View Full Version : Time Travel!

05-09-05, 21:48
Want to know how to go to the future or past the easy way...?

Time travel is possible by Clifford Pickover

What is time?
What is time? Is time travel possible? For centuries, these questions have intrigued mystics, philosophers, and scientists. Much of ancient Greek philosophy was concerned with understanding the concept of eternity, and the subject of time is central to all the world's religions and cultures. Can the flow of time be stopped? Certainly some mystics thought so. Angelus Silesius, a sixth-century philosopher and poet, thought the flow of time could be suspended by mental powers:
Time is of your own making;
its clock ticks in your head.
The moment you stop thought
time too stops dead.
The line between science and mysticism sometimes grows thin. Today physicists would agree that time is one of the strangest properties of our universe. In fact, there is a story circulating among scientists of an immigrant to America who has lost his watch. He walks up to a man on a New York street and asks, "Please, Sir, what is time?" The scientist replies, "I'm sorry, you'll have to ask a philosopher. I'm just a physicist."

Most cultures have a grammar with past and future tenses, and also demarcations like seconds and minutes, and yesterday and tomorrow. Yet we cannot say exactly what time is. Although the study of time became scientific during the time of Galileo and Newton, a comprehensive explanation was given only in this century by Einstein, who declared, in effect, time is simply what a clock reads. The clock can be the rotation of a planet, sand falling in an hourglass, a heartbeat, or vibrations of a cesium atom. A typical grandfather clock follows the simple Newtonian law that states that the velocity of a body not subject to external forces remains constant. This means that clock hands travel equal distances in equal times. While this kind of clock is useful for everyday life, modern science finds that time can be warped in various ways, like clay in the hands of a cosmic sculptor.
Science-fiction authors have had various uses for time machines, including dinosaur hunting, tourism, visits to one's ancestors, and animal collecting. Ever since the time of H.G. Wells' famous novel The Time Machine (1895), people have grown increasingly intrigued by the idea of traveling through time. (I was lucky enough to have chats with H.G. Wells' grandson, who told me that his grandfather's book has never been out of print, which is rare for a book a century old.) In the book, the protagonist uses a "black and polished brass" time machine to gain mechanical control over time as well as return to the present to bring back his story and assess the consequences of the present on the future. Wells was a graduate of the Imperial College of Science and Technology, and scientific language permeates his discussions. Many believe Wells' book to be the first story about a time machine, but seven years before 22-year-old Wells wrote the first version of The Time Machine, Edward Page Mitchell, an editor of the New York Sun, published "The Clock That Went Backward."

One of the earliest methods for fictional time travel didn't involve a machine; the main character in Washington Irving's "Rip van Winkle" (1819) simply fell asleep for decades. King Arthur's daughter Gweneth slept for 500 years under Merlin's spell. Ancient legends of time distortion are, in fact, quite common. One of the most poetic descriptions of time travel occurs in a popular medieval legend describing a monk entranced for a minute by the song of a magical bird. When the bird stops singing, the monk discovers that several hundred years have passed. Another example is the Moslem legend of Muhammad carried by a mare into heaven. After a long visit, the prophet returns to Earth just in time to catch a jar of water the horse had kicked over before starting its ascent.

Time travel is possible,
Today, we know that time travel need not be confined to myths, science fiction, Hollywood movies, or even speculation by theoretical physicists. Time travel is possible. For example, an object traveling at high speeds ages more slowly than a stationary object. This means that if you were to travel into outer space and return, moving close to light speed, you could travel thousands of years into the Earth's future.

Newton's most important contribution to science was his mathematical definition of how motion changes with time. He showed that the force causing apples to fall is the same force that drives planetary motions and produces tides. However, Newton was puzzled by the fact that gravity seemed to operate instantaneously at a distance. He admitted he could only describe it without understanding how it worked. Not until Einstein's general theory of relativity was gravity changed from a "force" to the movement of matter along the shortest space in a curved spacetime. The Sun bends spacetime, and spacetime tells planets how to move. For Newton, both space and time were absolute. Space was a fixed, infinite, unmoving metric against which absolute motions could be measured. Newton also believed the universe was pervaded by a single absolute time that could be symbolized by an imaginary clock off somewhere in space. Einstein changed all this with his relativity theories, and once wrote, "Newton, forgive me."

Einstein's first major contribution to the study of time occurred when he revolutionized physics with his "special theory of relativity" by showing how time changes with motion. Today, scientists do not see problems of time or motion as "absolute" with a single correct answer. Because time is relative to the speed one is traveling at, there can never be a clock at the center of the universe to which everyone can set their watches. Your entire life is the blink of an eye to an alien traveling close to the speed of light. Today, Newtonian mechanics have become a special case within Einstein's theory of relativity. Einstein's relativity will eventually become a subset of a new science more comprehensive in its description of the fabric of our universe. (The word "relativity" derives from the fact that the appearance of the world depends on our state of motion; it is "relative.")

We are a moment in astronomic time, a transient guest of the Earth. Our wet, wrinkled brains do not allow us to comprehend many mysteries of time and space. Our brains evolved to make us run from saber-toothed cats on the American savanna, to hunt deer, and to efficiently scavenge from the kills of large carnivores. Despite our mental limitations, we have come remarkably far. We have managed to pull back the cosmic curtains a crack to let in the light. Questions raised by physicists, from Newton to Kurt Gödel to Einstein to Stephen Hawking, are among the most profound we can ask.

Is time real? Does it flow in one direction only? Does it have a beginning or an end? What is eternity? None of these questions can be answered to scientists' satisfaction. Yet the mere asking of these questions stretches our minds, and the continual search for answers provides useful insights along the way

The future of time travel
Various researchers have proposed ways in which backward and forward time machines can be built that do not seem to violate any know laws of physics. Remember that the laws of physics tell us what is possible, not what is practical for humans at this point in time. The physics of time travel is still in its infancy. While all physicists today admit that time travel to the future is possible, many still believe time travel to the past will never be easily attainable. Don't believe anyone who tells you that humans will never have efficient technology for backward and forward time travel. Accurately predicting future technology is nearly impossible, and history is filled with underestimates of technology:
"Heavier-than-air flying machines are impossible." (Lord Kelvin, president, Royal Society, 1895)

"I think there is a world market for maybe five computers." (Thomas Watson, chairman of IBM, 1943)

"There is no reason for any individual to have a computer in their home." (Ken Olsen, president, chairman and founder of Digital Equipment Corp., 1977)

"The telephone has too many shortcomings to be seriously considered as a means of communication. The device is inherently of no value to us." (Western Union internal memo, 1876)

"Airplanes are interesting toys but of no military value." (Marshal Ferdinand Foch, French commander of Allied forces during the closing months of World War I, 1918)

"The wireless music box has no imaginable commercial value. Who would pay for a message sent to nobody in particular?" (David Sarnoff's associates, in response to his urgings for investment in radio in the 1920's)

"Professor Goddard does not know the relation between action and reaction and the need to have something better than a vacuum against which to react. He seems to lack the basic knowledge ladled out daily in high schools." (New York Times editorial about Robert Goddard's revolutionary rocket work, 1921)

"Who the hell wants to hear actors talk?" (Harry M. Warner, Warner Brothers, 1927)

"Everything that can be invented has been invented." (Charles H. Duell, commissioner, US Office of Patents, 1899) Wouldn't it be a wild world to live in if time travel devices played important roles in the development of humanity—like the computer and the telephone? Mathematicians dating back to Georg Bernhard Riemann (1826-1866) have studied the properties of multiple connected spaces in which different regions of space and time are spliced together. Physicists, who once considered this an intellectual exercise for armchair speculation, are now seriously studying advanced branches of mathematics to create practical models of our universe.

Science-fiction stories about space travel have already inspired humans to travel to the moon. Similarly, will time-travel stories inspire us to create real time-travel mechanisms? Will we ever find a way to overcome the Einstein speed limit and make all of spacetime home?

I wonder what humanity will discover about spacetime in the next century. Around four billion years ago, living creatures were nothing more than biochemical machines capable of self-reproduction. In a mere fraction of this time, humans evolved from creatures like Australopithecus. Today humans have wandered the moon and have studied ideas ranging from general relativity to quantum cosmology. Who knows into what beings we will evolve? Who knows what intelligent machines we will create that will be our ultimate heirs? These creatures might survive virtually forever, with our ideas, hopes, and dreams carried with them.

There is a strangeness to the cosmic symphony that may encompass time travel, higher dimensions, quantum superspace, and parallel universes—worlds that resemble our own and perhaps even occupy the same space as our own in some ghostly manner. Stephen Hawking has even proposed using wormholes to connect our universe with an infinite number of parallel universes. Edward Witten is working hard on superstring theory, which has already created a sensation in the world of physics because it can explain the nature of both matter and spacetime. By realizing that the fundamental laws of physics appear simpler in higher dimensions, string theory can unite Einstein's theory of gravity with quantum theory in ten dimensions. Our heirs, whatever or whoever they may be, will explore space and time to degrees we cannot currently fathom. They will create new melodies in the music of time. There are infinite harmonies to be explored.

Clifford Pickover is a research staff member at the IBM Thomas J. Watson Research Center. He is the lead writer for Discover Magazine's brain-boggler column and the author of Black Holes: A Traveler's Guide, among many other books. This article was adapted from: Time: A Traveler's Guide, by Clifford A. Pickover. Copyright © 1998 by Clifford Pickover. Used by permission of Oxford University Press, Inc.


Time Travel

This well-organized site, an excellent introduction to time travel, is designed for people with various levels of scientific knowledge. The site includes some of the mathematics that may support time travel as well as information on black-hole theory and the theory of relativity.

Virtual Trips to Black Holes and Neutron Stars

This site offers virtual trips via MPEG movies to neutron stars and black holes. Most movies are accompanied by a written description. The site also offers plenty of GIFs, a FAQ page, and links to other astronomy sites.

The Time Travel Research Center

This intriguing site offers authoritative studies on the history and philosophy of time, the physics of time travel, and experiments in time travel. Gain access to the Tri Star System, the world's largest information database of science, technology, and research related to time travel, and shop for time-travel-related products in the on-line store.

Brian's Views on Time Travel and Interdimensional Voyages

This page offers a paper that discusses the possibilities of time travel and covers the subjects of time dilation, wormholes, and the grandfather paradox.

The Theory Of Elementary Waves - Part 1

This site further develops the theory of time travel. It examines some of the basic principles of quantum physics, including the theory of elementary waves.

Black Holes and Time Warps: Einstein's Outrageous Legacy by Kip S. Thorne, Norton, 1994
In a book the Wall St. Journal called an "engrossing blend of theory, history, and anecdote," Kip Thorne, the Feynmann Professor of Theoretical Physics at the California Institute of Technology, discusses everything from black holes to wormholes, with the final chapter devoted to time travel. The book's glossary is excerpted in Timespeak.

Time: A Traveler's Guide by Clifford A. Pickover, Oxford University Press, 1998
Pickover, the lead writer for Discover Magazine's brain-boggler column, eases the reader into the arcane theory behind time travel with amusing fictional narratives, in which two people in a Museum of Music in New York experiment with time. See Traveling Through Time for an excerpt.

A Brief History of Time: The Illustrated, Updated, and Expanded Edition by Stephen Hawking, Bantam Books, 1996
Physics and the nature of time conveyed with the remarkable wit, clarity, and patience of the foremost theoretical physicist since Einstein. Illustrated with striking color imagery.

Time Machines: Time Travel in Physics, Metaphysics, and Science Fiction by Paul J. Nahin, Springer-Verlag New York, 1993
Paul Nahin doesn't write like an engineering professor, but that's what he is (at the University of New Hampshire). With often amusing references to novels, comics, and sci-fi films, Nahin takes on the daunting topic of time machines with erudition and flair.

Faster: The Acceleration of Just About Everything by James Gleick, Pantheon Books, 1999.
In his latest work, James Gleick explores our increasingly speed-driven world. He specifically investigates the newest paradox of time: as technology accelerates, offering more time-saving devices, the notion of haste only increases. From atomic clocks, to answering machines, to the bunkers of war, Gleick approaches the subject from diverse perspectives.

Special Thanks
Joe McMaster
Kip Thorne
Clifford Pickover
Oxford University Press
W.W. Norton and Company

Lauren Aguirre, Senior Producer
Kim Ducharme, Senior Designer
Tyler Howe, Assistant Designer
Brenden Kootsey, Technologist
Rob Meyer, Production Assistant
Jeffrey Oar, Intern
Peter Tyson, Producer

here is where I copyed it from
Here is the link (http://www.pbs.org/wgbh/nova/time/)

so, what do you think?

06-09-05, 06:51
you should rephrase that and say time travel is theoretically possible.

06-09-05, 10:43
I've always been fascinated by time travel, but I don't think it would be possible for humans to travel at light speed, though... I think something would happen like either we (and the machine, whatever it was) would burn up... or it would have some really drastic effect on the body. But I'm only thinking hundreds of years ahead... in thousands of years... who knows?

But time is only a relative concept anyway, and doesn't actually "exist" as such... I think by the time we've got to the stage of technology necessary to "visit" the past or future, we might not want to any more... :worried: ... There are also weird issues to get your head around, like the possibility of meeting yourself... would that be possible? :? And if so, what implications does that have for understanding consciousness? :mad:

06-09-05, 10:53
Before visiting your past our your future, what about simply visiting your familly, your friends? I'm sure that it will be much appreciated, and surely more usefull :valentine :thankyou:

(...easy to say. I'm the first one who should fellow that advice :wary:)

PS: should I add that I don't think that past travel is possible? Travel in the futur, well, dunnot know, but if it was the case, I don't believe that one could come back to his "present" time, as it will be his "past" in the "future" where he'll be. Past is not "behind". It's just "passed", no more existing, so no way to "find" it back (or perhaps just by recordings)...well, my point of view.

06-09-05, 11:10
Time travel is theoretically possible, and I think it will become physically possible someday. I think we will be able to go into the past and do what the hell we like, but still return to our own future. I think the changes we make in the past will just create a new parallel universe, but we will be forced back into our own present as that is the only one where our current selves could possibly exist. :souka:

06-09-05, 11:33
Tsuyoiko, what would be "the past" for you? Would it be a palce "somewhere" where you could go? If yes, will us (staying in the present) continue to live normaly, or will our time be stopped as long as you are away?

Another one: if "past" still exists "somewhere", -our- past, does it mean that people living there don't have the liberty of mouvement or thinking (of course, it's our past, and by definition, to become one day our "present", it has to follow the same line we followed before)? In other words, those people would have no other choice to follow that "destiny"? The same question for us, as we would be the "past" of any "future" in front of us...

My point is that, if past "still exists", we are doomed, because that would mean that is has to follow a specific destiny to become what we are living now. If it is not the case...then it would simply mean that it is not "our" past. Personnally, I don't want to believe that my path is already choosen ;-)

06-09-05, 12:14
Hi Mamoru-kun :wave: The way I see it, time is a 'place', it is just another dimension, exactly like the three spatial dimensions and n-quantum dimensions. I think every moment exists simultaneously, and it is only our very limited perceptions that make it seem otherwise. So anyone in the past or future is having exactly the same experience as we are - our past is their present, and each of us exists in our own present. If we were to go back in time, we would just be elsewhere. Those in our present would just say "Oh, Mamoru has gone away to 1969", it is no different from "Mamoru has gone away to Japan".

As for the destiny thing, I invoke the infinite parallel universes again. Each time you have a decision to make, a new parallel universe is 'created' (although they all already exist in some sense) for each outcome. So you have complete freedom to choose which universe you end up in, depending on which outcome you choose. :relief:

06-09-05, 12:47
Mmmm, I see. But in such conditions, would it be right to speak about our "past", if all those Worlds are not linked. If I well understood, my "father" I would meet in one of those parallel universe wouldn't be "my" father, just some kind of "copy" in that other dimention. So going back in time wouldn't bring you back to the one you've lost...I think that I still prefer to stay in our present time then, than meeting someone which only looks like someone I wanted to meet again ;-)

06-09-05, 14:40
Mmmm, good objection. I hadn't thought of that. But I would argue that the past you go back to is your own past, but any alternative presents you create will not change your own present. Even meeting yourself shouldn't be a problem, as it would just create another present in which you met yourself.

06-09-05, 15:05
Another tricky question: when you look at stars with a telescope, you see images which have been sent years ago. In other words, you see past images of the actual objects you are seing (as the light took years to arrive to you). Regarding our actual discution, would those "past" images be "actual" images of one of those "past" dimention? ;-)

06-09-05, 15:51
Actually, that is one reason I am convinced that time travel is possible. In a sense we look back in time every time we look at the sky, and it is only one more step to actually go there.

Dutch Baka
06-09-05, 21:51
I dont want to time travel, i will **** up everything then haha.. travel to the future? mmm i am happy now!!! i dont want to know what i look like when i am 60.. i already know i will look like sean connery so no worries :p

but yeah.. seems fun, for people who want to :-)

Sensuikan San
09-09-05, 04:41
One day, I'm sure they will get time travel to work properly - but, take my word for it, they haven't to date!

I can't get back!

and ... hell! This is a long time ago, isn't it ... !


W :biggrin:

09-09-05, 06:23
Another tricky question: when you look at stars with a telescope, you see images which have been sent years ago. In other words, you see past images of the actual objects you are seing (as the light took years to arrive to you). Regarding our actual discution, would those "past" images be "actual" images of one of those "past" dimention? ;-)

whats a discution and did you mean dimension? of course we see past images, things are very very very far away, light doesnt travel at an instant speed. however light travels the fatest out of anything we know. even looking at your computer now you are seeing a very short glimpse of the past without even noticing it. with that said, how is there another dimension. we live in a 3rd dimension so you must show some evidence to prove that the images we see from space are captured in another dimension. most of the time it is in the 2nd dimension because that is a man made world. The only reason it is 2d is because of the devices that we use. as for time travel, maybe going to the past would screw things up but i havent seen a theory to travel back in time yet, only the future.

09-09-05, 10:04
Someone said one day that only lovers can travel in time ;-)
More seriously, what I said above is that what you see while looking distant stars is a past image of them. If it's true that there is other dimensions with other times lines of our actual universe, what do prove that what you are seeing is a past image of our actual universe, and not an actual image of one of those "parallel universe"? Would it be unthinkable that the space around us, as far as we can see it, is not one single universe, but infinite parallel universes just intricating one in another (like a onion skin. Its center would be yourself, and each skin part (sorry, don’t know the English term) around you would be a parallel universe slightly in your past)? And eh, there is also no way proving that this way of thinking is not true ;-)

09-09-05, 10:20
Thanks Mamoru-kun! Onion skins is a great description. I was trying to think of something based around the parallel universes being layers, but I couldn't describe it well. We live in a big onion! (No wonder I'm always crying :bawling: :emblaugh: )

09-09-05, 17:17
if you think of a dimension as in sight we can not see other dimensions with our vision, and if we see something from another dimension then something has to happen between the two dimension for something to cross over, sure we could see light from another dimension but it would be in our own dimension at the time. makes sense doesnt it?

13-09-05, 03:08
If you could travel into the past.. you couldn't travel before the time machine was created, because the time machine wouldn't have existed. Also, as soon as we turned on the time machine (even if it was to allow particles to go through time) it would open the door for time travellers in our future to send messages to us.

Also there are many paradoxes of time travel. What if you went back to the future when your grandfather was alive, before he had your father, and you shot him? And killed him. Then when you travelled to the future, theres a few possbilites that would happen.
a) You wouldn't exist because you killed your grandfather, who in turn had your father, and then your father had you.
b) You would end in in a parallel universe, which looks the same, but in which different things have happened. i.e Hilter might have won the war. You would be lost in time and space. If the theory is true, there may be an infinite amount of universes, each slightly different.

Currently, there are no laws of physics that permit the speed faster than light. However, there are of course a few loopholes out of this. There is rule in phyiscs called time dilation. It says the faster you travel, the slower time moves around you, and you age less relative to an observer in a stationary position. Astronauts are known to have aged a few microseconds less than someone on earth. However, there would be many, many problems getting to the speed of light. As you approach the speed of light (C), it takes more energy and relative to stationary obeserver you appear to flatten. Eventually it will require an infinite amount of energy, which is impossible. Your mass increase(?) as you travel faster. Um lets see what else. Oh yeah

Light travels at a constant speed to all obeservers. I think its 186,000 Miles per SECOND. Which is important, although I don't remember why.
Also, if you could somehow travel at C, alot of strange things would happen. Light would appear to stop?

Therefore, alot of people talk about approaching C or -> C
Oh yes, and if you could travel FASTER than the speed of light, you would travel into the past.
a good forum for this subject would be www.physicsforums.com

13-09-05, 03:11
One more thing, if you watched the "Time travel" 1 hour show on the science channel, you would find out there is already at least on phycist working on creating a time machine. He is using high powered lasers to warp spacetime. It might just do the trick.

13-09-05, 12:32
Also there are many paradoxes of time travel. What if you went back to the future when your grandfather was alive, before he had your father, and you shot him? And killed him. Then when you travelled to the future, theres a few possbilites that would happen.
a) You wouldn't exist because you killed your grandfather, who in turn had your father, and then your father had you.
b) You would end in in a parallel universe, which looks the same, but in which different things have happened. i.e Hilter might have won the war. You would be lost in time and space. If the theory is true, there may be an infinite amount of universes, each slightly different.
Look at my posts above for a third possibility - i.e. that there are parallel universes, but you will always be forced back to your own present.

15-03-12, 20:20
I think it`s safe to say that time travel might never be possible, why? Well surely we would have come back at some stage to tell about it!

15-03-12, 22:06
I think it`s safe to say that time travel might never be possible, why? Well surely we would have come back at some stage to tell about it!
Good point. Few thousand years of written history and there are no reports about knowen travelers from the future.

16-03-12, 17:51
I would think in the future if time travel is ever possible. There would be rules for it's use much like Star Trek's prime directive. Not to interfere with the past mostly just observe from a safe distance.

04-12-12, 16:30
too long didn't read...but I know you what you are going to say. Do anyone is a doctorwho fan? Is it possible to build a TARDIS to have a time travel in future? It's quite complicated if we are able to time-travel since there is too many conflict that may change the history and present in a tiny act. You will understand if you know about time. wibbly wobbly timey wimmy..

08-07-13, 10:36
Time travel is impossible

26-08-18, 20:19
Fine thought

27-08-18, 15:33
Wikihistory | Tor.com (https://www.tor.com/2011/08/31/wikihistory/)

27-08-18, 15:37
Wikihistory | Tor.com (https://www.tor.com/2011/08/31/wikihistory/)

ALIENCON Baltimore MD, Nov 9-11 2018 ( Giorgio will be there too )


01-10-18, 15:46
Everything in the universe is traveling through time. As NASA pointed out, we’re all going at the same rate: 1 hour per hour. But can this rate be changed? Increased? Decreased?
Space Journal speculated that time — coined “the arrow of time” for its forward movement — bears a striking similarity to the second law of thermodynamics, which states that entropy (or chaos) only increases. That is, entropy only flows in one direction.
Any theory of time travel, therefore, must answer two critical questions: Can we speed up time and make it go faster? And, can we change its direction?

18-06-19, 14:25
That's an interesting concept. Hope humanity will reach it someday.