Time travel is best described as being able to move between two points in time much the way a person moves between two points in space. Time travel is a concept most often seen in science fiction. Questions about time travel can be directed here.
Asked in Physics, Scientists, Quantum Mechanics, Time Travel
What type of physicist studies time travel?
Theoretical physicist more than likely. As far as time travel I fear physicists have already discovered what is worth to be know. Travel towards future is in principle possible. It is sufficient to move with a speed near the light speed with respect to the starting inertial reference (the earth for one of us). The relativistic phenomenon of time compression provoke the time to pass much slower for the traveler with respect to the persons remaining in the "fixed" reference. When the traveler returns in the initial reference (the earth in our example) he effectively traveled towards the future. Unfortunately, travel towards the past is effectively impossible due to the causal nature of the laws of physics. As a matter of fact, reversing the time in only one phenomenon (the travel of our traveler in this case) violate the essential law of relativity that causal order has to survive between events happening in the same point of the space. Thus it is simply impossible. (look, I'm not going to retype his entire response but: e-mc^2 thus a particle with a negative mass will go at a negative velocity and thus backwards in time. such particles are thought to be possible (at least not counted out yet) there are also a million other ways that intelligent forces can bypass naturally unbreakable laws such as wormhole's, however improbable they may be, given infinite time and flexible enough conditions anything is possible. so go ahead and become a theoretical physicist and prove this guy wrong.) This renders traveling to future quite unattractive: It is impossible to return from such a travel.
Asked in Children's Books, Time Travel
How many pages are in Molly Moon's Hypnotic Time Travel Adventure?
Asked in Baseball, Cincinnati Reds, Time Travel
What is the time travel book about the Cincinnati Reds?
I just happen to be a huge Reds fan, an Aaron Boone fan, and an Adam Dunn fan. Anyway, enough about me. The book is "If I Never Get Back" by Darryl Brock. The copyright date is 1989. Buy it; it's a good one. Answer There's also a sequel called "Two in the Field." I really enjoyed them both, and I'm not even a big Reds fan. There's some great history and they're a quick, fun read.
What is the answer for Puzzle 97 Professor Layton's Last Time travel?
Professor Layton and the last time travel has now been renamed Professor Layton and the Unwound Future. Professor Layton 3, Professor Layton and the Unwound Future, has a confirmed release date of 20 September 2010 for North America. Expect a similar release date for Europe The Latest update for the release of the Unwound Future in the UK is Early October 2010. With this information in mind..can't answer puzzle 97 as I haven't seen the puzzle yet?
Asked in Santa Fe Trail, Time Travel
What was the record time travel to Santa Fe trail?
Francois-Xavier Aubry, a merchant trader, holds the uncontested record of traveling an seven hundred and eighty mile trip from Santa Fe to Independence in five days, 16 hours on horseback from September 12 to September 17, 1848. 190 miles a day. He broke six horses during the ride, walked twenty miles, slept two and a half hours and ate only six meals. Alexander Majors was the only man to leave an eye-witness account of Aubry's famous ride. Aubry's scheme of placing horses at stations along the way would be the inspiration for what became known as The Pony Express.
Update on Dr Ronald Mallett time travel information?
Asked in Inventions, Drawing, Benjamin Franklin, Time Travel
How do you draw a time machine?
Time machines do not exist, therefor drawing anything and claiming it is a time machine will be fine. Time travel is very likely impossible, so making something up might actually be more accurate than basing your idea on a theory which will later be said to have no possibility of working. Here's an idea to get you started see the Related Links
Asked in Inventions, Physics, Time Travel
What is needed for time-travel?
An infinitely long rotating cylinder. [cf. Frank J. Tipler's 1974 paper "Rotating Cylinders and the Possibility of Global Causality Violation", which shows that closed timelike curves are mathematically possible in the vicinity of such an object.] Barring that, you're pretty much out of luck, unless you just mean "into the future at one second per second," in which case a cardboard box will work fine. Being in an accelerating frame causes time to slow down for you relative to an observer in a non-accelerating frame, which could be considered a form of time travel. It still won't allow you to go backward in time, so in science fiction terms it's more like "suspended animation" than "time travel."
Asked in Time Travel, London Bridge
How did people in shakespeares time travel across the London bridge?
Asked in Inventions, Physics, Time, Time Travel
Will time travel ever become a reality?
Answer: In Metaphysics: Yes, time travel already is a reality. If time travel were not a reality, how then did we get suspended here in this temporal dimension of time and space? Time exists as a polar opposite to eternity, an opposite and equal reaction to time. This is evident when we try to measure the immeasurable universe. Time travel in our perception would imply rifts in the space-time continuum, causing a paradox, much like that seen in the movies "Back to the Future" and "Minority Report". Time travel is a reality according to Einstein's theory of relativity, where the faster an object travels, the slower time goes. Simply put, this is only possible with exponential proportions of speed, resulting in an explosive force that causes the matter traveling to turn into energy at the speed of light squared--this is to say that matter is what is traveling through time and space. If time travel ever became a reality for people, wouldn't we already known it by the rifts being caused? Let's say 1,000 years from now someone comes back to this time or to a time before this; we certainly would have historical records of the person that traveled through time; because they may even be pictured or written in history books! In the Bible: Apparently, time travel must be possible in order for the Bible to stand true, because the religious leaders said, "We are the children of Abraham." And Jesus responded, "I tell you the truth, before Abraham was, I AM." In a manner that truly defies space and time. In this case, this man is, was, and will always be the timeless man who defies the laws of nature; also, in order for people to see the future and write it down as prophecy, time travel must therefore be possible for this to work. Changing the events of prophecy, such as Nineveh with Jonah predicting their doom, is also apparent. This city turned to God and the prophecy of doom was taken back, and they were forgiven. This idea gives us a paradox of what would have happened had they not turned to God and the city was destroyed; certainly some people alive today would have then not been born! Time travel would therefore be too dangerous for us humans to play with. In Physics: It is an observation that two watches synched to exactly the same time, will show variations to the thousandth of a second when one watch is sent with a pilot at incredible speeds for a set duration on a fighter jet. However, this is barely measurable or even notable in our standards of "time." Nevertheless, if you had a hypothetical time machine, you could travel at a great speed and come back to earth thousands of years later, and only minutes would have passed in your relative dimension of "time." (But you'd have to travel precisely to the location earth would be in those thousands of years later... since earth is traveling through space! It's a long shot). Einstein proved with his theory of relativity that time travel is possible, but it's only scientifically proven to be able to travel forward in time. In conclusion, the only historical evidence of significant time travel is recorded in the Bible, since Jesus must have that power in order to be who he claimed to be--and in order for the prophets to obtain knowledge of the future to precision. This brings many questions to mind about paradoxes and destiny. In the television series "Heroes", Hiro can travel through time and space, even stop time--this is an interesting concept for those who wish to change the past or see what the future holds. Answer: Answer1, two parts: a) Time travel into the past probably never will be, but if it does happen, it will be only possible to "watch", and not interact or change things. Although this has not yet been proven, there are plenty of logical paradoxes that have been thrown up by time travel thought experiments that should convince us that this is the case. b) Time travel into the future is possible now. Travelling through space at high speeds means you also travel through time as well, although you only move forwards in time by small amounts unless your speed approaches that of light. The astronauts that went to the moon travelled forwards in time by a few seconds, i.e. the atomic clocks they took with them slowed by a few seconds, and the astronauts aged a few seconds less than they would have on earth. The answer 2 below is not incorrect (and this answer does not contradict it) - it's just that the further forwards in time you want to go and the faster you want to get to that future, time both get exponentially more difficult and expensive, because the power required gets exponentially great the faster in space you go because your mass increases exponentially towards infinity. If a cheap source of power is found to propel an ordinary space ship towards light speed, it would take a long time to get near to light speed, then time travel forwards will become commonplace. Answer 2: No, TIME TRAVEL IS NOT POSSIBLE. According to Einstein, time travel is not possible. We know that E=M(C*C). That is Energy = Mass into square the speed of light in vacuum speed of light in vacuum. Suppose we invent a machine for time travel and as we reach the speed of light, think of the energy needed to move the machine forward. i.e.: E=M(C*C) As the speed increases, the energy required to move the machine forward also increases and it is directly proportional to the fuel required as we near the speed of light; the energy required becomes nearly infinity and the fuel required to push the machine forward also nears infinity. But, the resources available right now in finite, so logically, time travel is not possible. Answer 3: Food for thought. I recall news announcements a few years back about a spaceship that was being built. It was past the theory of warping space to be able to travel to Mars, I think, in only hours. I seem to recall it was a European country?. If true perhaps this will mean time travel is indeed likely. There was an article on newscientist.com that described this, but has now been removed it seems. It was based on something called a Z particle. And it is USA not Europe sorry. After all, what man dreams today is tomorrows reality.<br><p>I think we all are travellers in time. Time and space, as I see it are being created at the border of the known universe. The bigger the universe becomes, the more space is created. In order to travel through space time is required. We think of speed as distance per time. I would like to turn this upside down and make time per distance of it. Now if one would like to travel faster than time, one would have to travel at less than zero seconds per distance! This implicates back in time. As E equals MC square, the energy added to increase speed would be converted to mass. I don't think time travelling is practicable. The answer above is practical. Talking more, it is actually possible to travel time. Relativity claims that time is another dimension, so like any other dimension it is possible to break the barrier of time too. The theory states that anything faster than light can travel time. But again the problem is the theory itself. It states (by equation E=MC2) that as the speed tends to increase the mass required to keep the speed increases and proportionately the energy required to power the body too increases. Thus by the speed of light the mass turns infinite and thus the energy turns infinite too. It is impossible to achieve infinite energy thus it is impossible to travel time. Ha, ha, ha, what a catch to the theory right. But the law doesn't stop using Tachyons which always travel faster than light. But Tachyons can only be used for information. No it can not be done because it passes on and that is just the way it goes.
Asked in Physics, Stephen Hawking, Time Travel
Do you guys think time travel is possible?
Yes it is possible. If you orbit a black hole a bit away from the event horizon in the speed of light then your movement in the time axis will be drastically slowed down with respect to the rest of the universe. Suppose you keep doing this for about a week and return to Earth. You would be baffled to see that the earth has probably aged a 1000 years or even more. Or maybe there is no Earth to return to. --- Yes, it is possible...but only if we can build a machine that can accelerate and reach the speed of almost the speed of light (the cosmic speed limit)...unfortunately, such a technology is still a long shot as people, enterprises, and even the governments are focusing on doing something else.
What experiments were they doing with time travel during the period 1939-45?
Asked in Astronomy, Black Holes, Astrophysics, Time Travel
Who can time travel in a black hole?
From what I've heard and read about the black hole, I don't believe anyone can enter a black hole and live. From what I've read, it sounds like you would be compressed. It would be like being crushed slowly without being touched. I'm just wondering if we can travel underneath it. If so, then we would know for sure it leads to another galaxy. It would be proof that time and space can be "torn" to go somewhere else. (Aside: You are only compressed in the relativistic dimension of travel. As you approach the speed of light you get less thick to an outside observer. To you, the traveler, everything is just fine.) Time doesn't really exist. It's merely a concept that exists because our lives eventually come to an end. Therefore we need to keep track of time. It is impossible to go back in time because time is only a mental concept. For time travel to be possible there would have to be an infinite number of realities all playing each moment simultaneously. Even so we would have no way of accessing these alternate realities. (Aside: Einstein says something about reality that is applicable to time as well. He stated "Reality is an illusion, albeit a persistent one. ...") Time exists because without time, the six string theory comes crashing down to a halt if you look at it carefully. It is not just a mental concept because we die, it is as real as anything else, and just because some people can't look behind the wall doesn't make it any less real. If you could time travel, the most complicated way is to send everything in reverse. But, I would most likely use the void (using the theories of alternate realities, there must be a void. otherwise the similar energy would merge (the void is the space between universes of universal radiation, and like two magnets repelling each other, the void is made up of a repelling force), for it does not accommodate time in any sort; it just merely exists, and you could basically just go from one spot of the time-space in the universe to another. But to answer the original question, no one can because you are just being crushed into a size which most people believe to be impossible to measure, so they call it infinitely small. Research on all the science fiction standbys (time travel, teleportation, etc.) is regularly reported in "Nature" magazine, a stodgy, peer-reviewed, British science publication. I have also found material prepared by Dr. Michio Kaku, co-founder of the string field theory who has written on the role of time travel in modern physics. In one of his discussions he states: "However, before Einstein died, he was faced with an embarrassing problem. Einstein's neighbor at Princeton, Kurt Godel, perhaps the greatest mathematical logician of the past 500 years, found a new solution to Einstein's own equations which allowed for time travel! The "river of time" now had whirlpools in which time could wrap itself into a circle. Godel's solution was quite ingenious: it postulated a universe filled with a rotating fluid. Anyone walking along the direction of rotation would find themselves back at the starting point, but backwards in time!" "In his memoirs, Einstein wrote that he was disturbed that his equations contained solutions that allowed for time travel. But he finally concluded: the universe does not rotate, it expands (i.e. as in the Big Bang theory) and hence Godel's solution could be thrown out for "physical reasons." (Apparently, if the Big Bang was rotating, then time travel would be possible throughout the universe!)." "Then, in 1963, Roy Kerr, a New Zealand mathematician, found a solution of Einstein's equations for a rotating black hole, which had bizarre properties. The black hole would not collapse to a point (as previously thought) but into a spinning ring (of neutrons). The ring would be circulating so rapidly that centrifugal force would keep the ring from collapsing under gravity. The ring, in turn, acts like the Looking Glass of Alice. Anyone walking through the ring would not die, but could pass through the ring into an alternate universe. Since then, hundreds of other "wormhole" solutions have been found to Einstein's equations. These wormholes connect not only two regions of space (hence the name) but also two regions of time as well. In principle, they can be used as time machines." Time is both a concept and physical, it is a concept because it exists without being touched by anything, it is physical because we exist in it. Though there are mathematical ways that may allow one to travel back in time, there is no real way to do that with any technology that we know of. Time is real. It is real just as space is real. We exist in the space-time continuum. In a relativistic universe, time is part of space-time. What is being debated is the nature of consciousness. And that is addressed elsewhere on the boards. Certainly time travel does happen in a black hole, if we chose to look at it that way. It's possible in that time for the (unlucky or lucky?) traveler who sails in will slow down. It won't appear that way to that traveler, of course, but to the outside observer, things will be slowing up until those outside observers lose sight of the voyager making the trip into the unknown. Whether or not the person travels back in time, goes "through" the black hole and emerges somewhere and sometime else, or simply becomes part of the collection of matter at the bottom of the gravity well can be debated ad infinitum. See the related question below. It is, "What is time?" It may help, or it may not. Time is REAL, although it is an illusion, because of Einstein's General Theory of Relativity in where gravity can effect time. So you see, because of the Earth and it's mass, and the other large bodies of mass around us, it shapes our "time." If we were to go to a different planet, it would have a different "time" than our own. Where I am going with this, is that black holes have such immense gravity, that it would completely warp time around you, but they think that you can time travel in one. It would have to be a rotating black hole so that the singularity would be ring shaped, because then it could be skipped, and thus (as is postulated) there would be an "Einstein-Rosen Bridge" that would put you into another time/universe. But, the bridge would always collapse right before entry, so you would be crushed into oblivion in the singularity.
Asked in Physics, Time Travel
Is time travel possible?
Various opinions, then the problems... There are several applications of theoretical physics that allow travel from one point in space-time to another. Some address the issue of travel into the past or the "future" but the concept of time as a "one-way arrow" makes future travel simply suspended time followed by a return to the present as the past. Some calculations include theoretical rotating black holes and their effects on time dilation (a generally accepted concept related to speed in a separate reference frame). But the principle of causation would create problems with interacting with or altering the past, which created the world from which the time traveler departs. At the current time (no pun intended) we can't prove the idea of time travel, seeing how we can not time travel right now. But we also can't just discard the idea seeing how physics doesn't disprove it. Memory may be considered time travel, a one way image of the past. If you can revisit the past through memory, that really is a ''time machine". It is theoretically possible to travel back in time. When an object is going extremely fast, such as the space shuttles, Time slows down just a little. The astronauts come back 2-3 seconds younger than they should be. This is called time dilation. Now if we talk about, hypothetically, if an object with mass traveling the speed of light, theoretically time would seem to "halt". And if you go faster than the speed of light, time would begin to go again, except backwards. In some mathematical theories, this is possible. But the only problem with proving this theory right is the Mass Factor. As you get closer to light speed, your mass increases. When you are traveling at light speed, you have infinite mass, which would make it impossible to go faster. Keep in mind, this only works to travel back in time, theoretically. One Way to the Future (time dilation) If you were to travel into outer space and then return to Earth at light speeds, you could actually "travel" thousands of years into the Earth's future! This is because traveling at close to the speed of light actually alters the passage of time: an object traveling at extremely high speeds will not age in the same way as an object which is static. So, if you were to stay on Earth, and your friend was to travel into space and travel distances at the speed of light and then return to Earth, your friend would return to Earth much younger than you, even though you were the same age before they left! Einstein explained motion in time with his theory of relativity: the stars bend time in space: it is time in space which dictates how the planets move, and at what regularity. Time in space is not absolute, i.e. it is not fixed, because it is relative to the speed at which you are moving. So really, time travel already occurs! But there are MAJOR Problems here... It seems that all the answers here are talking about the physical and fantastical possibility of time travel rather than a common sense approach to its possibility, with a pragmatic understanding of the limitations of physics and quantum mechanics. There are several problems with the arguments. To move backwards in time one would have to travel faster than light, in the same way as hypothetical particles called "tachyons", which would, if observed, disappear before they appeared (if you could believe that). However, Einstein showed that for a mass to travel at the speed of light it would require an infinite amount of energy as the mass of the object increases to infinity as well as time slowing down, so that an infinite amount of force would be needed to accelerate that infinite mass, and an infinite amount of energy needed to do so. Therefore matter cannot travel at light speed, let alone faster than light. Therefore, by Einstein's reckoning alone, time travel would not be possible. Secondly, as regards the principle of cause-and-effect, time travel would cause great paradoxical problems. The old chestnut of the grandfather paradox is a prime example. Suppose you travelled back in time, and met your grandfather and shot him dead, which may be perfectly possible. Your grandfather, being dead, would not have sired your father and therefore you would not exist - yet you must have existed to go back in time in the first place. Such a paradox sounds silly, but is perfectly possible if time travel existed. Therefore, anyone going backwards (or forwards) in time cannot have any effect on the surroundings (both in time and space)of where he or she ends up. Yet, the mere fact that they are there alters history. By the Chaos Theory, even a minor event can create a major difference in the nature of a place. Therefore just by being 'in history' could eventually change that history so much that our "history" would become different. But as it isn't different as texts, documentation and sources tell us, not even minor events could have been changed. In other words, no one must have been able to reach the past to cause that change. Thirdly, time travel is impractical even if you don't consider the almost infinite energy required. It's because you also need to consider the acceleration necessary to reach that speed. To reach the speed of light (or near it) with an acceleration of 1g (which would feel to the astronauts that they were back on the earth although 'weightless' in space) would take over 54 years of CONSTANT acceleration. Even at a constant 5g - the maximum experienced by astronauts in the space shuttle, and then only for very short periods because of the dangers, the time taken would be 13 years of constant 5g acceleration (meaning a 150 pound man would weigh 750 pounds for 13 years - enough to break his bones unless it was for a very brief period, let alone 13 years!). Even at 12g - the point at which the human body experiences brown outs, loss of peripheral vision blackouts, brain damage and death, even after short exposure, the time needed would be over four and a half years constant acceleration at this rate. Therefore, any attempt to even get close to time dilation speed is absolutely futile. Finally, if time travel will one day exist in the future, how is it that we have never seen travellers from the future visit us? UFO sightings are sometimes claimed to be 'time travellers' from the future, but the evidence is very scarce for this - and even more scarce for UFOs in the first place. It seems then that using simple common sense, time travel is an impossibility. So, I am sorry to disappoint everyone, but possibly Time Travel should be confined to H.G. Wells and Dr. Who, for science fiction is where it belongs. Einstein Would Say Yes First of all, to travel through time (forward) is what humans always do. However, to travel back in time.... well, Einstein would say it's possible. But the necessary technology currently does not exist. Time-travel as we consider it, will never be possible. Time is a concept, but not a physical dimension or place, nor is it something we can physically touch or measure. Time in reality is only motion. The motion is only forward. No matter what we do, we are unable to make this motion reverse and go backwards. At our best, if we managed to go faster than light, we could only observe the effects of what has happened, not reverse any of the processes of the universe itself. Einstein proved that time is relative. The faster the relative motion of a traveling object, the slower the progression of time observed in its reference frame. In effect, the aging of traveling cosmonauts will slow down. Because motion is relative, a cosmonaut who returns after traveling for 10 years at near the speed of light may find that the Earth has aged 100 years or more. This is not time travel. It is just a consequence of relative motion on a subatomic level near the speed of light. The cosmonauts may experience the effect as that they have traveled into the future. But in reality, they have only slowed down their atoms' motion, hence gaining the effect of slower/relative aging. Wormholes may still exist (or be created) for traveling to different places in the cosmos in a manner faster than light, but in no way will this allow for actual time-travel. Not forward in time - the perceived travel forward in time is a consequence of relative motion due to high speed. Not backwards in time - we cannot make universe go backwards. The motion in the cosmos cannot be undone, hence we can not travel back, only calculate motion backwards at best. By calculations, we can simulate how objects move and behave backwards and forwards in our concept of time. But to actually shift the universe so that we can end up at a fixed "stored" physical image of the cosmos itself...forget it.
How can you explain the Grandfather paradox?
Asked in Time Travel
If you could go back in time and do whatever what would you do and what time period?
What are the dangers of having a time machine?
you could change time so something doesnt exist such as a computer this would change everything as it is used in alomost every job.also you could change time so a certain someone doesnt exist such as the priminister then a war wouldn't happen then slodiers would be doing different jobs people would still be alive .The main risks are; -changing something so someone or something doesnt exist -getting stuck in the past/future coz something crushed your time machine then you cant go back to the present day.