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I used to teach a class on the history of contemporary science (WW2-present) and I started the class with Trinity. There’s no other moment better.

We know how it turned out, but the people there waiting for the test did not know how it would turn out. The bomb might not have worked. Or it might have ignited a fusion reaction in the atmosphere and destroyed the world. Hans Bethe had sat down and done the calculations on that exact scenario and said it would not, but there was always the possibility of missing something. Enrico Fermi was offering bets on it on the day of the test, as a dark joke.

In the end it worked as expected; one of the most successful and horrifying experiments in the history of science.

Of all the photos from the test the one that struck me the most looking through them today was the photograph of the plutonium core being carried into the ranch house for assembly in a little heavy box. It’s a small thing, about the size of a grapefruit, although twice as dense as lead. It looked just like a sphere of any old metal, but it was something profoundly alien, made inside nuclear reactors. And it still is so strange to me that something that small has so much energy locked up inside and that, by imploding the little sphere just right, we can let the demon out.

Trinity is one of the pivotal moments in the history of our species and eighty years on we still don’t know what the eventual consequences of it will be. The bombs are still here waiting for us and they still pose all sorts of terrifying questions for the future that most people prefer not to think about.

My grandfather was a student of Kistiakowksy and worked on the simultaneity part of the firing unit and was present at the assembly of the bomb and to watch the detonation. He recounted being quite nervous that his contribution would fail (as it had a short while before the final test) and the test would be a dud, but no one involved seriously in the scientific and engineering part of the building of the bomb had serious doubts that it would work once the technical issues were overcome, and none of them worried that it would ignite the atmosphere, because they knew enough to know that was silly. They'd all been working on this and doing thousands (!) of tests for months or years at that point. During the test he was given what he called the "chicken switch" that could abort the test at the last moment, and he always said that his biggest worry had been that he would stupidly abort the test in a moment of panic (surely this was exactly why he was given the switch). He described the actual explosion as the most beautiful thing he saw in his life.

When one looks at the history one needs to remember that these were scientists and engineers who behaved as such. My grandfather, for example, was the sort of person who always loved blowing things up. He'd nearly blown up the family home as a kid when given a chemistry set ... and he studied chemistry because he liked blowing things up ... and he wrote a PhD thesis about the shock waves generated by blowing up a really big (conventional) bomb. It all gets dressed up as studying shock waves and so forth, but it's really kids blowing things up. They get caught up in the challenge of it. The consequences, political, moral and otherwise, are not forefront in the thinking of most. None of them are innocent, but some have misgivings or second thoughts. Others are more cynical and ambitious and even sinister. There are Oppenheimers and there are Tellers.

Funny enough Adam Savage just posted a youtube video about building a replica of the demon core and the box to hold it. https://www.youtube.com/watch?v=V1Y4UR8xqxA
> Or it might have ignited a fusion reaction in the atmosphere and destroyed the world

"The “near zero” chances Oppenheimer unnerves Groves with in-movie probably come from Manhattan Project physicist Arthur Compton, who told author Pearl S. Buck in a 1959 interview that they’d calculated the odds at “slightly less than one-in-three-million.” In 1975, Bethe denied that there had ever been a less-than-one-in-three-million chance of setting the atmosphere on fire, but the idea had already lodged itself in the public imagination."

https://www.inverse.com/science/did-oppenheimer-really-worry...

> Or it might have ignited a fusion reaction in the atmosphere and destroyed the world

Someone's got to explain to me how this was even remotely plausible.

We've had orders of magnitude more energetic events in earth's history that they would be aware of (dinosaur slaying asteroid for instance). These didn't manage to destroy the earth by turning the atmosphere into a fusion reactor. Surely they were aware of this.

So was the theory that neutrons are somehow special in a non-thermal way for causing fusion (not fission). And specifically that a concentrated neutron burst could somehow set off a chain reaction? And I guess that [edit: solar] neutrons weren't concentrated enough to cause this even at a detectable level?

Was it a single solid core that was imploded? I thought it was at least two non-critical-mass hemispheres, or more, that were smashed together by the conventional explosives/detonators, to create a critical mass.
Increasingly with more powerful and precise technology the relative danger of the bomb will decrease, to the point where the bombs will become meaningless. The stigma is too big, the blowback is too severe and we have countless other ways to pummel each other into oblivion with more finesse.
It was probably all pretty silly but there were a few probably-not-all-nutcases that were concerned about the LHC causing something horrible.
Do you mind linking the photo you mentioned? I’d love to see it if you are able to find it
Enjoyed this article, but was immediately distracted into another rabbit hole from the editor's note on the time zone, which I hadn't heard before:

> If you’d like to pinpoint the instant when the world entered the nuclear age, 5:29:45 a.m. Mountain War Time on 16 July 1945

So, I went digging because time zones have been a weird fascination for me due to dealing with all their annoyances as an engineer, and found this article from 2019 [0]!

From the article:

> In February 1942, Congress implemented a law instating a national daylight saving time to help conserve fuel and "promote national security and defense," which is why it was nicknamed "war time." The time zones were even known as that: Eastern War Time, Pacific War Time, etc.

[0] https://www.war.gov/News/Feature-Stories/story/Article/17791...

edit: grammar

Of course later they renamed it to Eastern Defense Time, Pacific Defense Time, etc. so we have EDT, PDT today.
That is so cool! Thanks for picking up on this and following through.
There is a heart breaking documentary about the people who live in the vicinity of the trinity test site, the lack of communication with them around the test, and the lack of recognition and support of their increased rates of cancer and medical spending [1]. I learned a lot from it. While many downwinders [2] gained recognition and compensation for their radiation exposure in the Radiation Exposure Compensation Act of 1990 [3], the population around the Trinity test site was excluded and has never been recognized or compensated for being the first victims of an atomic bomb.

[1] https://www.firstwebombednewmexico.com/ [2] https://en.wikipedia.org/wiki/Downwinders#Current_status [3] https://en.wikipedia.org/wiki/Radiation_Exposure_Compensatio...

The link [1] reads:

> On July 4, 2025, in a historic and unexpected move, Congress expanded RECA legislation, finally awarding overdue compensation to New Mexico families. Our newly revised film captures this emotional victory.

Were the families (at the very least) compensated to some extent at last?

I went and visited the Trinity site a bunch of years back during the open house day in October. They gave us a little pamphlet at the gate that said there was no radiation danger to worry about. Then we passed signs along the way to the site saying things like, "don't eat, don't drink, don't apply make-up, don't rub your eyes." The mixed messages didn't exactly inspire confidence.

You can see the few little bits of tower legs, what is left of the trinitite on the ground, and are surrounded by the enormous quiet of the empty desert all around you. It definitely felt like a haunted place. Not in the literal "there are ghosts here" way. Similar feeling to what I had at Dachau. Just very uncomfortable to be there.

I remember similar warnings from when I visited Chernobyl ~20 years ago. The ambient radiation exposure was not that different from the average flight, but there could be some actual risks if you accidentally ingest radioactive dust.
as a rockhounder i was recently introduced to the idea that each bomb dropped is given its own name for unique recombinations of matter(trinitite, hiroshimite, etc) and that for a while they let people just collect it and its in circulation in rock shops
One of my big gripes with the film Oppenheimer was the blast itself, obviously a climactic moment in the film.

It looked like someone set off a bunch of chemical explosives. That’s not how it looked in real life. Totally bizarre decision. I don’t know if they were trying to avoid effects on purpose of go gritty and retro or something but the “unearthly cosmic horror” feel of the first a-bomb blast is important. It’s what led Oppenheimer to recite “I am become death, destroyer of worlds.”

Because that's exactly what it was. I agree with you, the puritanism around special effects doesn't make sense when there's plenty of high quality archival footage out there, and instead of using that or CGI to look similar, you do something that looks completely wrong.
I felt the same, my thinking at the time was they didn’t want the bomb to steal the show. The movie was about the man not the machine.

/hah very articulate of me for this early in the morning

Yeah, Nolan's well known for practical effects - to the extent of actually driving a 747 into a warehouse! - but this is one spot where that approach failed hard.
I’m of a similar opinion, Lynch created a better depiction of it in twin peaks season 3.
With the films budget they could have sourced a small nuclear bomb the size of the original Trinity test and detonated it just for the movie. Just make sure the camera is rolling as it's a one take shot.
I'm never watching this movie again. The dead silence to 100dB boom was unreasonable, dangerous, and amateurish filmmaking. And not the least of which Atomic bombs aren't that loud.
> And physicist George Kistiakowsky found himself certain that “at the end of the world—in the last millisecond of the Earth’s existence—the last human will see what we saw.”

I highly doubt it. The last human will likely live many years in agony, fighting disease and starvation.

Or in a zoo refusing to mate.
I doubt it. I've ruminated a little on this and what I think is that as people start dying off, the survivors will find a rather pleasant existence before the end.

People start dying off, and all of a sudden housing prices go down. There's more parks open. The air feels fresher gradually. It's a gradual decline as human influence tapers off near the end. I think it will be more "The Last of Us" than "Mad Max"

Yes, but don’t be pedantic. Of course nuclear holocaust is more nuanced than that, but we was making a point as to the cause of the end of the world, not exactly how the last human will literally die.
Currently reading Command and Control after visiting the Titan missle silo I'm Tucson Az. If you're into Nuclear history check it out. https://en.wikipedia.org/wiki/Command_and_Control_%28book%29
There is an excellent three part documentary from Sandia National Labs:

"Always/Never: The Quest for Safety, Control, and Survivability." (part 1) https://www.youtube.com/watch?v=DQEB3LJ5psk

They cover both the technology itself and its history, including the incidents you are reading about. These people are the ones who developed the methodology and the technology for nuclear device safety, or at least a significant chunk of it. I think it has recently become much more mathematically heavy, with zero knowledge proofs and other fancy stuff used to talk to the locks in the devices.

What a coincidence, just yesterday Adam Savage made replica of demon core enclosure seen at: https://spectrum.ieee.org/media-library/black-and-white-phot...
Was actually almost a year ago https://x.com/DJSnM/status/1947293757612994886
What I find so strange about the awe and horror of the atom bomb, its utter power and violence, is how it was the result of decades - well, centuries - of abstract thinking in mathematics and theoretical physics. And how it required particularly new paradigms about the nature of the material world.

Imagine a cosmic being looking at the Earth through a microscope, and seeing this bubble pop on the surface in mid-20th century. Then another, and another pop. Some of them evaporated hundreds of thousands of human beings, melting and dying in gruesome ways you can't imagine in the worst nightmares of hell. Later these organisms learn to harness this destructive force for more useful and productive purposes, powering their cities and data centers for machine intelligence. And this massive amount of energy is released by breaking up the tiniest particles of matter, the nucleus of an atom, how clever and strange is that. Well, no more strange than the phenomenon of life itself, I suppose.

The really mad thing is that while you say it's centuries of abstract thinking and the like, it was only 50 years between the discovery of X-rays and radiation and the first atom bomb, or 40 between the first idea that you could use fission to make a bomb. Neutrons and the nuclear chain reaction was only theorized in the 30's, about 10-15 years before the first nuclear bomb was detonated.

But likewise, there was only a few decades between the first airplane and the first person on the moon (although rocketry goes back hundreds of years. Actually TIL rocketry is older than Newton's laws of physics)

Whenever I’m tempted to think that potential AGI/ASI scenarios sound “too sci-fi” I have to remind myself of this. We live in a world with nuclear weapons and spaceships and microwave ovens. It might prove impossible and it might not, but we can’t predict that based on a general vibe of sci-fi-ness.
At the end of the day.... everything we see and do is just the abstract result of potential energy being released in some form. What is an atom bomb other than an extreme form of this?

The survival of the human species relies on its ability to expend energy. Grow food? We need gas to run the tractors.

Travel to your jobs? Gas or electricity.

Travel to another planet? Massive amount of energy.

Ride away on a spacecraft to another solar system? Massive amount of energy.

The amount of energy required to do these things is probably more than the amount of energy required to erase ourselves from existence. And when we have the ability to harness that energy, do we really think we are responsible enough to not do that, accidentally or adversarial-y?

I have to remark how moved I was during the explosion scene of the Christopher Nolan's Oppenheimer film.

It had no music and actually (if I recall correctly) had no sound at all for what seemed like the longest time.

It really did make the extreme gravity of the event sink in very deeply.

Fully agree with libraryofbabel's comment here of it being "one of the most successful and horrifying experiments in the history of science".

The picture I find most meaningful it the one showing the back side of an instrumentation bunker with the foreground occupied by welders on skids with the broom and shovel in the dirt. Those things are essentially the same today even down to their construction. The way they are used is the same. Yet the world we live in is completely different.
Those units appear to be US Army PE-95 generators, not welders.

https://www.purplewave.com/auction/210310/item/IG9246/US_Arm...

I keep a small collection of nuclear testing-photography related books, looks like I'm going to have to add this one.
Would love to know your complete list. My copy of 100 SUNS has lived on my coffee table(s) for decades. https://www.michaellight.net/suns-intro
Been to the Trinity Site a few times. White Sands Missile Range opens it to the public twice a year. I've been there and seen very unusual people with cameras with massive zoom lenses looking at military stuff on the mountains and hills nearby. Totally nothing out of the ordinary with that.......
The rogue fissile material left in Iran sounds like an unoriginal plot device from the sketch "American Knights" in 2003-2005 satirical BBC cartoon Monkey Dust, and there are now reports the US intended to reinstall Mahmoud Ahmadinejad, for reasons hitherto unknown.
I suspect the actual first frames are still classified as they likely evidence detonator tech/performance. So the real first moments of the nuclear age will never be shown. (The high-speed cameras would have started filming shortly before the blast.)
Some stunning images, looks like a sun plopped down in the middle of the desert.
Were the founders of EG&G the ones charged with developing the technique to capture the photos?
We should get the AI to launch all of the world's nukes at one spot to make the biggest boom we possibly can to mark "world independence day." It would require a little blind trust on the part of a few different nations, but it would be talked about for generations. "Remember when the world blew up all the nukes in a singular huge explosion over Antarctica, grandpa?"