The Elusive Element 118

This is the first of  a series of posts looking back at the science news of 10 years ago. Read on to see how much things have changed (or perhaps how much they haven’t).

In August 1999 Physical Review Letters, one of the most prestigious journals in physics, published a report from a US team at Lawrence Berkeley National Laboratory announcing the successful synthesis of the heaviest atom ever observed – element 118. This team of nuclear scientists were claiming to have created a new kind of matter, to have observed a substance never before seen. Then barely two years later, 10 years ago this week, New Scientist reported that the team had retracted their findings.

The trouble started when two other labs – the Centre for Heavy Ion Research in Germany and the Riken Institute in Japan – were unable to replicate the findings. By convention, a new discovery in the field won’t be accepted (and the element in question not officially named) until the original result can be independently corroborated. But synthesising an unstable element is no simple endeavour, requiring rare expertise, vastly expensive machinery, and luck. Perhaps these other labs were just being unlucky.

It was when the original Lawrence Berkeley team failed repeatedly to reproduce its own findings that serious doubts set in – followed by a thorough internal enquiry. Eventually, the investigating committee were to find that data from the original experiments had been altered – allegedly by Dr Victor Ninov, a highly respected scientist – to make it look as if element 118 really had made a fleeting appearance.

Synthesising an element such as element 118 involves throwing together atoms of other elements in a particle accelerator in the hope that they’ll briefly stick, forming the new unstable element for a tiny fraction of a second. The atoms thrown together need to have the right numbers of protons in their nuclei – for instance, lead (with 82 protons) and krypton (with 36 protons) might be fused to make element 118. Since the synthesised element would only stick around for an instant, evidence for its existence is sought by looking for signs of its decay chain – a series of elements each decaying into the next before something relatively stable is reached. What the researchers claimed they had found was a chain from element 118 through elements 116, 114, 112, all the way to seaborgium, element 106, whose most stable isotope has a whopping half-life of nearly 2 minutes. The problem was that Dr Ninov was the only member of the team at the time with the specific expertise to interpret the raw data. All empirical evidence from the actual experiments went through this one person.

In its report the investigating committee registered surprise at this arrangement: “The committee finds it incredible that not a single collaborator checked the validity of Ninov’s conclusions of having found three element 118 decay chains by tracing these events back to the raw data tapes.” But this is often how things work in small teams at the cutting edge of science. Very few people are experts in everything. Collaborative science depends enormously on honesty and mutual trust. As the New York Times noted in an article on the scandal, “Everyone was working from the numbers Dr. Ninov had gleaned from his own analysis. No one felt a need to go back and examine the original raw data.” (Perhaps equally surprising was the revelation that the team were also depending on software that they knew to be buggy: “The initial suspect was the analysis software, nicknamed Goosy, a somewhat temperamental computer program known on occasion to randomly corrupt data”, the New York Times reports.)

Element 118 was legitimately synthesised in 2006 by collaborating scientists from Dubna in Russia and Lawrence Livermore National Laboratory in the US. However, because of that need for independent corroboration the discovery has only recently been approved by the International Union of Pure and Applied Chemistry. It is now official that at least three atoms of element 118 once existed for the briefest of instants. Part of the reason for the delay is likely to be because of the need to work with californium, used in the 2006 synthesis. “Not many labs in the world either want to work with it or have the capabilities to work with it”, observed Mark Stoyer, one of the US researchers.

This is now the way of things at the cutting edges of science, and of physics in particular: very few individuals, in increasingly few laboratories around the world, have the capabilities to carry out  ground-breaking research. What does this mean for the collaboration and the corroboration so essential to science?

A couple of weeks ago the internet was all of a twitter with reports of a breakthrough at the Large Hadron Collider. Had the elusive Higgs been spotted? It is quite possible that we really are close to pinning down, like an exotic butterfly, this decade’s most desirable specimen. But when Cern scientists report a blip in the detectors we must bear in mind – as they themselves obviously do – all of the things other than the Higgs that might explain it, such as a flawed model, human error, or some form of interference. The Guardian’s Ian Sample revealingly discusses on his blog the difficulty of writing about this kind of event in the mainstream media: reporting a “potential glimpse” with all the necessary caveats just isn’t exciting news. Though he chose his words carefully, his piece in the Guardian still had to appear under the headline “Cern scientists suspect glimpse of Higgs boson God particle”, which is just what Sample had been trying not to say.

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