That's a real number. Here's the catch.

A picogram is a trillionth of a gram. Eighty of them wouldn't even register on the most sensitive ordinary lab balance. Yet if our best theory of particles is right, that tiny amount, placed in exactly the right way, could start a chain reaction that swallows galaxies.

First, a clarification. We're not talking about 80 picograms of some doomsday material. We're talking about 80 picograms' worth of energy. Einstein showed that mass and energy are two forms of the same thing, so every bit of energy has a weight. Here's the maths. It's the only equation you really need tonight:

7,200 joules is about the energy of five burning matches. 🔥 That's it. That's the whole budget.

So how could a few matches' worth of energy threaten the universe? Because it isn't a bomb. It's a trigger.

Drop a single match in a dry forest and it can set off a wildfire that releases a hundred trillion times more energy than the match ever held. The match didn't contain the fire. It unlocked it.

The 80 picograms are a handful of matches. The forest is empty space itself.

To see how empty space could "burn", we need to start with a surprising fact: empty space isn't empty.

Chapter 1

Empty space is hiding something

Take a box, remove every atom, every speck of light, everything. What's left isn't nothing. Space is filled with invisible fields. Think of a field as a setting that exists at every point in the universe, a bit like the temperature in a room, except it's built into space itself.

One of them is the Higgs field. Its setting is what gives electrons, quarks and other basic particles their mass. Without it, atoms couldn't hold together, and neither could you.

Everywhere in the universe, the Higgs field has settled into one calm, steady setting. Physicists call that resting state the vacuum. It's the ground floor of reality.

Here's the unsettling part. The rulebook can tell us whether our ground floor is really the bottom. The answer depends mostly on two measured numbers: the mass of the Higgs boson (125 GeV) and the mass of the top quark (about 173 GeV), the heaviest elementary particle we know of, nearly as heavy as an entire gold atom.

GeV is the energy unit particle physicists use. One GeV is roughly the energy locked inside the mass of a single proton.

Plug those two numbers in, and the answer comes out: probably not. Imagine every possible setting of the Higgs field laid out as a landscape, where height means energy. At extreme energies, around a hundred billion GeV, that landscape seems to tip over and slope down to somewhere much lower.

Picture a ball resting in a little dip on a hillside. It looks settled, and for now it is. But it isn't at the bottom. Just past a small bump, there's a far deeper valley. Try giving it a push 👇

A universe resting in a dip like this is in what physicists call a false vacuum. False, because it looks like the bottom but isn't. The deeper valley is the true vacuum. Physicists call our situation metastable: stable for now, but not forever.

If the Standard Model is the whole story, the measurements say that's where we live. (Whether it is the whole story is a big "if", and we'll come back to it at the end.)

Chapter 2

The universe's lottery

Nobody is pushing our universe. So how could it ever get over the bump? It doesn't have to climb. In the quantum world, things can do something that's impossible for a ball: pass straight through a barrier they don't have the energy to climb.

This is quantum tunnelling, and it's not science fiction. The Sun only shines because particles in its core tunnel through a barrier that should keep them apart. Your phone's memory chips rely on it too.

So every patch of space is, in effect, rolling dice, over and over, to see whether a tiny piece of it tunnels through. If one ever wins, a microscopic bubble of true vacuum appears inside our universe. Go ahead, roll:

You'll never win a roll, and neither will the universe, practically speaking. The chance of a win on any single roll works out to roughly:

1 in 10⁸³⁰

That's a 1 followed by 830 zeros. It's like winning the EuroMillions jackpot about 100 times in a row. Space is made of so many tiny patches, each rolling unimaginably fast, that over our whole visible past the universe has rolled more than 10²⁰⁰ times. That still isn't remotely enough.

Physicists have run the full calculation, and they sum it up as a lifetime of about 10¹⁶¹ years. That's the time over which you'd expect one bubble to appear somewhere in a patch of space 10¹⁶¹ light-years across. The patch that could ever reach us is unimaginably smaller, so the wait for a bubble that could actually touch us is far longer: well over 10⁶⁰⁰ years, by this page's extrapolation from the same calculation. (That calculation used a top quark mass of 173.1 GeV. The latest measurements come out slightly lighter, which makes the vacuum last even longer.) Here's what the age of the universe and that 10¹⁶¹-year lifetime look like written out:

Chapter 3

Once it starts, it never stops

Suppose a bubble does appear, by freak luck or on purpose. What happens next comes down to a simple tug of war.

The bubble's wall costs energy, like the skin of a soap bubble. Its inside pays energy back, because the true vacuum sits lower than ours. A small bubble is mostly wall, so the cost wins and it collapses. A big bubble is mostly inside, so the payoff wins and it grows.

A cube always beats a square eventually. Drag the bubble's size and watch where it tips:

Notice the shape of that curve: a hill with a peak. It's the same bump the ball had to get over in chapter 1, seen from a different angle. The top of the hill is the critical bubble.

Past the tipping size, every bit of growth pays for the next bit. Nothing ever needs to be added again. The released energy goes into shoving the wall outward. A bubble forced into existence, like the one in this story, is moving at 99% of the speed of light within about 10⁻³³ seconds (a billionth of a trillionth of a trillionth of a second). A naturally tunnelled bubble, tens of millions of times smaller, gets there in about 10⁻⁴¹ seconds. Either way, it keeps speeding up from there.

You would never see it coming. The wall arrives right behind its own light.

That's not poetry. Nothing outruns light, and the wall moves so close to light speed that the warning and the wall arrive practically together. There's no moment in between to notice anything.

What's actually inside

Saying the particles inside just get different masses would undersell it. Behind the wall, everything that makes our universe work changes at once, and none of it can be undone. It isn't an explosion that scatters things. It's a rewrite of what things are allowed to be.

What changes	Our universe	Inside the bubble
Higgs field setting	246 GeV	at least 10 billion GeV, likely far more
Electrons and quarks	light enough to build atoms	at least 10 million times heavier (electrons at least 40 million)
The weak force	strong enough to let the Sun burn	at least a million billion times weaker
Atoms and chemistry	everything you're made of	nothing we would recognise
Space itself	expanding, a little faster every year	caving in on itself
How long it lasts	13.8 billion years and counting	about 10−34 seconds

The Higgs field jumps. Its new setting is at least 40 million times higher than ours, and by the Standard Model's own numbers probably far higher still. Everything that gets its mass from the Higgs (electrons, quarks, and the particles that carry the weak force) gets heavier along with it. Electrons and the weak-force carriers go up by about the same factor. Quarks go up somewhat less, at least 10 million times, because how strongly they grip the Higgs field shifts at high energies.

The forces change. With its carriers that much heavier, the weak force becomes at least a million billion times feebler. That's the force behind the very first step of the Sun's fusion. And with electrons and quarks unrecognisably heavy, the chemistry we know has nothing left to work with.

Space itself caves in. Our vacuum holds a tiny amount of positive energy, which is why the universe's expansion is gently speeding up. The true vacuum holds an enormous amount of negative energy. In 1980, Sidney Coleman and Frank De Luccia worked out what that does: gravity pulls the inside of the bubble into a "big crunch". Using the Standard Model's numbers, each region collapses within about 10⁻³⁴ seconds of the wall reaching it (for a naturally tunnelled bubble, about 10⁻⁴⁰ seconds), while the wall itself keeps racing outward.

So there's no rebuilding afterwards. No matter clumping back into new stars, no strange new life billions of years later. Coleman and De Luccia noted that people could once take comfort in imagining the new vacuum might someday be home to something that could feel happiness. Then they closed the door: "This possibility has now been eliminated."

So could it have already happened?

If a bubble had swept through us, we wouldn't be here. But we can also check directly, and every clue says no.

We can measure our own vacuum. The Higgs field's setting (246 GeV), the mass of every known particle, and the gentle positive energy of empty space all match the dip, not the deep valley.

The universe also kept fossils. Helium forged in the first few minutes after the Big Bang, the pattern frozen into the cosmic microwave background 380,000 years later, and quasar light that left its source billions of years ago all obey the same physics we measure today. The quasar light alone pins one of nature's key constants to within a few parts per million. A bubble in between would have wiped out those records and crunched everything.

Physicists have also run the numbers directly. The chance that a bubble should already have formed anywhere in our visible past is about 1 in 10⁶⁰⁶.

Which leaves one question about a bubble born today: how far does "never stops" actually go?

Chapter 4

Why only 5%?

Even a wall racing at nearly light speed forever can't reach the whole universe. Space itself is stretching, and the stretching is speeding up.

Picture an ant crawling across a balloon while someone inflates it faster and faster. The ant reaches the nearby parts. The far side keeps pulling away faster than the ant can ever close the gap.

Light has the same problem. Across all of cosmic time, light only ever gets about 62.8 billion light-years of travel (measured in today's distances). Light that set out right after the Big Bang has used up 46.2 of them, which is why the observable universe, everything whose light has had time to reach us, is about 46 billion light-years in every direction. Light we send out today has only about 16.6 billion left.

A light-year is the distance light travels in a year: about 9.5 trillion kilometres.

A bubble wall rides just behind light, so it gets essentially the same budget. Point a torch 🔦 into space and follow the beam:

Given forever, the beam (and any bubble) stops gaining ground at about 16.6 billion light-years. That sounds like everything. But the observable universe stretches 46 billion light-years in every direction, and a sphere with a radius of 16.6 billion light-years holds only about 4.6% of its volume. Call it 5%. (That assumes dark energy, the push behind the speed-up, never changes. Measurements from 2025 and 2026 hint that it may be slowly weakening. If so, the limit would sit farther out and the 5% would grow. It's a hint, not a discovery.)

The other 95% is out of reach forever. Not because anything stops the wall, but because those galaxies are carried away too fast to catch. We can still see them. We just can never touch them. 🌌

Chapter 5

Making one on purpose

Nature almost never makes a bubble. What would it take to force one?

Instead of tunnelling through the bump, you'd push over it, like the ball in chapter 1. You'd need to build a critical bubble: one balanced right at the tipping point, so the slightest nudge sends it growing forever. Using the Standard Model's own numbers, this page estimates the recipe:

This is a rough estimate: the recipe comes from a published calculation, and this page plugs in today's measurements, including the full shape of the Higgs field's landscape. The true figure could be three or four times higher or lower, mostly because the top quark's mass and the strength of the strong force aren't known precisely enough.

Cheap energy, impossible place

A few matches' worth of energy is easy to find. The problem is where it has to go: into a spot about 3 × 10⁻²⁶ metres in radius.

How small is that? If a single proton were blown up to the size of the Earth, the bubble would be a grain of sand. Flip it around: if the bubble were a grain of sand, a single hydrogen atom would swallow the Sun and the inner planets, reaching past Mars into the asteroid belt. Zoom in and see for yourself:

And the full stop at the end of this sentence? It's about ten billion trillion times too big.

All at once, in perfect step

The energy also has to arrive within about 10⁻³⁴ seconds, the time it takes light to cross the bubble. If that instant were stretched to last one second, a real second would last about twenty million billion times the current age of the universe.

And it can't be heat or random smashing. It has to be a few thousand particles of the Higgs field itself, each carrying around a million times the energy of an entire collision at the world's biggest particle collider, all moving in perfect step. Picture a stadium crowd clapping randomly versus the same crowd clapping in perfect unison. Only the unison works.

Packed that tightly, the energy density is about 10⁸⁰ joules per cubic metre. The core of a neutron star, where a single teaspoon of matter weighs billions of tonnes, is about 10⁴⁵ times less dense.

Can you cheat a little?

What if you came up just short and let quantum luck cover the rest? Tunnelling can help, but the odds collapse brutally fast. Drag to see what each missing particle costs:

It's all or nothing, almost exactly. Short by just 1% and you might as well have done nothing.

Why smashing things together doesn't work

A particle collider. One collision at the Large Hadron Collider carries about 2 millionths of a joule, roughly the energy of a dozen flying mosquitoes. What makes it special is how tightly that energy is packed. The bubble needs about three billion collisions' worth of energy, in a spot a few million times smaller, as one coordinated object.

A cosmic ray. In 1991, a detector in Utah caught the most energetic particle ever seen, nicknamed the "Oh-My-God particle": a single atomic nucleus from space, perhaps a proton, hitting with the energy of a baseball thrown at 60 mph. But when a fast particle hits a still one, most of the energy stays locked up in motion. Only about 750,000 GeV was usable, roughly sixty million times too little. Particles like it have been colliding all over the universe for billions of years without ever making a bubble. They fall far short of what a bubble needs, but they do show that our colliders, far weaker still, can't start one.

Heat. Heat is random jiggling, the opposite of perfect unison. High temperatures actually make the bump taller.

A black hole. To make a black hole as small as the bubble, you'd need about 20 kilograms of mass-energy crammed into that spot: roughly the weight of a packed suitcase. The bubble needs only 80 picograms' worth. The difference is that a black hole forms from any energy in any arrangement, while the bubble needs one precise arrangement, and nobody knows how to build it. (One 2015 study suggested that tiny evaporating black holes might help seed bubbles; later work disputes it. Luckily, we can't make those either.)

Chapter 6

From a match to the end of the world

Now for what makes this story different from every other doomsday scenario. Let's rank the ways of releasing energy by one honest question: how much of the fuel's own weight turns into energy?

Thanks to E = mc², every gram of anything is packed with energy. Almost every reaction unlocks only a sliver of it. Climb the ladder one rung at a time 👇

Did you see the chart zoom out? Everything from a match to antimatter fits on one scale, and each rung is a climb you can picture. The bubble broke the scale so badly that everything below it got squashed flat against the floor.

Chapter 7

A number too big to feel

Antimatter is the most efficient fuel that actually exists. When it meets ordinary matter, both vanish completely into energy. That's the ceiling for anything that burns, splits, fuses or falls.

So how much more destructive, gram for gram, is the bubble than antimatter? Measured by what it destroys, about 4 × 10⁶⁴ times. A 4 with 64 zeros after it.

Your brain can't hold a number like that. So let's build it in layers:

Here's another way to feel it. To cause the same destruction by brute force, you'd have to turn every atom within 16.6 billion light-years into pure energy: about 6 × 10⁶⁸ joules. That's as much energy as about five trillion trillion Suns will give off over their entire lives.

About five matches' worth of energy. Five trillion trillion Suns' worth of damage.

Chapter 8

Everything, ranked

Here's the complete lineup, from a phone battery to the bubble. "1 gram packs" tells you how much TNT one gram of each is worth. "Weight turned into energy" is the honest efficiency. Tap a column to sort it, or filter by type.

Chemical fuels count only the fuel's own weight, since the oxygen they burn with comes free from the air. Anything over 100% is borrowing from its surroundings: antimatter gets its partner matter for free, and the bubble gets everything within its reach for free. "On a log scale" means every step to the right is ten times more.

Single events, from a dozen mosquitoes' worth to the end of the world

A different lineup: not "per gram", but the total wallop of one whole event. Watch where the little 80-picogram trigger lands.

Triggers versus what they set loose

Finally, the trigger's view. The bubble trigger holds about as much energy as five matches. Everything that separates them is in what they unlock.

Chapter 9

Bonus villain: the magnetic monopole

The bubble isn't the only "tiny thing, cosmic consequences" idea in physics. Meet the last rung of the ladder.

Theories that try to unite the forces of nature (called grand unified theories) predict monopoles should exist. Each would be absurdly heavy for a single particle: about the weight of a grain of pollen.

Here's the nightmare part. In those same theories, a monopole could act as a catalyst that makes protons fall apart. A proton, a building block of every atomic nucleus, touches the monopole and decays into lighter particles and energy, while the monopole drifts on completely unharmed, ready to do it again. And again. Forever.

That's why its rung on the ladder has no fixed top: unlike any fuel, it never gets used up, so its score keeps climbing for as long as it finds matter to eat. But it can't beat the bubble. It can only eat the matter it actually meets, and the same stretching of space that stops the bubble at 5% fences it in too. Even if it somehow ate every atom the bubble could reach, it would still score hundreds to thousands of times lower, simply because it starts out hundreds to thousands of times heavier than the 80-picogram trigger. 🍽️

Before you worry: it would be slow. A monopole passing through Earth would destroy only a vanishingly tiny fraction of its protons, and eating a whole planet would take far longer than the age of the universe. Its terror isn't speed. It's that it never runs out.

So… should you be scared?

No. Genuinely, no. Here's why you can close this tab and sleep fine tonight. 🌙

And even in the worst case, the stretching of space that limits any bubble to 5% also means that far-away disasters can never reach us. Distance is the ultimate quarantine.

What makes this story worth telling isn't fear. It's awe. That the universe could hinge on something this small, that the rules allow it at all, is one of the strangest and most beautiful things humans have figured out about reality.

Eighty picograms. A loophole in the fine print of the universe that, as far as anyone can tell, will simply never be used.