We all love a movie about a mad scientist that creates the means to end humanity, posthaste. James Bond, for example, has faced a long line of literary megalomaniacs with apocalyptic designs.

The Star Wars Saga frequently entails a climax with selfless warriors swarming around a huge embodiment of a maligned, civilization-destroying power–“Starkiller Base” is the most current example in The Force Awakens.

Throughout much of history, humans have only been able to imagine that level of destructive power. Now, we live not with a singular, hulking manifestation of doomsday destruction, but instead, with a proliferating and compartmentalized technology that has a similar aim. The hydrogen bomb, as it’s termed in media, could truly end human civilization or at least make those who survived a thermo-nuclear war wish humanity was finished.

It’s beyond anticlimactic to inform billions of humans that our civilization’s climax passed before most people on Earth in 2016 were even born. Oppenheimer indicated his suspicion that the apocalypse might be near when his team detonated the first “atom” bomb in a New Mexican desert. During a TV interview, he quoted an ancient Hindu text: “Now I am become death, the destroyer of worlds.”

It was, at the very least, an annoying grammatical construction. Originally written in Sanskrit, a nearly dead language, Oppenheimer would have struggled to find more apocalyptic words to usher in the nuclear age. Oppenheimer had the peculiar distinction of being a fluent reader of Sanskrit, so we should assume his translation is a good as it gets.

Oppenheimer didn’t trace his ancestry to South Asia–both of his parents were areligious Jewish-German immigrants to USA–but he was obviously intrigued by Vedic Theology. Oppenheimer’s statement was haunting. To make it easier for me to comprehend Oppenheimer’s words, I assume “become” is more of a noun than a verb making “become death” an embodiment as opposed to a process.

Oppenheimer was JV, or perhaps we should say a warm up for the main act, Edward Teller.

Teller was the principle progenitor of the Teller-Ulam configuration. Evidently, the process was first brainstormed by the famous nuclear physicist, Enrico Fermi. In the interest of keeping this explanation as simple as possible, let’s just say Teller-Ulam uses a fission bomb–media and popular culture like to call it an atom bomb–to trigger a larger fusion explosion.

The “hydrogen bomb” is an apt and precisely correct name. The fuel is hydrogen, the simplest atom. The process is challenging not in its complication, but in the energy necessary to light the fuse, so to speak. Without the mastery of fission weaponry, fusion bombs are impossible–until we have an alternative to Tellar-Ulam. To create a hydrogen bomb, just “push” a bunch of hydrogen nuclei together to form half as many helium atoms. Helium is the second simplest atom.

USA detonated Ivy Mike, the first hydrogen bomb, on November 1, 1952 near the Marshall islands.

To say Ivy Mike had a ten megaton yield is meaningless to most. I might deepen your confusion if I were to say that’s the same as 10,000 kilotons. Let’s use a clarifying example: Little Boy, the fission bomb that destroyed Hiroshima was 15 kilotons.

Here is a video from the documentary Hiroshima that will put August 6, 1945 into a more humane perspective; it’s over eight minutes but worth the time investment.

Once again, to make it as simple as possible, Ivy Mike had the energy of nearly 667 Little Boys.

Why are fusion weapons (aka hydrogen bombs) so much more energetic than fission weapons (aka atom bombs)? It has to do with the peculiar nature of strong nuclear force and how it changes mass into energy under  certain circumstances…

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After Little Boy exploded 600 m (2000 ft) above Hiroshima, people in the 1940’s said “USA has the atom bomb.”

To call Little Boy an “atom” bomb wasn’t wrong but it’s not precise. Here’s a simple model of the atom with the fewest number of parts, Hydrogen.

The defining characteristic of Hydrogen is the single proton in the nucleus. Hydrogen has other isotopes–the same number of protons, different number of neutrons.

A nucleon can be a proton or a neutron. The nucleon number doesn’t affect the chemical properties of an atom; only the proton number can change how an atom interacts with other atoms. Most of the time, there are the same number of electrons “orbiting” as there are protons in the nucleus. The number of electrons determines how an atom reacts with other atoms. Essentially, chemistry is the study of how the electrons of different atoms interact. These atom interactions are commonly called chemical reactions.

Most bombs create energy from interactions between the electrons–chemical reactions–and since electrons are part of the atom: All bombs, are atom bombs.

What made Little Boy different from all the other bombs detonated throughout history? First off all, Little Boy was the second atom bomb. Trinity Test was first.

Of course, atoms were involved in the energy release during Trinity and Hiroshima, but virtually none came from electron interaction. The energy source was the nucleus.

Little Boy used a much larger atom than Hydrogen: Uranium-235 (Trinity used Plutonium, another atoms with a fissionable nucleus). Uranium’s proton number is 92; the 235 stands for the number of nucleons. If you take the number of protons and subtract it from the number of nucleons, it will give you the neutron number. Here’s a model of U-235. (This isn’t what U-235 really looks like; no one can say for certain because it’s so small that we’ll never be able to see it in the way we see a spherical collection of small balls.)

It’s somewhat correct to say the atom bomb gets its energy by splitting the atom. First of all, we split the nucleus; it’s true that the electrons end up coming along in the process, but what’s taking place with the electrons is irrelevant once we start tinkering with the nucleus. We don’t really split the nucleus either. The goal isn’t to break the nucleus apart like a rack of billiard balls. What we need to do is destabilize the nucleus so it falls apart. We destabilize the nucleus by facilitating a neutron absorption to a U-235 nucleus.

Protons have positive charge and neutrons are changeless. Like charges repel more strongly the closer they are to each other. In a nucleus, the protons are extremely close; they should accelerate away from each other, not maintain a tight, orderly arrangement. This is how we know there must be some other, attractive force in play. It’s called strong nuclear force (SNF). As the name indicates, SNF is quite strong: more than 100 times stronger than the repulsive forces between protons. As of now, SNF is the strongest force we know.

Adding a neutron creates U-236, an unstable nucleus that falls apart quickly. U-236 is unstable because repulsion between protons briefly gains an advantage over the SNF binding all nucleons; this drives the nucleus apart and into smaller, stabler fragments. Energy is released because the new particles move away with relatively more kinetic energy.

The explanation for where the energy comes from is abstract. SNF is so strong, and peculiar in nature, that it can change mass into energy, or energy into mass depending on the arrangement of the nucleons and the type of nuclei they form. The fission of U-236 causes a nuclear rearrangement that releases energy.

The fission byproducts are often unstable, radioactive. The squiggly arrows with a greek letter gamma at the heads represent gamma decay–one of three types of radioactivity. It’s these byproducts that create the infamous radiation sickness long after the blast fades.

The fission of a single nucleus doesn’t produce much energy. But if each neutron flying away from a preceding fission finds another U-235, there can be a chain reaction.

There were over a billion-trillion U-235 nuclei in Little Boy. Although each nucleus was part of an atom, it’s more precise to call Little Boy a nuclear bomb because the energy arises almost exclusively from the rearrangement of nucleons and the creation of smaller nuclei.

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