November 10 was World Science Day for Peace and Development, which the UN designates for highlighting the importance of science to society and to people’s daily lives. According to their official website (https://www.un.org/en/observances/world-science-day), the purpose of World Science Day is to
- “Strengthen public awareness of the role of science for peaceful and sustainable societies;
- Promote national and international solidarity for shared science between countries;
- Renew national and international commitment for the use of science for the benefit of societies;
- Draw attention to the challenges faced by science in raising support for the scientific endeavour.”
Making ordinary people, or citizens as they are referred to in this context, more aware of and more involved in the field of science and current scientific developments and issues is a fundamental theme of this day, championed by UNESCO (United Nations Educational, Scientific, and Cultural Organization). Science, along with it ever-present ally mathematics, is a way of knowing more about reality through original inquiry and investigation. It is good for everybody to learn as much scientific knowledge as they can and also to be involved in the original inquiry and investigation that produces such knowledge. Most people think of this activity as being something only for scientists, experts that specialize in this and have all the right tools. But just like there are professional athletes who specialize in activities like running and swimming, but every person can and should exercise and be involved in running and swimming to make themselves healthy, so every person can be involved in science, no matter what their role in life is. Science will also help a lot in shaping that role in life. Hence is the importance of the science-society interface.
What is also of critical importance, of course, is utilizing science for the right purposes. Science tells you how things are and how they can be. By itself, it doesn’t say how things should be and what we should do. It is up to us to act responsibly and use science for ends that make the world better (and be careful not to end the world with it). It helps that delving into science enables people to realize what they need to do and what is important.
The twentieth century is a long story of society learning about how ethics and science play out together. The devastation wrought by the world wars was made possible by major scientific advancements. Backlash against science for the same reason emerged during the Vietnam War, when students saw how scientists were contributing to the war effort, such as by developing the chemical defoliants destroying Indochina’s forests. But scientists also uncovered and drew attention to the effects of the war on Vietnam. It took scientific inquiry to understand the full impact of war. It has taken the same also to understand at all the toll that human activity is taking on the natural environment.
Now is a time when science’s role in society and society’s role in science is particularly relevant. The theme for this year’s World Science Day for Peace and Development is “Science for and with Society in dealing with the global pandemic”. The COVID-19 pandemic is such a major event, with an enigmatic cause and an extensive impact on the world and the lives of people, that scientific inquiry on a vast scale is needed to understand it. Plus, the world’s people have to play an outsized role in the response to the pandemic, which calls for dissemination of scientific education on an unprecedented scale.
In fact, scientific awareness is taking on elevated importance for numerous reasons. Due to a variety of factors, the world over the past year is enduring its biggest state of crisis since World War 2. During WW2, the urgent need for scientific expertise and awareness spurred tremendous advancements in numerous areas of science from nuclear physics to aerodynamics to oceanography to weather forecasting and many people got involved in scientific know-how (like the personnel who learned to operate telecommunication equipment during the war and then went on to make so many television sets upon return to civilian life). Now, there is again a need for a boost in science and, instead of using it to wage war against other people, we need it for the direct cause of bettering humanity’s lot and solving the world’s challenges. A whole lot of challenges, indeed, have popped up within the last year and we need science to understand them and to find solutions to them.
Just how much all those world issues need science, though, is up for assessment, if, indeed, science itself can be clearly defined. Some of today’s challenges, such as the dispute over the presidential election in America, the outbreak of war over Nagorno-Karabakh, or the economic downturns, do not seem like matters that can be related to science in any significant degree, at least science as we tend to think of it. It looks like other subjects on the classroom curriculum are needed instead. The word “science” can have different meanings. In past centuries, it used to mean just “knowledge” but now it is typically construed as, essentially, knowledge of the material world. That is the definition that will be used in this article. Some classify subjects like political science, social science, and economics (which are of immense importance for 2020 as well) as belonging to the realm of science, but for now, it is just going to be the two fields that define how reality fundamentally works, physics and chemistry, and the fields that study the natural world, the life sciences, Earth sciences, and astronomy, as well as the various subjects concerning all that humanity creates by its own prowess, what go under the general labels of technology and engineering.
All these areas of study strongly underpin recent global developments as a whole. And in particular, 2020 is a time in which disasters are breaking out across the world and new threats are emerging. Science is always needed in order to effectively manage such issues, so let us look at where science is crucial in today’s environment and how we can use it to grasp the crises that are swirling around us.
The coronavirus strain that scientists call SARS-CoV-2 is the supreme topic on the news. This infectious agent came to humanity’s notice only within the last year, so when the outbreak began, there was a lot that science did not know about it and the disease it causes. That still holds true, but only to a much lesser extent. Research is being conducted on COVID-19 on a grand scale and builds upon the vast amount of knowledge we have about infectious diseases, an area that cuts across a huge number of disciplines, most of which are part of the vast field of biology, the study of life.
Viruses, like the one that causes COVID-19, are not considered life-forms but are very much a part of the living world. Studying them is called virology. Viruses are an enigmatic part of our planet. They are tiny particles that transfer genetic material between different organisms and cells and use those cells to reproduce, often being the source of diseases in humans. The domain of viruses cuts into the very foundations of life, so we need to delve into the deepest secrets of life in order to truly understand the existence of viruses. Studying viral infections involves cell biology and molecular biology, which is a part of biochemistry. The battle between COVID-19 and the human body largely takes place at the molecular level, involving complex chemical interactions. To fight COVID-19, we need to know everything going on in this invisible and intricate realm, making biochemistry and molecular biology vital tools. We also need to create our own molecules and chemicals to fight the virus. That is where pharmacology comes in, the study of medical drugs and how they affect the human body.
Speaking of the human body, it is studied as anatomy, the study of how the human body is structured, and physiology, the study of how the human body functions. We need an intimate knowledge of the human body in order to study how people get sick with COVID-19, especially as the disease seems to affect the body from head to toe in various ways. But since it is mainly a respiratory disease, special focus has to be on pulmonology, the study of the human respiratory system. Even more important is immunology, the study of the human immune system, which is the mechanism by which the body fights COVID-19 and also is ironically often responsible for making the disease worse.
When it comes to how the pandemic itself works, how the virus spreads in the world, we need epidemiology, the study of the prevalence and spread of disease. It is a very complex field that incorporates a lot of disciplines. If you need to know how the virus inhabits the world, you really need to know the world. This pandemic is a time when we are being driven to really get to know more about ourselves, in fact, and it’s more than just our bodies. Human behavior is a fundamental factor in the pandemic and our chances of fighting it, so it is imperative to turn to the scientific disciplines that deal with this subject, which carry the labels of anthropology, psychology, or simply behavioral science.
Genetics, the science of heredity, is of overarching importance to this pandemic. The coronavirus exists purely as a genetic agent, being a gene-containing capsule that manipulates the reproductive system of cells. It also is capable of undergoing genetic mutations that change how it infects people, so we need to know if and how the virus is changing and the likelihood that will happen. Special focus is on molecular genetics, the study of the very molecules themselves (DNA and RNA) that govern the genetic process. We need genetics so that we can detect the virus and diagnose infections, track the spread of the virus (genetic tracing), and develop drugs and vaccines to fight the virus. Genetics describes what gives living things their existence, which is why it is of such broad usefulness, particularly as SARS-CoV-2 is one of the newest things to come into existence.
It will be extremely useful to know how that happened. The coronavirus almost certainly originated as a zoonosis, a pathogen switching from animals to humans. SARS-CoV-2 is believed to have come from an ancestor (or ancestors) that infected bat species in Asia and possibly jumped to pangolins as a reservoir host before making its way into people. This likely required a sudden genetic change that produced a new strain of the virus, what is call an antigenic shift. Zoology and ecology now come into the fold, as we need to know the animals that were the original hosts for the virus and how they transmitted it to humans. Did environmental degradation play a role in the pandemic’s origin? What are the disease dynamics in the wet markets that are theorized to be the coronavirus’s final source? Why is it that bats are host to a lot of viruses but manage to avoid getting sick all the time? Answers to these questions will help us not only with the current pandemic but future ones as well.
When it comes to finding solutions to the crisis and innovating our way out of the pandemic, biotechnology has a big role to potentially play here. Biology is just studying how life works, but biotechnology is manipulating life itself and altering how it works to achieve the outcome you want. One of the most radical examples we have achieved with the COVID-19 pandemic is the mRNA vaccine that is certain genes taken out of the coronavirus and injected into people’s bodies so their cells produce pieces of the virus. Biotechnology is a contentious field. There are many ethical questions that go into playing around with life. There are also the consequences that we may have to watch out for. Such issues may pop up with the coronavirus pandemic, now that the world is making its biggest forays into biotechnology yet.
There is just so much science that has to go into saving the world from COVID-19. For now, I will go no further than drawing attention to the insights we can gain just from this seemingly unassuming article in Bloomberg, Covid-19 Mutation in Denmark’s Mink is Danger Sign for Vaccines, https://www.bloomberg.com/opinion/articles/2020-11-12/covid-19-mutations-in-denmark-s-mink-is-danger-sign-for-vaccines?srnd=opinion.
It suggests that history is repeating itself in a short span of time. The pandemic is believed to have started when a coronavirus circulating in animals kept in Chinese wet markets mutated into a form that infects humans, SARS-CoV-2. Now, it seems that SARS-CoV-2 circulating in Danish-farmed minks has mutated into a different strain that again has jumped back to humans, which could potentially alter the course of the pandemic for the worse. Even if the new strain itself is not more contagious or virulent, just by being different, people who gained immunity to COVID-19 from prior infection may be infected again and the vaccines being developed right now may not work against the new strain. The entire pandemic may essentially start all over again. Furthermore, the more widespread the virus is circulating in the human population, the more likely that new strains will develop. With this insight, we can realize the importance of maintaining measures that flatten the curve until everyone can be vaccinated. To assess the threat of the coronavirus evolving, we have to understand how it all began in the virus’s original animal hosts, how Covid-19 reinfection works, the dynamics of the pandemic, and the inner workings of the virus’s genome.
Besides the pandemic, the next big plague of 2020 is of locusts. There are several outbreaks across the world of various locust species, but the most significant is the desert locust which is wiping out agricultural harvests in dozens of countries across Asia and Africa. This is just as complex a problem as the coronavirus. Entomology is the study of insects, of course, and locusts are unique animals to study. Locusts are certain kinds of grasshoppers that undergo a physiological change and then gather and migrate in giant swarms that can strip land bare of vegetation. They have what is called extreme phenotypic plasticity, allowing them to change into their swarming form through certain biochemical processes. This happens when favorable environmental conditions cause locusts to become more abundant and congregate more densely.
Locust invasions are primarily an ecological issue and ecology is a complex field that studies the relationship of living things with their environment. Biogeography is another designated field that cuts deep into the subject here. At the center of the matter are the locusts themselves and how their numbers can increase so much. We therefore need to study the population dynamics or population biology of these insects. Under the rubric of population ecology, it makes up the first tier of ecology and deals with how organisms of the same species interact with each other to influence the extent and location of the whole population. Locust swarming depends upon locusts breeding and interacting in dense formations. The next tier of ecology is community ecology, how all living organisms in an environment interact. Locust populations are determined to a large degree by the plants locusts eat, the animals locusts are eaten by, and the pathogens locusts are infected by. Finally, there is ecosystem ecology, an ecosystem being the sum of both all the living things in the environment and the non-living materials they interact with.
The Earth sciences therefore come into play in our study of environmental factors in locust abundance. We need to know the soil conditions involved, the science of which is called pedology, and the influence of the water cycle, which is called hydrology. Meteorology, the study of weather, is crucial to the fight against locust upsurges because weather conditions determine how and where locusts breed, how long they live, what they eat, and where they move. Weather events are always what trigger locust outbreaks. Weather forecasting helps us to forecast locust patterns.
And let’s not forget the individual locust that we have to get to know in order to combat it. There is quite a lot of science that has to go into this small animal alone. There is its anatomy and physiology. There is its biophysics, such as the aerodynamics of how it flies. There are the properties of its body, such as of its exoskeleton, for which material science comes into the fray. We need to know how its brain works and how its hormonal system works. There is its biochemistry. There is its behavior. We have to know its life cycle.
Applying pesticides is currently the main way to fight locusts, which depends upon using chemistry to find and produce the substances that most effectively kill locusts. This often has adverse environmental effects (and makes it unsafe to eat locusts in order to find relief from hunger) and we need to fully understand what those effects are, which requires comprehensive ecological analysis. But we can get smarter than just using brute force against locusts. All we may need to do is target the biochemical keys to their swarming phase. Recently, scientists studying migratory locusts found a pheromone that they emit in swarms that attracts other locusts (https://www.sciencealert.com/researchers-have-finally-worked-out-the-chemical-that-triggers-locust-swarms). This discovery might be used to lure locusts into areas where they can be killed or develop chemicals that shut off locust chemical receptors to the pheromone.
Also, instead of using manmade tools to control locust populations, we can enlist the help of other living things in locust habitats. This is called biological pest control and, to make it possible, we have to not only know the natural relationships between locusts and other wildlife but intricately study a wide range of living organisms to see what they can do, especially those endemic to the areas under the reach of locust species. That includes the vast regions across Africa and Asia that provide the maximum range for the desert locust. This means that extensive inroads into biogeography and community ecology need to be made to make possible the integration of locust control with the local ecosystems.
Extreme weather is responsible for 2020’s locust outbreaks, most notably that the strongest positive Indian Ocean dipole on record (that is when the western side of the Indian Ocean is very warm) delivered enough rainfall to East Africa near the end of 2019 to cause a surge in the desert locust outbreaks. And a lot of other major weather-related natural disasters have occurred in 2020, including the Australian bushfires caused by the same Indian Ocean dipole. Severe weather, in fact, is getting to be more rampant across the world than ever before in what is, without doubt, an escalation of the climate crisis. So, as usual, the science of climate change is of paramount importance for us.
Climatology is the science that deals with the Earth’s climate, the standard behavior of the world’s weather conditions. It studies why the climate is the way it is and how it can change. Meteorology is the study of weather, the dynamics of the Earth’s lower atmosphere. And also remember that atmospheric science is the study of the entire atmosphere, from the surface of Earth to the edge of outer space. These are some highly sophisticated scientific fields, as the Earth’s atmosphere is an extremely complex and highly dynamic system. Climatology incorporates not only the atmospheric sciences but also geology, hydrology, biology, and astronomy. When we factor in the influence of climate on the world, the whole picture gets a whole lot more complex. Regarding current climate change, we need to know if the climate is changing, what is causing it to change, and what this will lead to in the future.
We have to start with the basic physics and chemistry, especially of the greenhouse gases that are being emitted by human activity. Then we can understand how they capture the Sun’s warmth and how long they stay in the atmosphere. This is the greenhouse effect, which humans are enhancing by emitting gases in various ways. Some of these sources require scientific study to measure, such as emissions from agriculture and deforestation and, of course, positive feedback loops from global warming. Oceanography plays a big role in climate and weather science. Of the many ways that Earth systems interact in response to rising greenhouse gas emissions, one of the most important is how the oceans absorb most of the heat from the Sun, vastly dampening the impact of the greenhouse effect. Otherwise, emissions from human activity would have already fried the climate by now!
Many weather events this year are highly out of place compared to what has normally been observed in the past. That points to them being the result of climate change. But to be sure of that, we need attribution science, which assesses the probability that a weather event would not have played out the way it did had climate change not been happening. It is not a simple task. Basic meteorology alone is hard to fully grasp. But it has now become all the more important because of the rise in weather disasters.
Meteorology incorporates a lot of physics and some chemistry. It involves using fluid mechanics to study how the atmosphere and air behaves as a whole, the complicated and important role water plays in the atmosphere, thermodynamics and the way heat moves through and moves the atmosphere, electrodynamics and electrostatics and the very active role electricity plays in the atmosphere, the particulate matter in the atmosphere and its influence, the large variety of chemicals in the atmosphere and the big role many of them play (that includes the trace chemicals besides water, diatomic oxygen, and diatomic nitrogen), and how the atmosphere interacts with the Earth’s imposing surface. All this comes together to form a science that is mind-bogglingly complex. Chaos theory is often used to explain how weather works, or rather, how it is difficult to know the weather. Regardless, weather forecasting is the prime goal of meteorology.
The Indian Ocean Dipole, which caused Australia’s epic drought and heat, East Africa’s deluge, and the most active cyclone season the Arabian Sea has ever known in late 2019-early 2020, is an example of a climate oscillation, a system in which part of the climate regularly switches from one condition to the other. It is not very entirely known how climate oscillations happen and even less how they are changing in today’s world. Another oscillation to watch out for is the Pacific’s ENSO, which has a huge influence on the entire world. Right now, it is developing into a La Nina phase. We should be very concerned about where it is taking us, as the potential for further weather hazards across the world, which means we should be up on our weather forecasting as much as we can.
We also need to use scientific investigation to understand all the extreme and unusual weather events that already have occurred in recent months, discovering why and how they happened. This includes the incredibly unusual 2020 Atlantic hurricane season, the Saharan dust cloud that rolled across the Atlantic in June, the hole that opened in the ozone layer over the Arctic in March and April, the floods wreaking endless havoc across East Africa, the mounting droughts in the western and central United States, and the devastating monsoon floods that took place in various parts of Asia. We need to understand not just their impacts as the disasters many were but also their collective and long-term effect on the planet. By knowing all of this, we can build up a clearer picture of how the climate is changing and where it is taking us.
Of all the natural disasters ravaging the world this past year, wildfires stand out. Among several wildfire outbreaks of a scale rarely seen before, the most notable are the unprecedented bushfires in Australia, forest fires in California, and tundra fires in Siberia. Wildfires are complex phenomena very diverse in their form and behavior, as evident in what we have seen this year. Many of Siberia’s wildfires this summer sprang from “zombie” wildfires that were smoldering through the winter, the burning of peat and other organic matter buried underneath the tundra soil while everything may look normal above the surface, an astounding natural phenomenon indeed. In California, epic “dry lightning” storms, which are thunderstorms in which the lightning reaches the ground but the rain does not because they evaporated mid-air, were responsible for kick-starting many of the state’s massive blazes. And the Australia bushfires burnt through every habitat where there was ample vegetation, including places that typically don’t experience wildfires such as old-growth rainforests. All three fire mega-outbreaks created plumes of smoke that stretched across the planet.
A lot of ecological factors go into wildfires, which are the chemical combustion of vegetation and can spread to manmade infrastructure. This makes ecology, botany, and chemistry some of the most important fields regarding wildfires. There is very complicated physics involved as well. The science of wildfires will help us to predict wildfires, will help us to prevent and fight wildfires, and will help us to prepare for them. We have to know the factors, both meteorological and ecological, that enable wildfires, as well as the human involvement in wildfire risk. And we need to know the impact of wildfires on human infrastructure, the economy, and health. One of the important things to know about is wildfire smoke, which gets emitted into the atmosphere in large quantities and can wreak havoc on human health. We need chemistry to know what may be in the smoke emitted from fires of every kind and what happens to that smoke when it is in the air. When it gets to the human respiratory tract (and eyes), we have to break out everything we know about human physiology and health to figure out what the effect is on the human body in both the short-term and long-term.
Wildfires also have major consequences for the natural environment. They are often beneficial if they follow a natural pattern, which seems to now be a thing of the past everywhere, and many plants and animals have adapted to fire very well and actually benefit from them. But the wildfires the world has been having lately have been very ecologically harmful. This was especially the case with the vast bushfires of what is known as Australia’s 2019-2020 Black Summer. Reportedly, a billion animals (counting only mammals, birds, and reptiles, what scientists call amniotes) died and many species were driven closer to extinction. Australia’s wildlife is still on the long road to recovery. The Black Summer bushfires, one of the biggest ecological catastrophes in recent human history, are is a major lesson in ecological dynamics. Australia has some of the world’s most unique wildlife and ecosystems, which have long been adapted to frequent and widespread bushfires during the summer. But human influence, both directly and indirectly through climate change, is subjecting them to destructive changes, as these unprecedented bushfires have shown. How changes in Australia’s environment made the inferno possible and how the inferno changed Australia’s environment is a hugely complex subject for science.
Flooding is another very common disaster recently running rampant across the globe. Sudan has experienced its worst floods on record on the Nile, hurricanes have devastated the Caribbean region and the United States, a third of Bangladesh went underwater, East Africa has been endlessly flooded since October 2019, Vietnam is being wracked by monsoon floods and typhoons, and rivers in China such as the Yangtze turned into deluges so furious that the very Three Gorges Dam itself appeared to be under a significant risk of weakening and even collapse. The science of flooding events like these is complicated. It does not only deal with the flood or outbreak of floods itself but also where these floods fit within a longer-term pattern. That is something we should not lose sight of in 2020. These floods are happening all over the world now, but many of them have been a long time in the making and will leave behind changes that will last long after human recovery is finished. And floods are another natural hazard with a strong human influence.
Flooding, which is part of the water cycle, is typically the result of a meteorological phenomenon, usually intense precipitation or heat melting snow and ice. But a flood itself is not a weather event, any more than a river or a lake is a weather process. It is an event on the Earth’s surface in which land that was dry before is submerged by water. Floods are hydrological phenomena with strong geological, meteorological, and biological aspects, often artificial aspects as well, especially in the case of urban flooding. The study of flooding falls under the field of hydrology, which studies the immensely diverse role water occupies on our planet. This science hinges upon fluid dynamics (hydrodynamics in the case of water specifically), the study of how fluids such as liquids behave when moving and being subjected to forces. A mathematical understanding of fluid mechanics can help forecast the behavior of floods.
Precipitation is ultimately behind all flooding and studying precipitation processes, patterns, and levels helps us to forecast and chart floods. Water that evaporates into the atmosphere always comes back down, but a variety of factors determine when, how much, and in what way it does so, such as movement of air currents causing adiabatic temperature changes and condensation nuclei. Causes of flooding are usually prolonged rainfall, intense rainfall, melting snow and ice, rivers being jammed by debris, or embankments containing water bodies collapsing. The recipe for flooding is a lot of water coming into a certain area in a short amount of time, such as rainfall being more concentrated in time and space. This often means less water available for other places or times and so drought and flooding have a tendency to go hand in hand.
It is not just the water being delivered in the first place that determines flooding but also what happens to that water in its journey over the ground. Topography then is the prime factor in whether floods happen in any given location, how deep they are, and how fast they move. It concerns the shape of the land surface and orientation with respect to Earth’s gravity. Also important are soil hydraulic properties, as water doesn’t just move over the land but also seeps into sediment. The less the ground is able to absorb water, the more likely flooding is, such as when the soil had dried up before (another way drought and flood supplement each other). It is not just soil that soaks up large amounts of water. Vegetation cover does too and an area covered with a hefty quantity of live plant matter is less prone to giving rise to floods. Water that seeps into the soil gets soaked up by plant roots and is delivered to the leaves where they easily evaporate, a process called transpiration. This combined with evaporation directly from soil is termed evapotranspiration, the total loss of water from land to the air.
Water really shapes the planet and floods are one of its most powerful forces. It is a force that we must respect and understand using science. Regular riverine flooding, for example, actually safeguards against worst floods. When water spills from the riverbanks, the sediment it is carrying is deposited along the sides, building up a natural levee over time. Humans are now endeavoring to know everything they can about how natural processes like these work so that they can approach flood management and adaptation in a more sustainable manner. Technology can play along through the right scientific innovations, but we must be very careful in how we behave towards the natural balance of water. We have been doing a lot to disturb this balance with the result that floods have been getting worse in every which way.
A warming planet allows more water to evaporate and thereby precipitate. There are also getting to be more events in which precipitation comes down in narrow, short bursts. Higher temperatures are melting more snow and glaciers. Development of floodplains blocks the ability of water to drain away. Widespread deforestation removes much of a landscape’s ability to get rid of water. These factors are almost certainly at play in all the floods that have affected human lives in 2020.
Some of the most serious issues to come out of 2020’s floods concern the way China’s flooding put the stability of its innumerable dams under question. As river water levels rose to record-breaking heights, most dams in the flooded basins were seriously strained. Some of China’s small dams and dykes collapsed. Even China’s largest dam of all, the mighty Three Gorges Dam, ended up at the center of serious concerns. The reservoir behind the Three Gorges reached its full capacity at certain points and some experts voiced alarm over the possibility of the dam being weakened and even collapsing, based upon apparent deformations in the dam and weaknesses that some believe the dam has. Any threat to the structural integrity of the dam is a serious matter as the Three Gorges is the world’s largest hydroelectric dam and millions of people live along the river downstream, all of whom are at extreme risk if the dam is ever to suddenly fail.
So it is important to be cognizant of these issues with the Three Gorges and all the other dams in China and understand what happened to them in this summer’s flooding and what could possibly happen with extreme events like these. In particular, was the Three Gorges really at risk of collapse? These questions revolve around the field of mechanics. That includes knowledge of the material properties of the dams and of the behavior of the water they interact with, which fall under the fields of hydrodynamics and hydrostatics. The construction of dams is a matter of structural engineering, which is a branch of engineering that deals with non-moving structures. It also relies a great deal upon geotechnical engineering, which studies the relationship of a manmade structure with the natural environment it is set in and how to manipulate that environment to serve the structure’s purpose. In the case of dams, that is the ground a dam is built on and the water body it is built across. The mechanical physics surrounding how dams behave involves both dynamics, the movement of water through the dam’s spillways or over the dam and the dam’s interaction with water waves, and statics, the water pressure behind the dam and the stress and strain within the dam.
Issues surrounding dams have a major role in today’s world as humanity increasingly relies more and more upon dams. Indeed, another part of the world saw its own dam-related problem spring up in the summer of 2020 in the form of Ethiopia beginning to fill up the reservoir of the newly completed Grand Ethiopian Renaissance Dam (GERD). This hydroelectric dam, the largest in Africa, is expected to bring much-needed economic development to Ethiopia by providing electricity. But it is built on the Blue Nile, the main tributary to the Nile River that provides Egypt and Sudan with almost all the water they need. The completion of the GERD will therefore affect the downstream flow of the Nile in ways that can cause problems for these two nations, especially Egypt.
The Nile Basin begins with several tributaries in East Africa and ultimately runs through the Saharan Desert in the form of one great river, the Nile. This environment is highly prone to flooding and drought. The Grand Ethiopian Renaissance Dam was designed in part to fix such problems, but it won’t come without its downsides, the foremost of which, at least for now, is that the filling of the reservoir behind the dam will result in a period of time in which Sudan and Egypt receives reduced water flow, affecting agriculture and energy production. The discrepancy is so big that the filling period that Egypt desires is several years, rather much for Ethiopia’s patience. Egypt is also worried that Ethiopia will use the dam to hold back water in times of drought and that evaporation in the dam’s reservoir could reduce the overall downstream flow. This is a political dispute that stems from the natural environment and the workings of Earth’s water cycle. As important as diplomacy is, resolution of this issue greatly depends upon science, specifically knowledge of physics, engineering, hydrology, meteorology, and environmental science.
Egypt could make use of the reservoir behind its own Aswan Dam to compensate for losses. Also, as Egypt’s water availability is steadily decreasing over time, isn’t it best Ethiopia’s reservoir be filled as soon as possible before Egypt becomes too water-scarce? But Egypt, not wanting to deplete its water reserves, is adamant that the GERD reservoir be filled slowly, preferably during periods of above-average river flows. Incidentally, that is very much what happened since Ethiopia started filling the dam. Sudan’s Nile floods this August and September, caused by rainfall over Ethiopia, are the worst in recorded history, with the Nile reaching levels not seen in a century. Egypt was spared the floods as it sealed off the Aswan Dam. This could serve as an opportunity for Ethiopia to set the reservoir filling at maximum so that water quickly fills the reservoir while Sudan and Egypt would be protected from the floods and continue to have plenty of water. Is that really a possible advantage of the floods? In any case, the extreme flooding that followed the start of the dam’s filling has a big influence on GERD’s outlook. It has furthered the case that the dam will go a step further in taming the Nile waters if it is managed properly. In a changing climate, this role may expand in importance. But dams have a tremendous environmental impact that is not controllable. The building of the Aswan Dam and the Grand Ethiopian Renaissance Dam both mean the end of the historic sediment flow that built the Nile River Basin, for instance. Whatever the crises and boons at hand right now, the long-term impact of the GERD and the future evolution of the Nile is something that the nations of the region need to be concerned about.
One of the calamities of 2020 that most struck us on the TV screen was the August 4 Port of Beirut explosion. It was a terrible tragedy, killing more than 200 hundred people, injuring nearly 7,000, and rendering 300,000 homeless, wreaking havoc on the city of Beirut and worsening Lebanon’s long-running troubles. This disaster was caused by 2,700 tons of stored ammonium nitrate (used as fertilizer) detonating into one of the largest manmade non-nuclear explosions ever recorded. There is a lot of chemistry and physics that goes into this event; chemistry in the ammonium nitrate (NH4NO3), how it degraded into a volatile form during storage over several years, how exactly it ignited, and the substances it changed into such as toxic nitrogen dioxide (NO2); and physics in how the material expanded into a fireball and the kinetic energy this spread into the surrounding environment, mainly seismic waves in the ground, water waves in the sea, and the highly destructive blast wave in the air, and how this energy produced damage in the area. The scientific study of explosions is called blast physics and blast engineering is how this knowledge can be put to practical use, mostly for safety from explosions.
This science has been put to good use already in identifying the cause of the explosion, if you don’t trust Lebanon’s governmental authorities. Just by watching footage of the blast, physicists and chemists were able to assess that it was likely caused by ammonium nitrate by observing the color of the plume of smoke and estimating the detonation velocity. Scientific knowledge of the Lebanon blast will also help in safeguarding against future accidents of this kind everywhere. That will mostly fall upon the engineers and planners who apply expertise knowledge to enact policies to prevent explosions or to ensure that such explosions result in less harm. But it is also good for ordinary people to know about how explosions work so that they can take actions that maximize safety.
That can be even after the very detonation has happened. Many of the people that fell victim to the Lebanese blast were in the wrong spot at the wrong time. If they were not close enough that the shockwave got them, then they were close to an object or structure that fell on them or glass that shattered all over them. It seems that this kind of hazard comes too fast for anyone to react in time, but there is actually a warning sign that can be used. In videos of the explosion overcoming the city, you can see a brief thunderous rumble followed by the boom in which everything is destroyed. These are two longitudinal waves (like scaled-up sound) released by the explosion, one that is the seismic waves that travel through the ground and only shake things up and the other is the blast wave that travels through air and actually causes most of the damage. Since sound travels faster through solid ground than through gaseous air, the seismic waves travel ahead of the blast wave. People who can recognize this rumble for what it is and are quick-witted enough can immediately get away from hazards like windows or even just avert or cover their faces and eyes from glass panes before everything is shattered. It is impressive that scientific knowledge of how things work can go so far in getting you through extreme events, when ordinary experience is not enough.
Some of the threats that are currently emerging across the world are that of warfare and conflict. The year began with USA and Iran on the brink of war due to Qasem Suleimani’s killing. Now, war already broke out for real between Armenia and Azerbaijan and a new civil war has erupted in Ethiopia. Tensions are rising between Greece and Turkey, China and its neighbors, and with the aforementioned Nile River dispute, and tensions involving Iran have just reignited after Iran’s top nuclear scientist was assassinated. War is one of the world’s toughest problems. Its consequences are often hugely devastating and it tends to be extremely tricky and difficult to resolve. Let’s hope we can use diplomacy to defuse today’s hostilities, but it is important also to know, if war breaks out anywhere, what its effects will be and how to counteract it, which will require science. The innocent are often harmed by war without anyone intending it. It is always because of all the weaponry used in war and the damage inflicted on the human and natural environment.
Modern weaponry and tactics as used in all conflicts is the result of wide-ranging applications of science in what is termed technology, engineering, and applied sciences. The people who make and use these weapons already know a lot about the science involved. Those whose goal is to mitigate the scourge of war itself should know the same and should investigate fully the effects of war on the world. Because technology continues to rapidly advance nowadays, new war-related hazards are emerging all the time. Look at the Nagorno-Karabakh war, which featured extensive use of drone technology. It is a snapshot of the high-tech warfare that is increasing in availability and the new risks in the field that come with it, along with old problems such as the unexploded ordinance left behind by the Nagorno-Karabakh clash which make the former battlefield a continued danger zone. But some believe technological innovations can make war safer.
Moves towards a more belligerent world are evident in the world’s greatest military power as well, the United States. At the end of January 2020, the President authorized the use of landmines by the military, reversing a ban that was in effect for years. This sparked dismay across the world because landmines are one of the most harmful weapons of war. They can remain hidden in the ground permanently and maim and kill anyone who steps on them long after a conflict is over. But the Pentagon said it will pursue the use of “smart landmines” which can be remotely controlled, be activated and deactivated on command, and self-destruct after some time. These proposed innovations are part of a pattern many believe exists. Developments in technology have made war more destructive over the last two centuries, but now further technological innovations are promising to make war less destructive, like precision-guided missiles that can spare all except the enemy. It remains to be seen if such a promise will hold. Science holds most of the answers. We just have to use it properly. Designing weapons of the future which are effective and have minimal collateral impact will require sophisticated inroads into mechanical engineering, electronics, digital technology, computing, robotics, artificial intelligence, aeronautics, blast engineering, and ballistics.
We have to go far beyond just designing weapons. Hopefully, the landmines the US army might deploy will be reliably safe, but they have to be integrated with landmine clearance programs. Clearance of mines, IEDs, and unexploded ordnance is a major field in which a variety of techniques are pursued. Detection is the main challenge and science is being extensively utilized in this. Metal detectors, using electromagnetic induction, are a traditional method. Various advanced electromagnetic technologies are being developed in their place, like ground penetrating radar, sensitive thermography, hyperspectral imaging, electrical impedance tomography, and backscatter X-ray imaging. Acoustic and seismic waves can also be sent into the ground to listen for bombs. Abandoned bombs usually leak chemicals into the surroundings which researchers are seeking ways to detect, such as making use of fluorescence, piezoelectricity, electrochemistry, and spectroscopy. Some of the most advanced techniques are nuclear quadrupole resonance and neutron probing. But researchers are also turning to nature for help. Mammals, insects, plants, and bacteria have been considered in searching for the chemical signatures of bombs. Besides dogs, giant pouched rats and mongooses have been trained to detect explosives. Even bees have been trained to do so.
Even the ultimate weapon of war has been becoming ominously more relevant in the news nowadays, the nuclear bomb. In May and June this year, reports came out that the US president was requesting that testing of nuclear explosions, which the US has not done since 1992, be resumed in response to alleged Russian and Chinese tests. This and the landmine policy shift indicate that the US is moving towards getting ready for conventional warfare with other nations, instead of asymmetrical warfare like the Afghanistan war it is ending now. This means that the threat of nuclear warfare may be on the rise. Nuclear war is unthinkable. It would have a devastating impact on the world, even if done on a tactical level. Even if that does not happen, nuclear testing itself is an activity with very harmful consequences. In the US itself, there are many people suffering from health defects because of living downwind of test sites.
It is here that one of the world’s longest-running scientific issues come into play, that concerning nuclear technology, which is the manipulation of nuclear energy. Nuclear physics the study of the nucleus, which is composed of protons and neutrons and makes up almost all the mass of all atoms. Nuclear energy, based upon the equivalence of mass and energy (E=MC2), is the huge amount of energy in the nuclear bonds of protons and neutrons, which can be released by either splitting or combining atomic nuclei. It is easy for humans to do so with the atoms of some elements, like hydrogen and uranium, to the point that they can make nuclear chain reactions happen in a sudden explosion. When a nuclear bomb is detonated, a huge amount of energy in the form of electromagnetic radiation is released and makes the surrounding environment explode. Besides this huge blast, radioisotopes, which are radioactive atoms that continue to emit energy, are released. These have a very wide-ranging and long-lasting effect, being responsible for the radioactivity left behind. Radioisotopes released from nuclear testing in the 50s and 60s have spread all over the world and some of them have altered the bone chemistry of every human by getting into the human body and being treated by the cells as calcium.
A thorough scientific understanding of the effects of nuclear energy, not just of how to harness it, led to the end of nuclear testing by almost all countries. It is importance that awareness of this knowledge remains widespread among both decision makers and ordinary people. Even though nuclear physics has loomed large in the public imagination ever since the nuclear attack on Japan, misconceptions and a lot of understanding of how it actually works abound. The dangers and downsides of nuclear energy will only become a bigger issue as time goes on, even if the world becomes peaceful enough that nuclear warfare retreats into the shadows of our concerns, because of humanity’s increasing reliance on nuclear power. Controlling our use of nuclear energy is one of the greatest responsibilities of science.
So that is a rundown of some of the scientific issues of the present-day. The world is in a tumultuous state and most of us are going through a difficult time right now. All these challenges may seem to be overwhelming, but hopefully, you have learned a little bit about how a correct utilization of science enables us to go a long way in overcoming them and improving the lot of the world.
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