the fuel cells； and the hydrogen would kill you。 And your last thought would be： This alien device was obviously made to test bacterial intelligence and to kill us if we make a false step。
〃Now； that would be correct from the standpoint of the dying bacterium。 But that wouldn't be correct at all from the standpoint of the beings who made the satellite。 From our point of view； the munications satellite has nothing to do with intelligent bacteria。 We don't even know that there are intelligent bacteria out there。 We're just trying to ＇＇363＇＇ municate； and we've made what we consider a quite ordinary device to do it。〃
〃You mean the sphere might not be a message or a trophy or a trap at all？〃
〃That's right；〃 Harry said。 〃The sphere may have nothing to do with the search for other life forms； or testing life； as we might imagine those activities to occur。 It may be an accident that the sphere causes such profound changes in us。〃
〃But why would someone build such a machine？〃 Norman said。
〃That's the same question an intelligent bacterium would ask about a munications satellite： Why would anyone build such a thing？〃
〃For that matter；〃 Beth said； 〃it may not be a machine。 The sphere may be a life form。 It may be alive。〃
〃Possible；〃 Harry said； nodding。
Beth said； 〃So； if the sphere is alive； do we have an obligation to keep it alive？〃
〃We don't know if it is alive。〃
Norman sat back in the chair。 〃All this speculation is interesting；〃 he said； 〃but when you get down to it； we don't really know anything about the sphere。 In fact； we shouldn't even be calling it the sphere。 We probably should just call it 'sphere。' Because we don't know what it is。 We don't know where it came from。 We don't know whether it's living or dead。 We don't know how it came to be inside that spaceship。 We don't know anything about it except what we imagine…and what we imagine says more about us than it does about the sphere。〃
〃Right；〃 Harry said。
〃Because it's literally a sort of mirror for us；〃 Norman said。
〃Speaking of which； there's another possibility；〃 Harry said。 〃It may not be alien at all。 It may be man…made。〃 That took Norman pletely by surprise。 Harry explained。
〃Consider；〃 Harry said。 〃A ship from our own future went through a black hole； into another universe； or another part ＇＇364＇＇ of our universe。 We cannot imagine what would happen as a result of that。 But suppose there were some major distortion of time。 Suppose that ship； which left with a human crew in the year 2043； actually has been in transit for thousands and thousands of years。 Couldn't the human crew have invented it during that time？〃
〃I don't think that's likely；〃 Beth said。
〃Well； let's consider for a moment； Beth；〃 Harry said gently。 Norman noticed that Harry wasn't arrogant any more。 They were all in this together； Norman thought； and they were working together in a way they never had before。 All the time underwater they had been at odds； but now they functioned smoothly together； coordinated。 A team。
〃There is a real problem about the future；〃 Harry was saying； 〃and we don't admit it。 We assume we can see into the future better than we really can。 Leonardo da Vinci tried to make a helicopter five hundred years ago； and Jules Verne predicted a submarine a hundred years ago。 From instances like that； we tend to believe that the future is predictable in a way that it really isn't。 Because neither Leonardo nor Jules Verne could ever have imagined； say； a puter。 The very concept of a puter implies too much knowledge that was simply inconceivable at the time those men were alive。 It was； if you will； information that came out of nowhere； later on。
〃And we're no wiser； sitting here now。 We couldn't have guessed that men would send a ship through a black hole…we didn't even suspect the existence of black holes until a few years ago…and we certainly can't guess what men might acplish thousands of years in the future。〃 〃Assuming the sphere was made by men。〃
〃Yes。 Assuming that。〃
〃And if it wasn't？ If it's really a sphere from an alien civilization？ Are we justified in erasing all human knowledge of this alien life？〃
〃I don't know；〃 Harry said； shaking his head。 〃If we decide to forget the sphere 。。。〃
〃Then it'll be gone；〃 Norman said。
Beth stared at the table。 〃I wish we could ask someone；〃 she said finally。
＇＇365＇＇ 〃There isn't anybody to ask；〃 Norman said。
〃But can we really forget it？〃 Beth said。 〃Will it work？〃
There was a long silence。
〃Yes；〃 Harry said； finally。 〃There's no question about it。 And I think we already have evidence that we will forget about it。 That solves a logical problem that bothered me from the beginning； when we first explored the ship。 Because something very important was missing from that ship。〃
〃Yes？ What？〃
〃Any sign that the builders of the ship already knew travel through a black hole was possible。〃
〃I don't follow you；〃 Norman said。
〃Well；〃 Harry said； 〃the three of us have already seen a spaceship that has been through a black hole。 We've walked through it。 So we know that such travel is possible。〃
〃Yes 。。。〃
〃Yet； fifty years from now； men are going to build that ship in a very tentative； experimental way； with apparently no knowledge that the ship has already been found； fifty years in their past。 There is no sign on the ship that the builders already know of its existence in the past。〃
〃Maybe it's one of those time paradoxes；〃 Beth said。 〃You know； how you can't go back and meet yourself in the past。 。。。〃
Harry shook his head。 〃I don't think it's a paradox；〃 he said。 〃I think that all knowledge of that ship is going to be lost。〃
〃You mean； we are going to forget it。〃
〃Yes；〃 Harry said。 〃And； frankly； I think it's a much better solution。 For a long time while we were down there； I assumed none of us would ever get back alive。 That was the only explanation I could think of。 That's why I wanted to make out my will。〃
〃But if we decide to forget 。。。〃
〃Exactly；〃 Harry said。 〃If we decide to forget； that will produce the same result。〃
〃The knowledge will be gone forever；〃 Norman said quietly。 He found himself hesitating。 Now that they had arrived at this moment； he was strangely reluctant to proceed。 He ran ＇＇366＇＇ his fingertips over the scarred table； touching the surface； as if it might provide an answer。
In a sense； he thought； all we consist of is memories。 Our personalities are constructed from memories； our lives are organized around memories； our cultures are built upon the foundation of shared memories that we call history and science。 But now； to give up a memory； to give up knowledge； to give up the past 。。。
〃It's not easy；〃 Harry said； shaking his head。
〃No；〃 Norman said。 〃It's not。〃 In fact he found it so difficult he wondered if he was experiencing a human characteristic as fundamental as sexual desire。 He simply could not give up this knowledge。 The information seemed so important to him； the implications so fascinating。 。。。 His entire being rebelled against the idea of forgetting。
〃Well；〃 Harry said； 〃I think we have to do it； anyway。〃
〃I was thinking of Ted；〃 Beth said。 〃And Barnes； and the others。 We're the only ones who know how they really died。 What they gave their lives for。 And if we forget 。。。〃
〃Whe