Time travel

“ As a research physicist, I have for many years been convinced of this."
"You mean that time travel really is possible? That men can be transported into the future or the past—"
The other held up a restraining hand.
"Yes. Time travel is possible, if men could break through into that other dimension." A pause. "Yet up until tonight, I never believed that man had found a way to pass that barrier."
"But professor! Think what you're saying! You're telling me that I could go back and murder my own grandfather. ”

“ For obvious reasons, since time-travel has yet to be invented as far as we know, science fiction authors usually attribute it to the future. Yet there is always the possibility that somewhere, somehow, somewhen, it has already been put to use. ”

“ Instead, we travel in time. Surely any race that has progressed as far as your own must know, at least theoretically, that time travel is entirely possible. After all, we knew it, and we haven't been around nearly as long as you have. ”

“ Time-travel continues to exercise its mesmeric fascination upon writers, readers and editors of science fiction alike. Probably because almost all of us, at one time or another, have longed greatly to visit either the future or the past. ”

“ Such return, they claim, would immediately cause a forking of the Earthways, leaving our version of the world untrodden by time-traveling feet. As to the clincher, they counter-question with a How do we know we haven't had such visitors? Time-travel, when it comes, will come in a far-distant future. At such a distance the mere six thousand years of recorded human history is a mere fly-speck on the annals of Earth. ”

“ I said finally, "you're the G.L.E. on this future science stuff—"
"The what?"
"Greatest Living Expert. Latest Pentagonese. Tell me, what do you think of the possibility of ever being in touch with the future?"
"You mean time travel?"
"I guess that's what you'd call it."
"Time travel is nonsense," he said. "A logical absurdity. By definition, time is a series of infinitesimally small moments in succession. Once a point in time is established, it can't be changed, any more than energy can be destroyed." ”

“ Warp space with a rapidly moving object, move away from the observer with the speed of light—and the whole of human history assumed the firm contours of a landscape in space. Time and space merged and became one. And a man in an intricately-equipped Time Observatory could revisit the past as easily as he could travel across the great curve of the universe to the farthest planet of the farthest star. ”

“ I pressed the lever over to its extreme position. The night came like the turning out of a lamp, and in another moment came tomorrow. The laboratory grew faint and hazy, then fainter and ever fainter. Tomorrow night came black, then day again, night again, day again, faster and faster still. An eddying murmur filled my ears, and a strange, dumb confusedness descended on my mind.
“I am afraid I cannot convey the peculiar sensations of time travelling. They are excessively unpleasant. There is a feeling exactly like that one has upon a switchback—of a helpless headlong motion! ”

“ For example, if a person could leave the earth and travel about for a time and then return, the time between his departure and return would be less by his clocks than by those on the earth: the earth, in its journey round the sun, chooses the route which makes the time of any bit of its course by its clocks longer than the time as judged by clocks which move by a different route. This is what is meant by saying that bodies left to themselves move in geodesics in space-time. ”

“ There are really four dimensions, three which we call the three planes of Space, and a fourth, Time. There is, however, a tendency to draw an unreal distinction between the former three dimensions and the latter, because it happens that our consciousness moves intermittently in one direction along the latter from the beginning to the end of our lives.'
'That,' said a very young man, making spasmodic efforts to relight his cigar over the lamp; 'that ... very clear indeed.'
'Now, it is very remarkable that this is so extensively overlooked,' continued the Time Traveller, with a slight accession of cheerfulness. ”

“ The behavior of clocks during travel in the curved space-time of the general theory of relativity is discussed, and effects observable in journeys in the solar system or on earth satellites are examined. ”

“ At the risk of disappointing Richardson I stayed on, waiting for the Time Traveller: waiting for the second, perhaps still stranger story, and the specimens and photographs he would bring with him. But I am beginning now to fear that I must wait a lifetime. The Time Traveller vanished three years ago. And, as everybody knows now, he has never returned.
Epilogue
One cannot choose but wonder. Will he ever return? ”

“ The Time Traveler said nothing in reply, but smiled and began tapping his pipe upon the fender curb. This was the invariable presage of a dissertation.
"You have to admit that time is a spatial dimension," said the Psychologist, emboldened by immunity and addressing the Medical Man, "and then all sorts of remarkable consequences are found inevitable. ”

“ For instance, if I am recalling an incident very vividly I go back to the instant of its occurrence; I become absent-minded, as you say. I jump back for a moment. Of course we have no means of staying back for any length of time any more than a savage or an animal has of staying six feet above the ground. But a civilized man is better off than the savage in this respect. He can go up against gravitation in a balloon, and why should we not hope that ultimately he may be able to stop or accelerate his drift along the Time Dimension; or even to turn about and travel the other way?" ”

“ What will you take for the lot?'
The Time Traveller came to the place reserved for him without a word. He smiled quietly, in his old way. 'Where's my mutton?' he said. 'What a treat it is to stick a fork into meat again!'
'Story!' cried the Editor.
'Story be damned!' said the Time Traveller. 'I want something to eat. I won't say a word until I get some peptone into my arteries. Thanks. ”

“ The Man Animal and Nature's Timepieces The story of the watch that you hold in your hand to-day began countless centuries ago, and is as long as the history of the human race. When our earliest ancestors, living in caves, noted the regular succession of day and night, and saw how the shadows changed regularly in length and direction as day grew on toward night, then was the first, faint, feeble germ of the beginning of time-reckoning and time-measurement. ”

“ On a motion picture film you would call it the next frame, or still picture. In radio you would say it has a trifle different tuning. Thus we have a pseudo-movement—Events. And we say that Time—the Time-scroll—keeps them separate. It is we who change—who seem to move, shoved along so that always we are compatible with Time.
nd thus is Time-traveling possible. With a realization of what I have here summarized, Harl and the cripple Tugh made an exhaustive study of the vibratory factors by which Matter is built up into form, and seeming solidity. ”

“ Celerity of motion and brevity of duration are discovered to be its chief characteristics. Time is therefore depicted as flying,—fast, noiselessly, and uninterruptedly. It is a river, speeding on with imperceptible but resistless pace to the ocean of eternity. ”

“ How a Mechanical Toy Became a Scientific Timepiece Now, since we are at last well into the story of the watch, let us glance back over the road we have traveled. We have seen man first beginning to think of time by noting the positions of shadows or the motions of the stars. Next, we have seen him making his plans for days ahead by means of the changes in the moon, then by making such division in the flow of time as the month, the season, and the year. ”

“ Whoever says, “In the universe at large only the present state of things is real, only the present movement of the stars, the present streamings of radiant light, the present deeds and thoughts of men are real; the whole past is dead; the whole future is not yet,” — any such reporter of the temporal existence of the universe may be invited to state how long his real present of the time-world is. ”

“ The fourth and last chapter will deal with the astronomical motions on which our time-keeping is founded, our present hour zones of time, and close with suggestions for a universal time system over the whole world. ”

“ Even the geological epochs — though they should be to our measurements of time what the inter-planetary spaces are to the distances on our globe — what are they to Him whose existence is from eternity to eternity, from the illimitable past to the illimitable future? ”

“ But there is one thing in our modern timekeeping which we still have in common with the first men who ever kept the time. We still go by the sun and the stars and refer all our measure to that apparent revolution of the heavens which we know to be really the motion of our world itself. As did those wise men of old Babylon, so do we even now, spying upon the mighty master clock of the universe to correct all our little timepieces thereby. A man sits alone in an observatory, with his eye to a telescope. ”

“ This, which is not strictly true of our feeling of time per se, as an elementary bit of duration, is true of our feeling of date in its events.
[556] We construct the miles just as we construct the years. Travelling in the cars makes a succession of different fields of view pass before our eyes. When those that have passed from present sight revive in memory, they maintain their mutual order because their contents overlap. ”

“ For how could 'time' be measured in minutes or hours by a woman wearing a blindfold, shut away in the dark, and waiting a verdict that could cause the future to slough away into chill gulfs? And how could 'time' have any meaning when the stars faded out of the sky and a sunset gun boomed farewell to the joys of the physical world? ”

“ Events are then conceived to move from the past through the present into the future, just [Pg 37] as a pencil point may pass from the beginning of the line through its middle point to the end. But, unlike the pencil point, they can not go backward. This fact gives us a characteristic by which we may distinguish time from space even if we have represented time spatially. The spatial order is reversible, the temporal is not. Time is like a line on which you can go forward, but on which you can not go backward. But you can go forward. Everything goes from the past to the future. ”

“ She looked on a neat little world of Time: Time ran upon steel tracks, Time carried mites of human life rigidly down a tiny way. The trains, the houses, the streets, the wisps of sunny cloud through the roof’s gap ... all was a pasty toy-world: make-believe: the world of Time and Space. She gazed on it in passionate condescension within her sooty workroom, hands paying, brow in search paying.... ”

“ This Succession of temporal Ideas impressed, or excited in the Mind, as an Effect of Matter in Motion, producing a perpetual Change, both of Objects earthly and celestial, enables us not only to reflect upon past Vicissitudes of Nature, but from their regular Courses, known Order and Returns, predict Phænomena to come, and prove the periodical Effects of Nature's constant Laws so just and certain, that Time may be said with Truth, to co-exist with Motion. ”

“ There is only one portion of Time—one instant of Time—to which that vibratory rate is compatible. Time sorts us out; starts each consciousness in its proper niche.
We become thus, part of the Great Pattern. We are aware only of the Time-intervals between our changes. And so it seems to us that we move forward in Time—or that Time ticks past us, as you will. But in reality, upon the great Record of Time, is engraven as it were a myriad pictures of us in our progressive changes—and we have the consciousness to be aware of them. ”

“ Time travels in divers paces with divers persons. I'll tell you who time ambles withal, who time trots withal, who time gallops withal, and who he stands still withal. ”

“ Truly it is hard for us to realize what a part time has played in the earth's history,—just time, duration,—so slowly, oh, so slowly, have the great changes been brought about! The turning of mud and silt into rock in the bottom of the old seas seems to have been merely a question of time. ”

“ Now, just as she wrote, the clock, which I was careful not to meddle with, had been rapidly gaining time, and I was standing before it, watching it from hour to hour, and slightly changing its rate by dropping small weights upon its pendulum. Time is so important an element with the astronomer, that all else is subordinate to it. ”

“ Now I say that when a body travels, if it is left to itself, it chooses the route which makes the time between two stages of the journey as long as possible; if it had traveled from one event to another by any other route, the time, as measured by its own clocks, would have been shorter. ”

“ It is now come to fill a great chasm in the history of the universe. It is not intended to resemble the generality of modern travels, the agreeable and rational amusement of one vacant day, it is calculated to employ a greater space of time. ”

“ I saw his famous clock last winter at Mr. George Graham’s: the sweetness of its motion, the contrivances to take off friction, to defeat the lengthening and shortening of the pendulum through heat and cold, and to prevent the disturbance of motion by that of the ship, cannot be sufficiently admired.”—Ms. Journal. [18]
An exact measure of time is of the utmost importance to many of the sciences. Horology is indispensable to astronomy, in which the variation even of two or three seconds is of the greatest consequence. ”