Imagine a grain of sand holding enough energy to demolish a city. It sounds impossible at first, but Einstein’s renowned equation, E = mc², proves that it’s possible. Have you ever thought to yourself, “What is mass?” You hear it often but what really is it? Mass isn’t just “weight or stuff”; it is frozen energy that is waiting to be released. If properly unleashed, even the tiniest amount of mass can create unimaginable destruction and there is no better example than the infamous atomic bomb, which comprises of a central core of plutonium or uranium (which is barely wider than a basketball) containing enough potential energy to ravage an entire city’s skyline in a single moment.
Before we move on, we must understand what Einstein’s formula actually means.
E = mc² looks simple at first, but it possesses a profound meaning: mass and energy are the same thing, but in different forms. “E” stands for energy, “m” is mass, and “c²” is the speed of light squared. You might wonder what relationship "c" has with "E" and "m," and you're right to think that, because neither do I nor probably anyone in the world have a full understanding of all dimensions of this formula. For every argument, there is a counter-argument, and so on and so forth. But if I were to talk about the fundamentals, the speed of light appears in E = mc² not because of light, but because c is the universe’s fundamental speed—the constant that connects space and time, and since mass and energy are two forms of the same thing (as mentioned earlier), c² is sort of the built-in conversion factor between them. The value of "c" is so large—300 million meters per second—that when you square it, you get a number so huge that even a tiny amount of mass turns into an exponential amount of energy. In a way, the formula means to say that every object around you is like a tightly compressed battery. You don’t notice the energy because the mass is locked inside the nucleus of atoms, but if that mass is ever converted, it releases energy on a scale that our everyday world never prepares us to imagine.
Now let us address the secret that lies within the nucleus, which has protons and neutrons that are packed tightly. When you fire a neutron at the nucleus of either the uranium-235 or plutonium-239 isotope (which is the core of the bomb), it splits into fragments, releasing a tremendous amount of energy. Along with the release of energy, more neutrons are also released. Each of those neutrons is fired at other surrounding nuclei, and the reaction multiplies exponentially, in a process known as Nuclear Fission. In milliseconds, billions of nuclei split up, producing a fireball hotter than the surface of the Sun. Consequently, a shockwave is released that can flatten buildings and spread deadly radiation. If we take Hiroshima as an example, 64 kilograms of uranium unleashed energy equivalent to that of 15 kilotons of TNT and the city was reduced to rubble.
What makes the physics so interesting and incredible is the comparison of the scale versus the size. The bomb’s core is small enough to fit in the palm of your hands, yet it has the capacity of releasing energy that’s comparable to a volcano. Engineers and scientists didn’t invent this process, rather they unlocked a feature of atomic nuclei that nature had hidden for a long time.
The deep truth we need to realize is that the atomic bomb isn’t just a weapon, it's a reminder of how little we know about our own world. Fission is one concept we managed to understand, but nature is full of other such concepts, locked behind doors we may never open. We’ve barely even begun to understand the different particles of the world. If such power can exist in a handful of atoms, imagine what else lies in nature, still undiscovered and unimaginable.
