Science at Atheist Universe
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Çheck out this video on a robot that makes its own body parts with foam!
VIDEO OF THE WEEK: Tel-Aviv University demonstrates quantum superconductors locked in a magnetic field. It seems like sorcery, but it isn’t: it’s science!
Two very interesting ASTRONOMY/ASTROPHYSICS posts this week:
Dark Matter: Now More Mysterious Than Ever. One of the tenets of cosmological models is that dark matter exists as a dense core or clump in the center of galaxies, but recent observations of two dwarf galaxies, Fornax and Sculptor, which are 99% dark matter, have determined that their dark matter is spread out rather than concentrated. Dark matter can only be indirectly observed by measuring the rotation of stars around each galactic center, which is influenced by the amount and distribution of dark matter. So what is keeping these 2 dwarf galaxies in place, since they have no clump of dark matter? One hypothesis is that dark matter might interact more with ordinary matter than we currently think, and this would allow normal matter to stir up the dark matter and spread it out. Or maybe dark matter moves at a greater speed in these galaxies and therefore cannot cluster at the center. Astronomers will be kept busy for a long time over these matters (no pun intended).
Direct Image of Youngest Exoplanet Yet Discovered. These astonishing images are from a newly born star, LkCa15, slightly smaller than our sun, but a “baby” at only 2 million years of age. It is the youngest exoplanet ever discovered. The direct image comes from data obtained with the Keck telescope in Mauna Kea, Hawaii. LkCa14 has six times the mass of Jupiter and orbits its parent star at approximately the distance that Uranus is from our sun. The findings will be used by astronomers to get a clearer picture of planet formation. It is presumed that this new planet, which is really huge as planets go, could not have formed by core accretion (gradual accumulation of material), but rather by gravitational instability that very rapidly induced a large mass of gas and dust to form big clumps, and these clumps merged into the newly formed planet. Because LkCa15 is also very hot, it could have formed by a model called “hot start”, where a rapid collapse of material forms a planet.
NEUROSCIENCE: IQ is not fixed in the brains of teenagers. Teenagers are strange "beasts" from the point of view of brain development. several studies in the past have shown that their brains are not fully matured, in terms of neural networks, etc. And now a study just published in Nature that combines IQ measures with fMRI to look into the brain regions activated by different tasks (verbal and non-verbal), demonstrates that contrary to the belief that IQ is fixed very early on and that it is possible to distinguish the intelligent kids from the not-so-intelligent kids, teenagers followed through adolescence do show changes in IQ, both negative and positive, and that the brain scans accurately reflect these changes. This study should put an end to programs in which kids are selected at age 11 or 12 for the best schools while others are left behind, because the teenager's brain is very plastic with respect to IQ.
ZOOLOGY: It’s Complicated: Dragonfly Love Comes Calling. Great NYT article on a scientist who studies dragonfly sex. Rutgers university entomologist Dr. Michael May studies dragonfly penises. These insects have very elaborate and complicated reproductive organs. Believe it or not, understanding the mechanics of dragonfly sex is not so simple. Their penises are very ornate, they are articulated, they have horns, brushes, spreaders and other paraphernalia that evolved to deposit and to retrieve sperm. Male dragonflies can remove the sperm of males that copulated with the female before them. At the same time, female genitalia is complicated too, and the females have evolved to defend themselves from removal of rival males’ sperm. Looking under the microscope at elaborate insect penises may not be everyone’s idea of a fascinating subject, but read the article and I’ll bet you’ll be “hooked”, as Dr. May describes how he tries to understand what all the different penile accessories actually do. In addition to looking at a mechanics perspective, Dr. May hopes to use the genitalia to extricate the evolutionary relationships of different dragonfly species within the family Libellulidae.
LAST, BUT NOT LEAST: Category: “Bookmark this:” A creationist's "scientific" disproof of evolution. Kudos to The Guardian for publishing this great article by Andrew Brown. I love the simplicity with which Andrew Brown destroys the 7 supposedly scientific questions that "destroy" the theory of evolution. Here is a taste to whet your appetite:
Question 3 (that supposedly “destroys” the theory of evolution): How to create intelligence from non-intelligence? ANSWER: It's true that we find it easier to create stupidity. But given the extraordinary variety of intelligences on earth, it's clear that you can progress from simple forms to more complicated ones given enough time. And we have had enough time. It's one of the main difficulties when you're trying to grasp the fact of evolution that the time involved is so immense.
Science bits and news from other sites:
High definition topographic Earth maps! NASA and Japan have just released a brand new elevation map of the Earth. The last version was from 2011. The map was made with ASTER (cute name!), the Advanced Spaceborne Thermal Emission and Reflection Radiometer, a Japanese instrument that lives on the Terra satellite (NASA). ASTER creates stereo image pairs from which very high-resolution elevation maps of the surface of the Earth are compiled. To cover the Earth (99% coverage), they took >1/4 million images. As an example of what they get, check out the topographic map of the Grand Canyon in the picture. The ASTER is public, so anyone can download it. Are you going to try? You can get it from the US. Geological Survey web site here.
Did early humans hunted mastodons with weapons made of mastodon bone?. The “Manis mastodon” is a specimen that has been causing controversy for many years. The animal had a bone spear stuck in its ribs. But was it a fragment of one of its own bones, or a mastodon-bone spear made by human hunters. If it is a spear, then the date at which humans started hunting mastodon needs to be pushed back hundreds of years (not too long in Paleolithic terms). The rib has been recently re-analyzed using a CT scanner, and the new analysis points in the direction of man-made. DNA analysis shows that both the spear was made of mastodon bones. But the controversy is far from settled. Dr. Gary Haynes from the University of Nevada (Reno) doesn’t buy it, because he says that modern-day elephants push each other all the time, breaking ribs and causing splinters. However, Dr. Michael Waters, the scientist who analyzed the rib by CT scan, had the data analyzed by a bone pathologist who discarded that it could be the result of an internal injury. I tend to believe the bone pathologist, frankly. It would be difficult to imagine a broken bone that inserts itself through muscle and other tissue to end up deeply stuck into a rib. In any case, a lot of force is needed to plant a spear through mastodon hair, skin muscle, into the rib. Whoever threw the projectile must have had a strong arm. Naturally, the spear was so sharp that it is easy to imagine that it will have a lot of penetrating power if thrown properly.
Humpbacks make a comeback. I love good news, especially of species that are rebounding. At the end of the commercial whaling era in the 60s, there were only ~1400 humpback whales in the entire North Pacific. Thanks to the international whaling ban, there are at least 21,000 humpbacks, and possibly even more, according to numbers reported in this month's Marine Mammal Science. The whales were counted by project SPLASH (another cute acronym, it means Structure of Populations, Levels of Abundance and Status of Humpbacks. The whales were counted during a 3-year period by an international team of hundreds of scientists who photographed >18,000 tails, or flukes, all over the Pacific Ocean. The flukes and tails are like a fingerprint, pretty unique for each whale, with different pigmentation pattern. A statistical analysis of these photos yielded the approximate count of 21,000 whales. Although they have largely recovered from whaling, it will still take some time for them to reach their estimated historical number of 125,00 individuals worldwide.
Rare mutation results in a cyclops shark. In the era of Photoshop, everything needs to be taken with a healthy dose of skepticism, but this one is real, confirmed by shark experts who X-rayed and studied the cyclops shark. Cyclops mutations occur in mammals, including humans, and are lethal soon after birth, because of the massive cranial defects. In mammals, cyclopia is caused by mutations in the sonic hedgehog gene (ask me if you want to know why someone will give such a “silly” name to a gene). Cyclopia was reported in an Israeli baby in 1985, who died 30 minutes after birth, and in 2006, a kitten was born with the condition and lived for only a day. Its preserved remains were sold to the creationist Lost World Museum (*facepalm*). It's not the first strange shark fetus that the fisherman, Galvan Magana has found; he and his colleagues discovered two-headed shark embryos in two different female blue sharks.
Study links pollutants to a 450 percent increase in risk of birth d.... And while we are on the subject of mutations, pesticides and pollutants are linked to an alarming 450 percent increase in the risk of spina bifida and anencephaly in rural China, according to a collaborative study between the University of Texas at Austin and Peking University. Affected babies and stillborn fetuses had large concentrations of the pollutants endosulfan and lindane. Endosulfan is being phased out in America for treatment of cotton, potatoes, tomatoes and apples. Lindane was recently banned in the US, it was used to treat barley, corn, oats, rye, sorghum and wheat seeds. Spina bifida and anencephaly are also associated with high concentrations of polycyclic aromatic hydrocarbons (PAHs), byproducts of burning fossil fuels such as oil and coal. Spina bifida is a defect in which the backbone and spinal canal do not close before birth. Anencephaly is the absence of a large part of the brain and skull. PAHs were also high in the placentas of the affected babies and fetuses. The study was published in PNAS. It was a horrible unintended experiment, but at least the data really seal the evidence for birth defects, especially of the neural tube, and these pollutants. The region from rural China, Sanxi, where these unfortunate babies came from mines and uses a lot of coal, also used for home cooking. The pollutants cause cell death, and if the dead cell belongs to a progenitor population, it’s impossible for a fetus to develop into a healthy baby.
Winged Robots Hint at the Origins of Avian Flight. 150 million years ago, dinosaurs like Archaeopteryx took flight. Or did they glide? The fossil record has not settled the argument between the gliding model, also called “trees-down” model, or the “ground-up theory, that running at high speed and flapping their wings got the early bird ancestors to take off. A winged robot comes to the rescue to help settle the debate. UC Berkeley engineers created a very light robot called DASH+Wings. These robots are been developed to carry out reconnaissance missions for the military. The engineers added wings because the ground robots had issued going up steep inclines, but once built, they realized they could test evolutionary questions with it. They had the robot flap its wings, run up inclines, also glide down from a platform, etc , and they measured its performance with accelerometers and cameras. Flapping wings helps with both gliding and climbing steeper inclines. The robot increased its running speed by 90% by flapping its wings, but fell short of the 400% increase it needed to take flight. But flapping wings allowed a gliding robot to get much further from the platform than a similar robot with fixed wings. The engineers concluded that their results lend indirect support to the gliding model, the “trees-down” theory, but it doesn’t settle the question, since avian ancestors could have been capable of reaching sufficient ground speed for take off, such as that achieved by modern birds.
Toxic Seaweed Poisons Coral Reefs on Contact. A new study of reefs in the Fiji suggests that some multicellular algae can poison coral on contact. This chemical warfare is initiated as follows: when fishermen spear lots of herbivorous fish such as the parrotfish, seaweed near the coral reefs does not get pruned, and their tendrils extend closer to the ocean bottom, turning the waters into a green sludge. If the tendrils reach some coral species, it is the death of the coral. Experimental tests showed that in 2 weeks or less, the coral begins to lose its color and to die, when rubbed against the seaweed; for control, plastic seaweed was used and that had no effect. The poisonous ingredients are compounds called terpenes. Some seaweed species are so toxic, that many marine herbivores avoid it. But count on adaptation to exploit even the nasty seaweed; a species of rabbitfish thrives eating this algae. Fortunately, Fijian fishermen do not target this fish, because the seaweed it feeds on is the deadliest. Not all seaweeds are poisonous, but even the not-so-nasty ones are likely to be very toxic to young corals. In any case, terpenes are not the only reason for the mysterious global decline of corals, but it compounds the effects of usual suspects such as overfishing, pollution, and warming waters.