82
orsoelementsthatexisted,notonehadbeendiscovered
in Asia.”
Like heavy-element labs everywhere, Haba’s team had to
shareacceleratortimewithcompaniesmanufacturingradio-
activeisotopesformedicaluseorresearchersstudyingdif-
ferentelements.Inall,acrossnineyears,just 200 days were
allotted to the nihonium experiments.
Matthias Schädel, who was a nuclear chemist at GSI for
almost four decades until 2010, remembers the frustrations
well. First, he had to persuade colleagues to collaborate, and
then he had to apply for funding and for time with the acceler-
ator. “Sometimes this preparatory phase takes several years,”
he says. When a beam of projectile ions finally begins to shoot
toward its target, the scientists’ work enters a monotonous rou-
tine: checking settings, monitoring the beam. His colleagues
readjournalsornovelsinbetweencastinganeyeoverthedata
cascadingdowna computerscreen.It gottiring,particularly
bythetime“thenthnightshiftinaseveral-weekslong experi-
ment” rolled around. What jolted you wide awake, he says, was
if the data suddenly revealed an “event”—an unusual nuclear
reactionthatmight,afterweeksandweeksoffurtheranalysis,
turnouttobethesignatureofanunfamiliarelement.Schädel
pulledplentyofthesenightshifts,buthewasneverpartofthe
discoveryofa newelement.
Giventhesesteepinvestmentsoftimeandfunds,Gateswon-
dersif thesearchis alwaysworthit.“Intheamountofbeam
timeit takestomakea newelement,youcouldlearna ton
aboutthesuperheaviesthatwe’vealreadymade.”Ofcourse,
shesaid,studentsdon’tlearnwhogaugedtheionizationpoten-
tialoflawrencium;theylearnwhofirstmadetheelement.“So
if youwanttomakea biggerimpactinpublic,youwouldmake
a newelement,becausethat’sa muchflashierexperiment.The
politicsstartsdrivingit insteadofthesearchforscience.”T
heperiodictablewasneverexpectedtofurloutend-
lessly.Intheseextremereachesofthetable,cramming
protonafterprotonintoa nucleusrendersit moreand
moreprecarious.Thepositivechargesrepeloneanotheruntil
thenucleusdecaysnear-instantly—beforeelectronshavehad
a chancetosettleintoorbittoprovideanatomicstructureand
beforethepassageofa hundred-trillionthofa second,thetime
anatommustexisttocountasa newelement.Wereyouto
reachelement173,scientiststheorize,matterscouldgeteven
stickier.TheeffectsofEinsteinianrelativitywouldkickin,and
electronswouldbehaveinpeculiarways.Thoseatomsmay
notevenbeatomsasweknowthem—theirelectroncloudsdis-
solvingandtheregularperiodicityoftheirpropertiesswerv-
ingwildlyoffcourse.
Butphysicspresentsdifficultieslongbefore173.Evenfor
119,waitingjustoffstage,scientistsaren’tsurewhichtwo
elementstheymightfuse.Oganesson,No.118,wastheprod-
uctofanespeciallystableisotopeofcalciumslamminginto
californium.Butthatcalciumcan’tjustbedirectedtoward
einsteinium,thenextelementaftercalifornium;a handful
ofnuclearreactorsaroundtheworldgenerateonlya mil-
ligramorsoofeinsteiniumforresearcheveryyear.Seven
yearsagoatGSI,ChristophDüllmannandhisteamtrieda
combinationoftitanium(22protons)andberkelium(97pro-
tons), without results. In Japan, Haba has been working withvanadium(23protons)andcurium(96protons).Ina $60mil-
lion Superheavy Element Factory in Dubna, inaugurated in
March, scientists are pelting berkelium with an extra-stable
titanium isotope, its nucleus fat with six neutrons more than
standard titanium. But at the moment, Düllmann says, 118
“is the end of the story. We have no idea what combination
of elements is best for 119 and 120. The number of theories
is the same as the number of theorists you talk to.”
The theorists agree that 119 and 120 are probably within
reach. Elements tend to be discovered in bunches, says Paul
Karol, a nuclear chemist who chaired IUPAC’s working group
on new elements. “Right now there’s a gap, but it hasn’t died
out.” Beyond 120, everything is contested. Some scientists
speak hopefully of coming upon an “island of stability,” a
group of elements holding such ideal numbers of protons
and neutrons that they’re magically stable, deigning to stick
around for hours or days or even years. “But it’s sure going
tobetough,”Karolsays.“You’retryingtoheadina certain
direction,andthere’sa strongwindblowingyouoff-course.
It’spossiblethatyouwon’tmakeanything—that you drown
in the sea and not land on the island.”
And at that point, at long last, the campaign to expand the
periodic table will come to a halt. It won’t be for reasons of
material utility; the synthetic elements stopped being of any
practical use around No. 98. Rather, their value always lay in
the research they engendered: the design of experiments, the
careful consideration of beam speeds, and the study of the
physical properties of these fugitive atoms. “You’re training
people who can step aside from everyday science and come
up with something that’s new,” Karol says. But if elements
stop revealing themselves, research on the frontier dries up
as well. Grants will find new ventures, and scientists will fol-
low them; cyclotrons will be turned into more parking lots.
For the first time since 1869, when Dmitri Mendeleev stood
before the Russian Chemical Society and proposed a novel
way to arrange elements, his periodic table will cease to be
an unfinished work, a map with borders yet to be filled in. <BW>The Berkeley Lab in 1951COURTESY LAWRENCE BERKELEY NATIONAL LABORATORY