The dire lessons of the first nuclear bomb test

What's happening: Emerging technologies like synthetic biology and AI present new questions of control and new challenges to our future survival. Like the bomb, these technologies are a product of scientists doing what scientists do: advancing knowledge and making discoveries, with no way of fully predicting what they are bringing into the world.

• These technologies are also dual-use, meaning the same tools can be used for tremendous good and tremendous harm.
• And as they advance, they become easier to use for small groups and even individuals, something that has thankfully never been true of nuclear weapons.

Existential risk expert Nick Bostrom laid out the risks of these discoveries with a concept called "the vulnerable world hypothesis."

• Imagine if the Manhattan Project had discovered that nuclear bombs could be made with basic supplies, instead of expensive and hard-to-acquire radioactive materials. If anyone could make and wield a nuke easily, the world would likely not endure long.
• Bostrom's example is obviously counterfactual, but as synthetic biology advances, it may one day be as easy to engineer a deadly virus as it is now to program computer malware. Dangerous AI could eventually be unleashed — accidentally or on purpose — by a single company, or even a band of programmers.
• Should we reach such levels of technological development, Bostrom argues, we may hit a point where "civilization almost certainly gets devastated by default."

Flashback: At 5:29 a.m. on July 16, 1945, the first nuclear bomb was tested at Trinity Site, in a New Mexico desert valley called Jornada del Muerto, or Journey of the Dead.

• It was successful — far more successful than expected. Before the test, the scientists at the Manhattan Project had estimated the bomb — a 5-ton metal ball they referred to as "the Gadget" — would yield the explosive equivalent of between 700 and 5,000 tons of TNT. And that assumed it would work at all.
• In fact, after the blinding flash of light and that first awful mushroom cloud, observers discovered that Trinity's detonation force was equivalent to 20,000 tons of TNT, at a time when the most powerful conventional bomb in the U.S. arsenal was equivalent to 10 tons of TNT.
• For the authors of the bomb, "Trinity rapidly shifted their understanding of what they had made," nuclear historian Alex Wellerstein said on a recent podcast. "Many of these scientists were ecstatic about Trinity, but then they had a comedown when they realized what this thing would do if you used it on people."

The big picture: Even more than the Hiroshima bomb, which instantly killed some 80,000 when it was indeed used on people three weeks later, the Trinity test represents a hinge in history.

• For the first time, humans had the power to destroy themselves — and before that power was put in the hands of presidents and premiers, it was made possible by the work of some of the most brilliant scientists the world had ever seen.
• That is the lasting legacy of the Trinity test 75 years later: How do we control what science can produce when even scientists themselves can't always predict how their discoveries will be used?

The bottom line: We have to hope this generation of scientists is more cautious and more far-seeing than those of the Manhattan Project, many of whom turned against nuclear weapons only after they saw what they had done, when it was too late.

• The good news is that scientists in AI and synthetic biology are baking ethics directly into the practice of their work.
• Still, as Richard Rhodes wrote of Trinity's legacy in "The Making of the Atomic Bomb": "The scientific method doesn't filter for benevolence. Knowledge had consequences, not always intended, not always comfortable, not always welcome."

Editor's note: This story was corrected to reflect that the bomb itself weighed 5 tons, not 194 tons, which was the is the weight of steel container they were planning to use to contain the explosion, if needed.