I write a Mon­day Col­umn every cou­ple of months for 3 Quarks Dai­ly. This is the lat­est one.

For a time, in the sum­mer of 1933, the sci­en­tist who invent­ed the first weapon of mass destruc­tion – poi­son gas – was stay­ing in the same gen­teel Geor­gian square in London’s Blooms­bury as the man who would play a key role in the cre­ation of the atom­ic bomb.

Fritz Haber was a bro­ken man. He was suf­fer­ing from chron­ic angi­na and had been forced out of the research insti­tute to which he had devot­ed his entire life. For a proud man, it was a deeply humil­i­at­ing expe­ri­ence. To friends, the 64-year-old Ger­man chemist admit­ted feel­ing pro­found­ly bit­ter. Ein­stein, who had just renounced his Ger­man cit­i­zen­ship, wrote him a point­ed let­ter say­ing he was pleased to hear that “your for­mer love for the blond beast has cooled off a bit”. Haber had only months to live. Exiled by the coun­try he had tried to save dur­ing World War I with his chem­i­cal super­weapon, he spent his last days wan­der­ing through Europe.

In July 1933 he vis­it­ed Lon­don, stay­ing at a hotel on Rus­sell Square in Blooms­bury while he explored the pos­si­bil­i­ty of work­ing in Eng­land. He met Fred­er­ick G. Don­nan, a tall and rather dash­ing pro­fes­sor of chem­istry at near­by Uni­ver­si­ty Col­lege Lon­don, who sport­ed a black eye­patch. Dur­ing World War I, Don­nan had worked on the pro­duc­tion of mus­tard gas. Now he was attempt­ing to arrange a fel­low­ship for Germany’s lead­ing chem­i­cal war­fare expert.

That sum­mer, anoth­er sci­en­tist who had fled Hitler’s Ger­many was also liv­ing in Rus­sell Square. Leo Szi­lard, a Hun­gar­i­an physi­cist who had been work­ing in Berlin for the past decade, had brought his two suit­cas­es to the Impe­r­i­al Hotel in April. It was less cost­ly than Haber’s hotel, the Rus­sell, but for the sci­en­tist who had once declared that “there is no place as good to think as a bath­tub”, what made the hotel irre­sistible were its famous Turk­ish baths.

Both hotels over­looked the ele­gant gar­dens of Rus­sell Square, designed in the pre­vi­ous cen­tu­ry by Britain’s fore­most land­scape design­er, Humphry Rep­ton. The British Muse­um and Library, Uni­ver­si­ty Col­lege Lon­don, and the Lon­don School of Eco­nom­ics were all with­in a fif­teen-minute walk. T. S. Eliot (the “Pope of Rus­sell Square”) worked in his gar­ret office at num­ber 24 for the pub­lish­er Faber & Faber, and in near­by Gor­don Square was the fine Geor­gian town­house where Vir­ginia Woolf had once lived.

Szi­lard was essen­tial­ly run­ning the Aca­d­e­m­ic Assis­tance Coun­cil (lat­er the Soci­ety for the Pro­tec­tion of Sci­ence and Learn­ing), an organ­i­sa­tion he had helped found which ded­i­cat­ed itself to help­ing aca­d­e­mics flee­ing from the Nazis. His work for the AAC was unpaid. Szi­lard was liv­ing off earn­ings from patents which he held joint­ly with his close friend Albert Ein­stein. At the end of the 1920s, two of the great­est minds on the plan­et had applied their com­bined brain pow­er to the prob­lem of design­ing a safe refrig­er­a­tor. Unfor­tu­nate­ly, no one ever kept their gro­ceries cool in an Ein­stein-Szi­lard fridge. But their inven­tion of a liq­uid met­al refrig­er­a­tion sys­tem was lat­er used to cool nuclear reac­tors.

Polit­i­cal­ly, the nation­al­ist Haber and the social­ist Szi­lard had lit­tle in com­mon. How­ev­er, unlike sci­en­tif­ic purists such as Ernest Ruther­ford, for whom knowl­edge was its own reward, both men were enthralled by the idea of sci­ence as pow­er. Nei­ther Szi­lard nor Haber had set out in their careers intend­ing to cre­ate new weapons. But both sci­en­tists played key roles in devel­op­ing a new gen­er­a­tion of sci­en­tif­ic super­weapons. Haber thought that chem­i­cal weapons would make him the sav­iour of his coun­try. Szi­lard, an inter­na­tion­al­ist fired by an ide­al­is­tic vision of how sci­ence should trans­form human life and soci­ety for the bet­ter, want­ed to save the world with atom­ic ener­gy and cre­ate Utopia.

What might these two refugee sci­en­tists have said to each oth­er if they had met while walk­ing through the neat­ly man­i­cured gar­dens of Rus­sell Square, just out­side their hotels? Fritz Haber was at the end of his career, dis­owned by his coun­try and thrown out of the insti­tute he had found­ed by the Nazis. He was at the end of his life. Haber was a shad­ow of the dynam­ic man he had once been. Every few steps, he had to pause and catch his breath. By con­trast, Leo Szi­lard, the bud­ding nuclear physi­cist, was 35 years old, his fig­ure still slim and youth­ful. He would have been strid­ing past through the square, per­haps on his way to see his and Haber’s mutu­al friend, Pro­fes­sor Don­nan at UCL.

Through­out 1933, Szi­lard worked tire­less­ly and self­less­ly on behalf of his fel­low refugee aca­d­e­mics. His dai­ly rou­tine at the Impe­r­i­al Hotel began with break­fast in the plush restau­rant, fol­lowed by a leisure­ly and extend­ed soak in a bath – the only lux­u­ry the decid­ed­ly non-mate­ri­al­is­tic Szi­lard per­mit­ted him­self. It was not uncom­mon for him to spend three hours in a tub, await­ing Archimedean inspi­ra­tion. How­ev­er, it was not in the bath that Leo Szi­lard had his Eure­ka! moment in 1933, but on Southamp­ton Row, one of the main roads run­ning into Rus­sell Square.

Late on the morn­ing of Sep­tem­ber 12, 1933, Szi­lard was read­ing The Times in the foy­er of the Impe­r­i­al Hotel. An arti­cle report­ed Ernest Rutherford’s speech on how sub­atom­ic par­ti­cles might be used to trans­mute atoms. Ruther­ford was quot­ed as say­ing “any­one who looked for a source of pow­er in the trans­for­ma­tion of the atom was talk­ing moon­shine”. Leo Szi­lard frowned as he read these words. Moon­shine! If there was one thing in sci­ence that made Szi­lard real­ly angry, it was experts who said that some­thing was impos­si­ble.

Szi­lard always thought best on his feet. So he went for a walk. Many years lat­er in Amer­i­ca, Szi­lard would recall this moment, as he walked through Blooms­bury, pon­der­ing sub­atom­ic physics and Rutherford’s com­ments. “I remem­ber,” said Szi­lard, “that I stopped for a red light at the inter­sec­tion of Southamp­ton Row.” The Lon­don traf­fic streamed by, but he scarce­ly noticed the vehi­cles. Instead, in his mind he saw streams of sub­atom­ic par­ti­cles bom­bard­ing atoms.

As the traf­fic lights changed and the cars stopped, the physi­cist stepped out in front of the impa­tient traf­fic. A keen-eyed Lon­don cab­by, watch­ing Szi­lard cross, might have noticed him pause for a moment in the mid­dle of the road. Szi­lard may even have briefly raised his hand to his fore­head, as if to catch hold of the beau­ti­ful but ter­ri­ble thought that had just crossed his mind. For at that moment Leo Szi­lard saw how to release the ener­gy locked up in the heart of every atom, a self-sus­tain­ing chain reac­tion cre­at­ed by neu­trons:

“As I was wait­ing for the light to change and as the light changed to green and I crossed the street, it sud­den­ly occurred to me that if we could find an ele­ment which is split by neu­trons and which would emit two neu­trons when it absorbed one neu­tron, such an ele­ment, if assem­bled in suf­fi­cient­ly large mass, could sus­tain a nuclear chain reac­tion… In cer­tain cir­cum­stances it might become pos­si­ble to set up a nuclear chain reac­tion, lib­er­ate ener­gy on an indus­tri­al scale, and con­struct atom­ic bombs. The thought that this might be in fact pos­si­ble became a sort of obses­sion with me.”

I know Rus­sell Square well. It’s one of my favourite parts of Lon­don. I often walked through it on my way to class­es, first as a grad­u­ate stu­dent, then while lec­tur­ing at UCL. Two hun­dred years after its paths were first laid and its trees plant­ed, the gar­dens have now been restored to their for­mer glo­ry. It is a leafy haven of peace amidst the noise of the metrop­o­lis.

While research­ing Dooms­day Men, which tells the sto­ry of Szi­lard and Haber, I often worked at the Uni­ver­si­ty of Lon­don Library in the impres­sive art deco Sen­ate House which over­looks Rus­sell Square. Its foun­da­tion stone was laid in June 1933 and dur­ing the war George Orwell worked here in the Min­istry of Infor­ma­tion, an expe­ri­ence that pro­vid­ed the mod­el for his fic­tion­al “Min­istry of Truth” in 1984. On the way to the library each morn­ing, I walked through the square and was often struck by the thought that Szi­lard and Haber had passed under these very trees sev­en­ty years ear­li­er. Indeed, a stone’s throw from here Szi­lard realised how to release the ener­gy of the atom. In a sense, the road to Hiroshima’s destruc­tion begins here in this ele­gant Geor­gian square.

Strange­ly enough, a lit­er­ary sci­en­tist also dis­cov­ered the secret of releas­ing the atom’s ener­gy while work­ing in this part of Lon­don. In H. G. Wells’s The World Set Free (1914), the sci­en­tist Hol­sten suc­ceeds in “tap­ping the inter­nal ener­gy of atoms” by set­ting up “atom­ic dis­in­te­gra­tion in a minute par­ti­cle of bis­muth”. This explo­sive reac­tion, in which the sci­en­tist is slight­ly injured, pro­duces radioac­tive gas and gold as a by-prod­uct. The quest of the alchemists is over – gold can now be cre­at­ed on demand. But Hol­sten has also dis­cov­ered some­thing far more valu­able than even gold: “from the moment when the invis­i­ble speck of bis­muth flashed into riv­ing and rend­ing ener­gy, Hol­sten knew that he had opened a way for mankind, how­ev­er nar­row and dark it might still be, to worlds of lim­it­less pow­er”. When Hol­sten realis­es the impli­ca­tions of what he has found, his mind is thrown into tur­moil. Like Szi­lard, he goes for a walk to think things through.

What is aston­ish­ing is that Hol­sten makes his dis­cov­ery in Blooms­bury in 1933, the very year in which Szi­lard walked down Southamp­ton Row and had his Eure­ka moment. The sig­nif­i­cance of this coin­ci­dence in time and space was not lost on Leo Szi­lard. Indeed, the sim­i­lar­i­ties between the two sci­en­tists are strik­ing. Both the fic­tion­al and the real sci­en­tist were born at the begin­ning of the atom­ic age, Hol­sten in the year X‑rays were dis­cov­ered, 1895, and Szi­lard in the year radi­um was dis­cov­ered, 1898. Szi­lard had read Wells’s nov­el in 1932. It is clear that he regard­ed it as prophet­ic, and fre­quent­ly referred to it in rela­tion to key moments in both his life and the dis­cov­ery of atom­ic ener­gy. He shared Holsten’s dreams and his night­mares.

My knowl­edge of these his­tor­i­cal moments has giv­en this gen­teel Lon­don square a spe­cial res­o­nance for me. I’ve often sat on the grass while tak­ing time out from research and won­dered what oth­er meet­ings or Eure­ka moments have occurred in this green urban space. The square has gained a whole new dimen­sion for me. It is not just a few trees and flower beds sur­round­ed by some over-priced town­hous­es. It has a his­to­ry, its own unique time-scape, one charged with glob­al sig­nif­i­cance. A scene in a great sci­en­tif­ic tragedy unfold­ed on this urban stage. And who knows how many minor domes­tic dra­mas have also been act­ed out in the shade of its trees. I became so fas­ci­nat­ed by the secret his­to­ries of urban spaces like Rus­sell Square that I even wrote a book pro­pos­al on the sub­ject.

I was pow­er­ful­ly remind­ed of these themes recent­ly when read­ing The Spaces of the Mod­ern City: Imag­i­nar­ies, Pol­i­tics, and Every­day Life, edit­ed by Gyan Prakash and Kevin Kruse (Prince­ton 2008). This is an excel­lent col­lec­tion of essays by schol­ars who are unit­ed in the view that cities are not inert con­tain­ers for social, polit­i­cal and eco­nom­ic process­es, but his­tor­i­cal­ly pro­duced spaces that shape, and are shaped by, pow­er, econ­o­my, cul­ture, and soci­ety. They want to replace Rem Koolhaas’s post-mod­ern notion of a Gener­ic City “free from his­to­ry”, by invest­ing urban spaces with a new sense of place and his­to­ry, with­in a con­text of glob­al change.

As Gyan Prakash right­ly says, cities “are the prin­ci­pal land­scapes of moder­ni­ty”. Streets and side­walks, parks and squares, tube trains and bus­es – these are the every­day set­tings for “dynam­ic encoun­ters and expe­ri­ences”. Despite glob­al­iza­tion, our urban expe­ri­ences still depend on “local life­worlds”, rich with mem­o­ries and imag­i­na­tion. The Spaces of the Mod­ern City is a fas­ci­nat­ing attempt to map the poet­ics of the urban every­day – from the lim­i­nal spaces of racial­ly mixed neigh­bour­hoods in Lon­don of the 1950s, the Sit­u­a­tion­ists in West Berlin dur­ing the 60s, to Tokyo’s extra­or­di­nary Street Sci­ence Obser­va­tion Soci­ety in the 1980s.

In 2008, Homo sapi­ens became an urban species. This year, for the first time in the his­to­ry of the plan­et, more than half the pop­u­la­tion – 3.3 bil­lion peo­ple – are city dwellers. Two hun­dred years ago only 3 per cent of the world’s pop­u­la­tion lived in cities, a fig­ure that had remained fair­ly sta­ble (give or take the occa­sion­al plague) for the last thou­sand years.

The expe­ri­ence of liv­ing in cities is uni­ver­sal. It cross­es con­ti­nents, cul­tures and even time. Urban­ism is not a west­ern phe­nom­e­non. The ide­al of the glob­al vil­lage was first glimpsed in cities sev­en thou­sand years ago, in today’s Iraq. As one his­to­ri­an has writ­ten: “A town is always a town, wher­ev­er it is locat­ed, in time as well as space.”

I believe cities are our great­est cre­ation as a species. They embody our unique abil­i­ty to imag­ine how the world might be, and to realise those dreams in brick, steel, con­crete and glass. For our species has nev­er been sat­is­fied with what Nature gave us. We are the ape that builds, that shapes our envi­ron­ment. We are the city builders – Homo urbanus.

Undoubt­ed­ly, urban plan­ners face some daunt­ing chal­lenges in the com­ing years. About a bil­lion city dwellers are home­less or liv­ing in squat­ter towns with­out ade­quate access to clean water. That’s a sixth of the planet’s entire pop­u­la­tion. Indeed, until recent­ly more peo­ple died in cities than were born in them. Thomas Malthus, in his Essay on the Prin­ci­ples of Pop­u­la­tion (1803), said that half of all chil­dren born in Man­ches­ter and Birm­ing­ham died before the age of three.

Prob­lems remain, but cities are more pop­u­lar than ever. By 2030, six­ty per­cent of peo­ple will be urban­ites. Across the world from Shang­hai to São Paulo, peo­ple are flock­ing to the cities – to buy and sell, to find work, to meet lovers and like-mind­ed peo­ple, to be where it’s all hap­pen­ing. For like mag­nets, cities have always attract­ed cre­ative peo­ple from both the arts and the sci­ences.

So next time you’re strolling down the street and you notice some guy who is lost in thought, don’t for­get – he could be the next Leo Szi­lard, chas­ing visions of sci­en­tif­ic Utopia on a dusty urban side­walk.