Health & Science
At least 2 trillion galaxies
The vast scale of the universe just became even more unfathomable. Until now, astronomers believed there were up to 200 billion galaxies that could theoretically be detected from Earth. But a new study suggests the actual figure could be 10 times that—at least 2 trillion, and possibly many more. Researchers at the University of Nottingham in England used all the available data on deep space to create a 3-D map of the observable universe. When they then ran that information through their mathematical models, they concluded that for the universe to behave in the way it does, it must contain more than 2 trillion galaxies. The findings don’t suggest the universe is any bigger than previously thought, or that it contains more stars; they simply imply that stars are dispersed among a larger number of smaller galaxies. That would confirm the “top-down” theory of universe formation: the idea that many small galaxies grew over time, eventually merging into the ones we see today. The researchers believe the most powerful telescopes we have can pick up only about 10 percent of the 2 trillion galaxies. “It boggles the mind that over 90 percent of the galaxies in the cosmos have yet to be studied,” lead researcher Christopher Conselice tells Slate.com. “Who knows what interesting properties we will find when we study these galaxies with the next generation of telescopes?”
The Great Pyramid’s secret
More than 4,500 years after it was built, the Great Pyramid of Giza is still throwing up surprises. Researchers on the ScanPyramids project have for the past year been using various imaging techniques to study the interior of the last of the classical Seven Wonders of the World. Last week, they announced they had found evidence of a previously unknown cavity behind the structure’s north face, and another possible void along its northeast corner. The team, which made its discovery using an advanced scanning technique that measures how cosmic particles travel through a structure, believes the empty spaces could indicate the presence of a hidden corridor or a secret chamber. But the head of a committee overseeing their research has disputed the findings. “The core of the pyramid was built using long stones and small stones,” Zahi Hawass, the former Egyptian minister of antiquities, tells SmithsonianMag.com. “I think there are no secret rooms, and [that] these anomalies have to do with the way the pyramid was built.” The ScanPyramids team has been given additional time to find more evidence; more data is expected in the first half of next year.
Sensing touch with prosthetics
For the first time, scientists have enabled a paralyzed man to experience the sense of touch through a mind-controlled robotic arm. Nathan Copeland, 30, was left unable to use or feel any of his limbs after a car accident more than a decade ago. Last year, doctors from the University of Pittsburgh and the University of Pittsburgh Medical Center implanted four tiny electrodes into the sensory cortex of Copeland’s brain. They then wirelessly linked the electrodes to a robotic arm he could control using thought alone, and configured the prosthetic fingers to relay sensory signals back to the brain. Bypassing his damaged spinal cord, these signals stimulate the areas of Copeland’s cortex that used to light up when his fingers touched something— restoring his “natural” sense of touch. “I can feel just about every finger,” he tells NPR.org. “Sometimes it feels electrical, and sometimes it’s pressure, but for the most part, I can tell most of the fingers with definite precision. It feels like my fingers are getting touched or pushed.”
Eggs grown from stem cells
In a development that could lead to a breakthrough in infertility treatment, Japanese scientists have successfully fertilized mouse eggs made entirely from stem cells. Researchers at Kyushu University used cells from female mouse tails to grow pluripotent stem cells, which can be used anywhere in the body. To encourage these cells to develop into eggs, the team placed them among tissues taken from the ovaries of mouse fetuses. They then fertilized the mature eggs using sperm from male mice, and implanted them into the uteruses of female mice. The birth rate was very low: Just eight healthy pups were born from the 1,348 embryos used. But the success of the procedure suggests it may one day be possible for doctors to create viable human eggs from the skin cells of an infertile woman, reports NewScientist.com. “From a technical point of view it could work,” says lead researcher Katsuhiko Hayashi. “It could be a very powerful tool for curing infertility.” In theory, the process could also be used to create eggs from male skin cells—raising the prospect of children with two genetic fathers.
Health scare of the week
Calcium supplement risks
People who take calcium supplements to strengthen their bones may be increasing their risk of heart disease. Researchers analyzed the heart health and calcium intake of more than 1,500 adults between ages 45 and 84. At the start of the study, none of the participants showed signs of coronary artery calcification (CAC), a risk factor for hardened arteries. Overall, those who routinely consumed the most calcium had a lower risk for heart disease, but the opposite was true for participants whose calcium intake mostly came from supplements. In fact, taking a daily calcium supplement was associated with a 22 percent greater risk for CAC, reports The Washington Post. Unlike supplements, calcium-rich foods were not linked to heart disease. “We think the body metabolizes supplements and dietary calcium differently,” says the study’s leader, Erin Michos. “If you are worried about your bones, then get your calcium through food.”