按键盘上方向键 ← 或 → 可快速上下翻页，按键盘上的 Enter 键可回到本书目录页，按键盘上方向键 ↑ 可回到本页顶部！
————未阅读完？加入书签已便下次继续阅读！
coincidentally； at about the time that einstein was affixing a cosmological constant to histheory； at the lowell observatory in arizona； an astronomer with the cheerily intergalacticname of vesto slipher （who was in fact from indiana） was taking spectrographic readings ofdistant stars and discovering that they appeared to be moving away from us。 the universewasn’t static。 the stars slipher looked at showed unmistakable signs of a doppler shift5—thesame mechanism behind that distinctive stretched…out yee…yummm sound cars make as theyflash past on a racetrack。 the phenomenon also applies to light； and in the case of recedinggalaxies it is known as a red shift （because light moving away from us shifts toward the redend of the spectrum； approaching light shifts to blue）。
slipher was the first to notice this effect with light and to realize its potential importancefor understanding the motions of the cosmos。 unfortunately no one much noticed him。 thelowell observatory； as you will recall； was a bit of an oddity thanks to percival lowell’sobsession with martian canals； which in the 1910s made it； in every sense； an outpost ofastronomical endeavor。 slipher was unaware of einstein’s theory of relativity； and the worldwas equally unaware of slipher。 so his finding had no impact。
glory instead would pass to a large mass of ego named edwin hubble。 hubble was born in1889； ten years after einstein； in a small missouri town on the edge of the ozarks and grewup there and in wheaton； illinois； a suburb of chicago。 his father was a successful insuranceexecutive； so life was always fortable； and edwin enjoyed a wealth of physicalendowments； too。 he was a strong and gifted athlete； charming； smart； and immensely good…looking—“handsome almost to a fault；” in the description of william h。 cropper； “an5named for johann christian doppler； an austrian physicist； who first noticed the effect in 1842。 briefly； whathappens is that as a moving object approaches a stationary one its sound waves bee bunched up as they cramup against whatever device is receiving them （your ears； say）； just as you would expect of anything that is beingpushed from behind toward an immobile object。 this bunching is perceived by the listener as a kind of pinchedand elevated sound （the yee）。 as the sound source passes； the sound waves spread out and lengthen； causing thepitch to drop abruptly （the yummm）。
adonis” in the words of another admirer。 according to his own accounts； he also managed tofit into his life more or less constant acts of valor—rescuing drowning swimmers； leadingfrightened men to safety across the battlefields of france； embarrassing world…championboxers with knockdown punches in exhibition bouts。 it all seemed too good to be true。 it was。
for all his gifts； hubble was also an inveterate liar。
this was more than a little odd； for hubble’s life was filled from an early age with a levelof distinction that was at times almost ludicrously golden。 at a single high school track meetin 1906； he won the pole vault； shot put； discus； hammer throw； standing high jump； andrunning high jump； and was on the winning mile…relay team—that is seven first places in onemeet—and came in third in the broad jump。 in the same year； he set a state record for the highjump in illinois。
as a scholar he was equally proficient； and had no trouble gaining admission to studyphysics and astronomy at the university of chicago （where； coincidentally； the head of thedepartment was now albert michelson）。 there he was selected to be one of the first rhodesscholars at oxford。 three years of english life evidently turned his head； for he returned towheaton in 1913 wearing an inverness cape； smoking a pipe； and talking with a peculiarlyorotund accent—not quite british but not quite not—that would remain with him for life。
though he later claimed to have passed most of the second decade of the century practicinglaw in kentucky； in fact he worked as a high school teacher and basketball coach in newalbany； indiana； before belatedly attaining his doctorate and passing briefly through thearmy。 （he arrived in france one month before the armistice and almost certainly never hearda shot fired in anger。）in 1919； now aged thirty； he moved to california and took up a position at the mountwilson observatory near los angeles。 swiftly； and more than a little unexpectedly； hebecame the most outstanding astronomer of the twentieth century。
it is worth pausing for a moment to consider just how little was known of the cosmos at thistime。 astronomers today believe there are perhaps 140 billion galaxies in the visible universe。
that’s a huge number； much bigger than merely saying it would lead you to suppose。 ifgalaxies were frozen peas； it would be enough to fill a large auditorium—the old bostongarden； say； or the royal albert hall。 （an astrophysicist named bruce gregory has actuallyputed this。） in 1919； when hubble first put his head to the eyepiece； the number of thesegalaxies that were known to us was exactly one： the milky way。 everything else was thoughtto be either part of the milky way itself or one of many distant； peripheral puffs of gas。
hubble quickly demonstrated how wrong that belief was。
over the next decade； hubble tackled two of the most fundamental questions of theuniverse： how old is it； and how big？ to answer both it is necessary to know two things—howfar away certain galaxies are and how fast they are flying away from us （what is known astheir recessional velocity）。 the red shift gives the speed at which galaxies are retiring； butdoesn’t tell us how far away they are to begin with。 for that you need what are known as“standard candles”—stars whose brightness can be reliably calculated and used asbenchmarks to measure the brightness （and hence relative distance） of other stars。
hubble’s luck was to e along soon after an ingenious woman named henrietta swanleavitt had figured out a way to do so。 leavitt worked at the harvard college observatory asa puter； as they were known。 puters spent their lives studying photographic plates ofstars and making putations—hence the name。 it was little more than drudgery by another name； but it was as clos