2016: a fascinating scientific year

Planets, gravitational waves, viruses, bacteria, gene editing using advanced methods, restoration of the nervous system and climate change. The ten outstanding scientific studies and events of the past year

Science, it seems, is advancing faster and faster. Technologies that seemed imaginary until the last few years are becoming a reality before our eyes, for example removing cells from the body, genetically engineering them using an innovative method so that they attack cancer cells and returning them to the body. Another progress that we were privileged to witness is the connection of the nervous system to computers that allow paralyzed people to move their arms and legs, and amputees to operate robotic prostheses with the power of thought.

These are just examples of breakthrough technologies that made significant strides this year. They are joined by studies that shed new light on our world - from a look to the ends of the universe to a better understanding of life at the most basic level. The Davidson Institute for Science Education website system has selected the ten scientific studies and events of 2016, and they are summarized here.

Gravitational waves: a prediction that came true after 100 years

In his general theory of relativity published in 1916, Albert Einstein stated that the universe is a web of space-time, and that the gravity of different bodies distorts this web and causes heavy bodies to attract lighter bodies to them. One of the conclusions arising from the theory is that the movements of heavy bodies will produce gravitational waves, that is, tiny oscillations that will spread cyclically in space-time. For decades, scientists have been looking for evidence of the existence of such gravitational waves, but they are so weak that they have not been able to measure them even with the most sensitive detectors.

In February of this year, the LIGO detector in the United States announced First detection of waves Gravity. LIGO, a joint venture of 144 countries, is an interferometer - a device that measures tiny differences between two laser beams, sent in different directions. The rays travel in a vacuum tube 1,600 kilometers before returning to the detector. If a gravitational wave hits one of them, it increases the distance it travels by a tiny amount and thus the difference between the return times is created.

LIGO's report was an analysis of an event picked up a few months earlier at two detectors, one in Louisiana and the other in Washington state. The researchers concluded that the waves were created by the collision of two large black holes 1.3 billion years ago. Later in the year, scientists reported receiving several more events in the detector. At the same time, efforts are progressing Set up a detector of gravitational waves in space.

The detection of gravitational waves allows us to look into the universe in a way that was not possible until now, and to study phenomena in strong gravitational fields and in bodies that emit very little light, such as black holes or neutron stars. Physicists also hope that the detection of gravitational waves will finally allow creation unified theory which combines gravity with the other physical forces.

(see also: Gravitational waves: the most important discovery of 2016 according to the editors of Science magazine)

Video from MIT (Massachusetts Institute of Technology) about the LIGO detector and the discovery of gravitational waves (in English)

Zika virus

In 2016, Brazil hosted the Olympic Games in Rio de Janeiro. Many were afraid to reach the country and some athletes even canceled their participation in the games due to their fear of Zika virus. Zika fever, transmitted by striped Aedes mosquitoes, was already discovered in the middle of the 20th century in Africa, and later also in the South Pacific Ocean. It is usually a very mild fever, but the outbreak that began in Brazil at the end of 2015 was accompanied by another phenomenon - an increase in the number of births of babies with microcephaly, a syndrome characterized by a small head and developmental and intellectual disabilities.

Many studies done during the year strengthened the hypothesis that indeed There is a connection between the Zika virus and severe syndrome. However, it is still unclear why it causes the syndrome to appear almost exclusively in Brazil and not elsewhere, and how the virus creates this damage. Some Zika patients were also diagnosed in Israel, but There is currently no fear of the spread of the virus in the country. Efforts to develop a vaccine against the disease continue even now.

Warm, warming, whitening

The climate changes on Earth continue to give their signals in different ecosystems. New research shows that The air we breathe is more polluted (see also: The price of pollution - on the knowledge site) and that the concentration of carbon dioxide in the atmosphere is constantly increasing.

Many studies published in 2016 focused on changes in the marine environment, and especially on the phenomenon of coral bleaching. Although they don't look like it, corals are animals. They live in symbiosis with colorful algae, which give them a home and provide them with food. Stress conditions, especially the warming of the water, cause the algae to separate from the coral and as a result the coral bleaches and eventually dies.

A study published this year It found that almost all areas of the Great Barrier Reef off the coast of Australia had undergone bleaching to one degree or another, and in some places more than half the corals had died. The researchers estimate that recovery from this damage will take decades, and by then considerable damage will be done to the reef's biodiversity. (see also: The effect of warming on life in the sea – on the science website)

An opening to optimism comes from a study with the participation of Prof. Yossi Levia from Tel Aviv University. The researchers found out A species of algae resistant to high temperatures relatively. This acceleration is probably the reason why corals in the Red Sea and the Persian Gulf have been less affected by global warming than corals in other parts of the world. The researchers are still not sure if it is a separate species of algae that lives with corals, or more heat-resistant individuals that survived in these areas. In the meantime, there are also no answers to the questions of whether these algae will be able to help restore reefs in other areas, and whether they themselves will last if the water continues to warm at an increasing rate.

A colorful world is disappearing. A video (in English) about the coral bleaching in the Great Barrier Reef in Australia

the necessary minimum

The DNA of humans consists of approximately three billion base pairs, and more than 20 thousand different genes. to a bacterium E. coli There are only about five million base pairs, and about 4,0000 genes. to the smallest natural bacteria known to us, Mycoplasma genitalium, there are only about 580 thousand base pairs and 475 genes. Is this really the minimum number needed for life?

Craig Venter, who owns a research institute in California, and the institute's researchers tried to test this question by creating an artificial bacterium with as small a genome as possible. The researchers used a different species of mycoplasma, M. mycoides: They emptied the bacteria of genetic material, engineered its DNA in the laboratory and implanted the engineered DNA into it, each time missing other parts. Venter and his colleagues tested the survival of the bacteria in the various combinations, and in the end Engineered a bacterium known as Syn-3, And it has an extremely minimal genome: 531 thousand base pairs and 4733 genes.

The minimally engineered bacteria does survive in laboratory conditions, but it is unclear whether it will be able to survive in more hostile conditions. The genes found to be essential are mainly responsible for sugar metabolism and handling of the genetic material. The researchers still do not know the role of 149 of the bacterium's genes, which are almost a quarter of all its genes, and it is likely that they are essential in dealing with changes in the growing environment. The researchers hope to test this in follow-up studies, and find out what is really needed to live - at least at the genetic level.

The first artificial bacteria. A short article (in English) about the research of Craig Venter and his team

The fattening bacteria

While humans produce extremely thin bacteria, researchers at the Weizmann Institute of Science have discovered how bacteria produce extremely fat humans, especially after they are already thin. Dr. Eran Alinev and his colleagues discovered that diet changes the composition of our intestinal bacteria, and this change is probably one of the causes of repeated weight gain after effective weight reduction thanks to a change in diet.

The researchers saw that in mice that gained weight and lost weight again, antibiotic treatment that kills the intestinal bacteria reduced the re-obesity. Even when they implanted gut bacteria into mice devoid of such bacteria, mice that received bacteria from formerly obese mice gained more weight and had more diabetes.

The study by Alinev and his colleagues points out that flavonoids are most likely responsible for the phenomenon - substances that help the intestinal bacteria break down fat. In obese, or formerly obese mice, there are few flavonoids and therefore they have difficulty breaking down fat. The researchers showed that the addition of flavonoids helped the mice to moderate the recurrent obesity, and they now hope that the discovery will be the basis for developing a treatment that will help us lose weight and maintain our new weight.

The film of resistant bacteria

Another Israeli study on bacteria that caused a lot of buzz this year had a cinematic dimension. Prof. Roy Kishoni from the Technion and Harvard University Documented in an unusual way the development of antibiotic resistance in bacteria. The researchers used a huge Petri dish, which is a growth table measuring 120x60 cm. The concentration of the antibiotic at the edge of the substrate was relatively low, and it increased as you approached the center. In the middle of the table there was a concentration 1,000 times higher than at the edges.

The researchers sowed bacteria in the margins, and saw that when they consume the food at the current antibiotic concentration, mutants are created that can survive at the next concentration, and they spread to it. In just 12 days, bacteria resistant to the highest concentration were created, and photographic documentation of the scene made it possible to analyze the stages of the process.

On top of that, the researchers discovered that the most successful bacteria do not have the most efficient resistance mechanism, but rather those that acquire sufficient resistance the fastest. The research also revealed several previously unknown resistance genes, providing new insights into the possibilities of dealing with antibiotic-resistant bacteria, which kill more and more people every year.

The bacteria that live in the film. The video filmed by Kishoni and his colleagues with explanations about the acquisition of antibiotic resistance (Hebrew subtitles)

very close

The Centauri solar system is the closest to our sun, and is only about 4.25 light years away. It consists of three suns, A, B and Proxima. Proxima Centauri is a red dwarf - a small, pale sun, eight times lighter than our sun. In August 2016, researchers from the Southern European Observatory announced about Discovery of a planet in the sat region around Proxima Centauri, that is, at a distance from its sun that allows the presence of liquid water on its surface.

The existence of the planet, which is slightly larger than Earth, was discovered by precise measurements of its solar rotation. Slight deviations of the sun's rotation from its center of gravity indicate a body pulling it "out", and the calculations suggested that it is a planet that, according to its size, may be rocky, and that it orbits its sun once every 11.2 Earth days.

The discovery ignited the imagination of many, due to the potential for life only four and a quarter light years from us. However, it is still too early to celebrate: this planet has not yet been photographed, and we have no shred of evidence that there is indeed life there. We do not know what the prevailing conditions are on its surface, except for the calculated temperature - if there is water there, what is the intensity of the radiation, if the ground is solid and if it has an atmosphere.

Furthermore, while this planet is very close in cosmic terms, it is still very far in practical terms. Even the briefest conversation with intelligent beings who may be there will require many years - the question and the answer will make their way between the two planets for 8.5 years. A flight there in the fastest spaceships at our disposal would take about 70 thousand years. In the meantime, the scientists are satisfied with trying to look for evidence of the existence of life, such as signs of the presence of organic materials on the intriguing planet, and also with dreams of meeting its inhabitants.

(more on the subject on the science website - The Israeli astrophysicist's journey to Proxima Centauri - the plan is to launch a fleet of tiny spacecraft that will fly to Alpha Centauri within a reasonable time - 20 years and transmit findings from there)

A nice animated video (in English) explaining how the planet was discovered, what is known about it and what is not, and why it will be difficult to reach it

were cut in the edit

Just as we sometimes get sick because of bacteria or viruses that attack us, bacteria also have enemies, especially viruses, that infect them. We have an immune system that deals with the invaders, and bacteria have a system called CRISPR/Cas9. An invading virus integrates its genetic material into the bacteria's DNA, and when the CRISPR system detects such infected sequences it uses a protein called Cas9 and cuts them out. The discovery of the workings of this system in recent years has provided researchers with a precise tool for gene editing: a CRISPR sequence is created in the laboratory so that it recognizes a specific region of the genome and sticks to it, and then the protein cuts it out as desired.

In the past year there have been several developments in the use of CRISPR. in June First clinical trial approved in the United States In the treatment of cancer patients with the new method. The researchers remove cells from the immune system of patients with several types of cancer, edit their genes and return them to the patient's body. In editing, a gene for a protein that identifies the cancer cells is implanted in the cells and two others that may impair its effectiveness are removed. This experiment was less intended to test the effectiveness of the cancer treatment itself, and more to verify the safety of the method.

Researchers from Sweden and China reported this year that Successfully edited genes in human embryos in this method. They treated the embryos created in vitro and eventually destroyed them and did not implant them in the uterus, but reported that the embryos developed successfully the whole time. Most likely, in the coming years, CRISPR technology will become a central tool in various genetic therapies and personalized medicine, and more and more uses will emerge for it as a scientific research tool.

On the same subject - An interview for the science website of one of the developers of the CRISPR/Cas9 method Virginios Shikshinis from the University of Vilnius)

The robot inside us

Another scientific breakthrough this year came from the field known as "brain-machine interface". In an international study, researchers from the United States, Europe and China were able to restore the movement ability of monkeys whose leg was paralyzed due to spinal cord injury. The nerve fibers in the spinal cord cannot regenerate, but The researchers managed to create a bypass Using electrodes connected to the brain and transmitting the electrical signals of the motor activity to a chip implanted at the end of the monkeys' spine. A few days later, the monkeys were already able to walk on the paralyzed leg with the help of the new technology.

Researchers from the United States succeeded in another groundbreaking study To restore to amputees the sense of touch with their non-hands through precise stimulation of appropriate nerve cells. A good sense of touch is essential for effective operation of brain-controlled robotic arms. In recent years there have been several successes in activating such arms using electrodes implanted in the brains of amputees, and the current research provides the feedback that allows the hand to feed back to the brain information about the object it senses. In this way, the brain can adjust the strength of the grip, or the nature of the contact, and give the action a more human dimension.

These successes join several breakthroughs that have occurred in recent years, bringing us closer and closer to activating paralyzed limbs and connecting artificial limbs to our nervous system.

The monkeys are walking again thanks to the new technology. New Scientist video presenting the research

doing justice

Jupiter is the largest planet in the solar system, but very few spacecraft have passed by it, and only one of them entered orbit around it. until this year. In July 2016 The American spacecraft Juno entered orbit around Jupiter, after a five-year journey in space. It reached a distance of only a few thousand kilometers from the layer of clouds surrounding it and already provided spectacular images of the mysterious giant.

During a mission that should last two years, Juno is expected to decipher some of Jupiter's secrets, including the nature of the Great Red Spot - apparently a giant hurricane-like storm that has been raging for centuries, and try to find out if the gas giant also has a solid core. The team operating Juno's instruments includes two Israeli researchers - Dr. Roit Khaled from Tel Aviv University and Dr. Yohai Caspi from the Weizmann Institute of Science, who said when the spacecraft entered orbit: "Missions like this provide a unique opportunity to closely test the theories about Jupiter. We do not know what we will discover, and it is very possible that new questions will emerge following the findings. That's what's beautiful - that this mission will open new horizons for science."

New horizons for science. A spectacular video by the New York Times (in English) about Jupiter and the Juno mission