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the noise that penzias and wilson were hearing was； of course； the noise that gamow hadpostulated。 they had found the edge of the universe； or at least the visible part of it； 90 billiontrillion miles away。 they were 鈥渟eeing鈥潯he first photons鈥攖he most ancient light in theuniverse鈥攖hough time and distance had converted them to microwaves； just as gamow hadpredicted。 in his book the inflationary universe ； alan guth provides an analogy that helps toput this finding in perspective。 if you think of peering into the depths of the universe as likelooking down from the hundredth floor of the empire state building （with the hundredth floorrepresenting now and street level representing the moment of the big bang）； at the time ofwilson and penzias鈥檚 discovery the most distant galaxies anyone had ever detected were onabout the sixtieth floor； and the most distant things鈥攓uasars鈥攚ere on about the twentieth。
penzias and wilson鈥檚 finding pushed our acquaintance with the visible universe to within halfan inch of the sidewalk。
still unaware of what caused the noise； wilson and penzias phoned dicke at princeton anddescribed their problem to him in the hope that he might suggest a solution。 dicke realized at once what the two young men had found。 鈥渨ell； boys； we鈥檝e just been scooped；鈥潯e told hiscolleagues as he hung up the phone。
soon afterward the astrophysical journal published two articles： one by penzias andwilson describing their experience with the hiss； the other by dicke鈥檚 team explaining itsnature。 although penzias and wilson had not been looking for cosmic background radiation；didn鈥檛 know what it was when they had found it； and hadn鈥檛 described or interpreted itscharacter in any paper； they received the 1978 nobel prize in physics。 the princetonresearchers got only sympathy。 according to dennis overbye in lonely hearts of the cosmos； neither penzias nor wilson altogether understood the significance of what they had founduntil they read about it in the new york times 。
incidentally； disturbance from cosmic background radiation is something we have allexperienced。 tune your television to any channel it doesn鈥檛 receive； and about 1 percent of thedancing static you see is accounted for by this ancient remnant of the big bang。 the next timeyou plain that there is nothing on； remember that you can always watch the birth of theuniverse。
although everyone calls it the big bang； many books caution us not to think of it as anexplosion in the conventional sense。 it was； rather； a vast； sudden expansion on a whoppingscale。 so what caused it？
one notion is that perhaps the singularity was the relic of an earlier； collapsed universe鈥攖hat we鈥檙e just one of an eternal cycle of expanding and collapsing universes； like the bladderon an oxygen machine。 others attribute the big bang to what they call 鈥渁 false vacuum鈥潯r 鈥渁scalar field鈥潯r 鈥渧acuum energy鈥濃�攕ome quality or thing； at any rate； that introduced ameasure of instability into the nothingness that was。 it seems impossible that you could getsomething from nothing； but the fact that once there was nothing and now there is a universeis evident proof that you can。 it may be that our universe is merely part of many largeruniverses； some in different dimensions； and that big bangs are going on all the time all overthe place。 or it may be that space and time had some other forms altogether before the bigbang鈥攆orms too alien for us to imagine鈥攁nd that the big bang represents some sort oftransition phase； where the universe went from a form we can鈥檛 understand to one we almostcan。 鈥渢hese are very close to religious questions；鈥潯r。 andrei linde； a cosmologist atstanford； told the new york times in 2001。
the big bang theory isn鈥檛 about the bang itself but about what happened after the bang。
not long after； mind you。 by doing a lot of math and watching carefully what goes on inparticle accelerators； scientists believe they can look back to 10…43seconds after the moment ofcreation； when the universe was still so small that you would have needed a microscope tofind it。 we mustn鈥檛 swoon over every extraordinary number that es before us； but it isperhaps worth latching on to one from time to time just to be reminded of their ungraspableand amazing breadth。 thus 10…43is 0。0000000000000000000000000000000000000000001； orone 10 million trillion trillion trillionths of a second。
**a word on scientific notation： since very large numbers are cumbersome to write and nearly impossible to read； scientistsuse a shorthand involving powers （or multiples） of ten in which； for instance； 10；000；000；000 is written 1010 and 6；500；000bees 6。5 x 106。 the principle is based very simply on multiples of ten： 10 x 10 （or 100） bees 102； 10 x 10 x 10 （or1；000） is 103； and so on； obviously and indefinitely。 the little superscript number signifies the number of zeroes followingthe larger principal number。 negative notations provide latter in print （especially essentially a mirror image； with thesuperscript number indicating the number of spaces to the right of the decimal point （so 10…4 means 0。0001）。 though i salutethe principle； it remains an amazement to me that anyone seeing 〃1。4 x 109 km3鈥櫋ould see at once that that signifies 1。4 most of what we know； or believe we know； about the early moments of the universe isthanks to an idea called inflation theory first propounded in 1979 by a junior particlephysicist； then at stanford； now at mit； named alan guth。 he was thirty…two years old and；by his own admission； had never done anything much before。 he would probably never havehad his great theory except that he happened to attend a lecture on the big bang given bynone other than robert dicke。 the lecture inspired guth to take an interest in cosmology； andin particular in the birth of the universe。
the eventual result was the inflation theory； which holds that a fraction of a moment afterthe dawn of creation； the universe underwent a sudden dramatic expansion。 it inflated鈥攊neffect ran away with itself； doubling in size every 10…34seconds。 the whole episode may havelasted no more than 10…30seconds鈥攖hat鈥檚 one million million million million millionths of asecond鈥攂ut it changed the universe from something you could hold in your hand tosomething at least 10；000；000；000；000；000；000；000；000 times bigger。 inflation theoryexplains the ripples and eddies that make our universe possible。 without it； there would be noclumps of matter and thus no stars； just drifting gas and everlasting darkness。
according to guth鈥檚 theory； at one ten…millionth of a trillionth of a trillionth of a trillionthof a second； gravity emerged。 after another ludicrously brief interval it was joined byelectromagnetism and the strong and weak nuclear forces鈥攖he stuff of physics。 these werejoined an instant later by swarms of elementary particles鈥攖he stuff of stuff。 from nothing atall； suddenly there were swarms of photons； protons； electrons； neutrons； and much else鈥攂etween 1079and 1089of each； according to the standard big bang theory。
such quantities are of course ungraspable。 it is enough to know that in a single crackinginstant we were endowed with a universe that was vast鈥攁t least a hundred billion light…yearsacross； according to the theory； but possibly any size up to infinite鈥攁nd perfectly arrayed forthe creation of stars； galaxies； and other plex systems。
what is extraordinary from our point of view is how well it turned out for us。 if theuniverse had formed just a tiny bit differently鈥攊f gravity were fractionally stronger orweaker； if the expansion had proceeded just a little more slowly or swiftly鈥攖hen there mightnever have been stable elements to make you and me and the ground we stand on。 had gravitybeen a trifle stronger； the universe itself might have collapsed like a badly erected tent；without precisely the right values to give it the right dimensions and density and ponentparts。 had it been weaker； however； nothing would have coalesced。 the universe would haveremained forever a dull； scattered void。
this is one reason that some experts believe there may have been many other big bangs；perhaps trillions and trillions of them； spread through