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The Blue light malady from tech gadgets

The light from mobile phones and other tech gadgets can interfere with sleep.

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A mobile user. Wikimedia Commons

Many people like to use their phones, tablets or other gadgets at night before they go to sleep.

However, the light from mobile devices can interfere with sleep. But not all light carries the same risk.

Recent studies have shown that within the light spectrum, blue light can have the worst effect on sleep.

A study in the UK showed that blue light actually can keep sleepy people awake. Tired drivers who were exposed to blue light became as alert as those who drank two cups of coffee.

Blue light filters have been developed for mobile devices to help with sleep issues. Apps are available for Android devices that filter blue light on screens. Updates to the iPhone, iPad and Amazon Fire tablet have added blue light filters.

Twilight App – Android Devices

Twilight is a free app that filters blue light on Android device screens. It can be set to turn on by itself. Or users can turn it on and off when they want.In the app settings, you can change the intensity of the filter, the color and the time the filter turns on and off.

Twilight works across all apps, though some apps may not work fully when Twilight’s filter is on.

There is a YouTube video that explains Twilight use.

Watch this:

Twilight is available free for Android devices in the Google Play store.

Night Shift – iPhone and iPad

Apple updated its operating system for iPhone and iPad earlier this year. Included in the update is Night Shift, a blue light filter.

This feature is available on newer iPhones and iPads, including the iPhone 5s and later, and the iPad Air and later.

Night Shift can be set to turn itself on every night or for the user to turn it on and off as wanted.

To turn on Night Shift automatically every night, go to Settings, then Display, then Brightness and then Night Shift.On the Night Shift settings, move the switch to schedule Night Shift. It can be set for Night Shift to go on and off atspecific times, or at sunset and sunrise.

In Settings you can also adjust the color of the filter.

Night Shift can also be turned on and off in Control Center on the iPhone and iPad. Open Control Center by swiping up from the bottom of the screen.

The sun and moon icon there identifies Night Shift. Tap it to turn Night Shift on or off at any time.

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Blue Shade – Amazon Fire Tablets

In an update to Fire tablets at the end of last year, Amazon introduced Blue Shade to filter blue light on screens. Blue Shade is available on more recent Fire tablets.

To turn on Blue Shade on a Fire tablet, swipe down from the top of the screen and tap Blue Shade. To adjust the color, go to Settings, then Display and, finally, Blue Shade. (VOA)

References: http://learningenglish.voanews.com/content/blue-light-filters/3325898.html

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Oldest recorded solar eclipse occurred 3,200 years ago

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Solar eclipse

Cambridge University researchers have pinpointed the date of what could be the oldest solar eclipse yet recorded. The event, which occurred on October 30, 1207 BC, is mentioned in the Bible, and could help historians to date Egyptian pharaohs.

“Solar eclipses are often used as a fixed point to date events in the ancient world,” said Professor Colin Humphreys from University of Cambridge’s Department of Materials Science & Metallurgy.

Using a combination of the biblical text and an ancient Egyptian text, the researchers were able to refine the dates of the Egyptian pharaohs, in particular, the dates of the reign of Ramesses the Great, according to the study published in the journal Astronomy & Geophysics.

The biblical text in question comes from the Old Testament book of Joshua and has puzzled biblical scholars for centuries.

It records that after Joshua led the people of Israel into Canaan, a region of the ancient Near East that covered modern-day Israel and Palestine – he prayed: “Sun, stand still at Gibeon, and Moon, in the Valley of Aijalon. And the Sun stood still, and the Moon stopped until the nation took vengeance on their enemies.”

“If these words are describing a real observation, then a major astronomical event was taking place – the question for us to figure out is what the text actually means,” Humphreys said.

“Modern English translations, which follow the King James translation of 1611, usually interpret this text to mean that the Sun and Moon stopped moving,” Humphreys said.

“But going back to the original Hebrew text, we determined that an alternative meaning could be that the Sun and Moon just stopped doing what they normally do: they stopped shining. In this context, the Hebrew words could be referring to a solar eclipse, when the Moon passes between the earth and the Sun, and the Sun appears to stop shining,” Humphreys said.

This interpretation is supported by the fact that the Hebrew word translated ‘stand still’ has the same root as a Babylonian word used in ancient astronomical texts to describe eclipses, he added.

Independent evidence that the Israelites were in Canaan between 1500 and 1050 BC can be found in the Merneptah Stele, an Egyptian text dating from the reign of the Pharaoh Merneptah, son of the well-known Ramesses the Great, the study said.

The large granite block, held in the Egyptian Museum in Cairo, says that it was carved in the fifth year of Merneptah’s reign and mentions a campaign in Canaan in which he defeated the people of Israel.

Earlier historians had used these two texts to try to date the possible eclipse, but were not successful as they were only looking at total eclipses, in which the disc of the Sun appears to be completely covered by the moon as the moon passes directly between the earth and the sun.

What the earlier historians failed to consider was that it was instead an annular eclipse, in which the Moon passes directly in front of the Sun, but is too far away to cover the disc completely, the researchers said.

In the ancient world, the same word was used for both total and annular eclipses.

The researchers developed a new eclipse code, which takes into account variations in the Earth’s rotation over time.

From their calculations, they determined that the only annular eclipse visible from Canaan between 1500 and 1050 BC was on 30 October 1207 BC, in the afternoon.

If their arguments are accepted, it would not only be the oldest solar eclipse yet recorded, it would also enable researchers to date the reigns of Ramesses the Great and his son Merneptah to within a year.

Using these new calculations, the researchers determined that Ramesses the Great reigned from 1276-1210 BC, with a precision of plus or minus one year.(IANS)

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Is Longer Screen Time Bad for your Child’s Health? Experts say it might be time to relax the rules

Common Sense Media, a nonprofit group focused on kids’ use of media and technology, said in a report that kids ages 8 and younger average about 2 hours and 19 minutes with screens every day at home.

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New York, October 22, 2017 : Parents of small children have long been hearing about the perils of “screen time.” And with more screens, and new technologies such as Amazon’s Echo speaker, the message is getting louder.

And while plenty of parents are feeling guilty about it, some experts say it might be time to relax a little.

Go ahead and hand your kid a gadget now and then to cook dinner or get some work done. Not all kids can entertain themselves quietly, especially when they are young. Try that, and see how long it takes your toddler to start fishing a banana peel out of the overflowing trash can.

“I know I should limit my kid’s screen time a lot, but there is reality,” said Dorothy Jean Chang, who works for a tech company in New York and has a 2-year-old son. When she needs to work or finds her son awake too early, “it’s the best, easiest way to keep him occupied and quiet.”

Screen time, she says, “definitely happens more often than I like to admit.”

She’s not alone. Common Sense Media, a nonprofit group focused on kids’ use of media and technology, said in a report Thursday that kids ages 8 and younger average about 2 hours and 19 minutes with screens every day at home. That’s about the same as in 2011, though it’s up from an hour and a half in 2013, the last time the survey was conducted, when smartphones were not yet ubiquitous but TV watching was on the decline.

While the overall numbers have held steady in recent years, kids are shifting to mobile devices and other new technologies, just as their parents are. The survey found that kids spend an average of 48 minutes a day on mobile devices, up from 15 minutes in 2013. Kids are also getting exposed to voice-activated assistants, virtual reality and internet-connected toys, for which few guidelines exist because they are so new.

SCREEN TIME
Students play with their iPads at the Steve Jobs school, Aug. 21, 2013. The Steve Jobs schools in the Netherlands are founded by the Education For A New Time organization, which provides the children with iPads to help them learn with a more interactive experience. VOA

Mixed message

Some parents and experts worry that screens are taking time away from exercise and learning. But studies are inconclusive.

The economist Emily Oster said studies have found that kids who watch a lot of TV tend to be poorer, belong to minority groups and have parents with less education, all factors that contribute to higher levels of obesity and lower test scores. For that reason, it’s “difficult to draw strong conclusions about the effects of television from this research,” Oster wrote in 2015.

In fact, the Common Sense survey found that kids whose parents have higher incomes and education spend “substantially less time” with screens than other children. The gap was larger in 2017 than in previous years.

Rules relaxed

For more than a quarter century, the American Academy of Pediatrics held that kids under 2 should not be exposed to screens at all, and older kids should have strict limits. The rules have relaxed, such that video calls with grandma are OK, though “entertainment” television still isn’t. Even so, guidelines still feel out of touch for many parents who use screens of various sizes to preserve their sanity and get things done.

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Jen Bjorem, a pediatric speech pathologist in Leawood, Kansas, said that while it’s “quite unrealistic” for many families to totally do away with screen time, balance is key.

“Screen time can be a relief for many parents during times of high stress or just needing a break,” she said.

Moderation

Bjorem recommends using “visual schedules” that toddlers can understand to set limits. Instead of words, these schedules have images — dinner, bed time, reading or TV time, for example.

Another idea for toddlers? “Sensory bins,” or plastic tubs filled with beads, dry pasta and other stuff kids can play around with and, ideally, be just as absorbed as in mobile app or an episode of “Elmo.”

Of course, some kids will play with these carefully crafted, Pinterest-worthy bins for only a few minutes. Then they might start throwing beans and pasta all over your living room. So you clean up, put away the bins and turn on the TV.

In an interview, Oster said that while screen time “is probably not as good for your kid as high-quality engagement” with parents, such engagement is probably not something we can give our kids all the time anyway.

“Sometimes you just need them to watch a little bit of TV because you have to do something, or you need (it) to be a better parent,” Oster said. (VOA)

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Astronomers Discover New ‘Mid-size’ Black Hole 100,000 Times More Massive than the Sun

Scientists predict that nearly 100 million of these small black holes should exist in the Milky Way, however only about 60 have been found till now

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Black hole in milky way
A near-infrared image of a black hole at the center of the Milky Way galaxy as seen with Hubble Space Telescope/NICMOS. (NASA/STScI) (VOA)
  • Researches in Japan have discovered a super-massive black hole in Milky Way Galaxy
  • The black hole is believed to weigh as much as 400 suns
  • According to studies,  at least 100 million of these small black holes should exist in the Milky Way

Japan, September 5, 2017 : Astronomers have found new evidence for the existence of a mid-sized black hole, considered the missing link in the evolution of super-massive black holes.

Astronomers in Japan found the possible black hole in our own Milky Way galaxy, a long-theorized object which is bigger than the small black holes formed from a single star, but still much smaller than giant black holes such as the one at the center of the Milky Way.

Black holes are difficult to find because they do not emit any light. However, scientists can detect them by their influence on nearby objects.

The astronomers in Japan found new evidence of the so-called intermediate-mass black hole when they turned a powerful telescope in Chile’s Atacama desert on a gas cloud near the center of the Milky Way. The gases in the cloud move at unusual speeds, and the scientists believed they were being pulled by immense gravitational forces. They say the gravitational force is likely caused by a black hole measuring about 1.4 trillion kilometers across.

black hole in Milky way galaxy
Radio telescope antennas of the ALMA (Atacama Large Millimeter/submillimeter Array) project are seen in the Atacama desert, some 1500 km north of Santiago, Chile, VOA

The findings are published in the journal Nature Astronomy.

Theoretical studies predict at least 100 million of these small black holes should exist in the Milky Way, however only about 60 have been found.

The possible mid-sized black hole is much smaller than the super massive black hole that is located in the center of the galaxy, known as Sagittarius A, which weighs as much as 400 million suns.

“This is the first detection of an intermediate-mass black hole candidate in the Milky Way galaxy,” said the study’s leader, Tomoharu Oka from Keio University, Japan.

If confirmed, the intermediate-mass black hole could help explain how supermassive black holes operate. One theory is that supermassive black holes, which are at the center of most massive galaxies, are formed when smaller black holes steadily coalesce into larger ones. However, until now no definitive evidence has existed for intermediate-mass black holes that could indicate a middle step between the small and massive black holes already detected.

Researchers say they will continue to study the intermediate-mass black hole candidate in the hope of confirming its existence. (VOA)