Getting the Physics Right in a Thriller

There’s a moment early in The Tempest Toss where a man stands in a Coast Guard cutter’s combat center and watches every screen go dark at once. Not flicker. Dark. I rewrote that scene more times than I want to admit, because the easy version was a lie. The easy version is the one you’ve seen in a dozen movies: a flash, a hum, and then nothing works, anywhere, forever, like somebody flipped a cosmic light switch. That’s not what happens. And the truth is stranger, faster, and a lot more frightening.

I’m a chemist by training. Georgia Tech, master’s degree, twenty-two years of nights and weekends spent checking my own work against people who actually built this hardware and lived through this history. So when I sat down to write a military thriller built around an electromagnetic pulse, I made myself one rule and refused to break it. If it’s in the book, it’s based on something real. Not “feels real.” Real. Sourced. Defensible.

That rule cost me sleep. It also, I think, made the book scarier.

What an EMP Actually Does

Here’s the part most writers skip, because it takes a paragraph instead of a sentence.

A high-altitude nuclear detonation doesn’t produce one pulse. It produces three, and they arrive at wildly different speeds. Engineers call them E1, E2, and E3. You can ignore E2 for storytelling purposes (it behaves a lot like lightning, and most systems are already built to shrug off lightning). The two that matter are the bookends.

E1 is the fast one. When the weapon goes off, gamma radiation strips electrons off atoms high in the atmosphere, and those electrons get whipped sideways by Earth’s magnetic field at better than ninety percent of the speed of light. That motion radiates a pulse that rises to its peak in roughly five nanoseconds. Five billionths of a second. It’s gone almost before it exists. But in that sliver of time it slams a huge voltage into anything that can carry current, and it does its damage by pushing electronics past the voltage they were built to survive. Your laptop, a radio, the flight computer in an aircraft. That’s the E1 reaching out and frying the delicate stuff faster than any surge protector can close.

Then there’s E3, and E3 is a different animal entirely. It’s slow. It lasts tens to hundreds of seconds and comes from the blast briefly shoving the Earth’s magnetic field out of shape. It behaves almost exactly like a severe geomagnetic storm, the kind the sun throws at us. E3 doesn’t care about your phone. It cares about long wires. It induces slow, brutal currents in power lines hundreds of miles long and cooks the giant transformers at the heart of the grid. Those transformers are custom-built, weigh as much as a house, and can take a year or more to replace.

So the honest picture is two threats, not one. A nanosecond knife that guts electronics, and a minute-long flood that drowns the grid. They threaten different things, on different timescales, for different reasons. There’s no excuse for getting the shape of it wrong.

Why Writers Get It Wrong

Mostly because the wrong version is convenient.

If an EMP is a magic off-switch, the writer gets to skip the hard questions. Everything dies, the hero is special, the plot proceeds. But real physics is full of inconvenient specifics. Cars don’t all die (many keep running, and the ones that stop don’t stop uniformly). The effect drops off with distance and geometry. Hardened military gear is hardened for a reason. A submarine, wrapped in steel and submerged in seawater, is a very different target than a cell tower on a ridgeline.

Those specifics feel like obstacles when you’re plotting. They’re not. They’re the gift. Every real constraint is a place where tension lives.

We actually have a real-world preview of all this. In July 1962 the United States detonated a 1.4-megaton warhead about 250 miles above the Pacific, a test called Starfish Prime. Eight hundred-plus miles away in Hawaii, the pulse knocked out streetlights, tripped burglar alarms, and damaged satellites in orbit. The effect was so much larger than the physicists predicted that it drove their own instruments off scale, which means they couldn’t even measure what they’d done. Think about that. The people who built the bomb underestimated it. That’s not a detail you’d dare invent. Reality already wrote a better scene than I could.

Accuracy Is the Scary Part

People assume getting the science right makes a thriller drier, more like a lecture. I’d argue the opposite, and I’ll stake the whole book on it.

Vague danger is forgettable. “Everything stopped working” is a shrug. But “the E1 already burned through the protection circuits, and now the slow wave is climbing the transmission lines toward transformers that take eighteen months to build” is a problem you can feel closing in. Specificity is what makes a threat land in the gut. The reader who senses you actually know how the thing works will follow you anywhere, because they trust you. Break that trust with one lazy, physics-defying beat and they’re gone, arms folded, watching for the next cheat.

This is why I spent twenty-two years on a single novel instead of cranking out three. I corresponded with people who served. I wrote to a former KGB general for the view from the other side, and I once wrote to Tom Clancy, because if you’re going to learn a craft you learn it from the people who set the bar. You can read more about that long stretch of research and the people who shaped it, and about how I built the operational details to match real procedure.

The discipline is simple to state and hard to live. Don’t break real physics for a plot beat. If the science won’t let your hero out of a corner, then the corner is the story, and you write your way out the way real people would: with limited information, bad options, and time running down. That’s not a constraint on the thriller. That’s the thriller.

The EMP at the center of The Tempest Toss isn’t a fantasy weapon. It’s a real category of threat, grounded in declassified tests and public commission findings, and I think that’s exactly what should keep you up at night. If you want the deeper case for why this particular danger isn’t science fiction, I made it in a separate piece on the real-world EMP threat. And if you want to see what twenty-two years of refusing to cheat the physics actually reads like, the novel itself is where the rule gets tested, scene by scene.

I kept the promise. Every page of it.