Preserving the stars: light pollution and what you can do about it

Astrophysicist Ms Kirsten Banks explains what we can do to reverse the impact of "light glow".
Photo Credit: UNSW Sydney.

An astrophysicist from UNSW Sydney explains why it’s so important that we can all look up and see the stars. 

Astronomer Carl Sagan famously said that there were more stars in the universe than grains of sand on earth.  

It has been estimated that there are over 100 billion stars in the Milky Way galaxy. While there is a limit to how many stars we can see from earth with the naked eye, that number is dramatically reducing due to light pollution. 

“We should be able to see around 2500 stars with the naked eye on any night, and we can see about 125 of them at best in Sydney,” says astrophysicist, proud Wiradjuri woman and UNSW PhD candidate Ms. Kirsten Banks.

In fact, in a recent study published in Science, data collected by citizen scientists around the world found light pollution is increasing at a rate that is equivalent to the brightness of the sky doubling every eight years.  

This latest research continues to expose the extent to which we’re losing the darkness of our night sky. Not being able to look up and see the stars will have significant cultural impacts, but there are steps we can all be taking to reduce the effect of light pollution.

Turtle and crocodile species with unique characteristics are more likely to go extinct

A Mugger Crocodile (Crocodylus palustris). In Pakistan, this species is still illegally hunted for its skin.
Image Credit: Bishnu Sarangi

New research led by the University of Oxford has revealed that the most endangered turtle and crocodile species are those that are most unique. Their loss could have widespread impacts on the ecosystems they live in since they carry out critical processes important for many other species. The results have been published in Nature Communications.

"When it comes to the conservation of turtles and crocodiles, we are dealing with a critical scenario. Furthermore, our actions are affecting unevenly more so those species that are characterized by unique life strategies. Once they are gone, these life strategies will be gone too, with no other species being able to provide a back-up." 

Professor Rob Salguero-Gómez, Department of Biology, University of Oxford

Turtles and crocodiles are two of the world's most endangered animal groups, with approximately half of the species globally threatened (International Union for Conservation of Nature, IUCN). Greater understanding of which species are most threatened and why is urgently needed to inform conservation efforts to save them.

In a new study led by researchers at the Department of Biology, University of Oxford, an international team examined the greatest risks to wild populations of turtles and crocodiles worldwide. The results demonstrate that the most endangered turtles and crocodile species are those that have evolved unique life strategies. These species typically carry out highly specific roles within their ecosystems that are unlikely to be taken up by other species if they disappear.

Separated at last

In the new method, laser pulses of different power (green) are combined in such a way that single excitation (blue), double excitation (red) and triple excitation (yellow) can be distinguished, for example, in biological light-harvesting complexes.
Illustration Credit: Julian Lüttig / Universität Würzburg

Scientists at the Universities of Würzburg and Ottawa have solved the decades-old problem of distinguishing between single and multiple light excitations. They present their new method in the journal Nature.

The construction of the first laser in 1960 ushered in commercial applications with light that have become an integral part of our everyday lives. At the same time, this development opened up the scientific field of laser spectroscopy – a technique that is central to the analysis of materials and the study of fundamental physical phenomena.

Despite all the successes, however, research teams have struggled since the 1970s with the problem that a laser shining on a sample can excite it not just once, but several times per experiment. In this case, the measurement results of the single excitation and the multiple excitations overlap and usually cannot be separated, making it difficult to understand the material.

Climate change threatens lemurs on Madagascar

A female grey mouse lemur (Microcebus murinus) carrying an infant.
Photo Credit: Manfred Eberle

They are small, have a high reproductive output and live in the forests of Madagascar. During the 5-month rainy season, offspring are born and a fat pad is created to survive the cool dry season when food is scarce. But what happens when the rainy season becomes drier and the dry season warmer? Can mouse lemurs adapt to climate change thanks to their high reproductive output? Researchers from the German Primate Center – Leibniz Institute for Primate Research, together with colleagues from the University of Zurich, have analyzed long-term data from Madagascar and found that climate change is destabilizing mouse lemur populations and increasing their risk of extinction. The fact that climate change is leading to greater fluctuations in population density and thus increases extinction risk in a fast-paced, ecological generalist is an alarming warning signal for potential biodiversity losses in the tropics.

Effects of climate change have mostly been studied in large, long-lived species with low reproductive output. Small mammals with high reproductive rates can usually adapt well to changing environmental conditions, so they have been studied little in the context of climate change. Claudia Fichtel and Peter Kappeler from the German Primate Center – Leibniz Institute for Primate Research (DPZ) have been researching lemurs on Madagascar for many years and have thus built up a unique data set to fill this knowledge gap.

Adipose tissue as a culprit: How obesity leads to diabetes

A high-fat diet leads to obesity and the development of diabetes.
Photo Credit: Muffin Creatives

A research team at the University of Basel has discovered that a high-fat diet alters the function of adipose tissue, thus impairing its ability to regulate blood sugar. This explains why a high-fat diet poses a significant health risk, particularly for diabetes.

Diabetes is a medical condition in which the body is unable to keep blood sugar in a healthy range. Normally, the pancreas produces sufficient insulin to regulate the blood sugar level and maintain homeostasis. However, in diabetics, the body has lost this ability, leading to hyperglycemia.

Blood sugar levels that are persistently too high can cause long-term damage to blood vessels and lead to severe complications such as blindness or kidney failure. It has been known for some time that obese patients are particularly at risk of developing type 2 diabetes and that adipose tissue plays a critical role in the onset of the disease. In their recent study, researchers led by Professor Michael N. Hall at the Biozentrum, University of Basel, revealed how a high-fat diet triggers diabetes.

Electricity from Air

Graphic illustration of titanium-air battery properties, in the style of the periodic table of elements
Illustration Credit: Courtesy of Technion – Israel Institute of Technology

Scientists at Forschungszentrum Jülich have developed and successfully lab-tested a novel titanium-air battery in cooperation with researchers at the Technion – Israel Institute of Technology in Haifa. This is the first time that experimental results of such a battery have been published, in which titanium is used as an active material. The metal is of interest as an electricity storage material because each atom can donate up to four electrons for charge transfer, while at the same time being relatively light and extremely resistant.

Scientific Results

Titanium is known as a passive, stable material. The researchers succeeded in utilizing its electrochemical potential for the storage of electrical energy by applying an ionic liquid called EMIm(HF)2.3F. Ionic liquids consist of salts with an atypical, very low melting point, which are used in a variety of applications due to their special electrical and material properties.

Early study shows cones in retinal degeneration, thought to be dormant, may retain visual function

“While the sensitivity of the cones was about 100-1000 fold less than normal, we were surprised to find that that the drop-off in sensitivity for the ganglion cells that project to the brain was much less,” said senior author Alapakkam Sampath.
Photo Credit: Miranda Scalabrino

New UCLA research in mice suggests that “dormant” cone photoreceptors in the degenerating retina are not dormant at all, but continue to function, producing responses to light and driving retinal activity for vision.  

The cells in the retina that produce the visual experience are rods and cones. Rods are active in dim light and cones in daylight. Mutations in rods that cause them to die trigger most inherited retinal degeneration. Cones can remain alive after nearly all the rods die, but they retract key parts of the cells and appear “dormant.”  

But while past literature suggested that dormant cells were not functional, and earlier attempts to record from them revealed no light-driven activity, the new study indicates for the first time that the cells are still viable. Furthermore, downstream signals recorded from the retina show that visual processing is not as compromised as may be expected. The authors say their findings demonstrate that therapeutic interventions to protect these cells, or enhance their sensitivity, have the capability to preserve nearly normal daytime vision. 

New Study Reveals Potential Link Between Two of Astronomy’s Most Mysterious Phenomena

Artist's conception of fast radio burst reaching Earth.
Illustration Credit: Jingchuan Yu, Beijing Planetarium

International team of scientists reports a possible correlation between gravitational waves from neutron star mergers and fast radio bursts; results could improve understanding of how some deep-space bursts occur.

The secrets of deep space may be starting to reveal themselves, as rapid advances in technology and stronger research collaborations are making it possible for astronomers to piece together cosmological clues like never before.

  In the March 27 issue of the journal Nature Astronomy, an international team of scientists shows for the first time a possible relationship between neutron star mergers and fast radio bursts (FRBs) – two of the most mysterious cosmological phenomena studied over the past two decades.

  The team, which includes researchers from UNLV, University of Western Australia (UWA), and Curtin University, reports on the observation of a deep space neutron star merger followed just 2 ½ hours later by an observed FRB. If confirmed, the correlation between the two events could unlock part of the mystery of how FRBs are generated.

  Fast radio bursts (FRBs) are millisecond-long pulses of electromagnetic radio waves that occur in deep space and produce the energy equivalent to the sun’s annual output. Most FRBs occur as one-off events, while others present as repeating bursts. Though their origins are still a bit of a mystery, the fraction of FRBs emitted as repeated bursts are likely produced by highly magnetized neutron stars known as magnetars.

Eco-efficient cement could pave the way to a greener future

Wei Meng (left) and Bing Deng are co-authors on the study. Deng holds a sample of cement made with coal fly ash purified through a flash Joule heating-based process.
Photo Credit: Gustavo Raskosky/Rice University

The road to a net-zero future must be paved with greener concrete, and Rice University scientists know how to make it.

The production of cement, an ingredient in concrete, accounts for roughly 8% of the world’s annual carbon dioxide emissions, making it a significant target of greenhouse gas emissions reduction goals. Toward those efforts, the Rice lab of chemist James Tour used flash Joule heating to remove toxic heavy metals from fly ash, a powdery byproduct of coal-based electric power plants that is used frequently in concrete mixtures. Using purified coal fly ash reduces the amount of cement needed and improves the concrete’s quality.

In the lab’s study, replacing 30% of the cement used to make a batch of concrete with purified coal fly ash improved the concrete’s strength and elasticity by 51% and 28%, respectively, while reducing greenhouse gas and heavy metal emissions by 30% and 41%, respectively, according to the paper published in the Nature journal Communications Engineering.

How football-shaped molecules occur in the universe

Graphic Credit: Shane Goettl/Ralf I. Kaiser

For a long time, it has been suspected that fullerene and its derivatives could form naturally in the universe. These are large carbon molecules shaped like a football, salad bowl or nanotube. An international team of researchers using the Swiss SLS synchrotron light source at PSI has shown how this reaction works. The results have just been published in the journal Nature Communications.

“We are stardust, we are golden. We are billion-year-old carbon.” In the song they performed at Woodstock, the US group Crosby, Stills, Nash & Young summarized what humans are essentially made of: star dust. Anyone with a little knowledge of astronomy can confirm the words of the cult American band – both the planets and we humans are actually made up of dust from burnt-out supernovae and carbon compounds billions of years old. The universe is a giant reactor and understanding these reactions means understanding the origins and development of the universe – and where humans come from.

In the past, the formation of fullerenes and their derivatives in the universe has been a puzzle. These carbon molecules, in the shape of a football, bowl or small tube, were first created in the laboratory in the 1980s. In 2010 the infrared space telescope Spitzer discovered the C60 molecules with the characteristic shape of a soccer ball, known as buckyballs, in the planetary nebula Tc 1. They are therefore the biggest molecules to have been discovered to date known to exist in the universe beyond our solar system.