IF YOU o select t vivial stific field trip of all time, you could certainlydo ion of 1735. Led by a named Pierre Bouguer and a soldier-mati named C y of stists and adventurers o Peru riangulating distahe Andes.
At time people ely bee ied o uand to determine y’s goal o tle tion of t by measuring tance aroundt) along a line reaco, to just beyond ance of about two hundred miles.
1Almost at oo go imes spectacularly so. In Quito, torssome of toones. Sooion’s doctor anding over a anist became deranged. Ot senior member ofty, a man named Pierre Godin, ran off een-year-old girl and could not beio return.
At one point to suspend o sort out a problem s. Eventually opped speakingand refused to ogety it suspis from officials to believe t a group of Frencists ravel o measure t made no seall. ter it still seems a reasonable question. ts in Frand save t of ture?
tly t eigury stists, ticular,seldom did ternative ly ical problem t arisen ronomer Edmond o South America,much less had a reason for doing so.
* triangulation, tecric fact t if you knle and t all its otleaving your c you and I decided ulation, t t do is put some distas say fumentt you stay in Paris and I go to Mosco t time. Noing t is, you and I and t forms a triangle. Measuret be simplycalculated. (Because teriles of a triangle alo 180 degrees, if you knoantly calculate triangle and tells you t tronomer,o tance from Eart ground level, triangulatio triangles dont reaco space but rato side on amap. In measuring a degree of meridian, te a sort les marche landscape.
ional figure. In tive career, ain, a cartograpry at ty of Oxford, deputytroller of t, astronomer royal, and ior of te autatively on magism, tides, and tions of ts, and fondly on ts of opium. ed tuarial table, proposed met ts distance from ticalmet of season. t do, iingly enoug t bears t didn’tbee until 1758, some sixteen years after h.
For all s, est tribution to o take part in a modest stific hies of his day:
Robert remembered no person to describe a cell, andt and stately Sir Copually an astronomer first and arcectsed, t is not often generally remembered nouro tions of celestial objects.
It plas o orbit in a particular kind of oval knoo quote Ric it uood o a coupleof o wion.
aking credit for ideas t necessarily deed noo s oingand iive grounds t it isfa of disc tead “ceal it for some time, t ot kno.” If any more on tter, no evidence of it. o t t traveled toCambridge and boldly called upon ty’s Lucasian Professor of Matics, Isaae he could help.
Ne beyond measure, but solitary, joyless, pricklyto t of paranoia, famously distracted (upon s of bed in tedly sometimes sit for s to riveting strangeness. ory, tat Cambridge, but t bizarre experiments. Once ed a bodkin—a long needle of t used for seo and rubbed it arou my eye and to [t to see noting. Onanotared at to determio spend somedays in a darkened room before his eyes fave him.
Set atop traits, ional sendency topeculiarity. As a student, frustrated by tations of ventional matics, ed airely old no one about it for ty-sevenyears. In like manner, ics t transformed our uanding of ligion for troscopy, and again c to ss forthree decades.
For all ed for only a part of erests. At least o alcs. t meredabblings but ions. ad of a dangerously icalsect called Arianism, trinity(sligon’s college at Cambridge rinity). endless udying t temple of King Solomon in Jerusalem (teacter to s inal texts) in t it icalclues to tes of t and ttac toal 1936, t Jo a trunk ofNe au and discovered onis t t ics or plaary motions, but to turn basemetals into precious ones. An analysis of a strand of Neained mercury—a of io alcs, ters, and ter-makersbut almost no one else—at a tration some forty times tural level. It is pertle rouble remembering to rise in the m.
Quite o get from in August1684 to ter at of a Ne, Abra oriters:
In 1684 Dro visit at Cambridge [and] after timetoget t s supposing ttra too bereciprocal to tance from it.
to a pieatio t of tion, t sure exactly how.
SrIsaac replied immediately t it or, struck , asked . ‘edit,’ fart could not find it.
tounding—like someone saying couldn’tremember on agreed to redo tions and produce a paper. tired fortensive refle and scribbling, and at lengteruralis Principia Matiatical Principles of NaturalPter knohe Principia .
On a great e and ued t people ’t quite decide . Principia s. It made ly famous. Fort of s and person in Britain knigific ac. Even t Germanmati Gottfried von Leibniz, on ter figyfor tion of t ributions to matics equal to all ted al may approaceiment t herssince.
Alt inaccessible books ever ten”
(ionally made it difficult so t be pestered by matical“smatterers,” as o t. It not onlyexplained matically ts of also identified ttractive forcet got t place—gravity. Suddenly every motion in the universe madesense.
At Principia ’s on’s tion (e, very baldly, t ation in raigil some ots to slo it; and t every a e andequal rea) and ation. tates t every obje ts a tug on every ot may not seem like it, but as you sit cat—totle(indeed, very little) gravitational field. And t on s is, to quote Feynman again,“proportional to ta anotas, ttrabetimes most of us could make practical use of, but atleast e t it is elegantly pact. A couple of brief multiplications, a simpledivision, and, bingo, you knoational position really universal laure ever propounded by a on isregarded eem.
Principia’s produ drama. to as ion Nee over ty for ton refused to release t tle sense. Only ic stle diplomad t liberalapplications of flattery did o extract tic professor.
raumas yet quite over. ty o publis no, g financial embarrassment. ty ly flop called tory of Fised t t fora book on matical principles great, paid for tion out of . Neributed noto make matters ime accepted a positionas ty’s clerk, and ty could no longer afford to provideo be paid instead in copies of tory of Fishes .
ions ofplas, icular trajectory before to Eart flung into space as t spi ittook a o seep in. But one revelation became almostimmediately troversial.
tion t t quite round. Acc tal force of t in a sligtening at t tor, meant t t be taly as it land. Specifically, ten as you moved a good nes of tion t tsphere, which was everyone.
For ury people rying to tly bymaking very exag measurements. One of t suctempts o Bermudaending to make a fortune scooping pearlsfrom t Nor oo e an experience. Iury Bermuda e. t tional tools for deali eve an agreed lengtical mile. Over t miscalculations sen missed Bermuda-sized targets by dismaying margins. Nory and t a little matical rigorto navigation and to t end ermio calculate th of a degree.
Starting to ted yearsmarco York, repeatedly stretc, all t meticulous adjustments for tep o measure t York attime of day and on t measurement inLondon. From termiance around t ludicrouslyambitious uaking—a mistake of test fra of a degree by miles—but in fact, as Noro “ling”—or, more precisely, to six ric terms, at 110.72 kilometers per degree of arc.
In 1637, Norerion, tice , teeions and ill in printty-five years after uro Bermuda you are spinning depends on or to 0 at the poles.
successful planter aing o love, trigory. y-eig o report t ion. In fact, . On te, and someraumatized t ed muc of o persegNorwood in any small way hink of.
Norional pain by making poor marriages.
One of ted by tinually laid small or, causing ion and atied trips acrossBermuda to defend crials came to Bermuda and Nory, aken as unications reated to adreadful execution. So little is kno it may in fact be t is certainly true is t them.
Meanermining to France.
tronomer Jean Picard devised an impressively plicated metriangulation involving quadrants, pendulum clocks, zenitors, and telescopes (for tions of ter). After trundling and triangulatinge measure of 110.46 kilometersfor one degree of arc. t source of pride for t it ed ontion t t spon no .
to plicate matters, after Picard’s deateam of Giovanni andJacques Cassied Picard’s experiments over a larger area and came up s tsuggested t tter not at tor but at t Nely prompted to dispatco Souto take nes.
to measure or, to determiy t mountainslines. In fact, tains of Peru antly lost incloud t team often o , ted one of t nearly impossible terrains oo tado —“muced”—and t most certainly is. t only to scale some of t s—mountainst defeated even t to reas to ford , nearly all of it unced andfar from any source of supplies. But Bouguer and La ienacious, and tuck to task for nine and a ered years.
Sly before cluding t, t a sed Frenceam, takingmeasurements in nortable disforts of to dangerous ice floes), a degree longer on y-ters stouter op to bottom around the poles.
Bouguer and La i nearly a decade o t o learn no t even t to find it. Listlessly, ted t t Frenceam . till notspeaking, turo t and took separate ships home.
Sometured by Ne a plumb bob ain ain, affected by tain’sgravitational mass as . If youmeasured tion accurately and tain, you couldcalculate tational stant—t is, ty, kno th.
Bouguer and La ine ried t C ed by botecies and tion laydormant for anoty years until resurrected in England by Nevil Maskelyronomer royal. In Dava Sobel’s popular book Longitude, Maskelyne is presented as a ninnyand villain for failing to appreciate t ed to mentioned i foro ain of suffitly regular so judge its mass.
At y agreed to engage a reliable figure to tour tiso see if su could be found. Maskelyne kne suer and surveyor easure an astronomical event of great importance:
t Venus across tireless Edmond ed years before t if you measured one of ted points ulation to tao t calibrate tao all tem.
Unfortunately, transits of Venus, as t years apart, but t for a tury or more, and time.
3But t transit came due in 1761,nearly ter ifiical event before.
itinct for ordeal t cerized tists set off for more tions around to Siberia, Ccy-taineigill ot out from Saly, Germany, Ireland, andelsewhere.
It cooperative iional stifiture, and almost everyo problems. Many observers ions but opees to find equipment broken or ropical .
Once agaio provide t memorably unlucky partits.
Jean traveling to Siberia by coad sleigeinstruments over every perilous bump, only to find t vital stretc transit ietury.
rivers, t of unusually to blame oing strange instruments at to escape s.
Unluckier still il, il set off from France a yearaime to observe transit from India, but various setbacks left ill at sea on transit—just about t place to be sieady measurements g ship.
Undaunted, Le Gentil tinued on to India to a t transit in 1769. ityears to prepare, ed a first-rate vieatioed aed ruments,and ate of perfect readiness. On transit, June4, 1769, o a fine day, but, just as Venus began its pass, a cloud slid in front of t exactly tion of transit: teenminutes, and seven seds.
Stoically, Le Gentil packed up ruments a off for t port, but en routeracted dysentery and ill o a s er setting off, and ives ically plue.
In parison, tments experienced by Britaiered observers along ing partnersrus o travel to Sumatra and c transit t after just one nig sea ttacked by a Frence. (Altists ernationally cooperativemood, nations .) Mason and Dixo a o ty t itseemed an’t to be called off. In reply t and g t t tion and stifiunity ing on tto proceed in trievable loss of tations. ed,t en route ra o transit inclusively from topped on tlantic outcrop of St. Maskelyne, idalflows.
Soon afteruro England ly more seasoned—set off for four long and often perilousyears surveying to settle aboundary dispute betates of illiam Penn and Lord Baltimore and tive ies of Pennsylvania and Maryland. t er took on symbolic importance as tates. (Altask, tributed severalastronomical surveys, including one of tury’s most accurate measurements of a degreeof meridian—an ac t brougtlingof a boundary dispute betocrats.)Ba Europe, Maskelyne and erparts in Germany and Fra transit measurements of 1761 ially a failure. One of t too many observations, en proved tradictory and impossible to resolve. ting of aVenusian transit fell io a little-kno from a sunny op in tai, and t on to dclaim Australia for tisurn tion fortronomer Josepo calculate t tance from tottle over 150 million kilometers. (transits iury alloroo put t 149.59 million kilometers, ers.) t last ion in space.
As for Mason and Dixon, turo England as stifiersurn up atsemis in eigury sce, remarkably little is k aen references. Of Dixon tionary of National Biograpes intriguingly t o t to tion to supply a plausible explanatory circumstance, and adds t Dur from ion hing more isknown.
Mason is only slig in 1772, at Maskelyne’s be, ed to find a suitable mountain for tational defleexperiment, at lengting back t tain tral Scottis above Locay, and . uro tkno eriously, urned up in P cly on titution. been baerica sinpleting een years earlier and rons to greet er he was dead.
ito survey tain, to Maskelyne. So for four mo in a remote Scottis ing a team of surveyors, ion. to find tain from all t deal oftedious calculating, for on ion at some pointon or around tain. It ially just a fusing mass of numbers, but tonnoticed t if o ect points of equal , it all became mutly get a sense of tain.
ed tour lines.
Extrapolating from s, ton calculated t 5,000 million million tons, from s and ttour lines into t bad for a summer’s work.
Not everyone isfied s, ing of t it possible to get a truly accurate figure knoual density of tain. For venieon tain y as ordinary stone, about 2.5 times t of er, but ttle more ted guess.
One improbable-seeming person ter ry parsonnamed Joe e and paratively uation, Mic stific teentury and muceemed for it.
Among a great deal else, ure of earted muagism and gravity, and, quite extraordinarily, envisioy of black ive dedut not even Ne in life ronomy, it ru in making telescopes, a kindness for wary sce ever since.
4But of all t Micer impactt for measuring tunately, ts and boto a brilliant but magnifitly retiring London stist named henrydish.
diso a life of sumptuous privilege—ively, of Devons— gifted Englisistof alsest. o a “degree b on disease.” Any act .
Once o find an Austrian admirer, fres step. Excitedly trian began to babble out praise. For a fes diss as if t objed to takeany more, fled do te, leaving t door y. Eveer.
Altimes veo society—icularly devoted to tific soirées of t naturalist Sir Josep o ts t dis to be approac. t o o y as if by act and to “talk as4In 1781 person in to discover a pla. ed to call it Gee,after tis ead it became Uranus.
it o vacy.” If tifically receive amumbled reply, but more often t to to find an actual vad t of dishfleeing for a more peaceful er.
ary inations allourn o a largelaboratory ricity, , gravity, gases, anyto do ion of matter. teentury ime greenselyied in ties of fual tricity inparticular—and began seeing en e in aricalstorm. In France, a amed Pilatre de Rozier tested ty of a stroke t ible and t eyebro necessarily a perma feature ofone’s face. dis, ducted experiments in ed jolts of electrical current, diligently noting til imes his sciousness, no longer.
In tring of signal discoveries—among muc person to isolate to bine o form er—but almost notirely divorced from strangeness. to tinuing exasperation of ists, en alluded in publiso ts of ti experiments t told anyone about. In iveness merely resemble ively exceeded s ricalductivity ury aime, but unfortunately remained undiscovereduntil t tury er part of il te eentury ook on taskof editing disime credit o others.
Among muc telling anyone, disicipated tion of energy, Oon’s Laial Pressures, Ris, Cricalductivity. t’s just some of it. Acc to torian J. G. Croidal fri on sloation of t of localatmospures, and some of terogeneous equilibria.” Finally, clues t led directly to ts kno t of t found until 1962. But our i kno ty-seven, urention to tes of equipment t to ly out of simplestific respect—by John Michell.
us looked like ury version of a Nautilus ed orsion t of tational defle of t measurement of tational stant, and fromrictly speaking, th could be deduced.
Because gravity s in orbit and makes falling objects lao t as a po it is not really. It is only poivesense, o anot, like t aal level gravity is extraordinarily unrobust. Eacime you pick up a bookfrom a table or a dime from tlessly overe tatioion of aire pla. disrying to do y at tremely feat level.
Delicacy a o taining tus, so disook up a position in an adjoining room and made ions elescope aimed tingand involved seventeen delicate, interected measurements, ook nearly ayear to plete. last ions, dis ttle over 13,000,000,000,000,000,000,000 pounds, or six billion trillioris, to use tri is 1,000 kilograms or 2,205 pounds.)today, stists tect t of asingle bacterium and so sensitive t readings be disturbed by someone yay-five feet a t signifitly improved on diss of1797. t best estimate for Eart is 5.9725 billion trillioris, adifference of only about 1 pert from diserestingly, all of timates made by Nealevide all.
So, by te eigury stists knes distance from ts; and ermining tively straiger all, terials erally att. But no. tom and ielevision, nylon, and instantcoffee before t t.
to uand ravel norto Scotland and begin and genialman, of ed a new sce called geology.
5to a p, mass and e different tays tyour like a pla.
travel to ter but no less massive. Oical purposes, massaed as synonymous. at least outside the classroom.
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