For the first time, Technion scientists succeeded in forming a network of big and small blood vessels, necessary for supplying blood to implanted tissue
Researchers led by Technion Professor Shulamit Levenberg, who specialises in tissue engineering, have succeeded in creating a hierarchical blood vessel network, necessary for supplying blood to implanted tissue. In the study, recently published in Advanced Materials, Dr. Ariel Alejandro Szklanny used 3D printing for creating big and small blood vessels to form for the first time a system that contained a functional combination of both. The breakthrough took place in Prof. Levenberg’s Stem Cell and Tissue Engineering Laboratory in the Technion’s Faculty of Biomedical Engineering.
In the human body, the heart pumps blood into the aorta, which then branches out into progressively smaller blood vessels, transporting oxygen and nutrients to all the tissues and organs. Transplanted tissues need similar support of blood vessels, and consequently so do tissues engineered for transplantation. Until now, experiments with engineered tissue containing hierarchical vessel networks have involved an intermediary step of transplanting first into a healthy limb, allowing the tissue to be permeated by the host’s blood vessels, and then transplanting the structure into the affected area. (e.g. this study by Idan Redenski about engineered bone grafts, published earlier this year.) With Dr. Szklanny’s new achievement, the intermediary step might become unnecessary.
To create in the lab a tissue flap with all the vessels necessary for blood supply, Dr. Szklanny combined and expanded on two separate techniques. First, he created a fenestrated polymeric scaffold that mimics the large blood vessel, using 3D printing technologies. The fenestration served to create not just a hollow tube, but a tube with side openings that allowed the connection of smaller vessels to the engineered larger vessel. Using a collagen bio-ink, tissue was then printed and assembled around that scaffold, and a network of tiny blood vessels formed within. Finally, the large vessel scaffold was covered with endothelial cells, which are the type of cells that constitute the inner layer of all blood vessels in the body. After a week of incubation, the artificial endothelium created a functional connection with the smaller 3D bio-printed vessels, mimicking the hierarchical structure of the human blood vessel tree.
The resulting structure was then implanted in a rat, attached to its femoral artery. Blood flowing through it did what we would want blood to do: it spread through the vessel network, reaching to the ends of the structure, and supplied blood to the tissue without leaking from the blood vessels.
One interesting point to note is that while previous studies used collagen from animals to form the scaffolds, here, tobacco plants were engineered by the Israeli company CollPlant to produce human collagen, which was successfully used for 3D bioprinting the vascularized tissue constructs.
This study constitutes an important step towards personalized medicine. Large blood vessels of the exact shape necessary can be printed and implanted together with the tissue that needs to be implanted. This tissue can be formed using the patient’s own cells, eliminating rejection risk.
The study received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 Research and Innovation Programme.
For the full article in Advanced Materialsclick here
Technion, Carasso Family & Carasso Motors to Establish the Carasso FoodTech Innovation Center
Haifa, Israel, September 14, 2021: Forty-five years after the family’s first contribution to the Technion – Israel Institute of Technology, and now as part of a multigenerational initiative, the Carasso Family and Carasso Motors are contributing toward a new initiative, promoting cutting-edge food technologies, teaching and R&D in the Faculty of Biotechnology and Food Engineering. The building that until now has housed the Food Industries Center will be renamed the Carasso FoodTech Innovation Center. The donation will be used to renovate the building, as well as expand and upgrade the Center’s research infrastructure. Alongside this activity, a scholarship fund will be established for advanced research.
The gift, which will enhance Israel’s research presence in the global food industry, is part of the family’s legacy – which emphasizes Zionism, excellence in science education, closing gaps in the Israeli society, and investment in infrastructure.
The expanded and upgraded building will be one of its kind in Israel and one of the most advanced in the world; it will feature an R&D center for industrial production, a packaging laboratory, an industrial kitchen, as well as tasting and evaluation units that will be used for teaching and research in the Faculty of Biotechnology and Food Engineering. The Carasso FoodTech Innovation Center will be housed in an existing, dedicated structure alongside the faculty, and will include a visitor area that will expose high-school students to the world of FoodTech, and serve as a hub for startups, where they can benefit from R&D services.
“Eradicating world hunger and improving food security are among the main challenges facing humanity in the 21st century, as defined by the UN’s Sustainable Development Goals,” said Technion PresidentProf. Uri Sivan. “The Technion has the only faculty in Israel for research in food engineering, a faculty that leads the Israeli FoodTech industry. We are grateful to the Carasso Family for their generous contribution, which will establish the Carasso FoodTech Innovation Center, and will help us promote groundbreaking scientific research in the field, train the next generation of the Israeli FoodTech industry, and maintain the faculty’s position at the global forefront of research and development.
Yoel Carasso, Chairman of Carasso Motors, said: “In 1924, our Grandfather Moshe immigrated with his family to Israel from Thessaloniki, where he was one of the leaders of the Jewish community. In Israel, he cofounded Discount Bank, Ophir Cinema (one of the first movie theaters in Tel Aviv), and of course Carasso Motors Company. For me and for my uncle Shlomo and my cousins – Ioni, Orli, Sarah, Tzipa and Arik – this is coming full circle from a century ago. We chose to support the Carasso FoodTech Innovation Center since the Technion is synonymous with excellence. The Technion is an engine for combining basic and applied science in the Galilee and in Israel as a whole. We believe the Carasso FoodTech Innovation Center will contribute to the industry, and to collaborative work in this field, and thus strengthen the Israeli economy and society. Our family has a history of supporting the Technion, and when the opportunity to establish this center sprang, we knew it was our calling to lead.”
Prof.Marcelle Machluf, Dean of the Faculty of Biotechnology and Food Engineeringat the Technion, said “the faculty is one of the only ones in the world that combines the disciplines of bioengineering, technology, food sciences and life sciences. Coping with the COVID-19 pandemic has only emphasized the importance of food and biotechnology in maintaining our existence and meeting future existential challenges. To address the many challenges in this field, including access to healthy, affordable food and innovative medical treatments, we need advanced infrastructure that will enable the integration of new engineering and scientific tools; these will enable us to develop the necessary technologies, as well as the infrastructure and equipment that will support the development and assimilation of the knowledge required to tackle tomorrow’s food challenges. I would like to thank the Carasso Family for their generous contribution, which will allow the faculty to upgrade the infrastructure and equipment needed for the development and integration of the knowledge required to tackle future food challenges.”
Izaac Weitz, CEO of Carasso Motors: “Carasso Motors, with its various brands – Renault, Nissan, Infinity, and Dacia – is committed to innovation and connection with our diverse customer base in Israel. Food technology is an evolving field that brings value in many ways to our stakeholders. Food research tackles environmental and global warming challenges, providing food security and a balanced diet, accelerating paramedical developments that combine medicine and food, and of course contributing to the development of innovative solutions that will put Israel at the forefront of science globally. At Carasso Motors, we jumped at the opportunity to make such a significant contribution to the establishment of this advanced research center, which will also improve and advance Israel’s education and society.”
Hydrogen On the Way Researchers in the Schulich Faculty of Chemistry at the Technion have developed a new system for producing hydrogen from water with a low energy investment and using available and inexpensive materials
Water electrolysis is an easy way to produce hydrogen gas. While hydrogen is considered a clean and renewable fuel, efficient electrolysis today requires high electric potential, high pH and in most cases, catalysts based on ruthenium and other expensive metals. Due to the inherent promise of hydrogen, many research groups are striving to develop electrolysis technologies that will make it possible to produce hydrogen fuel at a low electric potential, at a pH between 7-9 and with catalysts based on available and inexpensive metals such as copper, manganese, and cobalt.
The Journal of the American Chemical Society recently reported on a unique solution for this issue developed at the Technion – Israel Institute of Technology. It is the fastest system of its kind reported so far that operates with available metal (copper) catalysts. The research was led by Professor Galia Maayan, head of the Biomimetic Chemistry Laboratory in the Schulich Faculty of Chemistry, and doctoral student Guilin Ruan.
The Technion researchers designed and developed a homogeneous electrolysis system, or in other words, a system in which the catalyst is soluble in water, so that all components of the system are in the same medium. The innovative and original system is based on (1) copper ions; (2) a peptide-like oligomer (small molecule) that binds the copper and maintains its stability; and (3) a compound called borate whose function is to maintain the pH in a limited range. The main discovery in this study is the unique mechanism that the researchers discovered and demonstrated: the borate compound helps stabilize the metallic center and participates in the process so that it helps catalyze it.
In previous studies, the research group demonstrated the efficacy of using peptide-like oligomers to stabilize metal ions exposed to oxygen – exposure that may oxidize them in the absence of the oligomer and break down the catalyst. Now, the researchers are reporting on the success in creating a very efficient and fast electrolysis system. The stable system oxidizes the water into hydrogen and oxygen under the same desired conditions: low electric potential, pH close to 9 and inexpensive catalysts. According to Prof. Maayan, the system was inspired by enzymes (biological catalysts) that use the protein’s peptide chain to stabilize the metallic center and by natural energetic processes such as photosynthesis, which are driven by units that use solar energy to transport electrons and protons.
The research was supported by the Israel Science Foundation (ISF) and the Nancy and Stephen Grand Technion Energy Program.
Click here for the paper in The Journal of the American Chemical Society
Technion scientists created a wearable motion sensor capable of identifying bending and twisting
Technion scientists have produced a highly stretchable electronic material and created a wearable sensor capable of precisely identifying bending and twisting motion. It is essentially an electronic skin capable of recognizing the range of movement human joints normally make, with up to half a degree precision. This breakthrough is the result of collaborative work between researchers from different fields in the Laboratory for Nanomaterial-Based Devices, headed by Professor Hossam Haick from the Wolfson Faculty of Chemical Engineering. It was recently published in Advanced Materials and was featured on the journal’s cover.
Prof. Haick’s lab is focused on wearable devices for various uses. Currently existing wearable motion sensors can recognize bending movement, but not twisting. Existing twisting sensors, on the other hand, are large and cumbersome. This problem was overcome by Ph.D. candidate Yehu David Horev and postdoctoral fellow Dr. Arnab Maity. Mr. Horev found a way to form a composite material that was both conductive (and thus, usable as a sensor) and flexible, stretchable, breathable, and biocompatible, and that did not change its electrical properties when stretched. Dr. Maity then solved the mathematics of analyzing the received signal, creating an algorithm capable of mapping bending and twisting motion – the nature of the movement, its speed, and its angle. The novel sensor is breathable, durable, and lightweight, allowing it to be worn on the human body for prolonged periods.
“This sensor has many possible applications,” Prof. Haick stated. “It can be used in early disease diagnosis, alerting of breathing alterations, and motor system disorders such as Parkinson’s disease. It can be used to assist patients’ motor recovery and be integrated into prosthetic limbs. In robotics, the feedback it provides is crucial for precise motion. In industrial uses, such sensors are necessary in monitoring systems, putting them at the core of the fourth industrial revolution.”
“Electrically conductive polymers are usually quite brittle,” explained Mr. Yehu about the challenge the group had overcome. “To solve this, we created a composite material that is a little like fabric: the individual polymer ‘threads’ cannot withstand the strain on the material, but their movement relative to each other lets it stretch without breaking. It is not too different from what lends stretch to t-shirts. This allows the conductive polymer withstand extreme mechanical conditions without losing its electrical properties.”
What makes this achievement more important is that the materials the group used are very cheap, resulting in an inexpensive sensor. “If we make a device that is very expensive, only a small number of institutions in the Western World can afford to use it. We want the technological advances we achieve to benefit everyone, regardless of their geographic location and socio-economic status,” said Prof. Haick. True to his word, among the laboratory’s other projects is a tuberculosis-diagnosing sticker patch, sorely needed in developing countries.
The scientists who contributed to this study are Yehu David Horev, Dr. Arnab Maity, Dr. Youbin Zheng, Yana Milyutin, Dr. Muhammad Khatib, Dr. Ning Tang, and Prof. Hossam Haick from the Department of Chemical Engineering and Russell Berrie Nanotechnology Institute at the Technion-Israel Institute of Technology; Miaomiao Yuan from the Eighth Affiliated Hospital, Sun Yat-sen University, China; Dr. Ran Yosef Suckeveriene from the Department of Water Industry Engineering at the Kinneret Academic College; and Prof. Weiwei Wu from the School of Advanced Materials and Nanotechnology at Xidian University, China.
From fighting COVID-19 to detecting heart disease, these are some of the Technion’s most innovative student projects in biomedical engineering
From detecting cardiovascular disease, to fighting coronavirus, Faculty of Biomedical Engineering students recently presented an array of innovative projects that integrated everything they had learned. During project development, the students had to go through all the stages needed to bring an idea to fruition. Starting with a medical problem which they had to tackle, they had to combine and implement medical know-how with engineering skills and scientific knowledge in order to provide a real-world solution. This hands-on experience exposes and prepares Technion graduates to the high-tech and biomed industries, and to biomedical research in a way that encourages multidisciplinary work. Therefore, such projects are vital for their future career and entrepreneurial skills.
Here’s a glimpse into some of the most intriguing (and often lifesaving) student projects in biomedical engineering.
Early detection of cardiovascular disease – Sivan Barash and Shachar Zigron took first place in the student project competition, presenting a novel way of labelling macrophage cells, making them detectable by MRI. Macrophages are cells involved in the detection and destruction of bacteria. Cardiovascular disease is strongly associated in the public mind with fat storage in the body, but recent studies have shown significant involvement of inflammation in the process. Since macrophage cells have a major role in inflammation, being able to observe their movement within the body would facilitate scientists’ exploration of the connection between inflammation and cardiovascular disease. The duo’s project has lain the groundwork for in-vivo studies soon to be conducted in the laboratory of Prof. Katrien Vandoorne.
AI-based decision support machine for fetal monitoring – Second place went to Amit Parizat and Rotem Shapira, who created an artificial intelligence (AI) system to analyze the output of the fetal monitor during labor and serve as a decision support machine. Complications during labor develop rapidly and can harm mother and child. The fetal monitor alerts healthcare providers of complications during labor. However, analyzing the monitor’s long signals manually is challenging and leads to obstetrics teams recommending a Caesarean “just in case” at the slightest indication, to the point that currently a third of all births in the U.S. involve a C-section, and only 20% of C-sections are later found to have been necessary. C-sections carry risks to the mother and involve a long recovery and long-term side effects. Amit and Rotem proved the feasibility of training an AI machine to predict complications during childbirth, preventing unnecessary invasive intervention, while ensuring that intervention is performed when needed. To achieve this, the two worked with the Obstetrics and Newborn Medicine Division at the Carmel Medical Center.
Treating cancer – Orel Shahadi and Or Levy, coming in third, developed a 3D model that simulates drug penetration into solid tumors, facilitating development of new drugs and drug combinations to treat cancer. Their innovative model features an inner cluster of cells engineered to display fluorescence, surrounded by an outer layer of cells. Change in the cells’ fluorescence served as an indicator, providing a way to measure drug penetration into the tumor with a high level of precision.
Detecting heart rhythm problems – Yonathan Belicha and Daniel Cherniavsky, who took fourth place, explored a novel approach to diagnosing cardiac arrhythmias (heart rhythm problems), using nothing more than a few 1-minute videos of the patient – the kind of videos one might make using one’s smartphone. The natural contraction and relaxation of the heart cause minute changes in the human skin color. Yonathan and Daniel extracted those very small changes from the video, and from them – the subject’s pulse. Using this, they trained an AI system to recognize cardiac arrhythmia.
Fighting coronavirus with… ultrasound – Finally, Mor Ventura, Dekel Brav and Omri Magen, coming in fifth, tackled one of the challenges posed by the COVID-19 epidemic. Classification of the COVID-19 severity degree is usually done in hospitals using CT. However, CT machines’ availability is strained, they are expensive, and the process is further complicated by the need to transfer a patient with a highly contagious disease to and from the machine. Mor and Omri explored the possibility of using lung ultrasound instead, obtaining the necessary diagnostic information faster and more easily at the patient’s bedside, also significantly reducing the workload in healthcare facilities. To this end, they first developed an image-processing algorithm to “read” and label lung ultrasounds, identifying areas of interest and ignoring artefacts. Using the results of this algorithm, the trio then trained a neural network to classify the ultrasound videos and identify the severity of the patient’s illness. The project was conducted in collaboration with the Tel Aviv Sourasky Medical Center.
Award-winning FemTech startup – Asaf Licht and Zeinat Awwad presented the entrepreneurship project. Just finishing their bachelor’s degree, the two have already turned their project into a startup called Harmony. Their project is a FemTech initiative, developing a wearable, continuous, and non-invasive tracker to monitor women’s hormonal levels, aiming to ease the process of IVF, but also relevant for avoiding pregnancy, or alternatively for increasing the chances of getting pregnant. Currently, IVF procedures requires a blood test multiple times a week; Harmony seeks to replace that with an at-home device that provides continuous measurements while reducing discomfort. This project won first place in the EuroTech Innovation Day startup competition.
To read about additional student projects recently presented at the Technion, click here
Could New Findings Explain Age-old Mystery, and Improve Use of Hematite to Split H2O Via Solar Energy?
Energy & Environmental Science has reported a scientific breakthrough in the study of hematite, an important and promising material in the conversion of solar energy into hydrogen through photoelectrochemical water splitting. The research project was headed by Professor Avner Rothschild of the Faculty of Materials Science and Engineering at the Technion – Israel Institute of Technology and Yifat Piekner, a doctoral student in the Nancy and Stephen Grand Technion Energy Program (GTEP).
The importance of solar energy to our lives is obvious. The sun transmits energy to Earth continuously, and if we are able to harness it for our needs, use of fossil fuels and pollutants such as petroleum and gas will no longer be necessary. The main challenge in switching to solar energy lies in the varying availability of sunlight as the day progresses and seasons change. Every place on earth experiences sunlight for a limited period during the day, but naturally, there is no sunlight at night. Since the electrical grid needs a stable power at all hours of the day and night, use of solar energy depends on our ability to store it so that we are able to use it at night and on overcast days. The problem is that the known form of electrical energy storage – batteries – is inapplicable when it comes to the supply of electricity for a city, a neighborhood, manufacturing site, etc. Moreover, the energy stored in batteries is adequate for a few hours, but batteries cannot provide a solution for long-term storage between seasons.
A possible solution to the storage problem is to convert solar energy into hydrogen using photoelectrochemical solar cells. These cells are similar to photovoltaic cells, which convert solar energy into electricity, but instead of producing electricity, they produce hydrogen using the electric power (current ´ voltage) generated in them. The power is used for photoelectrochemical water splitting – the use of sunlight energy to directly dissociate water molecules into hydrogen and oxygen.
The advantage of hydrogen over electricity lies in the fact that it easy to store and can be used when needed to generate electricity or for other requirements, such as to power FCEVs (fuel cell electric vehicles). In such cases, the fuel cell replaces the heavy, expensive batteries in Tesla cars and similar vehicles, and could also be used for residential and industrial heating, and the production of ammonia and other raw materials. The advantage of hydrogen as fuel is that its production and consumption do not involve greenhouse gas emissions, or any other emissions, other than oxygen and water.
One of the main challenges in photoelectrochemical cells is the development of efficient and stable photoelectrodes in a base or acid electrolyte, which is the chemical environment in which water can be efficiently split into hydrogen and oxygen. The photoelectrodes absorb the photons emitted by the sun, and use their energy to generate electronic charge carriers (electrons and holes, or missing electrons) that produce hydrogen and oxygen, respectively. Silicon, which is the semiconductor material used in photovoltaic cells, cannot serve as a photoelectrode of this kind, since it is unstable in an electrolyte.
This is the backdrop against which photoelectrochemical cells based on hematite photoelectrodes were developed. Hematite is an iron oxide that has a similar chemical composition to rust. Hematite is inexpensive, stable and nontoxic, and has properties that are suitable for water splitting. However, hematite also has its disadvantages, one of which is the gap between its theoretical energy yield and the yield achieved in practice in actual devices. For reasons that have not been clarified to date despite decades of research, the photon-to-hydrogen conversion efficiency in hematite-based devices is not even half of the theoretical limit for this material. By comparison, the conversion efficiency of photons in silicon solar cells is very close to the theoretical limit. In the present research, which extends and augments the findings recently published in Nature Materials, the research team headed by Prof. Rothschild puts forth an explanation for the mystery. It transpires that the photons absorbed by hematite produce localized electronic transitions that are “chained” to a specific atomic location in the hematite crystal, thus rendering them incapable of generating the electric current used for water splitting, i.e. the separation of water into its elements, hydrogen, and oxygen.
And now for the good news: Using a new analysis method developed by Yifat Piekner with the help of her research colleagues, Dr. David Ellis of the Technion and Dr. Daniel Grave, senior lecturer at Ben-Gurion University of the Negev, the following data were measured for the first time:
Quantum efficiency in the generation of mobile (productive) and localized (nonproductive) electronic transitions in a material as a result of photon absorption at different wavelengths
Electron-hole separation efficiency
This is the first time that these two properties (the first, optical in nature and the second, electrical) have been measured separately, whereas previous studies measured the combined effect of both properties together. Their separation allows for deeper understanding of the factors that influence the energy efficiency of materials for the conversion of solar energy into hydrogen or electricity.
Besides the achievement in terms of practical application, this is a scientific breakthrough that paves a new way for research into light-matter interaction in correlated electron materials.
The research study was sponsored by the Israel Science Foundation’s research center for photocatalysts and photoelectrodes for hydrogen production in the Petroleum Alternatives for Transportation Program, the Grand Technion Energy Program (GTEP) and the Russell Berrie Nanotechnology Institute (RBNI) at the Technion.
Click here for the paper in Energy & Environmental Science
The Shanghai Ranking, which ranks the world’s leading academic institutions, places Technion 94th in the world
Haifa, Israel – August 16, 2021 – The Technion is 94th on a list of the world’s top 100 universities, according to a report published yesterday by Shanghai Ranking, the world’s leading index for higher education. The Technion – Israel Institute of Technology is also on the top 50 list in two fields: aerospace engineering (16th place) and automation & control (46th place). In chemistry, the Technion ranks among the top 50-75 universities in the world. The Technion has consistently made the top 100 list of the Shanghai Ranking since 2012 (with one exception in 2020).
“The Technion is one of the world’s leading universities, and we will continue to invest efforts and resources to maintain this position for years to come,” said Technion President Prof. Uri Sivan. “The Technion’s strength lies in its excellent human capital, which leads to numerous achievements and breakthroughs in research and teaching. This is the result of hard work and dedication by Technion faculty, deans, administrative staff, and management.”
Prof. Sivan added that the Technion’s listing on the Shanghai Ranking and other indices “is not a purpose on its own. Global academic competition is rapidly intensifying, and while many governments around the world are steadily increasing their investments in academia and research, Israeli universities rely almost entirely on donations, which are becoming increasingly difficult to get.”
According to Prof. Sivan, “in order for Israel to preserve its standing at the forefront of global research, and to ensure the nation’s security, as well as its academic and economic future, the government should significantly increase investment in research and teaching, as well as adopt a welcoming stance toward the absorption of foreign faculty and students.”
While Prof. Sivan is “pleased that the Technion is among the three Israeli academic institutions on the top 100 list, we must remember that without government support and globalization of our research institutions, it will be harder for us to maintain this position.”
The Shanghai Ranking, first published in 2003, categorizes academic institutions according to objective criteria, such as the number of Nobel Prize laureates and other prestigious awards; the number of scientific articles published in the leading journals Nature and Science; the number of times scientific articles published by university researchers have been quoted; and researchers who’ve been frequently quoted in academic journals, relative to their peers in the field.
The index looks at 1,800 universities, from which the top 1000 are selected. Leading the list are Harvard University, Stanford University, University of Cambridge, MIT and UC Berkeley.
Letter from Uri Sivan, President Technion – Israel Institute ofTechnology Click Here
Scientists find an effective solution for the centuries-old famous three-body problem in physics, and all related to a drunkard’s walk
The three-body problem is one of the oldest problems in physics: it concerns the motions of systems of three bodies – like the Sun, Earth, and the Moon – and how their orbits change and evolve due to their mutual gravity. The three-body problem has been a focus of scientific inquiry ever since Newton.
When one massive object comes close to another, their relative motion follows a trajectory dictated by their mutual gravitational attraction, but as they move along, and change their positions along their trajectories, the forces between them, which depend on their mutual positions, also change, which, in turn, affects their trajectory et cetera. For two bodies (e.g. like Earth moving around the Sun without the influence of other bodies), the orbit of the Earth would continue to follow a very specific curve, which can be accurately described mathematically (an ellipse). However, once one adds another object, the complex interactions lead to the three-body problem, namely, the system becomes chaotic and unpredictable, and one cannot simply specify the system evolution over long time-scales. Indeed, while this phenomenon has been known for over 400 years, ever since Newton and Kepler, a neat mathematical description for the three-body problem is still lacking.
In the past, physicists – including Newton himself – have tried to solve this so-called three-body problem; in 1889, King Oscar II of Sweden even offered a prize, in commemoration of his 60th birthday, to anybody who could provide a general solution. In the end, it was the French mathematician Henri Poincaré who won the competition. He ruined any hope for a full solution by proving that such interactions are chaotic, in the sense that the final outcome is essentially random; in fact, his finding opened a new scientific field of research, termed chaos theory.
The absence of a solution to the three-body problem means that scientists cannot predict what happens during a close interaction between a binary system (formed of two stars that orbit each other like Earth and the Sun) and a third star, except by simulating it on a computer, and following the evolution step-by-step. Such simulations show that when such an interaction occurs, it proceeds in two phases: first, a chaotic phase when all three bodies pull on each other violently, until one star is ejected far from the other two, which settle down to an ellipse. If the third star is on a bound orbit, it eventually comes back down towards the binary, whereupon the first phase ensues, once again. This triple dance ends when, in the second phase, one of the star escapes on an un-bound orbit, never to return.
In a paper accepted for publication in Physical Review X this month, Ph.D. student Yonadav Barry Ginat and Professor Hagai Perets of the Technion-Israel Institute of Technology used this randomness to provide a statistical solution to the entire two-phase process. Instead of predicting the actual outcome, they calculated the probability of any given outcome of each phase-1 interaction. While chaos implies that a complete solution is impossible, its random nature allows one to calculate the probability that a triple interaction ends in one particular way, rather than another. Then, the entire series of close approaches could be modeled by using a particular type of mathematics, known as the theory of random walks, sometimes called “drunkard’s walk.” The term got its name from mathematicians thinking about a drunk would walk, essentially of taking it to be a random process – with each step the drunk doesn’t realize where they are and takes the next step in some random direction. The triple system behaves, essentially, in the same way. After each close encounter, one of the stars is ejected randomly (but with the three stars collectively still conserving the overall energy and momentum of the system). One can think of the series of close encounters as a drunkard’s walk. Like a drunk’s step, a star is ejected randomly, comes back, and another (or the same star) is ejected to a likely different random direction (similar to another step taken by the drunk) and comes back, and so forth, until a star is completely ejected to never come back (and the drunk falls into a ditch).
Another way of thinking about this is to notice the similarities with how one would describe the weather. It also exhibits the same phenomenon of chaos the Poincaré discovered, and that is why the weather is so hard to predict. Meteorologists therefore have to recourse to probabilistic predictions (think about that time when a 70% chance of rain on your favorite weather application ended up as a glorious sunshine in reality). Moreover, to predict the weather in a week from now, meteorologists have to account for the probabilities of all possible types of weather in the intervening days, and only by composing them together can they get a proper long-term forecast.
What Ginat and Perets showed in their research was how this could be done for the three-body problem: they computed the probability of each phase-2 binary-single configuration (the probability of finding different energies, for example), and then composed all of the individual phases, using the theory of random walks, to find the final probability of any possible outcome, much like one would do to find long-term weather forecasts.
“We came up with the random walk model in 2017, when I was an undergraduate student,” said Mr. Ginat, “I took a course that Prof. Perets taught, and there I had to write an essay on the three-body problem. We didn’t publish it at the time, but when I started a Ph.D., we decided to expand the essay and publish it.”
The three-body problem was studied independently by various research groups in recent years, including Nicholas Stone of the Hebrew University in Jerusalem, collaborating with Nathan Leigh, then at the American Museum of Natural History, and Barak Kol, also of the Hebrew University. Now, with the current study by Ginat and Perets, the entire, multi-stage, three-body interaction is fully solved, statistically.
“This has important implications for our understanding of gravitational systems, and in particular in cases where many encounters between three stars occur, like in dense clusters of stars,” said Prof. Perets. “In such regions many exotic systems form through three-body encounters, leading to collisions between stars and compact objects like black holes, neutron stars and white dwarves, which also produce gravitational waves that have been first directly detected only in the last few years. The statistical solution could serve as an important step in modelling and predicting the formation of such systems.”
The random walk model can also do more: so far, studies of the three-body problem treat the individual stars as idealized point particles. In reality, of course, they are not, and their internal structure might affect their motion, for example, in tides. Tides on Earth are caused by the Moon and change the former’s shape slightly. Friction between the water and the rest of our planet dissipates some of the tidal energy as heat. Energy is conserved, however, so this heat must come from the Moon’s energy, in its motion about the Earth. Similarly for the three-body problem, tides can draw orbital energy out of the three-bodies’ motion.
“The random walk model accounts for such phenomena naturally,” said Mr. Ginat, “all you have to do is to remove the tidal heat from the total energy in each step, and then compose all the steps. We found that we were able to compute the outcome probabilities in this case, too.” As it turns out a drunkard’s walk can sometime shed light on some of the most fundamental questions in physics.
It has been 50 years since esteemed alumna, Aviva Goldenberg, graduated from the Technion’s Faculty of Architecture and Town Planning in 1971. This summer, a special reunion was organized in Israel for the graduates to celebrate this meaningful milestone.
Although Aviva was not able to attend the event, the Faculty has remained close to her heart over the past 50 years. Aviva and her husband, Dr. Andrew Goldenberg, are both accomplished entrepreneurs and avid supporters of Technion and the State of Israel. Aviva founded her own architectural firm while Andrew, a Technion grad from the Faculty of Electrical Engineering, is a renowned expert in the field of robotics whose career combined both academia (at the University of Toronto) and industry.
Responding to the reunion invitation, Aviva shared that she and Andrew had gratefully and proudly funded the newly established Dr. Andrew & Aviva Goldenberg Architecture Studio Pavilion at the Technion. The donation expresses their thanks and appreciation to the Technion for providing them both with tools for successful and rewarding careers. Moreover, the Technion is the place where the couple met for the first time in December 1967.
The news of the new building from their fellow Faculty graduate was warmly and excitedly received by Aviva’s classmates, who were thrilled that Israel’s future architects will be learning and working in a beautiful, state of the art facility.
In recognition of their outstanding commitment to the Technion, Aviva and Andrew were awarded honorary doctorates in 2018, and Andrew was recently appointed to the Technion’s International Board of Governors.
Technion’s graduating Computer Science students presented projects done in their last year
In a project fair held at the end of term, students graduating from the Henry and Marilyn Taub faculty of Computer Science presented their work. The faculty puts high value of independent work as part of a graduate’s training process, and the projects are the students’ opportunity to integrate everything they have learnt.
The students presented projects varied in the field of computer science they belong to and the subjects they chose to tackle. Some created mobile apps for different uses; some wrote programs to solve diverse problems; some delved into virtual reality; some built devices, delving into the evolving field of the Internet of Things.
Multiple projects focusing on the Internet of Things were led by Itai Dabran and supervised by Tom Sofer, Michael Mendelson Mints, Vladimir Parakhin and Alon Binder, and others.
Almog Algranti, Nadav Abayov, and Yarden Wolf, created air drums: using computer vision algorithms, their app detects the drumsticks in the user’s hands, and plays music as if the user were seated at a drum set, recognising both which drum is being struck, in what manner and with what force. “I play the piano, and recently got interested also in the drums,” Almog explained. “This was an opportunity for me to create a tool that would let me practice without the financial investment in a drum set, and without disturbing the neighbours.”
Suad Mansour, Sereen Diab and Aseel Khateeb, turned the nostalgic Icy Tower game into a sports app by attaching an exercise stepper. Now the game character would only move so long as the player kept moving. If the player stopped, the character would fall, resulting in a game-over. Like any sports app, the three girls’ project displays feedback about steps walked and calories burnt, as well as the game’s leaderboard. “As children, we played this game, it’s lots of fun” the three explained, “but it’s not very healthy to spend a long time by the computer, moving nothing but the arrow keys.”
Eliezer Alter, Barel Cohen Adiv and Eliad Ben Haiem, who all three live in the campus dorms, decided to smartify their clothesline. Equipped with a water sensor, a light sensor, and a tarp, their clothesline now unrolls the tarp over the clothes if it rains, folds the tarp back when the sun comes out, and even sends reminders to do the laundry when the weather promises to be fine.
Nadav Ashkenazi, Asaf Bialystok and Nathan Voldman constructed a dog that recognises its owner, follows him around, and barks at strangers. Ethan Baron, Ron Klaz and Snir Green’s spider recognises music and dances to the rhythm. Daniel Shkolnik, Omer Hemo and Mordechai Ben Harush created a queuing app for individual exercise machines at the gym.
All in all, students created projects that are interesting, sometimes useful, sometimes fun, all demonstrating implementation of diverse skills.
A considerable number of projects stood out for being purposely built to help the community. You can read about those here.
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