Weizmann Institute scientists - Tell me why!

A magnificent new Hebrew book in which Rehovot scientists answer questions about the world will soon appear in English.

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January 7, 2018 00:08
Madanei He’atid: Yeladim Shoalim: Madanei Machon Weizmann Lemada Onim (Scientists of the Future: Chi

Madanei He’atid: Yeladim Shoalim: Madanei Machon Weizmann Lemada Onim (Scientists of the Future: Children Ask, Scientists of the Weizmann Institute of Science Answer). (photo credit: Courtesy)

There seems to be no limit to the number of times children can ask “Why?” as they wonder about the fascinating world around them. Adults who retain this curiosity may be young at heart, but they don’t always have answers when asked to explain these mysteries.

Now a bevy of scientists at Rehovot’s Weizmann Institute of Science has taken up the challenge to provide explanations to 100 questions that youngsters of all ages may ask. They range from “Why do we kiss?” “Why do we forget?” and “Why do we have two nostrils?” to “Why should you never put a magnet near a computer drive?” “Why can’t I be in two places at one time?” and “Why don’t the many stars in the universe light up the night sky?” The magnificent 208-page, hardcover Hebrew-language book, published by Yedioth Books, provides the thoughtful questions and responses for all age groups.

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Not only do they provide explanations, but they also note what science does not yet understand on the topic.

And there is good news for English speakers, as the volume is being translated and is due to appear in that language in the spring. Titled Madanei He’atid: Yeladim Shoalim: Madanei Machon Weizmann Lemada Onim (Scientists of the Future: Children Ask, Scientists of the Weizmann Institute of Science Answer), it is priced at NIS 128, but discounts are available.

Some 19 writers who are experts in a wide variety of fields write their answers – each on a single page (or a little bit more). These are accompanied by humorous, colorful drawings by four illustrators; the excellent editor is Yivsam Azgad, the Weizmann Institute’s longtime spokesman and head of its publications and media relations department.

HERE IS a sample of some of the many interesting Q&As in the volume:
Why do we have so many facial expressions?
Prof. Rafael Malach of the institute’s neurobiology department explains that facial expressions tell others what we are thinking and feeling without saying a word. There are other creatures that send messages through movement of muscles under the skin – especially mammals like monkeys that speedily warn or transmit good news to their peers without wasting time on making a sound. Humans have a limited repertoire of expressions such as joy, sadness, anger, fear, surprise, disgust and shame, that are similar in different cultures around the world.

However, he continues, over the course of human development, such expressions took on new roles, and scientists discovered that certain brain regions “specialize” in identifying and deciphering their messages.

Weizmann scientists found very sensitive mechanisms for identifying “faces” and even helping one person who sees fear reflected on a face to understand what triggered that emotion.

Among the things that are not clear are whether we are born with the ability to show feelings through facial expressions or whether we learn it from our parents and grandparents and how brain mechanisms can identify facial expressions that are not natural, such as Emoji ideograms.

Why do we kiss?
Almost every person in the world kisses and even animal primates do it: mother monkeys chew food and transfer it to their babies in a kind of kiss. There are kisses of love for a mate, between parents and children and others, but in all, we express different wordless messages. Prof. Gil Levkowitz of the molecular cell biology department says that when we kiss, our bodies produce a special hormone named oxytocin that is transmitted to the brain and makes us feel safe, calm and happy and to cooperate with the person we kiss.

Why do we get bored?
In the process of evolution, explains Prof. Rony Paz of the neurobiology department, whoever is more bored has a bigger advantage, as do his offspring. This is because boredom made people look for new things and creative solutions that eventually allow them to overcome difficulties and develop further.

Our ancestors who lived in the caves, were affected by various diseases, Paz continues. “But those who were bored went on trips and found new, healthier and better places to hide. And so, in fact, our brain rewards us with a good feeling when – as a result of boredom – we go out to discover new things. But scientists still do not understand whether, when and how the brain halts boredom so that we do not seek challenges that are too risky.

Why can’t one be in two places at the same time?
This is an odd question, because it’s clearly impossible. But Prof. Roee Ozeri of the department of physics of complex systems writes that if we dwell on the question, this answer is not at all clear. True, every person has a precise and exact place in the world, but there are things that do exist in several places at once, such as waves in the sea that spread all over and are not in a single place. Similarly, small particles in a vacuum and are isolated from environmental influences can be found in several places at once.

Scientists who established quantum theory predicted this, and it has been proven in many experiments. But there is a fundamental difference between the waves in the sea and particles. The waves can be described as a wave, but also as a large collection of particles: water molecules, trapped air bubbles, small fishes, seaweed, sand and more.

On the other hand, scientists have proved the astonishing fact that even a single particle – an electron, a proton, a photon, an atom or even a molecule – behaves simultaneously as a particle that has a defined location and also as a wave that spreads. In other words, tiny particles can indeed be found in several places at the same time. But large objects, including humans, are too large, and therefore cannot do so, and are limited to living in one place at a time. So it is possible for tiny things but not large objects like human beings, Ozeri continues.

Yet scientists still are in the dark about exactly what is going on at the border between the world of large objects, where things can be in one place only, and the world of tiny particles, which can be found in several places at the same time.

Why can’t a cellphone receive calls in elevators? When you enter an elevator, which has a metallic lining, it’s not recommended to speak over your cellular phone. This is because the caller loses the signal from the cellular antenna outside. The device constantly measures the level of reception and when it declines, it boosts the power of its radiation to a higher level than that in which it can function. If you hold the phone to your head, says physicist Prof. Ron Naaman, you can feel it heating up because the metallic lining blocks radiowaves and has low resistance. This makes the electrons speed up and release radiation reflected by the metal that then slows down almost completely.

Why are there males and females in nature?
One of the great mysteries of the life sciences is why males exist in nature. After all, in most natural species, apart from mammals, females can do very well without males and bring offspring to the world by themselves, when the egg fertilizes itself asexually without the need for a sperm cell. Some species have very few males and other species have none at all.

Prof. Jeffrey Gerst of the molecular genetics department notes that about a billion and a half years ago, two different species were created by splitting one into two, as, for example, in tiny living organisms like yeast.

Usually, species reproduce by means of asexual reproduction, by duplicating themselves. But when the environment is challenging, with few nutrients, they split into two species that begin to look for each other and form genetic combinations with new traits.

Gerst and his team are investigating the mechanism of attraction and communication among yeast cells.

Sexual reproduction that occurs in yeast in stressful situations is not coincidental but is intended to enable better survival of the offspring. In fact, when sexual reproduction takes place, the offspring inherit traits that come from the mother as well as from the father, giving rise to new or different traits that may increase their ability to cope with the difficult environment.

But scientists are still puzzled by the processes that probably caused male creatures to lose their uterus and the females lost the ability to produce sperm.

Why do ants work on a team?
Those who cooperate with their species can more easily overcome difficulties and dangers, and humans and ants are the creatures who excel better than others in cooperation. For example, since all “working” ants in the nest are infertile and all of them want the queen ant to lay eggs from which larvae will develop later on into young larvae, this will also benefit the “working” ants; they cooperate to help their queen reproduce.

Physicist Dr. Ofer Feinerman and his team note that while some ants are looking for food, others are left behind to care for eggs and larvae or to build and maintain the tunnels in the nest or to protect their home and the queen.

Teamwork also allows ants to do things they can’t do on their own, such as carrying objects too heavy for a single ant to drag into the nest without help. But the physicists still don’t know why ants need a complicated “language” with some 100 “letters” when they can say what they have to using only a few of them.

Why doesn’t humanity build an elevator into space?
While those who built the ancient Tower of Babel ended badly, an elevator built toward the heavens is possible in principle. Prof. Ernesto Joselevich and colleagues in the nanotechnology department of materials, recall that at the end of the 19th century, a Russian scientist named Konstantin Tsiolkovsky suggested building a tower 36,000 kilometers high and made from a cable that would be dragged up using a weight at the other end using centrifugal force.

The idea has been discussed from time to time, but the main barrier to implementation is how to make such a cable resistant to such stress; until 1991, there was no material strong enough to withstand it. In that year, nanotubes of carbon 100 times stronger than steel but weighing only a sixth of that compound were discovered. While the Weizmann scientists are not planning an ambitious project like a space elevator, they are working on various engineering applications for nanotubes. But they still don’t know how to attach nanotubes together to create a cable whose strength relative to its width that would be like that of a single nanotube.

Why are we disgusted by the smell of feces?
We all wrinkle our noses with disgust when we counter the smell of feces; this reflex protects us. As feces may have many pathogens, we thus avoid contact with it. But is this reaction inborn, or were we taught to do this? Prof. Noam Sobel and his neurobiology team believe that regarding some odors as foul is part of our nature.

To test this hypothesis, they asked 150 experts to grade 160 smells as sweet, smoky, rotten and so on. After getting the answers, they ranked the odors from sweet and flowery to disgusting. They found that smells closer to each other on the ladder had a similar chemical structure and were able to predict in advance whether the odor was likable according to its structure. But they still don’t understand why women have a better sense of smell than men.

The final two pages of the book have what is probably the favorite question of the editor and the writers:

Why is it worthwhile to study sciences?
Dr. Liat Ben-David, director-general of the Davidson Institute, Weizmann’s science teaching arm, writes that people are very curious and get excited when they understand themselves and their surroundings. “We are proud when we can use our knowledge to make our lives better.”

Science, she continues, is the way to ask questions and answer them. Science raises hypotheses and investigates and examines whether they are correct or not through observation, experimentation, data, calculations and results. Many questions raise doubts about things that we took for granted and solves problems. This ability constantly improves our lives and is a good reason to continue.


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