my life in the Cage of Light became a little more civilized. If you imagine the contents of a cheap hotel room dumped into the middle of the floor of some vast ball room, you will have the picture of how I was living. When I pulled together the chair, trays and blankets I had something of a cosy nest, and I did not feel quite so exposed; I took to placing my jacket-pillow under the chair, and so sleeping with my head and shoulders under the protection of this little fastness. Most of the time I was able to dismiss the prospect of stars beneath my feet – I told myself that the lights in the Floor were some elaborate illusion – but sometimes my imagination would betray me, and I would feel as if I were suspended over an infinite drop, with only this insubstantial Floor to save me.
All this was quite illogical, of course; but I am human, and must needs pander to the instinctive needs and fears of my nature!
Nebogipfel observed all this. I could not tell if his reaction was curiosity or confusion, or perhaps something more aloof – as I might have watched the antics of a bird in building a nest, perhaps.
And in these circumstances, the next few days wore away – I think four or five – as I strove to describe to Nebogipfel the workings of my Time Machine – and as well seeking subtly to extract from him some details of this History in which I had landed myself.
I described the researches into physical optics which had led me to my insights into the possibility of time travel.
‘It is becoming well known – or was, in my day – that the propagation of light has anomalous properties,’ I said. ‘The speed of light in a vacuum is extremely high – it travels hundreds of thousands of miles each second – but it is finite. And, more important, as demonstrated most clearly by Michelson and Morley a few years before my departure, this speed is isotropic … ’
I took some care to explain this rum business. The essence of it is that light, as it travels through space, does not behave like a material object, such as an express train.
Imagine a ray of light from some distant star overtaking the earth in, say, January, as our planet traverses its orbit around the sun. The speed of the earth in its orbit is some seventy thousand miles per hour. You would imagine – if you were to measure the speed of that passing ray of star-light as seen from the earth – that the result would be reduced by that seventy thousand-odd miles per hour.
Conversely, in July, the earth will at the opposite side of its orbit: it will now be heading into the path of that faithful star-light beam. Measure the speed of the beam again, and you would expect to find the recorded speed increased by the earth’s velocity.
Well, if steam trains came to us from the stars, this would no doubt be the case. But Michelson and Morley proved that for star-light, this is not so. The speed of the star-light as measured from the earth – whether we are overtaking or heading into the beam – is exactly the same!’
These observations had correlated with the sort of phenomenon I had noted about Plattnerite for some years previously – though I had not published the results of my experiments – and I had formulated an hypothesis.
‘One only needs to loosen the shackles of the imagination – particularly regarding the business of Dimensions – to see what the elements of an explanation might be. How do we measure speed, after all? Only with devices which record intervals in different Dimensions: a distance travelled through Space, measured with a simple yardstick, and an interval in Time, which may be recorded with a clock.
‘So, if we take the experimental evidence of Michelson and Morley at face value, then we have to regard the speed of light as the fixed quantity, and the Dimensions as variable things. The universe adjusts itself in order to render our light-speed measurements constant.
‘I saw that one could express this geometrically, as a twisting of the Dimensions.’ I held up my hand, with two fingers and thumb held at right angles. ‘If we are in a framework of Four Dimensions – well, imagine rotating the whole business around, like this –’ I twisted my wrist ‘– so that Length comes to rest where Breadth used to be, and Breadth where Height was – and, most important, Duration and a Dimension of Space are interchanged. Do you see? One would not need a full transposition, of course – just a certain intermingling of the two to explain the Michelson-Morley adjustment.
‘I have kept these speculations to myself,’ I said. ‘I am not well-known as a theoretician. Besides, I have been reluctant to publish without experimental verification. But there are – were – others thinking along the same lines – I know of Fitzgerald in Dublin, Lorentz in Leiden, and Henri Poincaré in France – and it cannot be long before some more complete theory is expounded, dealing with this relativeness of frames of reference …
‘Well, then, this is the essence of my Time Machine,’ I concluded. ‘The machine twists Space and Time around itself, thus mutating Time into a Spatial Dimension – and then one may proceed, into past or future, as easy as riding a bicycle!’
I sat back in my chair; given the uncomfortable circumstances of this lecture, I told myself, I had acquitted myself remarkably well.
But my Morlock was not an appreciative audience. He stood there, regarding me through his blue goggles. Then, at length, he said, ‘Yes. But how, exactly?’
This response irritated me intensely! I got out of my chair and began to pace about my Cage. I came near to Nebogipfel, but I managed to resist the impulse to lapse into threatening simian gestures. I flatly refused to answer any more questions until he showed me something of his Sphere-world.
‘Look here,’ I said, ‘don’t you think you’re being a little unfair? After all, I’ve travelled across six hundred thousand years to see something of your world. And all I’ve had so far is a darkened hill-side in Richmond, and –’ I waved a hand at the encircling darkness ‘– this, and your endless questions!
‘Look at it this way, Nebogipfel. I know you will want me to give you a full account of my journey through time, and what I saw of History as it unfolded to your present. How can I tell such a tale if I have no understanding of its conclusion? – let alone of that other History which I witnessed.’
I left my speech there, hoping I had done enough to convince him.
He lifted his hand to his face; his thin, pallid fingers adjusted the goggles resting there, like any gentleman adjusting a pince-nez. ‘I will consult about this,’ he said at last. ‘We will speak again.’
And he departed. I watched him walk away, his bare soles pad-padding across the soft, starry Floor.
After I had slept once more, Nebogipfel returned. He raised his hand and beckoned; it was a stiff, unnatural gesture, as if he had learned it only recently.
‘Come with me,’ he said.
With a surge of exhilaration – tinged with not a little fear – I snatched my jacket up from the Floor.
I walked beside Nebogipfel, into the darkness which had encircled me for so many days. My shaft of sunlight receded behind me. I glanced back at the little spot which had been my inhospitable home, with its disordered trays, its heap of blankets, and my chair – perhaps the only chair in the world! I will not say I watched it go with any nostalgia, for I had been miserable and fearful during the whole of my stay in that Cage of Light, but I did wonder whether I would ever see it again.
Beneath our feet, the eternal stars hung like a million Chinese lanterns, borne on the breast of an invisible river.
As we walked, Nebogipfel held out blue goggles, very like the set he wore himself. I took these, but I protested: ‘What do I need of these? I am not dazzled, as you are –’
‘They