.  Then he realized that the unfamiliar lines were simply the bright emission lines from hydrogen gas that had been shifted to different wavelengths. According to Hubble’s Law, an object with that red shift must be located billions of light-years away. It must be brighter than a million galaxies to appear as bright as a star at that great distance.

3C 273 came to be known as a quasar, short for quasi-stellar radio source, since it looks like a star, but cannot possibly be one since it is so bright.  In subsequent years many more quasars were found, including some much further away than 3C 273. These findings dealt a serious blow the Steady State theory, which proposed that the universe is more or less uniform, so that young galaxies should be distributed evenly, with some close and some far away.  If quasars are only found at great distances, they could very well be young galaxies, since we are seeing them much earlier in the history of the universe. (Light from an object a billion light years away takes a billion years to reach us.)  Therefore, Maarten Schmidt’s discovery of quasars added another important piece of evidence in favor of the Big Bang theory.  It also amazed the readers of Time magazine that astronomers could look so far away in space and time.²

Known Quasars and Blazars

 PKS 1127-145

⁴

HE 1104-1805

⁵

The largest known structure in the universe is a large group of quasars rightly called the LQG (Large Quasar Group).  It’s four billion light-years from end to end! (Read More)

For more Quasars click here.

Some examples of blazars include 3C 454.3, 3C 273, BL Lacertae, PKS 2155-304, Markarian 421, and Markarian 501. The latter two are also called “TeV Blazars” for their high energy (teraelectron-volt range) gamma-ray emission.⁵

1 http://www.astronomy.com/en/News-Observing/Ask%20Astro/2011/01/Blazar%20vs,-d-,%20quasar.aspx

2 http://cosmology.carnegiescience.edu/timeline/1963

3 http://en.wikipedia.org/wiki/File:PKS_1127-145_X-rays.jpg

4 http://en.wikipedia.org/wiki/File:Quasar_HE_1104-1805.jpg

5 http://en.wikipedia.org/wiki/Blazar

New Physics “Most-Wanted” List — The Hunt for Dark Matter Particles

Now that it looks like the hunt for the Higgs boson is over, particles of dark matter are at the top of the physics “Most Wanted” list. Dozens of experiments have been searching for them, but often come up with contradictory results. Theorists from the Kavli Institute for Particle Astrophysics and Cosmology (KIPAC), a joint SLAC-Stanford institute, believe they’ve come up with an algorithm – a mathematical description of how the individual dark-matter particles behave – that could help narrow the search for these elusive particles, which are thought to make up more than 25 percent of the matter and energy in the universe.

It starts with assumptions, said Yao-Yuan Mao, lead author of a paper published in The Astrophysical Journal that outlines their new search tool. Assumptions are a good starting point when you don’t know where to look. A popular assumption about dark matter is that it’s made up of WIMPs, Weakly Interacting Massive Particles. The “M” in WIMP accounts for gravity’s ability to herd these particles around; the “P” and “I” hint at why they’re so hard to detect otherwise.

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Rare View of Ancient Galaxy Crash Revealed

Astronomers have caught two big ancient galaxies in the act of colliding, shedding new light on the role such megamergers played in galactic evolution during the universe’s youth.

The colossal smashup will eventually produce one giant elliptical galaxy, researchers said, suggesting that most such behemoths formed rapidly in this manner long ago, rather than growing slowly over time by gobbling up a series of relatively small galaxies.

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This Day in Science History

In 1906 the Wright Brothers were issued a patent for a flying machine. The patent included the steering system and the wing design. They then showed the patents and designs to Thomas Selfridge, a member of the Aerial Experiment Association established by Alexander Graham Bell in 1907.

The AEA then constructed several aircraft, including the Red Wing and the White Wing. Both looked a lot like the Wright’s patented designs. Glenn Curtis, a pilot, flew the White Wing 1,017 feet, which was far further than anyone had flown the plane before. Curtis then designed and piloted a plane called the June Bug, and in 1908 flew it 5,360 feet in one minute and forty seconds. The flight won him a prize offered by Scientific American to be the first plane to fly a kilometer in a straight line. A year later, Curtiss won another prize for flying 25 miles in a plane he designed. All of these planes used the same design the Wright’s had patented.

So the Wright’s finally sued Curtiss, claiming that he (and his company, the Herring-Curtiss Company) had stolen the Wright’s design. Then things got ugly. The U.S. Centennial of Flight Commission writes:

The battles that followed drained the financial resources of both parties with legal and court fees. Lawyers attempted to bring Curtiss and the Wrights together for an amicable settlement, but had no success. When Wilbur died of typhoid fever in 1912, the Wright family blamed Curtiss’ stubborn refusal to back down, claiming that Wilbur had lost his health over concern for the patent litigation.

The final verdict came in 1913. Orville Wright, now without Wilbur, was the unmistakable winner. All delays and appeals had been exhausted. The Federal Circuit Court of Appeals ordered Curtiss to cease making airplanes with two ailerons that operated simultaneously in opposite directions.

It didn’t end there either, it wasn’t until 1918, after World War I, that the suit was finally dropped.

(Source: blogs.smithsonianmag.com)

The Trifid Nebula (M20/NGC 1579)