Interesting Sites

Articles Cloud

Mysterious dimming of Tabby's star likely due to space dust, not alien superstructures, say scientists

AstronomyOn Wednesday, a team of over 200 scientists led by astronomer Tabetha Boyajian announced the mysterious dim-and-recover behavior of stellar object KIC 8462852, also called "Boyajian's Star" or "Tabby's Star," is likely to be due to clouds of color-warping space dust and not a planet, another star or, as some astronomers have hypothesized, a giant structure built by a distant civilization.

"If a solid, opaque object like a megastructure was passing in front of the star, it would block out light equally at all colors," Dr. Boyajian told the press. "This is contrary to what we observe." And, in a separate statement, "Dust is most likely the reason why the star's light appears to dim and brighten. The new data shows that different colors of light are being blocked at different intensities. Therefore, whatever is passing between us and the star is not opaque, as would be expected from a planet or alien megastructure."

The research team analyzed 22 months of data collected by an array of ground-based telescopes that covered many wavelengths of light. The study period lasted from March 2016 to December 2017, which included a number of decreases in brightness. The first dip started on the night of Thursday May 18. A robotic 14-inch Celestron telescope at Fairborn Observatory in Arizona watched Tabby's star lose brightness by a dramatic 3% by Friday, confirming a prediction the star would undergo its unusual dimming events once every 750 days. Other major telescope projects and citizen astronomers confirmed these findings. That dip was complex and continued through to the following Sunday, after a brief rise in brightness over the weekend. It ended a few days later, with Boyajian and fellow astronomer and co-author of the recent paper Jason Wright discussing the phenomena with the public via Twitter: "will we have a flurry of dips to come? Stay tuned!"

Researchers report rapid formation of new bird species in Galápagos islands

BiologyA study published on Thursday in the journal Science reported on formation of a new bird species on the Ecuadorean Galápagos Islands. Researchers from Princeton University in the United States and Uppsala University in Sweden reported the new species evolved in just two generations, though this process had been believed to take much longer, due to breeding between an endemic Darwin finch, Geospiza fortes, and the immigrant cactus finch, Geospiza conirostris.

Princeton University scientists B. Rosemary Grant and Peter Grant, who were conducting their field work on the island of Daphne Major, noticed a non-native male bird — cactus finches — on the island in 1981. The research team said they believe the immigrant bird was native to Española Island, which is located about 100 kilometres (60 miles) southeast of the Galápagos archipelago. Cactus finches have bigger body and beak as compared to other finch species living on the island at the time.

Singapore announces driverless buses on public roads from 2022

Engineering and TechnologyOn Wednesday, Singapore's government announced its intention to have driverless buses operating on public roads from 2022. Driverless buses are to be first launched in three towns on less crowded roads made to be suitable for the purpose. The autonomous buses are to run during off-peak times, complementing human-driven bus services.
File photo of a driverless shuttle.

According to the joint announcement from the Land Transport Authority and Singapore's Ministry of Transport, commuters will be able to use their mobile phones to hail a driverless shuttle. Transport Minister Khaw Boon Wan remarked, "The autonomous vehicles will greatly enhance the accessibility and connectivity of our public transport system, particularly for the elderly, families with young children and the less mobile."

Astronomers report dwarf star with unexpectedly giant planet

AstronomyIn findings reported on Tuesday, an international team of astronomers discovered an exoplanet, called NGTS-1b, revolving around M-dwarf star NGTS-1, that the team said does not fit existing notions of how stars and planets form. NGTS-1b is a gas giant, similar to Jupiter and of comparable volume and mass, but its parent star is about half the diameter and mass of the Sun, making this the most massive planet orbiting an M-dwarf ever discovered.

NGTS-1b, about 600 light years from the Earth, is so extremely close to its star that a revolution around its star takes only about 2.6 Earth days — 2.647298 ± 0.000020 — and its surface temperature is about 800 K. The planet was discovered by observing periodic fluctuations in the star's apparent brightness as NGTS-1b passed in front of it. NGTS-1b's mass is less than Jupiter, about 0.812 MJ (mass of Jupiter), but it has greater volume, with radius about 1.33 RJ (radius of Jupiter). Its density was reported to be 0.42 g cm-3 (with error: +0.59 to -0.28), meaning Jupiter, whose density is 1.326 g cm-3, is likely around thrice as dense as the exoplanet.

Arrangement of light receptors in the eye may cause dyslexia, scientists say

HealthResearch published in Proceedings of the Royal Society B on Wednesday by Albert Le Floch and Guy Ropars of French University of Rennes claims dyslexia may be caused by the way the photoreceptors in dyslexic individuals' eyes are arranged. Co-author Ropars said, "Our observations lead us to believe that we indeed found a potential cause of dyslexia".

In dyslexic individuals, the pattern of photoreceptors in the right eye is similar to that on the left and produces a "mirror image", while in non-dyslexic individuals, there are two different patterns in the two eyes, researchers found in their study. Individuals with dyslexia have difficulty reading, especially distinguishing between letters that are mirror images of each other, like the characters 'b' and 'd' or 'p' and 'q'.

In the back of the eye, there is a site called the fovea which contains cone cells, of three kinds responding either to red, green, or blue light. In one patch within the fovea, there are cone cells for red and green but none for blue. In the dominant eye, with greater connectivity to the brain, this spot was found to be round while in the other eye, it was asymmetrical. This, researchers speculate, allows the brain to choose just one of the two images to work with. The researchers observed the dyslexic individuals have round spots in both eyes, which produces mirror images, and the brain can not decide which one to consider.

"For dyslexic students their two eyes are equivalent and their brain has to successively rely on the two slightly different versions of a given visual scene," the researchers said. According to Ropars, this may also serve as a means of diagnosing dyslexia.
Render time: 0.54 seconds
586,348 unique visits