‘Newton’s great leap of the imagination,’ he said in his pedantic-sounding, sing-song voice, which was half Calcutta lecture theatre and half London gentlemen’s club, ‘was to understand, hundreds of years before Einstein, that time is relative.’ Here he paused for theatrical effect and also to dab rather primly at the water on his lips with the enormous, brightly coloured silk handkerchief he kept stuffed flamboyantly in the breast pocket of his suit. ‘Time is not straight or linear. It does not progress in a regular and ordered fashion, and the reason for this is because it is affected by gravity. Yes! Just as are motion and mass and light, and indeed all the properties of the physical universe. It is, of course, generally believed that Einstein first proposed the idea of universal relativity but we in this room and we alone now know that in fact the first man in the world to make this leap of thought was our own Sir Isaac Newton. And we know also that Newton leapt further and with surer foot than Einstein ever did. For just as Newton showed the world that gravity explained the circular and elliptical courses of the planets, he also understood that time moved in a similar manner, twisting and ever turning, shadowing the expansion of the universe, bound by the gravitational pull of every atom contained therein. To put it plainly, Newton saw that time was coiled, and just as an understanding of gravity allowed him to track and map the course of planetary motion, it also enabled him to track the movement of time. And so predict its course.’
Here Sengupta paused briefly for another sip of water. He knew he had a sensational story and clearly did not intend to rush it.
‘So what? I hear you asking yourselves,’ he continued. ‘Coiled or straight, time progresses and there is nothing we can do about it. Why in the blinking blazes was old Isaac getting his knickers in a twist? I will tell you why! Because gravitational pull is not uniform! Just as the planets deviate slightly from the perfect symmetry of their ancient courses, so it is with time. We must think of it not as a perfect spiral but more as a disobliging Slinky in which, once in a while, coils get crossed. Time will, on rare occasions, pass through the same set of dimensions twice. The coils of the Slinky touch only for a moment, within the most limited parameters, after which the spiral of time continues on its merry way. No harm done … But what, Newton asked himself in the tortured journeying of his fearful imaginings, if someone were present at that point in space–time when the coils of the Slinky touched? That person would exist at both the beginning and the end of a loop in time. And so now the spiral does not continue on its merry way. It turns back on itself. For simply by drawing breath, our intrepid time-straddler reboots the loop. All that had been in the past is now once more yet to come. History is unmade. The loop is begun again.’
Sengupta mopped his brow with his handkerchief and took yet another sip of water. The flickering of the candles cast a ghostly ripple across his face. The assembled Companions of Chronos leant forward on their walking sticks and Zimmer frames, hanging on the great physicist’s every word.
‘And Newton really did his sums,’ Sengupta continued. ‘It is scarcely possible to credit but this divine genius, working alone and without modern equipment, was able to tell us when and where time would next cross its own path. No wonder he went a bit loony. I think I’d be looking for secret codes in the Bible myself if I’d just written a map of time when everybody else was just starting to think about mapping Australia. Sir Isaac’s conclusion was most specific. He calculated that the next closed loop in the space–time continuum would be one hundred and eleven years long, and that the point at which the beginning and the end would cross would occur at midnight on the thirty-first of May 2025 and at a quarter past midnight in the very early morning of the first of June 1914. I’m sure all of you can see the reason for the fifteen-minute time lag.’
Stanton couldn’t see it, nor did he imagine that many other people in the room could either. Professor Sengupta had the self-satisfied habit common to many academics of pretending an intellectual equality with his audience in order to happily demonstrate his own superiority.
‘It is, of course, because, as I have explained, gravity is not even or symmetrical. As each loop of space and time progresses, space and time are gained, just as in the case of leap years. And so although the two moments of departure and arrival are simultaneous, our time traveller will in effect arrive fifteen minutes after he leaves. And of course one hundred and eleven years before. Ha ha.’
Sengupta grinned broadly as if he’d made a great joke. There was a sycophantic murmur of forced mirth in reply, in which Sengupta allowed himself to bask for a moment before continuing.
‘The contact of these two separate moments in time will be minimal and fleeting. It will last for less than a second in time, and the spatial juxtaposition will be, to employ Newton’s own delightfully colourful phrase, “no bigger than a sentry box outside St James’s Palace”. Any person standing in that imaginary sentry box in 2025 would also be standing in it in 1914, instantly wiping out the previous reality and beginning the creation of an entirely new one. The whole one-hundred-and-eleven-year loop will be begun again. And the location where that notional sentry box will stand, the spatial coordinates where the twisted Slinky of space–time will cross itself, occurs in Istanbul.’
‘Constantinople!’ McCluskey shouted, unable to resist jumping up. ‘In Europe! I mean, come on! Is that fate or what? The place is barely seven hundred miles from Sarajevo! Fifteen hundred from Berlin! Newton’s coordinates could have dumped our man anywhere: the summit of Everest, the middle of the South China Sea—’
‘The burning superheated core of the planet,’ Sengupta interjected. ‘Space–time is no respecter of physical mass.’
‘Exactly,’ McCluskey went on exultantly. ‘Instead it’s “Who’s for a cup of Turkish coffee and a bit of belly dancing?” This is divine intervention, I tell you – it’s got to be. God gives us one shot at changing history and puts it exactly where it’s needed most.’
‘Let us be clear, Professor McCluskey,’ Sengupta said sternly, ‘whatever may be your religious beliefs, this is all about science. Newton, as I say, did the maths. He places his junction in space and time in Istanbul and his coordinates are fantastically specific. The crucial point occurs in the cellar of an old residential palace in the dockland area of the city. Newton secretly arranged for the purchase of the building, endowing that a hospital be established in it and ordering that the cellar henceforth remain forever locked.’