SCIENCE IS EYE OPENER: MANY IN ONE:KAVIGNAR THANIGAI’S 632nd POST
1.THANKS: THE HINDU.SCIENCE & TECH.-report PTI.
Mars to lose a moon, wear ring like Saturn
Mars’ largest moon Phobos is slowly falling towards the planet and is likely to be shredded into pieces that will be strewn about the red planet in a ring like those encircling Saturn and Jupiter, scientists say.
Though inevitable, the demise of Phobos is not happening anytime soon. It will probably happen in 20-40 million years, leaving a ring that will persist for anywhere from one million to 100 million years, say scientists at the University of California, Berkeley.
UC Berkeley postdoctoral fellow Benjamin Black and graduate student Tushar Mittal estimate the cohesiveness of Phobos and conclude that it is insufficient to resist the tidal forces that will pull it apart when it gets closer to Mars.
Just as Earth’s moon pulls on the planet in different directions, raising tides in the oceans, for example, so too Mars tugs differently on different parts of Phobos. As Phobos gets closer to the planet, the tugs are enough to actually pull the moon apart, the scientists say.
This is because Phobos is highly fractured, with lots of pores and rubble. Dismembering it is analogous to pulling apart a granola bar, Mr. Black said, scattering crumbs and chunks everywhere.
The resulting rubble from Phobos — rocks of various sizes and a lot of dust — would continue to orbit Mars and quickly distribute themselves around the planet in a ring. While the largest chunks would eventually spiral into the planet and collide at a grazing angle to produce egg-shaped craters, the majority of the debris would circle the planet for millions of years until these pieces drop onto the planet .
The research appears in the journal Nature Geoscience.
Memory awakens with a full night of sleep, says U.S. study
People who sleep for eight hours at a stretch every night are significantly better at remembering faces and names after seeing them once, a study has found.
Researchers at the Brigham and Women’s Hospital in Boston showed the 14 participants of the study 20 colour photographs of adult faces with corresponding names and asked to memorise them.
After 12 hours, they were shown the photos again with the names either matched as earlier or not.
Apart from being asked whether the photos and names matched, participants were to rate their confidence on a scale of one to nine.
“We know that many different kinds of memories improve with sleep. While a couple of studies have looked at how naps might affect our ability to learn new faces and names, no previous studies have looked at the impact of a full night of sleep in between learning and being tested,” said Jeanne F. Duffy, associate neuroscientist in the Division of Sleep and Circadian Disorders of the hospital.
Each participant took the test twice — once with an interval of sleep in between and once with a period of regular, waking day activities in between.
When given an opportunity to sleep for up to eight hours, participants correctly matched 12 per cent more of the faces and names.
Name to face
“We found that when participants were given the opportunity to have a full night’s sleep, their ability to correctly identify the name associated with a face — and their confidence in their answers — significantly improved,” she added.
The new findings, conducted on healthy subjects in their 20s, suggest that sleep after new learning activities may help improve memory.
The findings were published in the journal Neurobiology of Learning and Memory.
NASA finding bolsters Indian theory on black hole
An Indian astrophysicist says the recent observation by NASA scientists of giant flares of X-rays from a black hole confirms his theory that the so-called black holes are not “true” black holes but actually ultra hot balls of fire like our Sun.
According to mainstream astrophysicists, extremely massive stars collapse into ultra compact objects called black holes whose gravitational field is so powerful that even light cannot escape from its imaginary boundary called “event horizon”.
Naturally, it came as a surprise when NASA announced last month that two of its space telescopes caught a huge burst of X-ray spewing out of a super massive black hole.
What is unique about this giant flare is it appeared to be triggered by the eruption of a massive corona (charged particles) from the “black hole”. If nothing can get out of a black hole, how did the corona come out of it?
Abhas Mitra — till recently head of theoretical astrophysics at the Bhabha Atomic Research Centre (BARC) in Mumbai and currently Adjunct Professor at the Homi Bhabha National Institute — says NASA’s observation has only bolstered his theory that “true” black holes do not exist and that the so-called black holes are in fact hot balls of magnetized plasma (ionized gas stripped of electrons).
As a massive star contracts to the size of a black hole, the radiation trapped within the extremely hot star must exert an outward force to counter the gravitational pull resulting into a state of eternal contraction with an infinitesimally slow rate, Mr.Mitra explained.
“Thus, instead of true black holes predicted by Einstein’s theory, we proposed that massive stars end up as balls of fire — termed Magnetospheric Eternally Collapsing Objects or MECOs.”
Mr. Mitra, a distinguished alumnus of Mumbai University, said NASA’s observation of giant X-ray flares from black hole can be most naturally explained by this MECO paradigm.
MECOs possess accretion disks around them, something similar to the rings of Saturn, and also may be immersed in a sea of interstellar gases, he said.
“Gas streams pulled inward by gravity get extremely hot by friction and may radiate X-rays.”
Mr. Mitra said relevant proofs behind this new paradigm have been published in leading peer-reviewed journals beginning 2000.
“Our best example of a magnetized ball of fire is our Sun which is surrounded by a tenuous aura of plasma called Corona,” he said.
“Instabilities associated with this magnetized plasma result in intermittent eruptions from the Sun in the form of solar flares and coronal mass ejections.”
While a true black hole cannot possess any intrinsic magnetic field, there can be magnetic field associated with the disk or gas surrounding a MECO.
Strong magnetic fields have indeed been detected around several so—called “black holes” suggesting that they are actually MECOs and not true black holes.
The super strong flare witnessed by NASA, which appeared to originate right from the central part of MECO, is akin to the well-known phenomenon of ‘Coronal Mass Ejection’ from the Sun, Mr. Mitra said.
“This latest astrophysical observation by NASA should prompt astrophysicists to take a closer look at the MECO paradigm,” Mr. Mitra said.
What is dark energy?
Dark energy is some kind of energy which is said to exist but scientists know very little details of it. About 14 to 15 billion years ago, when the Big Bang happened, the universe came into existence. The matter formed from huge energy started expanding due to outward force of the Big bang. From the theory of gravity postulated by Einstein, the particles having mass should attract each other and the expansion of the Universe should stop at one point of time.
However from the observations made by the astronomers, it appeared that the rate of expansion has increased after about 7 billion years. This shows that some other force is acting against the gravity which is forcing the expansion of universe instead of contraction. Scientists gave name to this unknown force as the ‘dark energy’.
It is interesting to know that what we see as the matter in the universe in the form of stars, planets, clouds of dust, only forms about 5 per cent of the universe’ mass, rest being dark energy (about 68 per cent) and dark matter (about. 27 per cent).
S P S JAIN
5.Health and Science:
Drinking pie melon juice may counter diabetes
Juice should not be consumed if the fruit tastes bitter
Drink juice of Mother Mary’s Pie Melon (Dosakaya in Telugu; Dosaka in Tamil) and counter the lifestyle diseases like diabetes, obesity and cardiovascular disorders.
With sugar-laden diet and beverages posing a major risk factor for lifestyle diseases such as diabetes, obesity and cardio-vascular disorders, a group of scientists from Indian Institute of Chemical Technology, Hyderabad has studied the effect of Dosakaya (DK) (Cucumis melo var. chito) juice on sucrose-induced glucose intolerance and oxidative stress. While glucose intolerance leads to more than normal levels of glucose in the blood stream (also called pre-diabetes state), oxidative stress is caused by free radicals and associated with many diseases, including diabetes, cardiovascular disorders and cancer.
Dosakaya fruit is widely used in different culinary items in South India. It displays multiple anti-oxidant activities which help in preventing damage to tissues caused by free radicals.
During the study, the scientists orally administered prepared sugar solution to rats for a month. When the animals were given Dosakaya juice, it was found that the glucose intolerance inducing capacity of sucrose was significantly reduced. In addition, Dosakaya juice boosted the indigenous anti-oxidant defence system of the body by multiple mechanisms.
The results of the research work were published in Pharmacognosy Magazine in the October-December, 2015 issue.
Lead author of the study and senior principal scientist at IICT, Dr. Ashok Kumar Tiwari, said “our literature as well as international literature over the years has shown that people who adhere to traditional dietary practices are least prone to develop modern-day lifestyle diseases”. Since the past 50 years, people around the world have been increasingly consuming processed calorie-rich and energy-dense foods and beverages.
He said the study looked at finding a traditional dietary method which would be beneficial in terms of health.
Another unique finding was that Dosakaya juice reduced sucrose feeding induced hyperlipidemia (excessive amounts of fats and fatty substances in blood), a major risk factor for heart diseases. It was also found that it reduced triglyceride levels in blood. “We are the first group to work on Dosakaya. Our highlight is its therapeutic effects against diabetes and cardio-vascular risk factors”, he added.
Dr. Tiwari cautioned against consuming juice when the fruit tastes bitter as it could be toxic. He said diabetics should consult their physicians before consuming as its cumulative effect might lead to hypoglycaemia.