Chapter 1: The Nature of Existential Risks

Initially, the chilling idea seemed feasible: detonating an atomic bomb underwater could yield a far more powerful explosion—this concept later evolved into the hydrogen bomb. Edward Teller, a key figure in these discussions, questioned the necessity of water in this scenario. What if air was used instead?

The principle was straightforward. When an atomic bomb detonates in a container filled with heavy water, it initiates a cascading explosive reaction. The bomb's energy forces hydrogen atoms in the water to collide, releasing bursts of energy with each collision, eventually resulting in a massive nuclear explosion.

This seemed manageable to scientists, provided the goal was merely to obliterate a city. However, Teller proposed a more radical idea: if heavy water could facilitate a hydrogen bomb, what about seawater? The oceans are abundant in hydrogen, making them vulnerable to a similar explosive reaction. Unlike the hydrogen bomb, though, the ocean's vastness would render any resulting chain reaction uncontrollable.

Could an underwater atomic detonation potentially unleash a cataclysmic chain reaction that would engulf the Earth in nuclear flames? This notion was alarming, but the situation could worsen. What if the bomb were detonated in the atmosphere, as Los Alamos scientists intended to do in six months?

Though the atmosphere contains minimal hydrogen, it is rich in nitrogen, which could also participate in a similar explosive chain reaction. As scientists prepared to ignite the first atomic bomb, Teller pondered whether they might inadvertently trigger a nitrogen-based chain reaction that would annihilate humanity and transform Earth into a miniature star.

This daunting prospect reached the upper echelons of the Manhattan Project, prompting scientists to investigate the risk. A notably titled paper, “Ignition of the Atmosphere With Nuclear Bombs,” concluded that such fears were negligible.

The physicists determined that igniting the atmosphere was implausible. The nitrogen in the air was too dispersed, and the bomb’s heat too insufficient. Six months later, the Trinity test proceeded as scheduled. The explosion in the atmosphere was controlled, the air remained intact, and the Earth was not consumed in flames.

Concerns that scientists might inadvertently bring about the world’s end have persisted beyond the era of nuclear weapons. Today, fewer people worry about igniting the atmosphere; instead, they fear black holes generated by powerful particle colliders or the emergence of unknown forms of matter that could devour the planet.

While many scientists view these fears as unfounded, one must ask: Are they truly baseless? What level of risk is tolerable when contemplating the potential for global destruction? Even as physicists assure us of the safety of their experiments, isn't the fundamental aim to uncover something unknown, potentially hazardous?

A portion of this anxiety stems from the perception that scientists are engaging in unnatural activities. Atomic bombs and particle colliders feel worlds apart from our daily experiences—and indeed they are. These experiments delve into extreme physics—but not unnatural phenomena.

An exploding nuclear device, even the most potent ever designed, releases only a fraction of the energy produced by the Sun. While particle colliders achieve high energies, even more powerful particles bombard our planet daily from deep space without any adverse effects—no black holes or strange matter materialize.

This rationale serves as a potent defense for physicists. Present-day experiments on Earth mirror occurrences that are already happening naturally elsewhere. The primary distinction lies in the controlled environments where we can closely monitor and analyze these events.

Even if some unforeseen physics were to manifest, creating bizarre particles, we can confidently assert that they wouldn't obliterate the planet. Naturally, this reasoning doesn't apply universally. The Sun—a self-sustaining nuclear reaction—offers little reassurance when arguing against similar occurrences on Earth.

For such scenarios, scientists must adopt an alternative approach. The potential for catastrophe must be evaluated based on established physics and what can be inferred about unknown physics. In the case of the atomic bomb, physicists had a reasonably clear understanding of nitrogen-based nuclear reactions.

From this knowledge, they could predict the aftermath of a detonation. Their calculations suggested that no alarming outcomes would ensue. Any nuclear reaction that did occur would quickly dissipate. A sustained chain reaction was deemed improbable.

However, what about the unknown variables? Physicists cannot presume to know every possible outcome. There was a minuscule chance that an unexpected nuclear reaction might occur. In such instances, the best scientists could do was estimate the likelihood of a catastrophic event.

This estimation relied on established physics and observable phenomena. For instance, in the span of four billion years, Earth's atmosphere has never exploded in a nuclear fireball. While this may seem self-evident, it underscores the atmosphere's inherent stability.

Moreover, we understand the properties of nitrogen and other atmospheric gases. Drawing from centuries of experimentation, we can set boundaries on what is feasible. Ultimately, in the case of the atomic bomb, scientists concluded that the odds of the atmosphere igniting were less than one in three million. Faced with the threat of Nazi domination, this was deemed acceptable by the Manhattan Project’s leadership.

Should we adopt a similar risk threshold for contemporary physics experiments? Some might argue that the benefits of the atomic bomb justified a higher risk level. However, while particle physics experiments may yield significant scientific advancements, they are unlikely to produce comparable benefits.

One extreme viewpoint posits that there should be no risk whatsoever. After all, annihilating the planet would be disastrous—not only would it eliminate every known living entity in the universe, but it would also erase our cultural heritage and thwart the existence of countless future generations.

Yet this perspective resembles a call for inaction. It is impossible to eradicate all risks. We navigate life aware of the slight chance of death every day. Furthermore, the world could end even without human interference—an asteroid might strike Earth, or a nearby supernova could erupt, bombarding the planet with radiation.

While these scenarios are improbable, they are not impossible. Some scientists argue that experiments should carry a lower risk than these natural threats. The likelihood of a civilization-ending asteroid is approximately one in one hundred million, which can serve as a benchmark.

At this rate, scientific experiments would scarcely increase the background risk we accept in daily life. Arguments exist for reducing this threshold—shouldn't we minimize risk to the greatest extent possible?—or for accepting a higher one—the odds are already very low. Ultimately, the level of acceptable risk is a societal decision.

Engaging in these discussions is beneficial. They compel scientists to contemplate potential failures and justify why risks should be undertaken. Governments and scientific organizations must accurately evaluate their experiments, balancing benefits against risks.

Transparent evaluations do not undermine science; rather, they fortify it and enhance public trust. The risk can never be eliminated—but neither are experiments devoid of merit. Over time, breakthroughs in fundamental science can enhance quality of life for all, as evidenced by the technological marvels of the computer age.

In the end, perhaps these assessments overlook the true dangers. The nuclear bomb's threat was not merely the risk of incinerating the atmosphere but rather the likelihood of their actual use to obliterate the world. The odds of that scenario appear significantly higher than one in three million.

The first video titled "7 Things That Could Destroy Earth" explores various catastrophic scenarios that could potentially lead to the end of our planet.

The second video, "How To Destroy The Earth In -10- AMAZING Ways," presents a thought-provoking look at imaginative and extreme methods that could theoretically bring about Earth's destruction.