Trevize stared at Pelorat for a long moment, and withan expression of clear displeasure. Then he said, "Is there somethingyou saw that I did not, and that you did not tell me about?""No," answered Pelorat mildly. "You saw it and, as I just said,I tried to explain, but you were in no mood to listen to me.""Well, try again."Bliss said, "Don't bully him, Trevize.""I'm not bullying him. I'm asking for information. And don't youbaby him.""Please," said Pelorat, "listen to me, will you, and not to eachother. Do you remember, Golan, that we discussed early attemptsto discover the origin of the human species? Yariff's project? Youknow, trying to plot the times of settlement of various planets on theassumption that planets would be settled outward from the world of originin all directions alike. Then, as we moved from newer to older planets,we would approach the world of origin from all directions."Trevize nodded impatiently. "What I remember is that it didn't workbecause the dates of settlement were not reliable.""That's right, old fellow. But the worlds that Yariff was workingwith were part of the second expansion of the human race. By then,hyperspatial travel was far advanced, and settlement must have grown quiteragged. Leapfrogging very long distances was very simple and settlementdidn't necessarily proceed outward in radial symmetry. That surely addedto the problem of unreliable dates of settlement.
"But just think for a moment, Golan, of the Spacer worlds. Theywere in the first wave of settlement. Hyperspatial travel was lessadvanced then, and there was probably little or no leapfrogging. Whereasmillions of worlds were settled, perhaps chaotically, during the secondexpansion, only fifty were settled, probably in an orderly manner, inthe first. Whereas the millions of worlds of the second expansion weresettled over a period of twenty thousand years; the fifty of the firstexpansion were settled over a period of a few centuries almostinstantaneously, in comparison. Those fifty, taken together, shouldexist in roughly spherical symmetry about the world of origin.
"We have the co-ordinates of the fifty worlds. You photographed them,remember, from the statue. Whatever or whoever it is that is destroyinginformation that concerns Earth, either overlooked those co-ordinates, ordidn't stop to think that they would give us the information we need. Allyou have to do, Golan, is to adjust the co-ordinates to allow for thelast twenty thousand years of stellar motions, then find the center ofthe sphere. You'll end up fairly close to Earth's sun, or at least towhere it was twenty thousand years ago."Trevize's mouth had fallen slightly open during the recital and ittook a few moments for him to close it after Pelorat was done. He said,"Now why didn't I think of that?""I tried to tell you while we were still on Melpomenia.""I'm sure you did. I apologize, Janov, for refusing to listen. Thefact is it didn't occur to me that " He paused in embarrassment.
Pelorat chuckled quietly, "That I could have anything of importanceto say. I suppose that ordinarily I wouldn't, but this was somethingin my own field, you see. I am sure that, as a general rule, you'd beperfectly justified in not listening to me.""Never," said Trevize. "That's not so, Janov. I feel like a fool,and I well deserve the feeling. My apologies again and I must nowget to the computer."He and Pelorat walked into the pilot-room, and Pelorat, as always,watched with a combination of marveling and incredulity as Trevize'shands settled down upon the desk, and he became what was almost a singleman computer organism.
"I'll have to make certain assumptions, Janov," said Trevize, ratherblankfaced from computer-absorption. "I have to assume that the firstnumber is a distance in parsecs, and that the other two numbers are anglesin radians, the first being up and down, so to speak, and the other,right and left. I have to assume that the use of plus and minus in thecase of the angles is Galactic Standard and that the zero-zzzzzzzzz markis Melpomenia's sun.""That sounds fair enough," said Pelorat.
"Does it? There are six possible ways of arranging the numbers, fourpossible ways of arranging the signs, distances may be in light-yearsrather than parsecs, the angles in degrees, rather than radians. That'sninety-six diferent variations right there. Add to that, the point thatif the distances are light-years, I'm uncertain as to the length of theyear used. Add also the fact that I don't know the actual conventionsused to measure the angles from the Melpomenian equator in one case,I suppose, but what's their prime meridian?"Pelorat frowned. "Now you make it sound hopeless.""Not hopeless. Aurora and Solaria are included in the list, and Iknow where they are in space. I'll use the co-ordinates, and see ifI can locate them. If I end up in the wrong place, I will adjust theco-ordinates until they give me the right place, and that will tell mewhat mistaken assumptions I am making as far as the standards governingthe co-ordinates are concerned. Once my assumptions are corrected,I can look for the center of the sphere.""With all the possibilities for change, won't it make it difficultto decide what to do?""What?" said Trevize. He was increasingly absorbed. Then, whenPelorat repeated the question, he said, "Oh well, chances are that theco-ordinates follow the Galactic Standard and adjusting for an unknownprime meridian isn't difficult. These systems for locating points in spacewere worked out long ago, and most astronomers are pretty confident theyeven antedate interstellar travel. Human beings are very conservativein some ways and virtually never change numerical conventions once theygrow used to them. They even come to mistake them for laws of nature,I think. Which is just as well, for if every world had its ownconventions of measurement that changed every century, I honestly thinkscientific endeavor would stall and come to a permanent stop."He was obviously working while he was talking, for his words camehaltingly. And now he muttered, "But quiet now."After that, his face grew furrowed and concentrated until, afterseveral minutes, he leaned back and drew a long breath. He said quietly,"The conventions hold. I've located Aurora. There's no question aboutit. See?"Pelorat stared at the field of stars, and at the bright one near thecenter and said, "Are you sure?"Trevize said, "My own opinion doesn't matter. Thecomputer is sure. We've visited Aurora, after all. We haveits characteristics its diameter, mass, luminosity, temperature,spectral details, to say nothing of the pattern of neighboring stars. Thecomputer says it's Aurora.""Then I suppose we must take its word for it.""Believe me, we must. Let me adjust the viewscreen and the computercan get to work. It has the fifty sets of co-ordinates and it will usethem one at a time."Trevize was working on the screen as he spoke. The computer worked inthe four dimensions of space-time routinely, but, for human inspection,the viewscreen was rarely needed in more than two dimensions. Now thescreen seemed to unfold into a dark volume as deep as it, was tall andbroad. Trevize dimmed the room lights almost totally to make the viewof star-shine easier to observe.
"It will begin now," he whispered.
A moment later, a star appeared then another thenanother. The view on the screen shifted with every addition so that allmight be included. It was as though space was moving backward from theeye so that a more and more panoramic view could be taken. Combine thatwith shifts up or down, right or left Eventually, fifty dots of light appeared, hovering in three-dimensionalspace.
Trevize said, "I would have appreciated a beautiful sphericalarrangement, but this looks like the skeleton of a snowball that hadbeen patted into shape in a big hurry, out of snow that was too hardand gritty.""Does that ruin everything?""It introduces some difficulties, but that can't be helped, Isuppose. The stars themselves aren't uniformly distributed, and certainlyhabitable planets aren't, so there are bound to be unevennesses in theestablishment of new worlds. The computer will adjust each of thosedots to its present position, allowing for its likely motion in thelast twenty thousand years even in that time it won't mean muchof an adjustment and then fit them all into a `best-sphere.' Itwill find a spherical surface, in other words, from which the distanceof all the dots is a minimum. Then we find the center of the sphere,and Earth should be fairly close to that center. Or so we hope. Itwon't take long."70It didn't. Trevize, who was used to accepting miraclesfrom the computer, found himself astonished at how little time ittook.
Trevize had instructed the computer to sound a soft, reverberatingnote upon deciding upon the co-ordinates of the best-center. There wasno reason for that, except for the satisfaction of hearing it and knowingthat perhaps the search had been ended.
The sound came in a matter of minutes, and was like the gentlestroking of a mellow gong. It swelled till they could feel the vibrationphysically, and then slowly faded.
Bliss appeared at the door almost at once. "What's that?" she asked,her eyes big. "An emergency?"Trevize said, "Not at all."Pelorat added eagerly, "We may have located Earth, Bliss. That soundwas the computer's way of saying so."She walked into the room. "I might have been warned."Trevize said, "I'm sorry, Bliss. I didn't mean it to be quite thatloud."Fallom had followed Bliss into the room and said, "Why was there thatsound, Bliss?""I see she's curious, too," said Trevize. He sat back, feelingdrained. The next step was to try the finding on the real Galaxy, tofocus on the coordinates of the center of the Spacer worlds and see if aG-type star was actually present. Once again, he was reluctant to takethe obvious step, unable to make himself put the possible solution tothe actual test.
"Yes," said Bliss. "Why shouldn't she? She's as human as we are.""Her parent wouldn't have thought so," said Trevize abstractedly. "Iworry about the kid. She's bad news.""In what way has she proven so?" demanded Bliss.
Trevize spread his arms. "Just a feeling."Bliss gave him a disdainful look, and turned to Fallom. "We are tryingto locate Earth, Fallom." ,"What's Earth?""Another world, but a special one. It's the world our ancestors camefrom. Do you know what the word `ancestors' means from your reading,Fallom?""Does it mean ?" But the last word was not inGalactic.
Pelorat said, "That's an archaic word for `ancestors,' Bliss. Our word`forebears' is closer to it.""Very well," said Bliss, with a sudden brilliant smile. "Earth is theworld where our forebears came from, Fallom. Yours and mine and Pel'sand Trevize's.""Yours, Bliss and mine also." Fallom sounded puzzled. "Bothof them?""There's just one set of forebears," said Bliss. "We had the sameforebears, all of us."Trevize said, "It sounds to me as though the child knows very wellthat she's different from us."Bliss said to Trevize in a low voice, "Don't say that. She must bemade to see she isn't. Not in essentials.""Hermaphrodism is essential, I should think.""I'm talking about the mind.""Transducer-lobes are essential, too.""Now, Trevize, don't be difficult. She's intelligent and humanregardless of details."She turned to Fallom, her voice rising to its normal level. "Thinkquietly about this, Fallom, and see what it means to you. Your forebearsand mine were the same. All the people on all the worlds many,many worlds all had the same forebears, and those forebears livedoriginally on the world named Earth. That means we're all relatives,doesn't it? Now go back to our room and think of that."Fallom, after bestowing a thoughtful look on Trevize, turned and ranoff, hastened on by Bliss's affectionate slap on her backside.
"I'm wondering if there's any point in checking it out now. We won'tbe able to make a Jump for several days.""And you'll be spending them agonizing over the possibilities. Findout now. Waiting won't change matters."Trevize sat there with his lips compressed for a moment, then said,"You're right. Very well, then here goes."He turned to the computer, placed his hands on the handmarks on thedesk, and the viewscreen went dark.
Bliss said, "I'll leave you, then. I'll make you nervous if Istay." She left, with a wave of her hand.
"The thing is," he muttered, "that we're going to be checking thecomputer's Galactic map first and even if Earth's sun is in the calculatedposition, the map should not include it. But we'll then "His voice trailed off in astonishment as the viewscreen flashedwith a background of stars. These were fairly numerous and dim, with anoccasional brighter one sparkling here and there, well scattered overthe face of the screen. But quite close to the center was a star thatwas brighter than all the rest.
"We've got it," said Pelorat jubilantly. "We've got it, old chap. Lookhow bright it is.""Any star at centered co-ordinates would look bright," said Trevize,clearly trying to fight off any initial jubilation that might proveunfounded. "The view, after all, is presented from a distance of a parsecfrom the centered co-ordinates. Still, that centered star certainly isn'ta red dwarf, or a red giant, or a hot blue-white. Wait for information;the computer is checking its data banks."There was silence for a few seconds and then Trevize said,"Spectral class G-2." Another pause, then, "Diameter, 1.4 millionkilometers mass, 1.02 times that of Terminus's sun surfacetemperature, 6,000 absolute rotation slow, just under thirtydays no unusual activity or irregularity."Pelorat said, "Isn't all that typical of the kind of star about whichhabitable planets are to be found?""Typical," said Trevize, nodding in the dimness. "And, therefore,what we'd expect Earth's sun to be like. If that is where life developed,the sun of Earth would have set the original standard.""So there is a reasonable chance that there would be a habitableplanet circling it.""We don't have to speculate about that," said Trevize, who soundedpuzzled indeed over the matter. "The Galactic map lists it as possessinga planet with human life but with a question mark."Pelorat's enthusiasm grew. "That's exactly what we would expect,Golan. The life-bearing planet is there, but the attempt to hide thefact obscures data concerning it and leaves the makers of the map thecomputer uses uncertain.""No, that's what bothers me," said Trevize. "That's not what we shouldexpect. We should expect far more than that. Considering the efficiencywith which data concerning Earth has been wiped out, the makers of themap should not have known that life exists in the system, let alonehuman life. They should not even have known Earth's sun exists. TheSpacer worlds aren't on the map. Why should Earth's sun be?""Well, it's there, just the same. What's the use of arguing thefact? What other information about the star is given?""A name.""Ah! What is it?""Alpha."There was a short pause, then Pelorat said eagerly, "That's it,old man. That's the final bit of evidence. Consider the meaning.""Does it have a meaning?" said Trevize. "It's just a name to me,and an odd one. It doesn't sound Galactic.""It isn't Galactic. It's in a prehistoric language ofEarth, the same one that gave us Gaia as the name of Bliss's planet.""What does Alpha mean, then?""Alpha is the first letter of the alphabet of that ancientlanguage. That is one of the most firmly attested scraps of knowledgewe have about it. In ancient times, `alpha' was sometimes used to meanthe first of anything. To call a sun `Alpha,' implies that it's thefirst sun. And wouldn't the first sun be the one around which a planetrevolved that was the first planet to bear human life Earth?""Are you sure of that?""Absolutely," said Pelorat.
"Is there anything in early legends you're the mythologist,after all that gives Earth's sun some very unusual attribute?""No, how can there be? It has to be standard by definition, and thecharacteristics the computer has given us ate as standard as possible,I imagine. Aren't they?""Earth's sun is a single star, I suppose?"Pelorat said, "Well, of course! As far as I know, all inhabited worldsorbit single stars.""So I would have thought myself," said Trevize. "The trouble isthat that star in the center of the viewscreen is not a single star,it is a binary. The brighter of the two stars making up the binary isindeed standard and it is that one for which the computer supplied uswith data. Circling that star with a period of roughly eighty years,however, is another star with a mass four-fifths that of the brighterone. We can't see the two as separate stars with the unaided eye, butif I were to enlarge the view, I'm sure we would.""Are you certain of that, Golan?" said Pelorat, taken aback.
"It's what the computer is telling me. And if we are looking at abinary star, then it's not Earth's sun. It can't be."71.
Trevize broke contact with the computer, and the lightsbrightened.
That was the signal, apparently, for Bliss to return, with Fallomtagging after her. "Well, then, what are the results?" she asked.
Trevize said tonelessly, "Somewhat disappointing. Where I expectedto find Earth's sun, I found a binary star, instead. Earth's sun is asingle star, so the one centered is not it."Pelorat said, "Now what, Golan?"Trevize shrugged. "I didn't really expect to see Earth's suncentered. Even the Spacers wouldn't settle worlds in such a way as toset up an exact sphere. Aurora, the oldest of the Spacer worlds, mighthave sent out settlers of its own and that may have distorted the sphere,too. Then, too, Earth's sun may not have moved at precisely the averagevelocity of the Spacer worlds."Pelorat said, "So the Earth can be anywhere. Is that what you'resaying?""No. Not quite `anywhere.' All these possible sources of error can'tamount to much. Earth's sun must be in the vicinity of theco-ordinates. The star we've spotted almost exactly at the co-ordinatesmust be a neighbor of Earth's sun. It's startling that there should bea neighbor that so closely resembles Earth's sun except for beinga binary but that must be the case.""But we would see Earth's sun on the map, then, wouldn't we? I mean,near Alpha?""No, for I'm certain Earth's sun isn't on the map at all. It was thatwhich shook my confidence when we first spied Alpha. Regardless of howmuch it might resemble Earth's sun, the mere fact that it was on themap made me suspect it was not the real thing.""Well, then," said Bliss. "Why not concentrate on the same co-ordinatesin real space? Then, if there is any bright star close to the center,a star that does not exist in the computer's map, and if it is verymuch like Alpha in its properties, but is single, might it not beEarth's sun?"Trevize sighed. "If all that were so, I'd be willing to wager halfmy fortune, such as it is, that circling that star you speak of wouldbe the planet Earth. Again, I hesitate to try.""Because you might fail?"Trevize nodded. "However," he said, "just give me a moment or two tocatch my breath, and I'll force myself to do so."And while the three adults looked at each other, Fallom approachedthe computer-desk and stared curiously at the handmarks upon it. Shereached out her own hand tentatively toward the markings, and Trevizeblocked the motion with a swift outthrusting of his own arm and a sharp,"Mustn't touch, Fallom."The young Solarian seemed startled, and retreated to the comfort ofBliss's encircling arm.
Pelorat said, "We must face it, Golan. What if you find nothing inreal space?""Then we will be forced to go back to the earlier plan," said Trevize,"and visit each of the forty-seven Spacer worlds in turn.""And if that yields nothing, Golan?"Trevize shook his head in annoyance, as though to prevent that thoughtfrom taking too deep a root. Staring down at his knees, he said abruptly,"Then I will think of something else.""But what if there is no world of forebears at all?"Trevize looked up sharply at the treble voice. "Who said that?" heasked.
It was a useless question. The moment of disbelief faded, and he knewvery well who the questioner was.
"I did," said Fallom.
Trevize looked at her with a slight frown. "Did you understand theconversation?"Fallom said, "You are looking for the world of forebears, but youhaven't found it yet. Maybe there isn't no such world."" Any such world," said Bliss softly.
"No, Fallom," said Trevize seriously. "There has been a very bigeffort to hide it. To try so hard to hide something means there issomething there to hide. Do you understand what I am saying?""Yes," said Fallom. "You do not let me touch the hands on the deck.
Because you do not let me do that means it would be interesting totouch them.""Ah, but not for you, Fallom. Bliss, you are creating a monsterthat will destroy us all. Don't ever let her in here unless I'm at thedesk. And even then, think twice, will you?"The small byplay, however, seemed to have shaken him out of hisirresolution. He said, "Obviously, I had better get to work. If I justsit here, uncertain as to what to do, that little fright will take overthe ship."The lights dimmed, and Bliss said in a low voice, "You promised,Trevize. Do not call her a monster or a fright in her hearing.""Then keep an eye on her, and teach her some manners. Tell her childrenshould be never heard and seldom seen."Bliss frowned. "Your attitude toward children is simply appalling,Trevize.""Maybe, but this is not the time to discuss the matter."Then he said, in tones in which satisfaction and relief were equallyrepresented, "There's Alpha again in real space. And to its left,and slightly upward, is almost as bright a star and one that isn't inthe computer's Galactic map. That is Earth's sun. I'llwager all my fortune on it."72"Well, now," said Bliss, "we won't take any part ofyour fortune if you lose, so why not settle the matter in a forthrightmanner? Let's visit the star as soon as you can make the Jump."Trevize shook his head. "No. This time it's not a matter ofirresolution or fear. It's a matter of being careful. Three times we'vevisited an unknown world and three times we've come up against somethingunexpectedly dangerous. And three times, moreover, we've had to leavethat world in a hurry. This time the matter is ultimately crucial andI will not play my cards in ignorance again; or at least in any moreignorance than I can help. So far, all we have are vague stories aboutradioactivity, and that is not enough. By an odd chance that no one couldhave anticipated, there is a planet with human life about a parsec fromEarth ""Do we really know that Alpha has a planet with human life on it?" putin Pelorat. "You said the computer placed a question mark after that.""Even so," said Trevize, "it's worth trying. Why not take a look atit? If it does indeed have human beings on it, let us find out what theyknow about Earth. For them, after all, Earth is not a distant thing oflegend; it is a neighbor world, bright and prominent in their sky."Bliss said thoughtfully, "It's not a bad idea. It occurs to me thatif Alpha is inhabited and if the inhabitants are not your thoroughlytypical Isolates, they may be friendly, and we might be able to get somedecent food for a change.""And meet some pleasant people," said Trevize. "Don't forget that. Willit be all right with you, Janov?"Pelorat said, "You make the decision, old chap. Wherever you go,I will go, too."Fallom said suddenly, "Will we find Jemby?"Bliss said hastily, before Trevize could answer, "We will look forit, Fallom."And then Trevize said, "It's settled then. On to Alpha."73"Two big stars," said Fallom, pointing to the viewscreen.
"That's right," said Trevize. "Two of them. Bliss, do keep aneye on her. I don't want her fiddling with anything.""She's fascinated by machinery," said Bliss.
"Yes, I know she is," said Trevize, "but I'm not fascinated by herfascination. Though to tell you the truth, I'm as fascinated asshe is at seeing two stars that bright in the viewscreen at the sametime."The two stars were bright enough to seem to be on the point of showinga disc each of them. The screen had automatically increasedfiltration density in order to remove the hard radiation and dim thelight of the bright stars so as to avoid retinal damage. As a result,few other stars were bright enough to be noticeable, and the two thatwere reigned in haughty near-isolation.
"The thing is," said Trevize, "I've never been this close to a binarysystem before.""You haven't?" said Pelorat, open astonishment in his voice. "How isthat possible?"Trevize laughed. "I've been around, Janov, but I'm not the Galacticrover you think I am."Pelorat said, "I was never in space at all till I met you, Golan, butI always thought that anyone who did manage to get into space ""Would go everywhere. I know. That's natural enough. The troublewith planet-bound people is that no matter how much their mind may tellthem otherwise, their imaginations just can't take in the true size ofthe Galaxy. We could travel all our lives and leave most of the Galaxyunpenetrated and untouched. Besides, no one ever goes to binaries.""Why not?" said Bliss, frowning. "We on Gaia know little astronomycompared to the traveling Isolates of the Galaxy, but I'm under theimpression that binaries aren't rare.""They're not," said Trevize. "There are substantially more binariesthan there are single stars. However, the formation of two stars in closeassociation upsets the ordinary processes of planetary formation. Binarieshave less planetary material than single stars do. Such planets as doform about them often have relatively unstable orbits and are very rarelyof a type that is reasonably habitable.
"Early explorers, I imagine, studied many binaries at close range but,after a while, for settlement purposes, they sought out only singles. And,of course, once you have a densely settled Galaxy, virtually all travelinvolves trade and communications and is carried on between inhabitedworlds circling single stars. In periods of military activity, I supposebases were sometimes set up on small, otherwise-uninhabited worldscircling one of the stars of a binary that happened to be strategicallyplaced, but as hyperspatial travel came to be perfected, such bases wereno longer necessary."Pelorat said humbly, "It's amazing how much I don't know."Trevize merely grinned. "Don't let that impress you, Janov. WhenI was in the Navy, we listened to an incredible number of lectures onoutmoded military tactics that no one ever planned, or intended to use,and were just talked about out of inertia. I was just rattling off a bitof one of them. Consider all you know about mythology, folklore,and archaic languages that I don't know, and that only you and a veryfew others do know."Bliss said, "Yes, but those two stars make up a binary system andone of them has an inhabited planet circling it.""We hope it does, Bliss," said Trevize. "Everything has itsexceptions. And with an official question mark in this case, which makesit more puzzling. No, Fallom, those knobs are not toys. Bliss,either keep her in handcuffs, or take her out.""She won't hurt anything," said Bliss defensively, but pulled theSolarian youngster to herself just the same. "If you're so interestedin that habitable planet, why aren't we there already?""For one thing," said Trevize, "I'm just human enough to want tosee this sight of a binary system at close quarters. Then, too, I'mjust human enough to be cautious. As I've already explained, nothinghas happened since we left Gaia that would encourage me to be anythingbut cautious."Pelorat said, "Which one of those stars is Alpha, Golan?""We won't get lost, Janov. The computer knows exactly which one isAlpha, and, for that matter, so do we. It's the hotter and yellower ofthe two because it's the larger. Now the one on the right has a distinctorange tinge to its light, rather like Aurora's sun, if you recall. Doyou notice?""Yes, now that you call it to my attention.""Very well. That's the smaller one. What's the second letterof that ancient language you speak of?"Pelorat thought a moment, and said, "Beta.""Then let's call the orange one Beta and the yellow-white one Alpha,and it's Alpha we're heading for right now.
"But just think for a moment, Golan, of the Spacer worlds. Theywere in the first wave of settlement. Hyperspatial travel was lessadvanced then, and there was probably little or no leapfrogging. Whereasmillions of worlds were settled, perhaps chaotically, during the secondexpansion, only fifty were settled, probably in an orderly manner, inthe first. Whereas the millions of worlds of the second expansion weresettled over a period of twenty thousand years; the fifty of the firstexpansion were settled over a period of a few centuries almostinstantaneously, in comparison. Those fifty, taken together, shouldexist in roughly spherical symmetry about the world of origin.
"We have the co-ordinates of the fifty worlds. You photographed them,remember, from the statue. Whatever or whoever it is that is destroyinginformation that concerns Earth, either overlooked those co-ordinates, ordidn't stop to think that they would give us the information we need. Allyou have to do, Golan, is to adjust the co-ordinates to allow for thelast twenty thousand years of stellar motions, then find the center ofthe sphere. You'll end up fairly close to Earth's sun, or at least towhere it was twenty thousand years ago."Trevize's mouth had fallen slightly open during the recital and ittook a few moments for him to close it after Pelorat was done. He said,"Now why didn't I think of that?""I tried to tell you while we were still on Melpomenia.""I'm sure you did. I apologize, Janov, for refusing to listen. Thefact is it didn't occur to me that " He paused in embarrassment.
Pelorat chuckled quietly, "That I could have anything of importanceto say. I suppose that ordinarily I wouldn't, but this was somethingin my own field, you see. I am sure that, as a general rule, you'd beperfectly justified in not listening to me.""Never," said Trevize. "That's not so, Janov. I feel like a fool,and I well deserve the feeling. My apologies again and I must nowget to the computer."He and Pelorat walked into the pilot-room, and Pelorat, as always,watched with a combination of marveling and incredulity as Trevize'shands settled down upon the desk, and he became what was almost a singleman computer organism.
"I'll have to make certain assumptions, Janov," said Trevize, ratherblankfaced from computer-absorption. "I have to assume that the firstnumber is a distance in parsecs, and that the other two numbers are anglesin radians, the first being up and down, so to speak, and the other,right and left. I have to assume that the use of plus and minus in thecase of the angles is Galactic Standard and that the zero-zzzzzzzzz markis Melpomenia's sun.""That sounds fair enough," said Pelorat.
"Does it? There are six possible ways of arranging the numbers, fourpossible ways of arranging the signs, distances may be in light-yearsrather than parsecs, the angles in degrees, rather than radians. That'sninety-six diferent variations right there. Add to that, the point thatif the distances are light-years, I'm uncertain as to the length of theyear used. Add also the fact that I don't know the actual conventionsused to measure the angles from the Melpomenian equator in one case,I suppose, but what's their prime meridian?"Pelorat frowned. "Now you make it sound hopeless.""Not hopeless. Aurora and Solaria are included in the list, and Iknow where they are in space. I'll use the co-ordinates, and see ifI can locate them. If I end up in the wrong place, I will adjust theco-ordinates until they give me the right place, and that will tell mewhat mistaken assumptions I am making as far as the standards governingthe co-ordinates are concerned. Once my assumptions are corrected,I can look for the center of the sphere.""With all the possibilities for change, won't it make it difficultto decide what to do?""What?" said Trevize. He was increasingly absorbed. Then, whenPelorat repeated the question, he said, "Oh well, chances are that theco-ordinates follow the Galactic Standard and adjusting for an unknownprime meridian isn't difficult. These systems for locating points in spacewere worked out long ago, and most astronomers are pretty confident theyeven antedate interstellar travel. Human beings are very conservativein some ways and virtually never change numerical conventions once theygrow used to them. They even come to mistake them for laws of nature,I think. Which is just as well, for if every world had its ownconventions of measurement that changed every century, I honestly thinkscientific endeavor would stall and come to a permanent stop."He was obviously working while he was talking, for his words camehaltingly. And now he muttered, "But quiet now."After that, his face grew furrowed and concentrated until, afterseveral minutes, he leaned back and drew a long breath. He said quietly,"The conventions hold. I've located Aurora. There's no question aboutit. See?"Pelorat stared at the field of stars, and at the bright one near thecenter and said, "Are you sure?"Trevize said, "My own opinion doesn't matter. Thecomputer is sure. We've visited Aurora, after all. We haveits characteristics its diameter, mass, luminosity, temperature,spectral details, to say nothing of the pattern of neighboring stars. Thecomputer says it's Aurora.""Then I suppose we must take its word for it.""Believe me, we must. Let me adjust the viewscreen and the computercan get to work. It has the fifty sets of co-ordinates and it will usethem one at a time."Trevize was working on the screen as he spoke. The computer worked inthe four dimensions of space-time routinely, but, for human inspection,the viewscreen was rarely needed in more than two dimensions. Now thescreen seemed to unfold into a dark volume as deep as it, was tall andbroad. Trevize dimmed the room lights almost totally to make the viewof star-shine easier to observe.
"It will begin now," he whispered.
A moment later, a star appeared then another thenanother. The view on the screen shifted with every addition so that allmight be included. It was as though space was moving backward from theeye so that a more and more panoramic view could be taken. Combine thatwith shifts up or down, right or left Eventually, fifty dots of light appeared, hovering in three-dimensionalspace.
Trevize said, "I would have appreciated a beautiful sphericalarrangement, but this looks like the skeleton of a snowball that hadbeen patted into shape in a big hurry, out of snow that was too hardand gritty.""Does that ruin everything?""It introduces some difficulties, but that can't be helped, Isuppose. The stars themselves aren't uniformly distributed, and certainlyhabitable planets aren't, so there are bound to be unevennesses in theestablishment of new worlds. The computer will adjust each of thosedots to its present position, allowing for its likely motion in thelast twenty thousand years even in that time it won't mean muchof an adjustment and then fit them all into a `best-sphere.' Itwill find a spherical surface, in other words, from which the distanceof all the dots is a minimum. Then we find the center of the sphere,and Earth should be fairly close to that center. Or so we hope. Itwon't take long."70It didn't. Trevize, who was used to accepting miraclesfrom the computer, found himself astonished at how little time ittook.
Trevize had instructed the computer to sound a soft, reverberatingnote upon deciding upon the co-ordinates of the best-center. There wasno reason for that, except for the satisfaction of hearing it and knowingthat perhaps the search had been ended.
The sound came in a matter of minutes, and was like the gentlestroking of a mellow gong. It swelled till they could feel the vibrationphysically, and then slowly faded.
Bliss appeared at the door almost at once. "What's that?" she asked,her eyes big. "An emergency?"Trevize said, "Not at all."Pelorat added eagerly, "We may have located Earth, Bliss. That soundwas the computer's way of saying so."She walked into the room. "I might have been warned."Trevize said, "I'm sorry, Bliss. I didn't mean it to be quite thatloud."Fallom had followed Bliss into the room and said, "Why was there thatsound, Bliss?""I see she's curious, too," said Trevize. He sat back, feelingdrained. The next step was to try the finding on the real Galaxy, tofocus on the coordinates of the center of the Spacer worlds and see if aG-type star was actually present. Once again, he was reluctant to takethe obvious step, unable to make himself put the possible solution tothe actual test.
"Yes," said Bliss. "Why shouldn't she? She's as human as we are.""Her parent wouldn't have thought so," said Trevize abstractedly. "Iworry about the kid. She's bad news.""In what way has she proven so?" demanded Bliss.
Trevize spread his arms. "Just a feeling."Bliss gave him a disdainful look, and turned to Fallom. "We are tryingto locate Earth, Fallom." ,"What's Earth?""Another world, but a special one. It's the world our ancestors camefrom. Do you know what the word `ancestors' means from your reading,Fallom?""Does it mean ?" But the last word was not inGalactic.
Pelorat said, "That's an archaic word for `ancestors,' Bliss. Our word`forebears' is closer to it.""Very well," said Bliss, with a sudden brilliant smile. "Earth is theworld where our forebears came from, Fallom. Yours and mine and Pel'sand Trevize's.""Yours, Bliss and mine also." Fallom sounded puzzled. "Bothof them?""There's just one set of forebears," said Bliss. "We had the sameforebears, all of us."Trevize said, "It sounds to me as though the child knows very wellthat she's different from us."Bliss said to Trevize in a low voice, "Don't say that. She must bemade to see she isn't. Not in essentials.""Hermaphrodism is essential, I should think.""I'm talking about the mind.""Transducer-lobes are essential, too.""Now, Trevize, don't be difficult. She's intelligent and humanregardless of details."She turned to Fallom, her voice rising to its normal level. "Thinkquietly about this, Fallom, and see what it means to you. Your forebearsand mine were the same. All the people on all the worlds many,many worlds all had the same forebears, and those forebears livedoriginally on the world named Earth. That means we're all relatives,doesn't it? Now go back to our room and think of that."Fallom, after bestowing a thoughtful look on Trevize, turned and ranoff, hastened on by Bliss's affectionate slap on her backside.
"I'm wondering if there's any point in checking it out now. We won'tbe able to make a Jump for several days.""And you'll be spending them agonizing over the possibilities. Findout now. Waiting won't change matters."Trevize sat there with his lips compressed for a moment, then said,"You're right. Very well, then here goes."He turned to the computer, placed his hands on the handmarks on thedesk, and the viewscreen went dark.
Bliss said, "I'll leave you, then. I'll make you nervous if Istay." She left, with a wave of her hand.
"The thing is," he muttered, "that we're going to be checking thecomputer's Galactic map first and even if Earth's sun is in the calculatedposition, the map should not include it. But we'll then "His voice trailed off in astonishment as the viewscreen flashedwith a background of stars. These were fairly numerous and dim, with anoccasional brighter one sparkling here and there, well scattered overthe face of the screen. But quite close to the center was a star thatwas brighter than all the rest.
"We've got it," said Pelorat jubilantly. "We've got it, old chap. Lookhow bright it is.""Any star at centered co-ordinates would look bright," said Trevize,clearly trying to fight off any initial jubilation that might proveunfounded. "The view, after all, is presented from a distance of a parsecfrom the centered co-ordinates. Still, that centered star certainly isn'ta red dwarf, or a red giant, or a hot blue-white. Wait for information;the computer is checking its data banks."There was silence for a few seconds and then Trevize said,"Spectral class G-2." Another pause, then, "Diameter, 1.4 millionkilometers mass, 1.02 times that of Terminus's sun surfacetemperature, 6,000 absolute rotation slow, just under thirtydays no unusual activity or irregularity."Pelorat said, "Isn't all that typical of the kind of star about whichhabitable planets are to be found?""Typical," said Trevize, nodding in the dimness. "And, therefore,what we'd expect Earth's sun to be like. If that is where life developed,the sun of Earth would have set the original standard.""So there is a reasonable chance that there would be a habitableplanet circling it.""We don't have to speculate about that," said Trevize, who soundedpuzzled indeed over the matter. "The Galactic map lists it as possessinga planet with human life but with a question mark."Pelorat's enthusiasm grew. "That's exactly what we would expect,Golan. The life-bearing planet is there, but the attempt to hide thefact obscures data concerning it and leaves the makers of the map thecomputer uses uncertain.""No, that's what bothers me," said Trevize. "That's not what we shouldexpect. We should expect far more than that. Considering the efficiencywith which data concerning Earth has been wiped out, the makers of themap should not have known that life exists in the system, let alonehuman life. They should not even have known Earth's sun exists. TheSpacer worlds aren't on the map. Why should Earth's sun be?""Well, it's there, just the same. What's the use of arguing thefact? What other information about the star is given?""A name.""Ah! What is it?""Alpha."There was a short pause, then Pelorat said eagerly, "That's it,old man. That's the final bit of evidence. Consider the meaning.""Does it have a meaning?" said Trevize. "It's just a name to me,and an odd one. It doesn't sound Galactic.""It isn't Galactic. It's in a prehistoric language ofEarth, the same one that gave us Gaia as the name of Bliss's planet.""What does Alpha mean, then?""Alpha is the first letter of the alphabet of that ancientlanguage. That is one of the most firmly attested scraps of knowledgewe have about it. In ancient times, `alpha' was sometimes used to meanthe first of anything. To call a sun `Alpha,' implies that it's thefirst sun. And wouldn't the first sun be the one around which a planetrevolved that was the first planet to bear human life Earth?""Are you sure of that?""Absolutely," said Pelorat.
"Is there anything in early legends you're the mythologist,after all that gives Earth's sun some very unusual attribute?""No, how can there be? It has to be standard by definition, and thecharacteristics the computer has given us ate as standard as possible,I imagine. Aren't they?""Earth's sun is a single star, I suppose?"Pelorat said, "Well, of course! As far as I know, all inhabited worldsorbit single stars.""So I would have thought myself," said Trevize. "The trouble isthat that star in the center of the viewscreen is not a single star,it is a binary. The brighter of the two stars making up the binary isindeed standard and it is that one for which the computer supplied uswith data. Circling that star with a period of roughly eighty years,however, is another star with a mass four-fifths that of the brighterone. We can't see the two as separate stars with the unaided eye, butif I were to enlarge the view, I'm sure we would.""Are you certain of that, Golan?" said Pelorat, taken aback.
"It's what the computer is telling me. And if we are looking at abinary star, then it's not Earth's sun. It can't be."71.
Trevize broke contact with the computer, and the lightsbrightened.
That was the signal, apparently, for Bliss to return, with Fallomtagging after her. "Well, then, what are the results?" she asked.
Trevize said tonelessly, "Somewhat disappointing. Where I expectedto find Earth's sun, I found a binary star, instead. Earth's sun is asingle star, so the one centered is not it."Pelorat said, "Now what, Golan?"Trevize shrugged. "I didn't really expect to see Earth's suncentered. Even the Spacers wouldn't settle worlds in such a way as toset up an exact sphere. Aurora, the oldest of the Spacer worlds, mighthave sent out settlers of its own and that may have distorted the sphere,too. Then, too, Earth's sun may not have moved at precisely the averagevelocity of the Spacer worlds."Pelorat said, "So the Earth can be anywhere. Is that what you'resaying?""No. Not quite `anywhere.' All these possible sources of error can'tamount to much. Earth's sun must be in the vicinity of theco-ordinates. The star we've spotted almost exactly at the co-ordinatesmust be a neighbor of Earth's sun. It's startling that there should bea neighbor that so closely resembles Earth's sun except for beinga binary but that must be the case.""But we would see Earth's sun on the map, then, wouldn't we? I mean,near Alpha?""No, for I'm certain Earth's sun isn't on the map at all. It was thatwhich shook my confidence when we first spied Alpha. Regardless of howmuch it might resemble Earth's sun, the mere fact that it was on themap made me suspect it was not the real thing.""Well, then," said Bliss. "Why not concentrate on the same co-ordinatesin real space? Then, if there is any bright star close to the center,a star that does not exist in the computer's map, and if it is verymuch like Alpha in its properties, but is single, might it not beEarth's sun?"Trevize sighed. "If all that were so, I'd be willing to wager halfmy fortune, such as it is, that circling that star you speak of wouldbe the planet Earth. Again, I hesitate to try.""Because you might fail?"Trevize nodded. "However," he said, "just give me a moment or two tocatch my breath, and I'll force myself to do so."And while the three adults looked at each other, Fallom approachedthe computer-desk and stared curiously at the handmarks upon it. Shereached out her own hand tentatively toward the markings, and Trevizeblocked the motion with a swift outthrusting of his own arm and a sharp,"Mustn't touch, Fallom."The young Solarian seemed startled, and retreated to the comfort ofBliss's encircling arm.
Pelorat said, "We must face it, Golan. What if you find nothing inreal space?""Then we will be forced to go back to the earlier plan," said Trevize,"and visit each of the forty-seven Spacer worlds in turn.""And if that yields nothing, Golan?"Trevize shook his head in annoyance, as though to prevent that thoughtfrom taking too deep a root. Staring down at his knees, he said abruptly,"Then I will think of something else.""But what if there is no world of forebears at all?"Trevize looked up sharply at the treble voice. "Who said that?" heasked.
It was a useless question. The moment of disbelief faded, and he knewvery well who the questioner was.
"I did," said Fallom.
Trevize looked at her with a slight frown. "Did you understand theconversation?"Fallom said, "You are looking for the world of forebears, but youhaven't found it yet. Maybe there isn't no such world."" Any such world," said Bliss softly.
"No, Fallom," said Trevize seriously. "There has been a very bigeffort to hide it. To try so hard to hide something means there issomething there to hide. Do you understand what I am saying?""Yes," said Fallom. "You do not let me touch the hands on the deck.
Because you do not let me do that means it would be interesting totouch them.""Ah, but not for you, Fallom. Bliss, you are creating a monsterthat will destroy us all. Don't ever let her in here unless I'm at thedesk. And even then, think twice, will you?"The small byplay, however, seemed to have shaken him out of hisirresolution. He said, "Obviously, I had better get to work. If I justsit here, uncertain as to what to do, that little fright will take overthe ship."The lights dimmed, and Bliss said in a low voice, "You promised,Trevize. Do not call her a monster or a fright in her hearing.""Then keep an eye on her, and teach her some manners. Tell her childrenshould be never heard and seldom seen."Bliss frowned. "Your attitude toward children is simply appalling,Trevize.""Maybe, but this is not the time to discuss the matter."Then he said, in tones in which satisfaction and relief were equallyrepresented, "There's Alpha again in real space. And to its left,and slightly upward, is almost as bright a star and one that isn't inthe computer's Galactic map. That is Earth's sun. I'llwager all my fortune on it."72"Well, now," said Bliss, "we won't take any part ofyour fortune if you lose, so why not settle the matter in a forthrightmanner? Let's visit the star as soon as you can make the Jump."Trevize shook his head. "No. This time it's not a matter ofirresolution or fear. It's a matter of being careful. Three times we'vevisited an unknown world and three times we've come up against somethingunexpectedly dangerous. And three times, moreover, we've had to leavethat world in a hurry. This time the matter is ultimately crucial andI will not play my cards in ignorance again; or at least in any moreignorance than I can help. So far, all we have are vague stories aboutradioactivity, and that is not enough. By an odd chance that no one couldhave anticipated, there is a planet with human life about a parsec fromEarth ""Do we really know that Alpha has a planet with human life on it?" putin Pelorat. "You said the computer placed a question mark after that.""Even so," said Trevize, "it's worth trying. Why not take a look atit? If it does indeed have human beings on it, let us find out what theyknow about Earth. For them, after all, Earth is not a distant thing oflegend; it is a neighbor world, bright and prominent in their sky."Bliss said thoughtfully, "It's not a bad idea. It occurs to me thatif Alpha is inhabited and if the inhabitants are not your thoroughlytypical Isolates, they may be friendly, and we might be able to get somedecent food for a change.""And meet some pleasant people," said Trevize. "Don't forget that. Willit be all right with you, Janov?"Pelorat said, "You make the decision, old chap. Wherever you go,I will go, too."Fallom said suddenly, "Will we find Jemby?"Bliss said hastily, before Trevize could answer, "We will look forit, Fallom."And then Trevize said, "It's settled then. On to Alpha."73"Two big stars," said Fallom, pointing to the viewscreen.
"That's right," said Trevize. "Two of them. Bliss, do keep aneye on her. I don't want her fiddling with anything.""She's fascinated by machinery," said Bliss.
"Yes, I know she is," said Trevize, "but I'm not fascinated by herfascination. Though to tell you the truth, I'm as fascinated asshe is at seeing two stars that bright in the viewscreen at the sametime."The two stars were bright enough to seem to be on the point of showinga disc each of them. The screen had automatically increasedfiltration density in order to remove the hard radiation and dim thelight of the bright stars so as to avoid retinal damage. As a result,few other stars were bright enough to be noticeable, and the two thatwere reigned in haughty near-isolation.
"The thing is," said Trevize, "I've never been this close to a binarysystem before.""You haven't?" said Pelorat, open astonishment in his voice. "How isthat possible?"Trevize laughed. "I've been around, Janov, but I'm not the Galacticrover you think I am."Pelorat said, "I was never in space at all till I met you, Golan, butI always thought that anyone who did manage to get into space ""Would go everywhere. I know. That's natural enough. The troublewith planet-bound people is that no matter how much their mind may tellthem otherwise, their imaginations just can't take in the true size ofthe Galaxy. We could travel all our lives and leave most of the Galaxyunpenetrated and untouched. Besides, no one ever goes to binaries.""Why not?" said Bliss, frowning. "We on Gaia know little astronomycompared to the traveling Isolates of the Galaxy, but I'm under theimpression that binaries aren't rare.""They're not," said Trevize. "There are substantially more binariesthan there are single stars. However, the formation of two stars in closeassociation upsets the ordinary processes of planetary formation. Binarieshave less planetary material than single stars do. Such planets as doform about them often have relatively unstable orbits and are very rarelyof a type that is reasonably habitable.
"Early explorers, I imagine, studied many binaries at close range but,after a while, for settlement purposes, they sought out only singles. And,of course, once you have a densely settled Galaxy, virtually all travelinvolves trade and communications and is carried on between inhabitedworlds circling single stars. In periods of military activity, I supposebases were sometimes set up on small, otherwise-uninhabited worldscircling one of the stars of a binary that happened to be strategicallyplaced, but as hyperspatial travel came to be perfected, such bases wereno longer necessary."Pelorat said humbly, "It's amazing how much I don't know."Trevize merely grinned. "Don't let that impress you, Janov. WhenI was in the Navy, we listened to an incredible number of lectures onoutmoded military tactics that no one ever planned, or intended to use,and were just talked about out of inertia. I was just rattling off a bitof one of them. Consider all you know about mythology, folklore,and archaic languages that I don't know, and that only you and a veryfew others do know."Bliss said, "Yes, but those two stars make up a binary system andone of them has an inhabited planet circling it.""We hope it does, Bliss," said Trevize. "Everything has itsexceptions. And with an official question mark in this case, which makesit more puzzling. No, Fallom, those knobs are not toys. Bliss,either keep her in handcuffs, or take her out.""She won't hurt anything," said Bliss defensively, but pulled theSolarian youngster to herself just the same. "If you're so interestedin that habitable planet, why aren't we there already?""For one thing," said Trevize, "I'm just human enough to want tosee this sight of a binary system at close quarters. Then, too, I'mjust human enough to be cautious. As I've already explained, nothinghas happened since we left Gaia that would encourage me to be anythingbut cautious."Pelorat said, "Which one of those stars is Alpha, Golan?""We won't get lost, Janov. The computer knows exactly which one isAlpha, and, for that matter, so do we. It's the hotter and yellower ofthe two because it's the larger. Now the one on the right has a distinctorange tinge to its light, rather like Aurora's sun, if you recall. Doyou notice?""Yes, now that you call it to my attention.""Very well. That's the smaller one. What's the second letterof that ancient language you speak of?"Pelorat thought a moment, and said, "Beta.""Then let's call the orange one Beta and the yellow-white one Alpha,and it's Alpha we're heading for right now.