news – Page 2 – Reaching for the Stars

How are the Birds Coping with Climate Change?

Written by Star on April 25, 2022. Posted in news.

Researchers at Tel Aviv University have found changes in the morphology of many birds in Israel over the past 70 years, which they interpret to be a response to climate change. The body mass of some species decreased, while in others body length increased – in both cases increasing the ratio between surface area and volume. The researchers contend that these are strategies to facilitate heat loss to the environment: “The birds evidently changed in response to the changing climate. However, this solution may not be fully adequate, especially as temperatures continue to rise.”

Relying on the vast bird collection preserved by The Steinhardt Museum of Natural History at TAU, the researchers looked for changes in bird morphology over the past 70 years in Israel. They examined approximately 8,000 adult specimens of 106 different species – including migratory birds that annually pass through Israel (such as the common chiffchaff, white stork, and black buzzard), resident wild birds (like the Eurasian jay, Eurasian eagle-owl, and rock partridge), and commensal birds, that live near humans. They built a complex statistical model consisting of various parameters to assess morphological changes – in the birds’ body mass, body length and wing length – during the relevant period.

The study was led by Prof. Shai Meiri and PhD student Shahar Dubiner of the School of Zoology, The George S. Wise Faculty of Life Sciences, and the Steinhardt Museum of Natural History at Tel Aviv University. The paper was published in the scientific journal Global Ecology and Biogeography.

Cooling Down

Prof. Meiri explains that according to Bergmann’s rule, formulated in the 19th century, members of bird and mammal species living in a cold climate tend to be larger than members of the same species living in a warmer climate. This is because the ratio of surface area to volume is higher in smaller animals, permitting more heat loss (an advantage in warm regions), and lower in larger bodies, minimizing heat loss (a benefit in colder climates). Based on this rule, scientists have recently predicted that global warming will lead to a reduction in animal size, with a possible exception: birds living in the human environment (such as pigeons, house sparrows, and the hooded crow) may gain size due to increased food availability, a phenomenon already witnessed in mammals such as jackals and wolves.

Either Long or Slender

Shahar Dubiner: “Our findings revealed a complicated picture. We identified two different types of morphological changes: some species had become lighter – their mass had decreased while their body length remained unchanged; while others had become longer – their body length had increased, while their mass remained unchanged. These together represent more than half of the species examined, but there was practically no overlap between the two groups – almost none of the birds had become both lighter and longer. We think that these are two different strategies for coping with the same problem, namely the rising temperatures. In both cases, the surface area to volume ratio is increased (by either increasing the numerator or reducing the denominator) – which helps the body lose heat to its environment. The opposite, namely a decrease in this ratio, was not observed in any of the species.”

The researchers (from left to right): Shahar Dubiner and Prof. Shai Meiri

Global Phenomenon

Sadly, flying away from global warming is not an option. These findings were observed across the country, regardless of nutrition, and in all types of species: resident birds; commensal species living in the human environment – which, contrary to predictions, exhibited changes similar to those of other birds; and migrants.

A difference was identified, however, between the two strategies: changes in body length tended to occur more in migrants, while changes in body mass were more typical of non-migratory birds. The very fact that such changes were found in migratory birds coming from Asia, Europe, and Africa, suggests that we are witnessing a global phenomenon.

The study also found that the impact of climate change over time on bird morphology (the birds’ change in either weight or length over time, relative to the actual temperature change during that time) is ten times greater than the impact of similar differences in temperature between geographical areas (the birds’ differences in weight or length in different geographical areas, relative to the temperature differences between those areas).

What is the Limit of Evolutionary Flexibility?

Shahar Dubiner: “Our findings indicate that global warming causes fast and significant changes in bird morphology. But what are the implications of these changes? Should we be concerned? Is this a problem, or rather an encouraging ability to adapt to a changing environment? Such morphological changes over a few decades probably do not represent an evolutionary adaptation, but rather certain phenotypic flexibility exhibited by the birds. We are concerned that over such a short period of time, there is a limit to the flexibility or evolutionary potential of these traits, and the birds might run out of effective solutions as temperatures continue to rise.”

Featured image: Israeli birds have become either longer or slenderer over the past 70 years

The Ultimate Solution to Global Warming?

Written by Star on April 25, 2022. Posted in news.

Hydrogen-powered bicycles and cars have been in serial production for years. In these vehicles, the regular polluting lithium battery has been replaced by a fuel cell that converts hydrogen, a non-polluting fuel, to electricity. Most of today’s hydrogen is, however, still produced from natural gas in a highly polluting process and is therefore referred to as gray hydrogen. Not only is natural gas a non-renewable source of energy, but it also creates carbon dioxide gas when burned, damaging our environment and contributing to global warming.

Enter a new TAU discovery, which may boost the industrial transition from using polluting gray hydrogen to environmentally friendly green hydrogen: Researchers identified a mutant of a known strain of microscopic algae that allows, for the first time, the production of green hydrogen gas via photosynthesis on a scale suited to industrial requirements. Hydrogen gas can thus be produced solely through renewable energy and in a climate-neutral manner, reducing our carbon footprint and greenhouse gas emissions dramatically to stabilize global temperatures.

Humanity’s transition to the use of green hydrogen may be the ultimate solution to the problem of global warming.

The microscopic algae

Continuous Production Achieved

The study was led by doctoral student Tamar Elman, under the supervision of Prof. Iftach Yacoby from the Renewable Energy Laboratory of The George S. Wise Faculty of Life Sciences at Tel Aviv University. The study was recently published in the prestigious journal Cell Reports Physical Science.

While production of green hydrogen is possible through solar panels wired to devices that perform water breakdown into hydrogen and oxygen (electrolysers), the researchers explain that this is an expensive process, requiring precious metals and distilled water. In nature, hydrogen is produced as a by-product of photosynthesis for periods of minutes by micro-algae, unicellular algae found in every water reservoir and even in the soil. For this biological process to become a sustainable source of energy, however, humanity must engineer micro-algae strains that produce hydrogen for days and weeks.

Prof. Yacoby explains that as part of the laboratory tests, the researchers identified a new mutant in microscopic algae that prevents oxygen from accumulating at any lighting intensity, and therefore hypothesized that continuous hydrogen production could be achieved from it. With the help of bioreactor measurements in liter volumes, they were indeed able to prove that hydrogen can be produced continuously for more than 12 days.

According to Prof. Yacoby, the new mutant overcomes two major barriers that have so far hindered continuous production of hydrogen:

Accumulation of oxygen in the process of photosynthesis – As a rule, oxygen poisons the enzyme that produces hydrogen in algae, but in the mutation, increased respiration eliminates the oxygen and allows favorable conditions for continuous hydrogen production.

Loss of energy to competing processes – And this includes carbon dioxide fixation into sugar. This, too, has been solved in the mutant and most of the energy is being channeled for continuous hydrogen production.

To industrialize these results, the research team led by Prof. Yacoby is working on a pilot program of larger volumes and the development of methods that will allow the time of hydrogen harvest to be extended, in order to reduce its cost to competitive levels. “The rate of hydrogen production from the new mutant reaches one-tenth of the possible theoretical rate, and with the help of additional research it is possible to improve it even further,” concludes Prof. Yacoby.

Tamar Elman and Prof. Iftach Yacoby in the lab

Featured image: Tamar Elman and the microscopic algae

Work created by TAU-affiliated artists can’t exist on earth

Written by Star on April 8, 2022. Posted in news.

Many think that physics is an exact science that requires the application of analytical and quantitative abilities, while art is based on emotion and creativity. A collaboration between the physicist Dr. Yasmine Meroz of Tel Aviv University (TAU) and the contemporary artist Liat Segal challenges the boundaries between the two fields. Their joint work, called “Impossible Object,” will be launched in April to the International Space Station (ISS), as part of the “Rakia” mission of the Israeli astronaut Eitan Stiva.

Dr. Meroz is a senior faculty member at the School of Plant Sciences and Food Security at TAU’s Wise Faculty of Life Sciences, whose lab studies the physics of plant systems. Segal studied Computer Science and Biology and worked in the hi-tech industry for several years, before shifting her career to arts. The special bond between the two was created when they were graduate students at the same lab at TAU.

“Impossible Object” is a sculpture made of water. The liquid’s three-dimensional form does not get its shape from any vessel and so cannot exist on earth, but only in outer space in the absence of gravity.

The sculpture is made of interconnected brass pipes and rods, through which water is flown. In the absence of gravity, the water adheres to the rods and forms a liquid layer shaped by water tension, which envelopes the brass structure, yielding a three-dimensional shape that changes over time. The underlying brass structure is reminiscent of a wavy and directionless staircase, raising questions about shape and form in the absence of gravity and directionality. In particular, what is the shape of water? What does a “slice of the sea” or a “handful of a wave” look like?

“There is much in common between art and scientific research: Both are the result of a thought process in which creativity plays a central role and are motivated by the desire to ask interesting questions,” Dr. Meroz says. “‘Impossible Object’ is a research-based artwork, where the medium is basically the physics underpinning water behavior in the absence of gravity. I learned a lot in the process, and I have no doubt it will contribute to research in my laboratory. In this respect, this work expresses the unrealized potential of the synergy between art and scientific research.”

“I am very happy about my collaboration with Yasmine,” Segal adds. “In this collaboration we not only shared knowledge and inspiration, but we were also able to bring about a true co-creation, which could not have been realized by each one of us individually. ‘Impossible Object’ is timely, weighing the role of culture and art at an era when humanity is experiencing accelerated scientific and technological developments. Following incredible technological and scientific achievements in space, and as space tourism becomes tangible, it is important to reflect on the place of culture and arts in our lives, on earth and beyond.”

This is their second collaboration; their previous artwork, “Tropism,” has been exhibited at TAU’s Genia Schreiber University Art Gallery.

Inventive Study to Develop Biological Solutions for Agriculture

Written by Star on March 27, 2022. Posted in news.

Microplastics Increase Toxicity of Organic Pollutants by a Factor of 10

Written by Star on February 20, 2022. Posted in news.

Microplastics are tiny fragments of plastic that are found almost everywhere: in wells, soil, food products, water bottles, and even in glaciers at the North Pole. A new study by Tel Aviv University researchers found that in a marine environment, microplastics encounter environmental pollutants that attach to their surface and increase their toxicity by a factor of 10, which may cause severe harm to the environment and human health.

The study was conducted by Dr. Ines Zucker of the School of Mechanical Engineering and the Porter School of the Environment and Earth Sciences at Tel Aviv University, together with Ph. D. student Andrey Eitan Rubin. The study was recently published in the prestigious journal Chemosphere.

‘Magnets’ for Environmental Pollutants

In the study, the researchers examined the entire process that the microplastic undergoes, from the interactions it has with environmental pollutants to the release of the pollutants and the creation of increased toxicity.

The researchers found that adsorption of those organic pollutants to the microplastics increases toxicity by a factor of 10 and may also cause severe impact on humans who are exposed to contaminated food and drink.

“In this study we showed that even very low concentrations of environmental pollutants, which are non-toxic to humans, once adsorb to the microplastic result in significant increase in toxicity,” says Dr. Zucker. “This is because microplastics are a kind of ‘magnet’ for environmental pollutants, concentrating them on its surfaces, ‘ferrying’ them through our digestive tract, and releasing them in a concentrated form in certain areas – thus causing increased toxicity.”

From left to right: Ph. D. student Andrey Eitan Rubin, Dr. Ines Zucker and Dr. Amit Kumar Sarkar

Not Just a Remote Problem

Ph. D. student Andrey Eitan Rubin adds: “For the first time we are presenting a complete ‘life cycle’ of microplastics: from the moment of their release into the environment, through the adsorption of environmental pollutants and up to their joint toxicity in humans.”

“The amount of waste dumped into the ocean every year is enormous – the best known example is the plastic island in the Pacific Ocean, which has an area 80 times larger than the State of Israel.”

This is not just a remote problem. The researchers’ preliminary monitoring data show that Israel’s shores are among the most polluted with microplastic waste. “Each of the microplastic particles secreted in these areas has tremendous potential for harm, as they serve as an effective and stable platform for any pollutant that they may encounter on their way to the human body,” warns Rubin.

“This is another painful reminder of the dire consequences of polluting the marine and terrestrial environment with hazardous industrial waste, which has unfortunately been saturated with plastic in recent decades. The dangers are not theoretical but are more tangible than ever. Although there is a great deal of awareness of this problem, the preventive measures in the field are still far from imprinting a significant mark,” concludes Dr. Zucker.

Reading Tea Leaves

Written by Star on January 25, 2022. Posted in news.

What is the origin of tea, and does the climate crisis threaten its production?

Tea – the ancient beverage comes in different flavors and colors. The Queen of England will never go without her afternoon tea, in India it’s enjoyed with milk and spices and we all like to pour ourselves an occasional cup of Earl Grey, especially when winter comes knocking. But have you ever wondered whether the saying “all the tea in China” really does indicate where tea drinking started? Or if the soothing drink may be affected by the climate crisis? Should we, in fact, be drinking it? We have, and our researchers explained, surprised us and busted some myths in the process.

When the Chinese Mystics Met the Tea Plant

We’re not going to keep you in suspense: It turns out that the coveted drink was sipped by the Indian Buddhist monks two thousand years ago – long before it became an integral part of Chinese culture and a long, long time before it became popular in Western cultures.

“The tea plant was known in China as early as the first centuries BCE, but recent studies show that the custom of drinking tea was brought to China from India,” explains Prof. Meir Shahar from The Department of East Asian Studies of The Lester and Sally Entin Faculty of Humanities at Tel Aviv University, who researches, among other things, the influence of Indian culture on Chinese religion and literature.

“In the first centuries CE Buddhism came to China from India and the Buddhist monks, who wanted to stay awake during the meditation, used to drink tea. The Chinese monks would observe this, and went on to adopt the custom as well, which then continued to spread to the rest of the Chinese population.”

While tea originates from India, the origin of the word ‘tea’ in most of the world’s languages, however, is Chinese. “In northern China it is called cha, hence the Russian chai, and in southern China it is pronounced as tcha, which is the origin of the English word tea,” reveals Prof. Shahar.

Buddhist monks on their tea break

What’s in Your Cuppa?

Buddhist monks realized long ago that tea keeps them awake and today, thanks to science, we are able to explain how the active ingredients of the plant affect us.

“Contrary to many people’s beliefs, all types of tea are produced from the same plant, namely the leaves and buds of the Camellia Sinensis plant. While there are several varieties of the plant, the types of tea that we are familiar with – white, green, oolong and black – differ according to the part of the plant from which they are produced and the way they’re processed. Green tea, for example, contains less caffeine than black tea. The leaves used to produce green tea undergo a minimal drying process while the leaves intended for black tea undergo drying and fermentation,” explains Guy Shalmon, a sports nutritionist and exercise physiologist at the Sylvan Adams Sports Institute.

“Tea leaves contain substances known as flavonoids. Their composition, however, varies from one tea to another. For example, green tea has a higher concentration of a substance called epigallocatechin 3-gallate, known for short as ‘EGCG’, than black tea which undergoes a prolonged processing process. It has antioxidant activity and is attributed various health effects,” says Guy.

“Having said that, tea may reduce the absorption of iron-derived iron minerals. The polyphenols (compounds with antioxidant properties), which exist in tea leaves, may bind inorganic iron mineral before it is excreted in the feces. In order to prevent this, one does not need to give up drinking tea, but instead make sure not to drink it while consuming iron-rich plant foods,” he advises.

Will Tea Survive the Climate Crisis?

The climate crisis brings with it many changes and different regions of the world are experiencing major climate fluctuations, ranging from heat and droughts to floods, storms and extreme cold. This could threaten the continued survival of agricultural crops. Some plants have crossed oceans and been absorbed by other continents, but what about those that require special conditions to thrive? Will the tea plant survive the changing conditions?

“A plant can adapt to new conditions up to a certain limit,” says Prof. Shaul Yalovsky of the School of Plant Sciences and Food Security at The George S. Wise Faculty of Life Sciences, who studies plant development mechanisms and their response to environmental stresses. His lab has succeeded in developing tomato varieties that consume less water and still deliver the same amounts of fruit while maintaining its quality.

“Tea is a crop that grows in very rainy areas. Therefore, it is not cultivated in an area like Israel, for example. Tea plantations are usually located on hills, where the weather is humid and cool to the appropriate extent and the soil is deep enough.”

The tea fields stretching over hills and mountains. Tea harvest in action

Disguised as Tea

Did you know that red “tea” (also known as “red bush tea”) is actually an infusion from the Rooibos plant that grows in South Africa? Because it is processed in the same way as the tea plant, it is commonly referred to as “red tea”, while in reality it is not a tea, but an herbal infusion. It is naturally caffeine-free.

Just like many other plants, tea requires specific conditions to grow: deep and airy soil rich in minerals, and an optimal temperature range between 18 and 20 degrees Celsius. “Tea is sensitive to cold, dryness, humidity and lighting conditions. For example, high humidity impairs the quality of the tea while periods of dryness increase its quality, and growing at high altitudes increases the quality of the tea but lowers the amount of crop,” explains Prof. Yalovsky.

The tea is grown in Asia, Africa and South America. The six largest tea producers in the world are China, India, Kenya, Sri Lanka, Vietnam and Turkey. So what happens if growing conditions in East and Southeast Asia change? Prof. Yalovsky explains that it is necessary to adapt the types of tea plants according to their growing areas. “What works at one location does not necessarily work elsewhere: what grows well in East and Southeast Asia will not necessarily grow well in Kenya or Turkey, for example. Even if we should manage to copy a crop from one place to another, we may not succeed in maintaining its qualities and taste.”

When we drink Earl Grey tea we expect a very specific taste, and if the same tree were to be grown elsewhere – where the temperature may be the same as the original habitat but the soil is not – we would likely notice a change in the taste of the product. This is possibly one of the reasons why drinking Japanese green tea differs in taste from Chinese green tea.

With regard to the future of the in-demand beverage, Prof. Yalovsky says: “Even if the regions of the cultivated areas should experience floods – the tea plantations are positioned on the slopes of hills and mountains so it should not become an issue.” Another good news is that unlike many crops that depend on pollination to develop fruit – the tea plant is less reliant on this. “In the production of tea, we use its leaves and not its flowers or fruits and so it can be propagated by pruning (cutting a branch from a mature plant, a so-called ‘mother plant’, and creating a new plant through rooting). This method also ensures the genetic uniformity of the ‘daughter plants’, with everything that implies,” he concludes.

We made sure to ask Guy Shalmon which type of tea (if any) he recommends that our students drink during the exam period, to which he replied: “Actually, I wouldn’t say there’s any unique advantage or need to drink tea during an exam period. I’d say drink the kind of tea that you fancy and, ideally, try to rotate different types of tea. If the need for caffeine is the main consideration, black tea is the best choice, as it has the highest caffeine concentration. Black tea contains approx. 60-40 mg of caffeine per cup, while green tea contains only 20-15 mg.”

Well, who needs the exams as an excuse, anyway? If you’re like us, we suggest you pour yourself a cuppa on any day of the week – no special occasion required – and enjoy a peaceful break from everything and everyone.

How Can We Boost Our Fight Against Marine Plastic Pollution?

Written by Star on January 24, 2022. Posted in news.

Plastic wastes endanger marine life in many ways: animals get entangled in large plastic items or swallow small particles and chemicals, consequently dying of suffocation, starvation or poisoning. Awareness is growing, and research is expanding, but the effort to monitor and prevent plastic pollution encounters many obstacles, first of all due to the enormous complexity and diversity of plastic debris.

A new review from Tel Aviv University has determined that global standardization of methodologies for monitoring and measuring marine plastic pollution can significantly boost international efforts to mitigate this troubling phenomenon. In a comprehensive survey of all methods described in existing literature, the researchers charted the great complexity and diversity of marine plastic pollution, which makes unified measurement and accurate evaluation very difficult. According to the researchers, this is precisely why a standardized system is urgently needed, enabling comparisons, exchange of information, and effective tools for decisionmakers.

Grave and Immediate Threat

The study was led by Gal Vered and Prof. Noa Shenkar of the School of Zoology at The George S. Wise Faculty of Life Sciences and The Steinhardt Museum of Natural History at Tel Aviv University. Gal Vered is also a researcher at the Interuniversity Institute for Marine Sciences in Eilat. The review was published in Current Opinion in Toxicology.

According to Prof. Shenkar, plastic pollution, which is all human-made, poses a grave and immediate threat to the marine environment, with constantly rising amounts of plastic entering the oceans. Thus, for example, a 2013 survey conducted by Israel’s Ministry of Environmental Protection found that plastic accounts for about 41% of the volume of waste produced annually by Israelis. The Covid-19 pandemic, which has generated extreme demands for personal protective and single-use products, has further exacerbated the problem.

Comes in Different Shapes and Forms

The researchers explain that marine plastic pollution comprises many different types of plastic and plastic products of various shapes and sizes – from huge ghost nets to nanoparticles, as well as a vast range of chemical additives. Different methods for monitoring, sampling, and identifying plastic pollution relate to different properties of the sampled material: from size, source, and original use, through shape and color, to chemical composition and physical properties. Sampling is usually conducted with a towed net, with the size of collected pollutants dependent on the net’s mesh size, and tiny particles are identified in the lab using various spectroscopic and chemical methods. In addition to the diversity in sampling and identification methods, units used for reporting measured concentrations of pollutants also vary: from the number of plastic objects per area, to the weight of particles per organism, and more.

“These differences generate confusion and lack of communication among researchers in different parts of the world, hampering our efforts to work together toward our common goal: providing decision makers with reliable data in order to promote the efforts to reduce plastic pollution and its many hazards,” explains Prof. Shenkar. “We are in urgent need of standardized methods and comparable measures for monitoring, sampling, identifying, classifying, and quantifying marine plastic pollution and its impact.”

International Collaboration Needed

“This study is a response to problems encountered in my research, which deals with the impact of plastic and its chemical additives on marine life in the Eilat coral reef (presenting Israel’s largest marine biodiversity),” says Gal Vered and explains: “The differences in methodology make it difficult to use the findings of other researchers – as either a source of information or for comparing results. Thus, for example, most measurements worldwide relate to samples obtained with a towed net from the surface of the water, while I wish to discover which materials reach the seafloor and reef organisms.”

“Standardization will enable accurate evaluations and valid comparisons between plastic pollutions in different places on the globe. This will maximize the power of scientific research, enhance our understanding of the impact of plastic pollution on ecosystems and marine life, and help us develop effective tools for decisionmakers facing this crucial issue.”

Prof. Shenkar concludes: “Marine plastic pollution is a global problem, which requires extensive international collaboration. At the bottom line, we all wish to focus our efforts and obtain the best results. Like many others, we believe that efforts should begin close to the shoreline, in areas directly impacted by plastic pollution. However, a great deal of research is still required in order to establish this assumption and build effective strategies for managing plastic pollution. But first of all, we urgently need standardization that will enable all of us, all over the world, to work together.”

Featured image: Prof. Noa Shenkar

Out of This World

Written by Star on January 5, 2022. Posted in news.

A new star and satellite observatory is currently being set up on the roof of TAU’s Shenkar building, and is set to become one of the most sophisticated labs in the world.

If you’d like to take a look at the positioning of the receivers at the International Space Station or see how TAU’s own Nano-satellite, TAU SAT-1 (which has been orbiting the Earth for almost a year now) is doing, we’re here to tell you that you will soon be able to do so. A new state-of-the-art optical ground station is currently being built on the roof of Raymond & Beverly Sackler School of Physics & Astronomy. The new optical ground station will allow us to observe tiny details far above us.

The optical ground station will be used for advanced communication with satellites and other spacecraft and tracking of relatively close-up celestial bodies, but also stars that are millions of light-years away. At a later stage, the station will serve as a tool for quantum encryption in space, one that will allow us to best encrypt any type of information.

Moments before the most sophisticated telescope in Israel will be installed here at Tel Aviv University, we met with Prof. Yaron Oz, Head of the Quantum Center; Prof. Haim Suchowski from the School of Physics and Astronomy, and Michael Tzukran, a professional astronomy photographer who will be operating the new station, for a light conversation about, you know, the usual: quantum optical communication, space photography and surprise meetings that would lead to groundbreaking projects.

Replacing Light Pollution

Prof. Suchowski’s department, together with the University’s Engineering and Maintenance Division and partial funding from the Quantum Center, are currently working on making the Tel Aviv University campus free of celestial light pollution. This is a side-project that was born in conjunction with the construction of the new observation station. In the coming months, all polluting lighting on campus will be replaced with ecological lighting fixtures, making Tel Aviv University the first University in Israel to be free of light pollution.

Where it all started: Michael Tzukran in the old observatory on the roof of the Shenkar building the non-linear interaction of light with various materials in nature. In recent years, I’ve also been involved in the intensive activities at the Nano-Satellite Center and the new Quantum Center that have started operating on campus. What we’re dealing with on the roof these days is a combination of all these things,” he explains.

“The field of space once ‘belonged’ exclusively to NASA and very specific bodies, such as the aerospace industry in the case of Israel. Today, even high school students can send satellites into space,” explains Suchowski. “The New Space Revolution allows private companies to send and operate relatively affordable Nano-satellites into space and has changed our lives. Over the past 15 years, universities have been sending their own Nano-satellites as well.”

The University’s own Nano-satellite, TAU SAT-1, was devised, developed, assembled and tested under the leadership of Dr. Meir Ariel, Dr. Ofer Amrani of The Iby and Aladar Fleischman Faculty of Engineering and Prof. Colin Price of the Porter School of the Environment and Earth Sciences. The satellite, which carries scientific experiments, was launched about a year ago.

Up until now, the project has consisted in building a standard radio communication ground station to communicate with the launched satellite. According to Suchowski, one of the next projects will be to create optical communication through space, and thereafter quantum optical communication through space, which is a new and evolving field.

Quantum-Encrypted Communication Satellites

Information encryption is an essential subject with many applied meanings, and quantum mechanics is changing the rules of the game in this regard.

“Today, we encrypt our information based on complex mathematical algorithms, and assume that computers will take a long time to solve these problems and therefore the information is secure,” explains Prof. Yaron Oz, Chairman of the Tel Aviv University Quantum Science and Technology Center. “Quantum computers, however, are based on a different computational paradigm and can change the picture. Decomposing an integer into its primary factors – the complexity of which protects encryption algorithms that are widely used today – will be quickly solved by a quantum computer. Therefore, it is important to depict what the encrypted methods will be in the age of quantum computers.”

“Quantum systems have exceptional encrypted information transfer capabilities due to the fact that quantum mechanics do not allow information to be copied. Any attempt to copy or modify it destroys the original information. As a result, a quantum communication line is completely safe from eavesdropping. Transmitting a cipher key in a quantum communication network is completely secure, and indeed quantum optical encryption already exists via fiber optics,” he says.

Today, this type of encryption is possible, but limited to a distance of 150-200 km. Prof. Oz tells us that such communication networks already aid financial sectors in Switzerland. However, the transfer of information between continents (for example from New York to London) in this way is not yet possible.

Prof. Yaron Oz

Prof. Oz explains that in Israel there’s an understanding of the need to move in the direction of encrypting information on a satellite quantum communications network, and here at Tel Aviv University we have decided to take steps at the operational and research level. The new lab with the telescope on the roof is thereby about to take part in the future satellite project of the Nano-Satellite center.

With the help of various bodies here at TAU, the Quantum Center in particular, and with the support of Prof Erez Etzion, Head of the School of Physics and Astronomy, budget and space was ensured to build the advanced observatory and buy the massive equipment. With a telescope with a 24-inch mirror, the precise and huge robot will be able to track stars, galaxies, nebulae and other bodies. The robot, which weighs 300 kg, can move at an angular speed of up to 50 degrees per second and accurately track moving satellites at low altitudes, as well as lower flying aircraft. “We are already doing preliminary experiments in optical communication. With the level of accuracy of the new telescope we’ll be the only ones in Israel with such equipment,” promises Prof. Suchowski.

The construction of the new ground station, as documented in Michael Tzukran’s Instagram account

The Stargazer

Quite by chance, another actor entered the picture and helped Prof. Suchowski leverage the idea into practice: Michael Tzukran, a world expert in astronomical and satellite photography and research observatory construction consultant.

“As a seasoned astronomy photographer, I wanted to challenge myself and photograph the International Space Station. I needed an open roof close to the space station’s orbit as it passes over the skies of Israel. And so I simply asked whether it could be done here.” Tzukran brought his own equipment and took one of the most detailed photos ever taken of the space station from Earth. During the photography, the space station was flying at a speed of close to 28,000 km per hour. No big deal.

Passing at a speed of close to 28,000 km/h. The space station, photographed by Michael Tzukran

Michael’s specialty is to adjust and control the sophisticated robot, monitor the satellites and photograph them according to requests from researchers. With the new equipment, he plans to document satellites like they’ve never been observed before from Earth.

Prof. Ady Arie from the Faculty of Engineering and doctoral students Dolev Bashi, Georgi Gary Rosenman, Yonatan Piasetski, Sahar Shahaf, Tomer Nahum and Yuval Reches are also working on the establishment of the technological system for laboratory quantum optical communication.

Prof. Suchowski estimates that various industries, such as security and other universities, will be interested in using the new platform in the future: “This is a national resource. I believe it will become instrumental in promoting applied and basic research in Israel and the world,” he concludes.

Ancient Climate Crisis Transformed Us from Nomadic Hunters to Settled Farmers

Written by Star on December 6, 2021. Posted in news.

What made the residents in the Southern Levant, tens of thousands of years ago, put down their walking sticks and hunting gear and instead become settled farmers? Apparently, it was the result of a climate crisis that took place at the end of the last ice age, about 10,000 to 20,000 years ago.

A new record of significant climate changes in the region, based on the identification of ancient plant remains, sheds light on the dramatic transition. Against the background of the Glasgow Climate Change Summit, the researchers believe that understanding the response of the region’s flora to the dramatic past climate changes can help in preserving the regional variety of plant species and in planning for current and future climate challenges.

The Crisis that Marched Humanity Forward

The research was conducted by Dr. Dafna Langgut of the Department of Archaeology and The Steinhardt Museum of Natural History at Tel Aviv University; Prof. Gonen Sharon, Head of the MA Program in Galilee Studies at Tel-Hai College, and Dr. Rachid Cheddadi, expert in evolution and palaeoecology of University of Montpellier, Institute of Evolutionary Sciences (ISEM) Montpellier, France. The groundbreaking study was recently published in the leading scientific journal Quaternary Science Reviews.

The study was conducted at the prehistoric archaeological site Jordan River Dureijat (“Jordan River Stairs”) on the shores of the ancient Lake Hula. The site is unique for its exceptional preservation conditions yielding finds that enabled discovery of the primary activity of its early local residents – fishing. Preserved botanic remains also enabled researchers to identify the plants that grew 10,000 – 20,000 years ago in the Hula Valley and its surroundings.

The prehistoric archaeological site Jordan River Dureijat (“Jordan River Stairs”) on the shores of the Paleo Lake Hula

Two major processes in world history took place during this period, the first of which was the transition from a nomadic to a settled lifestyle that occurs during a period of dramatic climate change. Prof. Sharon, supervisor of the Madregot Hayarden (“Jordan Stairs”) excavation, explains: “In the study of prehistory, this period is called the Epipalaeolithic period. At its outset, people were organized in small groups of hunter-gatherers who roamed the area. Then, about 15,000 years ago, we are witness to a significant change in lifestyle: the appearance of settled life in villages, and additional dramatic processes that reach their apex during the Neolithic period that followed. This is the time when the most dramatic change of human history occurred – the transition to the agricultural way of life that shaped the world as we know it today.”

Dr. Langgut, an archaeobotanist specializing in identification of plant remains, elaborates on the second dramatic process of this period, namely the climatic changes that occurred in the region. “Although at the peak of the last ice age, about 20,000 years ago, the Mediterranean Levant was not covered with an ice sheet as in other parts of the world, the climatic conditions that existed nevertheless differed from those of today. Their exact characteristics were unclear until this study. The climatic model that we built is based on reconstruction of the fluctuation of the spread of plant species indicating that the main climatic change in our area is expressed by a drop in temperature (up to five degrees Celsius less than today), whereas the precipitation amounts (rain, snow, sleet, or hail) were close to those of today (only about 50 mm less than today’s annual average).

Dr. Dafna Langgut

Temperature Fluctuations

However, Dr. Langgut explains that about 5,000 years later, in the Epipalaeolithic period (about 15,000 years ago) a significant improvement in climate conditions can be seen in the model. An increased prevalence of heat-tolerant tree species, such as olive, common oak, and Pistacia, indicate an increase in temperature and precipitation.

During this period, the first sites of the Natufian culture appear in our region. It could very well be that the temperate climate assisted in the development and flourishing of this culture, in which permanent settlement, stone structures, food storage facilities, and more first appear on the global stage.

The next stage of the study deals with the end of the Epipalaeolithic period, about 11,000-12,000 years ago, known globally as the Younger Dryas period. This period is characterized by a return to a cold, dry climate like that of the ice age, causing somewhat of a climate crisis around the world. The researchers claim that until this study, it was unclear whether and to what extent there was any expression of this period in the Levantine region.

Little Rain, but Throughout the Year

According to the researchers: “The findings that arise from the climate model presented in the article show that the period was characterized by climatic instability, intense fluctuations, and a considerable drop in temperatures. Nevertheless, while reconstructing the precipitation, a surprising phenomenon was discovered: the average quantities of rainfall reconstructed were only slightly less than those of today; however, the precipitation was distributed over the entire year, including summer rains.”

The researchers claim that such distribution assisted in the expansion and thriving of annual and leafy plant species. The gatherers who lived in this period now had a wide, readily available variety of gatherable plants throughout the entire year. This variety enabled their familiarity just before domestication. The researchers are of the opinion that these findings contribute to a new understanding of the environmental changes that took place on the eve of the transition to agriculture and domestication of animals.

Summary

Why did humans settle down and start farming the land? While this study doesn’t fully answer this questions, it does reconstruct the climate in what is today Israel from 20,000 to 10,000 years ago, revealing the dramatic environmental and climatic changes that uniquely combined with social and technological innovations 12,000 years ago and formed the background for the development of acriculture in the Levant.

The warmer, more humid climate between 15,000 and 13,000 years ago coincided with the Natufian culture, and may have supported their practice of living in one place for a long time, thanks to increased gathering and storage opportunities. Around 13,000 years ago, temperatures sunk a bit and rains would fall throughout the year, favoring open-field vegetation and plants. 12,000 years ago, the Holocene (the current geological era) began, which in the Near East meant long hot and dry summers necessitating gathering and storing food during winter and spring. The new environmental conditions pushed people to make greater efforts to domesticate, farm and store their crops – setting the stage for the Neolithic revolution.

Dr. Langgut concludes: “This study contributes not only to understanding the environmental background for momentous processes in human history such as the first permanent settlement and the transition to agriculture, but also provides information on the history of the region’s flora and its response to past climatic changes. There is no doubt that this knowledge can assist in preserving species variety and in meeting current and future climate challenges.”

Dr. Dafna Langgut collects sediment samples for pollen investigation.

Featured image: An Israeli farmer in his vineyard

Climate Action: From Campus to Glasgow

Written by Star on November 26, 2021. Posted in news.

As more than 130 heads of state and thousands of delegates converged in Glasgow for the two week-long United Nations global climate summit known as COP26 and Tel Aviv University researchers were there as well, taking part in the international conversation.

This year’s summit aimed to set new targets for cutting emissions from burning coal, oil and gas that are heating our planet, as scientists urge nations to make an immediate switch away from fossil fuels to avoid the most catastrophic impacts of climate change. TAU has placed climate change research and action among its top priorities and has launched the Center for Climate Change Action to drive innovative solutions to the climate crisis.

Inside the Climate Summit

TAU researchers attended the summit, exchanging knowledge and gathering observations to apply on campus and throughout Israel. They shared with us their perspectives on what comes next to ensure a cleaner, healthier and safer world for the future:

Prof. Colin Price, Head of the Center for Climate Change Action and the Department of Environmental Studies at TAU, attended COP26 as a member of Israel’s 120-person delegation. “Academia has a role in advising the government and addressing uncertainty,” said Price, who debriefed Israel’s Prime Minister Naftali Bennett on local and global climate matters in the weeks preceding COP26. “It is the role of scholars to provide neutral views based on science that policy-makers can use to swiftly guide decisions. Otherwise, they could be misinformed by people with less expertise.”

Israel’s Prime Minister Naftali Bennett addresses the plenary at COP26. (Photo: Colin Price)

Price added that the national security risks posed by climate change, as discussed at COP26, are an imminent concern for Israel and that academia can help address this challenge by providing objective data and analysis. “Climate-spurred humanitarian issues in neighboring countries are perhaps one of the biggest external threats to Israel,” he stressed. He mentioned droughts in Syria that led to mass migration, civil unrest and resource drainage during the country’s ongoing civil war, noting similar cases could cause further instability in the Middle East. For example, rising sea levels could expel millions along Egypt’s Nile River, leading to an overwhelming refugee crisis at Israel’s door.

He said the topics of discussion covered at COP26 were in line with the Center for Climate Change Action’s four main foci this year: regional cooperation on finding solutions, the financial sector’s role in addressing climate change, public behaviors that influence our environment, and the public health risks of the growing crisis. Price pointed toward a reported UAE-backed deal between Israel and Jordan for a solar energy and water exchange as a current example of how these forces are taking shape on the ground.

“COP26 was the beginning of the hard work ahead of us all,” he concluded.

Prof. Colin Price (right) and PhD student Tsur Mishal at the climate conference in Glasgow.

Meital Peleg Mizrachi, a PhD student at TAU’s Department of Public Policy and social entrepreneur turned government advisor, attended COP26 on behalf of Israeli grassroots climate organizations “Change Direction” and “Life and Environment.” Locally recognized as a promising young leader in the field, her activism and research focus on sustainable fashion and environmental justice. She aims to raise awareness of the environmental and social ramifications of the fashion industry—the second-most polluting industry on the planet after oil—and to drive policies for greater ecological integrity in textile production and consumption.

“The unique encounter at COP26 of politicians, environmental activists, green entrepreneurs, researchers and so many different parties involved in global climate efforts allowed for new connections that otherwise would not have happened,” she reflected after the summit. “For the first time, I met with other sustainable fashion researchers from around the world. This was particularly beneficial as the field is rarely studied in Israel, and it is difficult to develop a professional network without such opportunities.”

TAU PhD student Metial Peleg Mizrahi at the climate conference. (Photo: Courtesy)

Tsur Mishal, a PhD candidate at the Department of Environmental Studies, was also at the convening in Glasgow. As part of a team from TAU’s Sagol Center for Neuroscience and the Porter School of the Environment and Earth Sciences, Mishal’s research contributes to virtual reality (VR) technology for climate change awareness.

“Meeting with climate media experts and leading scientists at the conference, I was happy to see interest in our VR model, which simulates the future climate in Tel Aviv,” he mused. “VR experiences can bring us closer to the lives of the people affected by the climate crisis today to create solidarity and empathy.” He explained that the technology further aims to bridge the psychological gaps people face in understanding the gap between the climate scenario today and its implications on the future, before it’s too late to reverse damages.

TAU PhD candidate Tsur Mishal tests virtual reality technology at COP26

During a special live broadcast on COP26 hosted from campus, Dr. Ram Fishman, a leading researcher on sustainable development in the Department of Public Policy underlined that, “Israeli climate innovation is key to these climate efforts, many of which are borne from ideas stemming from academia.”

Featured image: AU PhD students Tsur Mishal (4th from right) and Meital Peleg Mizrachi (3rd from left) among Israeli delegation members at COP26

Researchers detect changes in birds’ bodies, probably caused by global warming.