He said, ‘Half a mile?’ and wondered if that sounded naïve.
It must have, for Jerril chuckled a little. He said, ‘No. Just five hundred feet.’
‘What? But the elevator took about—?’
‘I know. But most of the time it was just getting up to ground level. Trantor is tunnelled over a mile down. It’s like an iceberg. Nine-tenths of it is out of sight. It even works itself out a few miles into the sub-ocean soil at the shore-lines. In fact, we’re down so low that we can make use of the temperature difference between ground level and a couple of miles under to supply us with all the energy we need. Did you know that?’
‘No, I thought you used atomic generators.’
‘Did once. But this is cheaper.’
‘I imagine so.’
‘What do you think of it all?’ For a moment, the man’s good nature evaporated into shrewdness. He looked almost sly.
Gaal fumbled. ‘Glorious,’ he said, again.
‘Here on vacation? Travelling? Sightseeing?’
‘Not exactly. At least, I’ve always wanted to visit Trantor but I came here primarily for a job.’
‘Oh?’
Gaal felt obliged to explain further, ‘With Dr Seldon’s project at the University of Trantor.’
‘Raven Seldon?’
‘Why, no. The one I mean is Hari Seldon – the psychohistorian Seldon. I don’t know of any Raven Seldon.’
‘Hari’s the one I mean. They call him Raven. Slang, you know. He keeps predicting disaster.’
‘He does?’ Gaal was genuinely astonished.
‘Surely, you must know.’ Jerril was not smiling. ‘You’re coming to work for him, aren’t you?’
‘Well, yes, I’m a mathematician. Why does he predict disaster? What kind of disaster?’
‘What kind would you think?’
‘I’m afraid I wouldn’t have the least idea. I’ve read the papers Dr Seldon and his group have published. They’re on mathematical theory.’
‘Yes, the ones they publish.’
Gaal felt annoyed. He said, ‘I think I’ll go to my room now. Very pleased to have met you.’
Jerril waved his arm indifferently in farewell.
Gaal found a man waiting for him in his room. For a moment, he was too startled to put into words the inevitable, ‘What are you doing here?’ that came to his lips.
The man rose. He was old and almost bald and he walked with a limp, but his eyes were very bright and blue.
He said, ‘I am Hari Seldon,’ an instant before Gaal’s befuddled brain placed the face alongside the memory of the many times he had seen it in pictures.
PSYCHOHISTORY … Gaal Dornick, using non-mathematical concepts, has defined psychohistory to be that branch of mathematics which deals with the reactions of human conglomerates to fixed social and economic stimuli …
… Implicit in all these definitions is the assumption that the human conglomerate being dealt with is sufficiently large for valid statistical treatment. The necessary size of such a conglomerate may be determined by Seldon’s First Theorem which … A further necessary assumption is that the human conglomerate be itself unaware of psychohistoric analysis in order that its reactions be truly random …
The basis of all valid psychohistory lies in the development of the Seldon Functions which exhibit properties congruent to those of such social and economic forces as …
ENCYCLOPEDIA GALACTICA
‘Good afternoon, sir,’ said Gaal. ‘I— I—’
‘You didn’t think we were to meet before tomorrow? Ordinarily, we would not have. It is just that if we are to use your services, we must work quickly. It grows continually more difficult to obtain recruits.’
‘I don’t understand, sir.’
‘You were talking to a man on the observation tower, were you not?’
‘Yes. His first name is Jerril. I know no more about him.’
‘His name is nothing. He is an agent of the Commission of Public Safety. He followed you from the space-port.’
‘But why? I am afraid I am very confused.’
‘Did the man on the tower say nothing about me?’
Gaal hesitated, ‘He referred to you as Raven Seldon.’
‘Did he say why?’
‘He said you predict disaster.’
‘I do. What does Trantor mean to you?’
Everyone seemed to be asking his opinion of Trantor. Gaal felt incapable of response beyond the bare word, ‘Glorious.’
‘You say that without thinking. What of psychohistory?’
‘I haven’t thought of applying it to the problem.’
‘Before you are done with me, young man, you will learn to apply psychohistory to all problems as a matter of course – observe.’ Seldon removed his calculator pad from the pouch at his belt. Men said he kept one beneath his pillow for use in moments of wakefulness. Its grey, glossy finish was slightly worn by use. Seldon’s nimble fingers, spotted now with age, played along the hard plastic that rimmed it. Red symbols glowed out from the grey.
He said, ‘That represents the condition of the Empire at present?’
He waited.
Gaal said finally, ‘Surely that is not a complete representation.’
‘No, not complete,’ said Seldon. ‘I am glad you do not accept my word blindly. However, this is an approximation which will serve to demonstrate the proposition. Will you accept that?’
‘Subject to my later verification of the derivation of the function, yes.’ Gaal was carefully avoiding a possible trap.
‘Good. Add to this the known probability of Imperial assassination, viceregal revolt, the contemporary recurrence of periods of economic depression, the declining rate of planetary explorations, the …’
He proceeded. As each item was mentioned, new symbols sprang to life at his touch, and melted into the basic function which expanded and changed.
Gaal stopped him only once. ‘I don’t see the validity of that set-transformation.’
Seldon repeated it more slowly.
Gaal said, ‘But that is done by way of a forbidden socio-operation.’
‘Good. You are quick, but not yet quick enough. It is not forbidden in this connection. Let me do it by expansions.’
The procedure was much longer and at its end, Gaal said, humbly, ‘Yes, I see now.’
Finally, Seldon stopped. ‘This is Trantor five centuries from now. How do you interpret that? Eh?’ He put his head to one side and waited.
Gaal said, unbelievingly, ‘Total destruction! But – but that is impossible. Trantor has never been—’
Seldon was filled with the intense excitement of a man whose body only had grown old. ‘Come, come. You saw how the result was arrived at. Put it into words. Forget the symbolism for a moment.’
Gaal said, ‘As Trantor