Nuclear War: Why Public Awareness Still Matters – A Perspective from a Nuclear Physicist

In today’s interconnected and diplomatically mature global society, the possibility of a nuclear war seems remote. Thanks to peace treaties, regular nuclear disarmament discussions. Further, due to the global consensus on non-proliferation, the fear of such an event has faded from public memory. However, the existence of thousands of nuclear warheads (weapons) around the world means that the risk/probability—however unlikely—is never zero. Also the fear of such incidnece is presnet in the back of public mind, as it has happened in past. Just as we prepare for fire accidents, flood, famine, earthquakes, industrial accidents, chemical disasters, pandemics, and environmental degradation, we must stay informed about nuclear emergencies as well.

As a nuclear physicist involved in education and experimental research over the last more than thirty years, I feel a strong sense of responsibility to tell society (under Scientific Social Responsibility) understand this subject. Awareness is not just about preparing for worst-case scenarios; it’s about empowering people with scientific understanding and recognizing the many peaceful benefits of nuclear energy.

POWER OF ATOMIC NUCLEUS

What Is a Nuclear Explosion?

Let me start with what a nuclear explosion is. A nuclear explosion results in a massive release of energy caused by reactions within atomic nuclei. These reactions release an extensive amount of energy, governed by the fundamental equation from Albert Einstein’s theory of relativity: E = mc². This equation states that even a small amount of mass can be converted into a huge amount of energy. There are two main types of nuclear reactions used in nuclear weapons: fission and fusion. In fission, the nucleus of heavy atoms like uranium-235 or plutonium-239 split into smaller nuclei, releasing a large amount of energy and a few neutrons. However, in case of fusion, light nuclei such as hydrogen isotopes combine to form heavier nuclei, releasing even more energy. These processes can produce a blast with temperatures in the millions of degrees Celsius and energy equivalent to thousands or even millions of tons of TNT. I have alreday given details, in my earler blogs, about the substantial amount of energy relesead in the process of fissionand/or fusion of atomic nuclei.

How a Nuclear Explosion Affects the Environment and People

The effects of a nuclear explosion in any eventualities can be really catastrophic. After the nuclear explosion, first comes the blast that is a kind of severe wave, created by the rapid expansion of air heated by the explosion. It may cause destruction over several kilometers, fully damaging buildings, plantation, trees etc. This is a direct result of high-pressure shock waves traveling outward. This isone of the applications of basic mechanics and thermodynamics. Next is the thermal radiation, producing a huge structure of growing fireball that causes intense burns and ignites fires over large areas, whatver comes in the way. Here, the physics principles explain how radiant energy travels as electromagnetic waves, with the intensity floowing the inverse square law—meaning areas closer to the center of explosion receive far more energy or more damage. The non-ionizing radiation—mainly gamma rays and neutrons—penetrates deeply into the body and surroundings. These high-energy radiations break molecular bonds in cells, especially DNA, leading to both immediate radiation sickness and long-term side effects as a rsult of this.

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The Dangers of Fallout and Radioactive Decay

When a nuclear bomb explodes near the ground, it lifts particles of soil and debris into the atmosphere. These material particles on ground become radioactive and return to Earth as radioactive fallout. This leads to the contamination of water, soil, and air. This radioactive fallout continues to emit harmful nuclear radiations through a process called radioactive decay. All students learn about radioactive decay from class 10, and physics students understand that unstable nuclei release nuclear radiation in the form of alpha, beta, and gamma radiation as they transform into more stable forms. By emitting nuclear particles, radioactive elements move closer to the line of stability.

The radioactive decay of the source itself follows the exponential decay law. This means that the amount of radiation emitted reduces over time, as every radioactive material has a certain half-life. The half-life is the time it takes for half of the radioactive atoms to decay, so while radiation diminishes as time progresses, it does not stop instantly. Secondly, as gamma rays travel through materials such as concrete, lead, or even air, their intensity is further reduced following the Beer–Lambert Law, which describes how radiation is exponentially attenuated with increasing distance or shielding thickness. These principles help us understand how long individuals may need to shelter and how much shielding is required to reduce exposure to safe levels. Therefore, both time and physical barriers play critical roles in protecting against gamma radiation in the event of a nuclear incident.

What Can Common Citizens Do?

As a common citizen, in the event of a nuclear emergency, there are three key physics-based principles to remember: time, distance, and shielding. The less time you are exposed to radiation, the lower your risk. Increasing distance from the blast or fallout zone drastically reduces radiation exposure. Wow, thanks to the inverse square law of radiation, which means that radiation intensity decreases as the square of the distance from the source. Also, thicker shielding—such as concrete walls, underground basements, or lead barriers—can absorb or block radiation effectively. This principle is based on the interaction of radiation with matter, something studied extensively in experimental nuclear physics. As soon as an announcement in this regard is made by the government, people should immediately take shelter in a basement or the innermost room of a concrete building, close all windows and all doors to block any radioactive dust entering, and avoid going outside the house for at least 24 to 72 hours. It is important to follow official advisories. Washing with soap and water can remove radioactive material particles from the human body—a process known as decontamination. This results in less effect to the person.

Understanding Health Effects of Radiation

It is important to let the people know that nuclear radiation damages biological tissues by ionizing atoms and molecules within cells, provided an exessive exposure takes place. The severity of damage depends on the dose, duration, and type of radiation. High doses over short periods can cause acute radiation syndrome, while lower doses increase the long-term risk of cancer. In nuclear physics terminoly, we use the unit sievert (Sv) to measure radiation dose and assess risk. Tools like Geiger counters ( a very common detector) and dosimeters are used to monitor radiation, but even without such tools, basic awareness and following safety guidelines can save lives.

The Peaceful Uses of Nuclear Energy

While nuclear weapons are destructive, it’s important to remember that nuclear science has many peaceful and highly beneficial applications. In medicine, radiation is used for imaging (like PET and SPECT scans) and treating cancer through radiation therapy. In agriculture, it helps improve crop varieties, control pests, and preserve food through irradiation. In industry, nuclear techniques detect internal flaws in materials using non-destructive testing. And in electric power generation, nuclear reactors provide clean, reliable energy without releasing greenhouse gases. These applications rely on the same nuclear physics principles as nuclear weapons—but are the constructive applications of nuclear science. The nuclear chain reactions in a nuclear power plant are controlled using moderators and cadmium control rods to keep the process safe and stable, showing how nuclear energy can serve humanity. May be in one of my next blog I will try to elaboarte for general public, how the nuclear reactors are used to generate electricity.

The Role of Scientists and Educators

I have spoekn on many platforms and as a nuclear physicist working in the field of education, I strongly believe that scientists must act as bridges between complex science and public understanding. It's our duty to inform and engage citizens, dispel myths, and promote a balanced view of nuclear science. Just as we don’t fear electricity because of the risk of shocks, we shouldn’t fear nuclear energy—we must understand it and use it responsibly. There is also a strong case for collaboration between scientific institutions and regulatory bodies. Initiatives like a Memorandum of Understanding (MoU) between the Atomic Energy Institues and educational institutions/universities having a rich legacy of nuclear physics teaching and reserach could immensly help in creating awareness programs, workshops, and curriculum enhancements to build a more informed society at an early age of students.

A Call for Preparedness and Optimism

Our goal should always be to serve people. Life is a precious gift from God. It must be protected with care and respect. We should believe in the timeless Indian philosophy of "Vasudhaiva Kutumbakam"—the world is one family. "वसुधैव कुटुम्बकम्" (Vasudhaiva Kutumbakam) is a Sanskrit phrase which means "The world is one family." It reflects the idea that all living beings on Earth are interconnected and should be treated with kindness, respect, and compassion. This ancient Indian philosophy promotes the idea of universal brotherhood and peace, encouraging humanity to think beyond borders and work together for the common good of all. This idea encourages us to look beyond borders, to see all humanity as one, and to work together for peace and harmony. As nuclear physicists and educators, we have a duty. We must help people understand both the risks and the benefits of nuclear science. A nuclear war is very unlikely, but it is not impossible. If people are well-informed, they will remain calm, act wisely, and be safe in any emergency.

At the same time, we must celebrate the incredible contributions of nuclear energy to society. Nuclear science supports us in many ways—through advanced medical treatments, food preservation, cancer therapy, improved agriculture, safer industries, and clean electricity. It plays a vital role in sustainable development. Like electricity, nuclear energy is a powerful tool. What matters most is how we use it.

We need to stay alert, not afraid.Let us be informed, not misled.Let us prepare—not because we expect disaster, but because we care about peace, science, and human life. Together, with science in our hands and compassion in our hearts, we can build a safer, smarter, and kinder world.

Let us be informed—not misled. Let us prepare—not because we expect destruction, but because we value peace, science, and human life.

Prof. B. P. Singh, Experimental Nuclear Physicist and Educator, Department of Physics, Aligarh Muslim University: BPS – The Atomic Explorer