Welcome to Sott.net
Sun, 11 Dec 2016
The World for People who Think

Science & Technology


Physicists are 'afraid' of mathematics

© Kings College London
Physicists avoid highly mathematical work despite being trained in advanced mathematics, new research suggests.

The study, published in the New Journal of Physics, shows that physicists pay less attention to theories that are crammed with mathematical details. This suggests there are real and widespread barriers to communicating mathematical work, and that this is not because of poor training in mathematical skills, or because there is a social stigma about doing well in mathematics.

Dr Tim Fawcett and Dr Andrew Higginson, from the University of Exeter, found, using statistical analysis of the number of citations to 2000 articles in a leading physics journal, that articles are less likely to be referenced by other physicists if they have lots of mathematical equations on each page.

Dr Higginson said: "We have already showed that biologists are put off by equations but we were surprised by these findings, as physicists are generally skilled in mathematics.

"This is an important issue because it shows there could be a disconnection between mathematical theory and experimental work. This presents a potentially enormous barrier to all kinds of scientific progress."

The research findings suggest improving the training of science graduates won't help, because physics students already receive extensive maths training before they graduate. Instead, the researchers think the solution lies in clearer communication of highly technical work, such as taking the time to describe what the equations mean.

Dr Fawcett said: "Physicists need to think more carefully about how they present the mathematical details of their work, to explain the theory in a way that their colleagues can quickly understand. It takes time to scrutinise the details of a technical article—even for the most distinguished physics professors—so with many competing demands on their time scientists may be choosing to skip over articles that take too much effort to digest."

"Ideally, the impact of scientific work should be determined by its scientific value, rather than by the presentational style," said Dr Higginson.

"Unfortunately, it seems valuable papers may be ignored if they are not made accessible. As we have said before: all scientists who care about the dialogue between theory and experiment should take this issue seriously, rather than claiming it does not exist."

Journal reference: New Journal of Physics


Researchers find mysterious 'cosmic whistles' rival supernovae in their explosive power

Penn State University astronomers have discovered that the mysterious "cosmic whistles" known as fast radio bursts can pack a serious punch, in some cases releasing a billion times more energy in gamma-rays than they do in radio waves and rivaling the stellar cataclysms known as supernovae in their explosive power. The discovery, the first-ever finding of non-radio emission from any fast radio burst, drastically raises the stakes for models of fast radio bursts and is expected to further energize efforts by astronomers to chase down and identify long-lived counterparts to fast radio bursts using X-ray, optical, and radio telescopes.

Fast radio bursts, which astronomers refer to as FRBs, were first discovered in 2007, and in the years since radio astronomers have detected a few dozen of these events. Although they last mere milliseconds at any single frequency, their great distances from Earth—and large quantities of intervening plasma—delay their arrival at lower frequencies, spreading the signal out over a second or more and yielding a distinctive downward-swooping "whistle" across the typical radio receiver band.

"This discovery revolutionizes our picture of FRBs, some of which apparently manifest as both a whistle and a bang," said coauthor Derek Fox, a Penn State professor of astronomy and astrophysics. The radio whistle can be detected by ground-based radio telescopes, while the gamma-ray bang can be picked up by high-energy satellites like NASA's Swift mission. "Rate and distance estimates for FRBs suggest that, whatever they are, they are a relatively common phenomenon, occurring somewhere in the universe more than 2,000 times a day."

Monkey Wrench

Genetically engineered cashmere sweater? Scientists in China have used CRISPR to make a modified goat that produces more of the fine wool

The extra-fluffy, genetically-altered cashmere goats at 6 months old
Cashmere is not merely goat hair.

No, no. Most hair on a goat—even a so-called cashmere goat—is coarse and thick, unsuitable for the neck of lady. Cashmere comes from a second undercoat that goats grow only in the winter, where the hairs are fine and soft and downy. But even goats specially bred to produce cashmere grow pitifully little—about half a pound per goat. Hence, your very expensive cashmere sweater.

In China, the world's top producer of cashmere, scientists have been trying to breed more productive cashmere goats. They've now used CRISPR, the genetic editing technique, to disrupt a single gene in cashmere goats. The change made hair in their undercoats even longer and more numerous—but not, crucially, any thicker. The genetic tweak boosts yield by about three ounces.


Unified Theory of Evolution: Darwin's theory that natural selection drives evolution is incomplete without input from evolution's anti-hero: Lamarck

© Pesticidewise
Environmental chemicals seem to trigger epigenetic effects in our DNA
The unifying theme for much of modern biology is based on Charles Darwin's theory of evolution, the process of natural selection by which nature selects the fittest, best-adapted organisms to reproduce, multiply and survive. The process is also called adaptation, and traits most likely to help an individual survive are considered adaptive. As organisms change and new variants thrive, species emerge and evolve. In the 1850s, when Darwin described this engine of natural selection, the underlying molecular mechanisms were unknown. But over the past century, advances in genetics and molecular biology have outlined a modern, neo-Darwinian theory of how evolution works: DNA sequences randomly mutate, and organisms with the specific sequences best adapted to the environment multiply and prevail. Those are the species that dominate a niche, until the environment changes and the engine of evolution fires up again.

But this explanation for evolution turns out to be incomplete, suggesting that other molecular mechanisms also play a role in how species evolve. One problem with Darwin's theory is that, while species do evolve more adaptive traits (called phenotypes by biologists), the rate of random DNA sequence mutation turns out to be too slow to explain many of the changes observed. Scientists, well-aware of the issue, have proposed a variety of genetic mechanisms to compensate: genetic drift, in which small groups of individuals undergo dramatic genetic change; or epistasis, in which one set of genes suppress another, to name just two.

Yet even with such mechanisms in play, genetic mutation rates for complex organisms such as humans are dramatically lower than the frequency of change for a host of traits, from adjustments in metabolism to resistance to disease. The rapid emergence of trait variety is difficult to explain just through classic genetics and neo-Darwinian theory. To quote the prominent evolutionary biologist Jonathan B L Bard, who was paraphrasing T S Eliot: 'Between the phenotype and genotype falls the shadow.'

And the problems with Darwin's theory extend out of evolutionary science into other areas of biology and biomedicine. For instance, if genetic inheritance determines our traits, then why do identical twins with the same genes generally have different types of diseases? And why do just a low percentage (often less than 1 per cent) of those with many specific diseases share a common genetic mutation? If the rate of mutation is random and steady, then why have many diseases increased more than 10-fold in frequency in only a couple decades? How is it that hundreds of environmental contaminants can alter disease onset, but not DNA sequences? In evolution and biomedicine, the rates of phenotypic trait divergence is far more rapid than the rate of genetic variation and mutation - but why?


Southern hemisphere recovered quicker from devastating asteroid strike

© Pic about Space
Researchers from the US and Argentina have analysed fossilised leaves and presented a new theory as to why the southern hemisphere recovered faster following the asteroid strike that killed the dinosaurs 66 million years ago.

Ecosystems in North America took 9 million years to recover from the asteroid, whilst in South America, insect life bounced back only after about 4 million years. This is the conclusion of the join US-Argentine research team that has published the results of its study in the journal Nature Ecology & Evolution.

Previous evidence had suggested that the asteroid strike - which killed all non-avian dinosaurs and a large number of other species - had a less severe impact on the southern hemisphere and one theory had argued that this was because it provided a sort of refuge for species. However, this new research points to a different explanation, being that ecosystems recovered much more quickly than in the north.

'This extinction is very important - it is one of the major extinctions in the history of the Earth,' commented lead researcher Michael Donovan of Pennsylvania State University. 'The biodiversity patterns we see today, where things are living, may be related to what survived - so it is important to learn about what was happening around the world at this time.'


Comets & asteroids summary for October 2016

© Remanzacco Blogspot
During the months of October 2016, 3 new comets were discovered. "Current comet magnitudes" & "Daily updated asteroid flybys" pages are available at the top of this blog (or just click on the underline text here).

The dates below refer to the date of issuance of CBET (Central Bureau Electronic Telegram) which reported the official news & designations.

Comet Discoveries

Oct 11 Discovery of C/2016 T1 (MATHENY)
Oct 13 Discovery of C/2016 T2 (MATHENY)
Oct 18 Discovery of C/2016 T3 (PANSTARRS)

Other news

Oct 14 Klim Ivanovich Churyumov (1937 - 2016), astronomer and co-discoverer (with Svetlana Gerasimenko) of comet #67P passed away on October 14, 2016

Oct 17 The third-largest object known beyond Neptune, 2007 OR10, has a moon. The discovery was reported in a poster by Gábor Marton, Csaba Kiss, and Thomas Mueller presented at the joint meeting of the European Planetary Science Congress and the Division for Planetary Sciences of the American Astronomical Society (DPS/EPSC) in Pasadena, California. The Hubble Space Telescope took the photo below of 2007 OR10 on September 18, 2010. Later analysis of the images revealed the presence of a moon (red circle).
© NASA/STScI/Wesley Fraser/Gábor Marton et al.


Mysterious x-rays coming from Pluto leave NASA scientists baffled

A space observatory has detected X-rays coming from Pluto, despite the fact that scientists believe that the dwarf planet is incapable of producing high-energy photons.

The X-rays were detected by NASA's Chandra X-ray Observatory on four separate occasions as it flew by Pluto between February 2014 and August 2015.

X-rays are usually produced by the interaction of solar wind, the flow of charged particles from the sun, and the neutral gas atoms around a planet or comet.


The mysteries of 'Dreamless Sleep' come to light

© Andrey_Popov/Shutterstock.com
Deep, dreamless sleep has long been thought of as a state of unconsciousness, but in a new paper, several researchers suggest that consciousness may not completely disappear when the mind recedes into deep sleep.

Instead, the article's authors suggest, people actually experience a range of different states within dreamless sleep. Traditionally, dreamless sleep has been straightforwardly defined as the part of sleep that occurs you're not dreaming, and it has been looked at as one uniform stage.

But "the idea that dreamless sleep is an unconscious state is not well-supported by the evidence," said Evan Thompson, one of the authors of the paper and a philosophy professor at the University of British Columbia.

Rather, research shows that people have conscious experiences during all states of sleep, including deep sleep, Thompson told Live Science.

Comment: For an in-depth look at the benefits of proper sleep, have a listen to The Health & Wellness Show: The Importance of Sleep


Exploring the Zone of Silence in Mexico

© David McNew/Getty Images/Staff
The Zone of Silence is found in the Mapimí Biosphere Reserve, which is a mostly uninhabited expanse. Here, amidst the desolate terrain, radio signal ceases and meteorites come crashing down.
The Bermuda Triangle is mystery enough, but a 50-kilometer patch of land in Mexico is becoming an increasingly common area of bizarre incidents.

According to a report from Atlas Obscura, the Zone of Silence is found in the Mapimí Biosphere Reserve, which is a mostly uninhabited expanse. Here, amidst the desolate terrain, radio signal ceases and meteorites come crashing down.

It's this strange radio silence that inspired the name of this area. In 1966, a national oil company called Pemex ordered an expedition to explore this place. When the group began experiencing problems with his radio, leader Augusto Harry de la Peña dubbed it the Zone of Silence.

The eerie phenomenon of dying radios has been attributed to be the effect of subterranean magnetite and debris from meteorites. After all, there have been significant meteorites landing in this particular area. The 20th century saw a few of this crashes, including two that even crashed in the same ranch in a span of less than 20 years. (And they say lightning don't strike the same place twice.)


Birds play an important role in maintaining rare plant species

© Tomás Carlo, Penn State
Bird eating fruit
Outside of human influences, why do rare plant species persist instead of dwindling away to extinction? It's a question that has plagued ecologists for centuries. Now, for the first time, scientists at Penn State and Universidad Nacional del Comahue, Argentina, demonstrate that fruit-eating birds play an important role in maintaining rare plant species.

"We show that fruit-eating birds, just by their food-gathering behavior, help to structure the diversity of forests," said Tomás Carlo, associate professor of biology, Penn State. "This is important because higher plant diversity is associated with increased provision of ecosystem services, such as nutrient cycling and the production of food and water."

According to Carlo, when birds eat fruits, they help plants to reproduce by spreading their seeds around.

"A couple years ago, I found some rare seeds in one of my seed traps in Puerto Rico, and I said to myself, 'Why are these birds eating this?" Carlo said. "This is improbable. These birds are surrounded by the fruits of common species and yet a sizable proportion of their diet includes fruits of rare species.'"