Could Oppenheimer’s Trinity test have wiped out humanity?

To mark the 29th anniversary of the Trinity test, UCL Physics & Astronomy Digital Student Ambassador Nishta Varma writes about the potential implications of the test, decades later.

The 16th of July marks the 79th anniversary of the Trinity test, the first successful detonation of a nuclear weapon. This test, led by J. Robert Oppenheimer and conducted in New Mexico, was so bright that it could be seen from Texas. And a fact that the recent 2023 movie ‘Oppenheimer’ glazed over was that the Trinity test had a radiation exposure level 10,000 times higher than the permitted safe level! In fact, there was a possibility that this test could’ve wiped out all of humanity.

While studying my High Energy Astrophysics course at UCL, we touched upon the two types of reactions governed by the nuclear force: nuclear fission and nuclear fusion. As their names suggest, fission is the process where one heavy atom (usually Uranium/Plutonium) interacts with a neutron and splits into two by-products releasing a huge amount of energy.

Fusion, on the other hand, is where two smaller atoms combine to form a larger one, also releasing tremendous energy. Since fusion involves forcing two atoms together, they need to overcome the interactive forces keeping them apart, which requires a lot of energy to kick things off.

The scientists working on the Trinity test had a pretty wild concern: they worried that the energy released from their fission test might be powerful enough to kick-start a fusion reaction in Earth's atmosphere. This could have sparked a chain reaction of nitrogen atoms fusing together, with the energy from one fusion sustaining another. Edward Teller, who later became known as the father of the hydrogen bomb, first proposed this theory. If his theory had been right, which it thankfully wasn’t, the explosion could have destroyed the atmosphere, leaving us with no oxygen and exposed to harmful radiation from the Sun, eventually ending all life on Earth. The scientists on the Manhattan project thoroughly investigated this concern, but ultimately decided the risk was too small, especially compared to the threat of Germany winning World War II.

Thankfully, their fears didn’t come true. Instead, the Trinity test marked a pivotal moment in history, kicking off the atomic age and changing the world forever. Today, we use nuclear fission and fusion in reactors to generate electricity. In fact, the London Geochronology Centre, which is accessible for UCL research students, actively studies Uranium and Thorium fission.

The world we live in today is a testament to groundbreaking advancements in science. The brilliant minds behind these discoveries navigated enormous risks with a lot of confidence in their studies. Today, nuclear fission and fusion are used in nuclear power plants to generate electricity. In fact, nuclear energy ranks second among sources of low-carbon energy. This shift highlights the dual-edged nature of scientific advancements; it can bring great innovations, altering the course of humanity forever, but it can also be very dangerous, reminding us that with great power comes even greater responsibility.

Author: Nishta Varma
Photo Credit: Creative Media Services