The bright side
Katie Mack, Astronomer
In popular culture, black holes have always been depicted as the harbinger of doom and destruction. Recent revelations from the Laser Interferometer Gravitational-Wave Observatory (LIGO) in the US, however, show they might be just the opposite. Last month, for the third time LIGO detected ripples in space-time from the merging of two galaxies over a billion years ago. According to an article written and tweeted by astronomer Katie Mack, the latest data seems to hint that black holes may form an essential part of the formation of galaxies. Not only that, black holes aren’t entirely dark as usually assumed. Mack writes that black holes can be among the brightest objects if observed in X-rays. In 1964, scientists zoomed in on a strong source of X-rays and radio waves near the Cygnus constellation. They found a black hole was slowly “eating up” a hot blue star that it was locked in binary orbit with. These X-ray binaries are easy to spot with X-ray telescopes, Mack writes. She adds that much larger supermassive black holes, on the other hand, can outshine entire galaxies. According to the article, almost every galaxy has a supermassive black hole at the centre of it called active galactic nuclei. These supermassive black holes serve as the “central engines” for the outflows of matter and radiation. Though it absorbs matter in a hot and swirling disc, the central back hole also acts as a pivot and sends matter and radiation shooting across the galaxy hundreds of millions of light years across. “Astronomers are still working to understand exactly how supermassive black holes in the centres of galaxies grow to such enormous sizes, but it seems clear that the growth of black holes and the growth of galaxies are inextricably linked,” Mack writes.
Medicine by robots
David Brin, Biologist
In what is being hailed as a first, scientists at University of California San Diego say they have invented tiny drug-delivering robots that could treat diseases inside the body. According to an article tweeted by biologist David Brin, the bubble-powered micromotors have cured bacterial infections in mice. These micromotors, the width of a human hair, use bubble-propulsion to move around the stomach and deliver the antibiotics. “The movement itself improves the retention of antibiotics on the stomach lining where the bacteria are concentrated,” the article quotes Joseph Wang, who led the research. The reason that such drugs are needed, Wang said, was that stomachs can be chemically violent due to their high acidic nature, and this can an issue when sensitive medicines are administered orally. The tiny robots protect the antibiotics until the stomach environment is safe for delivery. The robots have a round magnesium core that contains several layers of the medicine. The magnesium reacts with the acids in the digestive tract to produce hydrogen bubbles. These hydrogen bubbles propel the micromotors and also lower the pH of the stomach, which makes the drugs safe for delivery. In the case of the mice, the scientists found that the delivery method was significantly more effective than regular doses of medicine.
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