Can Element 115 Be Stable? A Trip to the Island of Stability
Physicists have a name for the place where element 115 might finally calm down, and it sounds like a holiday destination: the island of stability.
It's a real idea with real experiments behind it, and it's also the favorite comeback of fans of Bob Lazar, the man who says he worked on element-115-powered flying saucers near Area 51.
The moscovium atoms made so far fall apart in a fraction of a second, so the argument goes that the lab simply made the wrong version.
Could a different version really last longer, and would that turn it into fuel?
The answer starts with what "a different version" even means inside an atom.
What Makes One Version of an Element Different?
Each moscovium nucleus contains exactly 115 protons. Change that number and you're looking at a different element altogether.
Neutrons are where you get some wiggle room. Add or remove a few and you have a different isotope of moscovium, which may hold together for a very different length of time.
Take moscovium-289, one of the versions actually seen in the lab. Its nucleus holds 115 protons and 174 neutrons, which add up to the 289 in its name.
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Add ten neutrons on paper and you get moscovium-299, with 184 neutrons. The arithmetic takes a second, but writing the name down doesn't mean anyone has made the atom.
So why should the neutron count matter so much? Because of a fight going on inside every heavy nucleus.
Why Do Superheavy Atoms Fall Apart?
Protons all carry a positive charge, and like charges repel. Cram 115 of them into one nucleus and you've built a very crowded room full of people who can't stand each other.
The force that holds the nucleus together pushes back, but it doesn't make every arrangement equally sturdy. Some proton-and-neutron combinations resist decay far better than their neighbors.
Think of packing a suitcase: how things fit matters as much as how much you've squeezed in. Inside a nucleus, the particles settle into shells, and certain numbers fill those shells especially neatly.
Scientists map the combinations on a chart, protons one way and neutrons the other. Regions where lifetimes jump stand out from the short-lived nuclei around them.
For half a century, theorists have predicted such a region around 114 protons and 184 neutrons, as the discovery account from the Russian and American labs that made element 115 explains. That patch on the chart is the island of stability: a spot on a map, rather than a hidden deposit of metal waiting to be mined.
So what does "stable" mean once you get there? Less than the name suggests, and more than you might think.
Does Stable Mean It Could Sit on a Shelf?
In everyday language, sure. In this corner of physics, the word always comes with a comparison attached.
A nucleus can be far more stable than its neighbors and still be radioactive. Surviving longer doesn't mean surviving long enough to store in a jar or bolt into a machine.
Lawrence Livermore National Laboratory in California, one of those labs, spells out the goal in its overview of superheavy-element research: half-lives "longer than the millisecond timescale," perhaps long enough to be chemically useful. That's the ambition, and it's a long way from a fuel rod.
Here's the yardstick. A half-life is the time it takes for roughly half of a large group of identical radioactive nuclei to decay, and for moscovium-288 it's about 0.09 seconds, according to the Royal Society of Chemistry.
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After one half-life, about half the atoms are left. After a second, about a quarter, and so on down.
It isn't a timer that makes each atom expire on cue. Individual decays are unpredictable, while the pattern across a population is something scientists can measure with confidence.
For a researcher, a longer half-life is gold. Livermore nuclear chemist Dawn Shaughnessy points to an isotope of flerovium, element 114, that lasts about two seconds, "long enough to enable study."
Two seconds sounds like nothing, but it's enough to run chemistry on an atom. So why not just build the neutron-rich version and see how long it lasts?
Why Can't Scientists Just Add More Neutrons?
Unfortunately, an atom doesn't have a lid you can lift to drop in a few extras. Everything has to arrive in the collision that makes the nucleus.
That means a beam of one nucleus and a target of another, and their combined neutron count sets the ceiling. The 2003 discovery run fired calcium-48 into americium-243, which adds up to 176 neutrons at most, and the isotopes seen since, such as moscovium-288 and moscovium-289, carry 173 and 174.
That's ten neutrons short of the magic 184. Reaching it, the Livermore overview says, will take beams of heavier neutron-rich ions, or a new technique in which projectile and target swap several neutrons at once.
The targets are precious, too. For element 117, the overview notes, Oak Ridge National Laboratory in Tennessee produced just milligrams of berkelium-249, an isotope with a 320-day half-life, so "the clock was ticking" from the day it shipped.
Then the collisions themselves are stingy. Fewer than a dozen out of ten billion billion form a superheavy atom, and Livermore's Nancy Stoyer notes that "it takes about one billion random events before you see something that looks like the first true event."
So the hard part isn't naming a promising isotope. It's finding a practical way to make it, then catching enough decays to work out what you've got.
Which raises a fair question: has anyone actually reached the island?
Has Anyone Reached the Island Yet?
The shore, at least. The Joint Institute for Nuclear Research in Dubna, Russia, began its superheavy-element hunt in 1998 with a gas-filled separator, and over the next 15 years, working with Livermore and other labs, it synthesized six new elements, numbers 113 through 118.
Along the way the team measured more than 50 new nuclides. The pattern was clear: stability rose as the neutron count climbed toward 184, which the discovery account describes as "experimental proof" that the predicted island exists.
That's a real result. The island is a genuine feature of the nuclear map, and every neutron closer makes the atoms hang on a little longer.
It doesn't mean anyone has a shelf-stable version of anything. The best-behaved isotopes so far are measured in seconds, and moscovium's in fractions of a second.
More atoms would help. Dubna's new accelerator, Livermore nuclear chemist Mark Stoyer says, should lift production "from 30 to 50 atoms per year to thousands," which means far more chances to find a longer-lived combination.
That's the science. Now for the flying saucer.
Could a Longer-Lived Isotope Explain Lazar's Fuel?
Bob Lazar is the reason most people have heard of element 115 at all. In 1989 he told Las Vegas reporter George Knapp that he'd worked at S-4, a hidden site near Area 51, and that a stable form of element 115 fueled the craft kept there.
He even cited the theory. "Science today theorizes that up around Element 113 to 116," he said, "they should again become stable," which is the island of stability in 1989 television terms.
When scientists made element 115 in 2003 and its atoms fell apart in milliseconds, Lazar's answer was the isotope argument. On Joe Rogan's podcast in 2019 he said the lab's handful of atoms "did decay," while the fuel he handled didn't.
It's reasonable to distinguish between isotopes, because their lifetimes really do differ. The trouble starts when a possible improvement in lifetime is asked to explain everything the alleged engine could do.
A material that lasts longer hasn't automatically gained the power to produce antimatter or bend gravity. Those would need their own measurements and a demonstration.
Our Bob Lazar and element 115 timeline covers how his claim lines up with the later discovery. The search for longer-lived nuclei doesn't, on its own, put a craft or a fuel in the hangar.
So set the saucer aside for a moment. What would reaching the island actually give us?
What Would Reaching the Island Give Us?
Time, mostly. An isotope that lasts seconds instead of milliseconds gives chemists a chance to find out how the heaviest elements really behave.
That's a bigger deal than it sounds. Shaughnessy notes that in these atoms the electrons move so fast that relativity changes how they bond, and if the predictions hold, "science may need to rearrange the periodic table itself."
A longer-lived moscovium would also tell us how matter holds together at the far end of the table. Our real element 115 guide has the story of how the first atoms were caught.
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That's a good reason to keep looking. The island of stability doesn't have to deliver a flying saucer to be worth reaching, and if you'd rather have the version where it does, X-COM's Elerium 115 has you covered.
Element 115: The Real Element Behind the Flying Saucer Fuel Story
Bob Lazar and Element 115: How Did He Know?