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How to Build a Time Machine
frank249 writes "The September issue of Scientific American has an article discussing the possibility of time travel. They say that it wouldn't be easy, but it might be possible. It could be a while until we can expand worm holes and tow them to a neutron star but didn't someone say that if it is possible it will happen. If it is impossible it will just take a little longer."
I move we call for a slashback in a few hundred years when this might be possible. ;-)
Wouldn't the best way to speed up things for this be to leave a post-it note stuck in the files saying "when this is finally invented, please travel back to August 24, 2002AD and provide the HOW-TO."
--
Todd
Go back in time and stop CmdrTaco from starting Slashdot. This way the trolls would never be around to make asinine comments like the parent. You know you agree with me, too!
Well, I think it may happen in just 7 months and a few days. In April the 1st of 2003 is the expected deployment date, to be exact.
As long as you pay the toll...
"Somebody's gotta go back and get a shitload of dimes!"
This post made to eliminate an accidental bad moderation on the parent. please ignore.
I thought the reason that clocks ran faster in the attic than the basement was because of gravity's affect on the MECHANISM rather than gravity's affect on time. Likewise could be said about the atomic clocks. The clock is travelling thru quite a bit more space than it would if it were sitting, could subatomic particles affect it's function and accuracy?
The previous has been a secret message to my comrades.
This article was posted years ago.... Oh umm. Wait a minute. Never mind. I never saw this article before. Yea thats it. I never this article before. Realy I have never saw this article. Why are you looking at my third eye funny?
If something is so important that you feel the need to post it on the internet... It probably isn't that important.
The correlation between ignorance of statistics and using "correlation is not causation" as an argument is close to 1.
Quick lesson in physics for those that don't want to read the article...
Time travel. Possible? Yes. It happens relativly speaking every day.
When you get onto an airplane you slow down in time. To say this simply. The faster you go, the slower time moves around you. This was confirmed back in the 1970's using atomic clocks. Although this isn't exactly time travel it's called time dilation which is a product of the general theory of relativity.
A quick little reference for those not familar with Relativity is a set of lecture notes from a basic astronomy class in U of Oregon.
For a little more in depth reading I'd look into buying The Large Scale Structure of Space-Time by Stephen W. Hawking. Or for those that are sadistic you can read Quantum Field Theory in Curved Spacetime and Black Hole Thermodynamics. That is a collection of lectures from the University of Chicago. Although good in a sense of understanding relativity it kinda takes a tagent into the debate about light being a particle or a wave argument.
Of course, this induces the potential for paradox, causing great cosmological and philosophical consternation. I don't know what will happen if/when someone goes backwards through time, but here's some ideas:
- The universe forks in two when a paradox is induced.
- The universe forks in two at the instant the traveller enters history (because at a micro-level, paradox is induced as soon as they appear).
- Paradox induces a cascading feedback loop of self-modifying universes (each inducing a time-traveller who goes back and causes another chage) until the sequence halts with a universe in which time travel is not developed. My bet is that if time-travel is possible, then this is what has happened, because there is no evidence of time travel.
Forward time travel is of course possible right now, requiring only some patienceCrispin
----
Crispin Cowan, Ph.D.
Chief Scientist, WireX Communications, Inc.
Immunix: Security Hardened Linux Distribution
Available for purchase
Maybe this is dorky, but isn't the following evidence that time travel is impossible:
Since no person from the future has ever come back to say hello to us, wouldn't that imply that time travel will never be invented. Or else it will be invented, but our era in history was just too damn boring for people to come back to visit...
Artificial inteligence is no match for natural stupidity. --unknown
is first outlined by physicist Kip Thorn and widely accepted by the scientific community as a real possibility. It is a method which utilise the ability of keeping worm holes open and high speed travel IIRC.
:)
Black Holes and Time Warps: Einstein's Outragous Legacy by Kip Thorn is perhaps one of the best science books I read, though I didn't really read that many of them.
geek page at KY speaks
Perhaps they are visiting us now. Perhaps the UFO's are Time Machines instead of Space Ships, and the ETs are what humans will evolve into.
Quemadmodum gladius neminem occidit, occidentis telum est
I've given this some real thought and if it's possible to time travel at all, it would not be as how we see it in the movies. I'm a philosopher at heart and I think these points have been heard in many different forms:
I just don't see it as a reality. I think what will actually happen is something altogether different-- but not a physical human being traveling into the past to hang out with Babe Ruth. Know whut I mean, vern?
"Politicians find new names for institutions which under old names have become odious to the people."
Anyone else see this in the middle of page 3?
Censored!
Wear weird clothes (not weird in the everyday weird people sense, but truly out of place). Walk up to someone (inventing an accent is fun) and ask them what year it is. When they say, puzzled, "2002", get a huge smile and dance a future dance away yelling "it worked, it worked!"
Fun to confuse people with.
Just as fun: Dress up like a hippie or something else interesting from the past and change everything accordingly to the past.
There's another possibility that was not mentioned in the article, namely, the possibility of different quantum realities. Imagine for an instant, that whatever could happen, does in fact actually happen. Through what what called an Einstein-Rosen bridge (remember the TV show Sliders, the concept does have some scientific merit after all), different quantum realities can be bridged. So, if you go back in time and kill one of your parents, you would still exist because you entered a different reality, one amongst an infinite number of them. Paradox solved. QED.
The Twin paradox is about one twin who accelerates and then slows down (while the other hasn't accelerated or changed his speed significantly) and meets the other twin. This is the source of the assymmetry and not the speed itself.
did i get first post?
no, but perhaps someday you can go back in time and get it.
I mean, the possibility of it happening is endless and therefore a fact.
You took way too many math classes...
You can't take the sky from me...
The article says that altering the past is "obviously impossible". But isn't travelling back into the past a way of altering the past? Or was my arrival in the past something that happened back then, before I even made the trip back in time...? Or are such paradoxes impossible, maybe because every possible event in any given time in history exists in its own universe, waiting to happen when the right preceding event occurs? If someone changed what we call the past, would we notice it?
Will work for bandwidth
And tomorrow will be like today, only more so. -- Isaiah 56:12, New Standard Version
Freaky. What future bastard is playing with my head??
"They do not preach that their god will rouse them, a little before the Nuts work loose." Kipling, 'The Sons of Martha'
My understanding was that the time dilation effect was from a change in the rate of entropy related in some way to the change in mass. If that's so then you could speed up or slow down entropy, and hence the perceived passage of time, but you can't reverse it. I would think travel to the past would need to reverse entropy in some way. Or I could be wrong, physics class was a LONG time ago.
And if I were writing this script with you as the actor, you're going back to kill him would set off a chain of events that starts WWI.
Damn, can't they write some decent science fiction for once?
1. Build a time machine.
2. ?????
3. Profit.
1 tequila 2 tequila 3 tequila floor
With one of these gizmos, I'll be first posting every time!
If Slashdot were chemistry it would look like this:Cadaverine
But only as far back as when the worm hole is created in the first place.
NZ Electronics Enthusiasts: Check out my Trade Me Listings
Time travel. Possible? Yes. It happens relativly speaking every day.
Nonsense. Time dilation is not time travel. For whatever it's worth, nothing can move in time, forward or backward. The entire spacetime of relativity is frozen from the infinite past to the infinite future. I'll let the smart ones (i.e., the ones who were not irreparably brainwashed) figure that one out. In the meantime, those of you who are really interested in the truth can take a look at this following link for a complete debunking of time travel and other crackpottery from the physics community. Wild eyed Star-Trek fanatics need not bother.
Voodoo Physics
Forward time travel is of course possible right now
This is sad. Why does the physics community insist on putting out such unmitigated crackpottery? The truth is that nothing can move in time, forward or backward. The entire spacetime of relativity is changeless, from the infinite past to the infinite future. Karl Popper had a name for it: Einstein's block universe. More details can be found at this site:
Voodoo Physics
That event may be as meaningless to time travellers of the distant future as it was to the majority of inhabitants of the Roman Empire of 30 CE.
Quemadmodum gladius neminem occidit, occidentis telum est
I believe that travelling to the past would merely let us perform certain travelling at speeds faster than light.
...
.. quirks of worthy pursuit.
...
Or, put another way, the time required at maximum velocity to return to your point of origin is at least the amount of time you travelled back in time. I believe you must sacrifice time or sacrifice position.
Position may or may not be in the way we expect; I suspect it is based upon your "depth" in the gravitational field, and as such, you would travel towards or away from heavy celestial bodies, such as the sun. Travelling towards them requires velocity. By the same token, you can temporally return to the beginning of the universe if you travel far enough away from the centre of it (assuming that the gravitational "depth" continues to decrease with distance, and the exponential energy increase required to travel as such is not unreasonable)
Binary stars and other equilibrium comes to mind, but I conjecture that "free" time travel in perfect equilibrium would be impossible; your relationship with time can only be altered in respect to changes in the gravitational depth. However, they may have
So goes a theory
The man indirectly responsible for 80,000,000 deaths in 20th century alone. 80M. That's not a joke.
Debatable, it's quite likely that WWI would have happened whether Princip had assasinated Ferdinand or not...
SpamNet - a spam blocker that really works
The correct URL is: Voodoo Physics
Voodoo Physics
I predict the wormhole concept will be achievable. But there will be one hitch: you will only be able to travel through a wormhole in one direction, and the physical distance you emerge from the wormhole entrance will be equal to or greater than the time it takes to travel at the speed of light to that location.
Thus, you will be able to go back in time, but even if you then raced at the speed of light back home, you wouldn't be able to arrive before you departed.
So you'd travel back in time sure enough, but never able to affect your own past. Another way to phrase it would be: you can go back in time, but only someone else's history.
Of course, you could, say, still go back in time and kill someone in another part of the Galaxy. Maybe terrorist possibilities, etc. Gives a whole new meaning to a leader staying close to his people.
OK, one more speculation. Wormholes will turn out to repel each other, or maybe wormhole exits and entrances that are close to one another create catastrophic feedback loops, making them impossible.
Otherwise, you could take the W-80 (Milky Way --> Andromeda) from near Sol, then catch the W-95 (Andromeda--> Millky Way) near Kl'Kithus, which , it turns out, dumps you right out at Sol again.
And that would make your own past accessible and that's Bad (tm). I guess it could also allow you to go farther and farther into the past by traversing the loop multiple times.
Of course, it's not clear why someone would want to travel to a time before indoor plumbing or computer games.
Time Travel Ad
It's called a bed. Every night I close my eyes and in a moment it is six hours later.
"God fights on the side with the best artillery." - Napoleon, Marshal of France - speaking truth to power
Matter can neither be created nor destroyed. So, in the sense of time travel, either to the future or to the past, would we not be introducing new matter into a time by bringing it from another time? If matter can't be created, do the laws of physics allow for matter to be transposed across time?
Skiers and Riders -- http://www.snowjournal.com
I find it interesting that the article suggests towing a wormhole using a "spaceship, presumably of highly advanced technology" to place a created or expanded wormhole in a powerful gravitational field. Maybe I'm just envisioning this wrong, but I don't know if a wormhole is really what I'd consider to be an "object." Rather, as a rift in spacetime, I'd think would be a thing (for lack of a better word) that is defined by both lack of object, and by objects around it, like the hole in a doughnut, and thus the only way to "move" it would be to alter the objects that surround it, like stretching or shrinking areas of the dough to change the location of the hole with respect to locations on the dough . You can't just grab a hole in a doughnut with a pair of pliers and move it around. In the case of wormholes through spacetime, I'd imagine the way to move a wormhole is to warp the space around it with immensely powerful gravitational fields, folding the space around it and causing it to "fall" to its neutron star target. However, this would certainly require a mastery of gravity far beyond what we have presently attained. When the two ends of the wormhole are created/expanded to macroscopic size, they will need to be separated, with one end taken to a neutron star. Building a tow-ship that can warp the space around a wormhole would require far more knowledge about gravity than we presently possess and far more mastery. Despite being perhaps the most obvious of the fundamental forces of physics, it is probably the least well-understood. Gravitions have never been found in particle accelerators, nor Higgs bosons. Gravitational waves have not been conclusively detected. No coherent theory of quantum gravity exists. We will have to be able to manipulate gravity with the ease that we manipulate electromagnetism if an "interstellar tow truck" is to be built. "Highly advanced technology," indeed!
Using the neutron star itself to attract one but not the other would be very difficult, but possibly workable- especially if Podkletnov's spinning superconductor gravitational shield works (which it doesn't, that I am sure of). However, you certainly can't use a natural source to reunite the ends once you've "twin clocked" the exit end- the exit is sitting near the surface of a neutron star- so you really won't be able to pull it away with anything less than another neutron star or a black hole, perfectly positioned to make use of the three body problem to slingshot the wormhole out of the star system. Conceivable, but highly unlikely.
You can't just leave the exit there, either. It would continue to accumulate time difference, so each trip would take you farther from your present time, but actually further and further along in time, since you can never actually travel backwards to before the creation of the exit hole, and since it is in fact still moving forward, albeit slowly, in time. Also, you would leave the exit and find yourself right around the surface of a neutron star, which is a somewhat dangerous location. Worse, you would have to travel at a relativistic velocity to escape the neutron star's monstrous gravity, which means your fast clock would run very slow, so the rest of the universe would be aging faster than you. Also, the nearest neutron star is several light-years away, adding to your return-trip travel time. I'm sure it would be a fantastic adventure, but sort of a waste to fly into a wormhole, travel centuries back in time, and rocket away from a neutron star at nearly the speed of light- only to get back home and find that due to relativistic effects and travel time, you are right back where you started, or even farther along!
I haven't done the math, but I suspect that sort of scenario could be one of several ways the universe is protected from time travel paradoxes- you can go back in time, but due to relativistic time dilation and the effects of gravitational fields, you can never make it back in time to affect events in the past of your light-cone, preventiing you from creating an inconsistent causal loop.
"FDA staff reviewers expressed concern about the number of patients who were left out of the study because they died."
Someone could become very, very rich if this were possible. Let's see, travel back to 1997 and tell your past self to invest in Pets.com, Enron, and Worldcom, but tell your past self to get out by 2000.
I think Larry and Bill must be time travelers
I hope that someday we will be able to put away our fears and prejudices and just laugh at people. - Jack Handey
A couple of weeks ago I was in a used bookstore, and happened across a copy of Robert Monroe's Far Journeys, which spends a few words on the subject of time travel. Mr. Monroe was one of the first people to write about Out of Body Experiences in western society. To make what could be a very long post much shorter - time travel is real, it can be experienced - you just need to learn how to leave your physical body behind. OOBE's are just another way to hack your wetware. To quote the K5 story, "... anything is possible, when you have root access to your mind's /dev/."
Learn the rules so you know how to break them properly.
www.teslabox.com
Time travel isn't possible, except for the everyday kind that your wristwatch measures.
If time travel were possible, somebody (human, alien, whatever) from the future (perhaps billions of years into the future, or maybe just next week) would have traveled into the past already.
So, let's consider what can happen. Somebody will travel back in time to before the initial discovery in order to beat the ``original'' researcher to the punch. Now, we've got a cascade of ``inventions'' of the time machine racing backwards through time. Life and time-travel technology reach the earliest time after the Big Bang that the two are sustainable and both are prolifically spread throughout the infant universe. Clearly, that hasn't happened.
Don't think that some sort of morality would prevent this from happening, either. Time travel is an incredibly powerful weapon; consider what a knife to the throat of the infant Hitler would have done to history, and how many people would leap at the chance, consequences be damned. All it would take is one person to do so...at any time in the next many billion years.
The instant time travel becomes possible, the only possible method for self-preservation is to race to the beginning. After all, how do you know that some far-distant alien race with souls of pure evil won't do the same just out of spite?
There's a wonderful quote, and I wish I could remember who said it. ``Time is Nature's way of keeping everything from happening all at once.'' The obvious corollary is that, if you can break time, then everything will happen all at once.
Some people try to get around this in a few different ways. For one, there's the many-universes ilk: each act of time travel creates a whole new universe. In such a case, all of those universes would be on the same headlong rush to take time travel as early as possible. Besides, think of the incredible amount of energy and information needed to duplicate the universe--but I digress.
Others try to justify it by saying that it requires huge energy sources or otherwise make it hard. To this I say, ``so''? All you're talking about is a hard engineering project that'll take a lot of time. And--guess what? Even if it takes ten thousand years to build and the energy output of several stars, the payoff is worth it. Again, the alternative is to let somebody else do it...and invite certain disaster.
I take the mere fact that I'm typing this note as all the proof that I need that time travel is pure fantasy.
Cheers,
b&
All but God can prove this sentence true.
BTW the movie Timeline Movie trailer is out and looks pretty good if you like 13th century adventures mixed in with time travel.
Today's vices may be tomorrow's virtues.
For that to be valid, it has to be accelleration that's the key, not speed. Since speed is relative (someone should make a theory about that...), I never understood how it could play any role in time dialation. Without a static frame of reference we have no way to know who is moving faster and who is moving slower. The only other way to explain it seems to be accelleration, which in relativistic terms is the act of changing speed in either direction. This would seem to imply that running back and forth really fast would slow time down.
homer [as he is being sucked into a blackhole]: there's so much i don't know about astrophysics. i really wish i read that book by that wheelchair guy...
Satanists get good grades too...suspiciously good grades
A simple way to think of it is this: Movement through space is represented as distance/time. How would one represent movement through time? It should be time/, but there is nothing to put in the denominator.
This is the first original thing I've read all day here!
Hire a Linux system administrator, systems engineer,
Leela: Don't you want to go see the 20th century theme park?
Fry: ah, if I wanted to go back to the year 2000, I could just have myself frozen again.
Today's vices may be tomorrow's virtues.
Check out time travel here.
But seriously. The idea's I've seen on time travel aren't really based on going "back" or "forward" in time, but actually inventing a device which would need a 100% identical device to travel too.
For example (because sometimes I can't be clear enough): A equal pair of machines would be built. One would be sent into space and likely be sent at speeds approaching light speed. Then we could travel to that device (and back) and use that shortcut to save time in travel, and depending on the speed it flys maybe into the past or whatever.
Please correct me... I never understood this approach.
But Feynman Diagrams show that theoretically matter travels back and forth through time all the time.
But also since we are made of "star dust" we've already sort of time traveled. We are made up of particles (or waves for the cry babies) which existed forever, we can look at ourselves and see the big bang.
Get your Unix fortune now!
Did you check the couch cushions? Those carbon molecule gnomes can be a tricky bunch.
What, does he think that the universe revolves around his theories?
There's no place I can be, since I found Serenity.
The best thing about having a working time machine would be pushing all who find this fascinating into it and sending them elsewhen.
If time proves to be a complex number, while I would find that fascinating I wouldn't tempted in the slightest to project the terms "backward" or "forward" into a polar coordinate system.
If there's any virtue at all to a discussion about time travel, it's that you can't determine whether mathematics or linguistics is taking the worst beating.
has anyone considered that maybe the atomic clock measures time based upon it's velocity? The same goes for quartz.
Just because a clock measures time by how often an electron moves around a neucleus, how fast a crystal spins, or even how fast c12 decays doesn't mean that I experience time in the same fasion. Be sure you aren't trying to measure time with a ruler and call it evidence that they are related:)
Also someone asked how do we know what absolute zero velocity is. According to relativity, we can measure this with three rays of light from three non-coplaner axis, we can measure the difference of the phase shifts to determine which way we are moving absolutly. That is unless someone here says that light shining out of a front of a car going at 65mph travels at the c+65mph. (I'm not arguing that it does or doesn't, it's not a fact until it's proven.)
Karma Clown
For a little more in depth reading I'd look into buying The Large Scale Structure of Space-Time [amazon.com] by Stephen W. Hawking.
I'm sorry but I was just reminded of that episode of the Simpons where Homer is transported into the third dimension. Scared of the strange things he sees in this new universe he mutters to himself:
"I wish I read that book by that wheelchair guy!"
GMD
watch this
Your post intrigues me, but if you're really looking to prevent World War I, I can suggest people more culpable than Princip:
Grand Admiral Alfred Tirpitz: Led the drive to create the Imperial German High Seas Fleet, which aggravated tensions with the British Empire (the Naval Race and all that).
Colonel General Alfred von Schlieffen: Chief of the German General Staff before the war, architect of the Schlieffen Plan to attack France and defend against Russia, which included the violation of Belgium.
Bringing the British into the war was the real disaster. Had they stayed out, it is quite probable the France would have lost the Battle of the Marne and therefore the war. Germany would then have teamed up with Austria against Russia far earlier, and it is entirely conceivable that the war would have been over before the leaves fell, as the Kaiser had promised his troops.
A quick end to the war would have left the Central Powers dominant on the Continent, Russia in the throes of revolution (I imagine that defeat in the war would cause collapse), and France diplomatically isolated. Not a wonderful situation really, but nothing to lead to the Second World War.
Of course, the above is an exercise in what-if history, which generally gets dismissed as quackery...
~Chazzf
No statement is true, not even this one.
I have this strange urge to go save whales.
Table-ized A.I.
While real physics has always been about rigorous (and vigorous) lab work, the popular image of physics, and Science as a whole, has strayed from this considerably.
Gees. Not only do you insult theoretical physicists here but every other science that does not involve experimentation such as computer science and mathematics. Who are you to define what "real physics" and "real Science" is?
Witness, for example, the popular celebration of Einstein's thought experiments. The average layman is under the impression that Einstein reached his great intellectual climaxes by just sitting and thinking about things, maybe over a cup of hot chocolate. What people don't see is the hours of experimentation (real experimentation) as he tried to verify and correct the results of his thought experiments.
Einstein did some of his best work while employeed as a patent clerk [1] [2] [3]. As a patent clerk, he most likely did not have access to the laboratory equipment needed to perform experiments involving speeds close to that of light. In fact the first experimental verification of general relativity was done some years after his papers and by someone else.
So why is it like that? Are people just stupid?
Okay, you've called us all stupid. Now here's your chance to back up that claim by showing us proof of these supposed "hours of experimentation (real experimentation)" that Einstein needed to work out relativity.
Since the collapse of the Catholic Church in the times of Galileo Galilei, there has been a vacuum where religious fervor once stood. Science (or this fantastical mockery of Science) has filled that void, uncomfortably.
I don't know what country you live in, but here in the US, the Cathloic Church is a formidable force in people's lives and in public policies. It certainly has not collapsed.
Show the theorists some respect.
GMD
watch this
Slashdot is going to post this same story on 2/17/2003.
Damned editors!
Table-ized A.I.
That's strange. I always thought we were continually moving forward through time.
That's what you and I have been taught to believe but it is wrong nonetheless. What strange about it is that supposedly intelligent people in the physics community believe and teach the same crap to young people.
The impossibility of motion in time is easy to grasp if one is willing to put a little bit of thought into it. The truth is, there is only the present and time does not pass. Most physicists, including (and especially) the most famous and admired ones (we all know who they are), are completely out to lunch on this issue. That Scientific American can treat time travel as a serious scientific subject is a sad commentary of the sorry state of theoretical physics.
My advice is, think for yourself. Don't let charlatans and crackpots do your thinking for you, especially if they are famous. Don't believe what I write either. Figure it out on your own.
Voodoo Physics
Your theory, and millions of other ones, are based on the theory that one cannot travel faster than light(e).
You consede the fact that one can travel at half the speed of light(e/2). Assume that two object(a&b) both have a y and a z coordinate of 0 and that they each have a y and z velocity of 0. If object a is heading with an x velocity of e/2 and object b is heading with an x velocity of -e/2. Object a and object b then have a velocity of e relative to eachother.
Origin (0,0,0) only exists for the purposes of describing mathematical situations and velocity cannot be measured relative to a nonexistant point. When all speed is relative, it cannot be capped. Why the hell does everyone insist that nothing can go faster than light when no one can give me a reason WHY.
I've heard that it is "infinit speed". That's complete BS. Does infinity==299,792,458!? If it is not infinite speed, then a craft wouldn't need to carry infinite fuel. Hell, a craft doesn't even need to carry its own fuel!
I do not have a phd. I do not have a college degree. Hell, I don't even have my high school diploma yet. If you can explain this, please email me.
That said, time travel would be a great way to make seemingly instantanious trips. I think that "facsimily transmissions", such as that episode of the Outer Limits would be the fastest way, without time travel. That said, it would take a LOT of money to make it legally permissable.
You can't judge a book by the way it wears its hair.
How to Build a Time Machine by Paul Davies. A very fascinating look at this subject, and also addresses the issues of paradoxes and all the other "hang-ups" to time travel. Check it out.
"We shall show mercy, but we shall not ask for it" -- Winston Churchill
The important thing to remember is events that we consider important may not be viewed as important in the future, while events that seem trivial now may be considered very important at some future date. If the UFOs are in fact Time machines, then it could mean that an event that we hardly notice today could be considered a major turning point in history to future generations. Few people noticed the crufixiation of a man in 30 CE, yet it considered one of the major points in history some 2000 years later. Something may be going on now that we consider as unimportant as what most people of 30 CE considered an execution in a backwater outpost of the Roman Empire, but will be viewed ver diferenly by our ancestors.
Quemadmodum gladius neminem occidit, occidentis telum est
Incidentally, that's what he mentions in his article as 'redshift .2'
Now think of it this way: the magnitude of the various forces is being multiplied by this factor. The object continues to "move through time" at a constant rate, but the laws of physics affecting it are slowed down. If the time dilation was reduced to zero, rather than disappearing from the next "time frame", the object would continue to exist in the present, but would be in a frozen state.
Well, yes, and no... The laws are not slowed down, merely their effects. See below.
What if time dilation became a negative value? The object would remain in the present, the past would stay unaffected, and all forces on the object would reverse. Gravity would push. Magnetic opposites would repulse
Well, no... First, this doesn't follow from your earlier logic - if time dilation were negative, the object would be moving backwards in time but the forces would not be moving backwards... simply its direction along the time-axis of spacetime.
However, I think you're not fully understanding time dilation. Think of spacetime in a condensed format, with one axis representing time, and one axis (at a right angle) representing the three dimensions of space.
We normally move at almost the speed of light along the time axis and _very_ slowly in the space axis... Light, on the other hand, moves at the speed of light on the space axis and not at all in the time axis (there's a theory that photons don't experience time). Now, the faster you go along the space axis, the correspondingly less you go along the time axis, because your total motion (space motion + time motion) has to be equal to c.
That's time dilation. The faster you move in space, the slower you move in time.
-T
I'd travel back in time to 1994 with all my stock charts and ...
1) Buy a NYSE index fund in 1994 and sell it in 1999.
2) Short Nortel at $120.
3) Short Worldcom at $65
4) Buy Yahoo! in 1994 and sell it in 1999.
I could go on...
This space left intentionally blank.
Physics was never my strong point. Someone explain to me how, if it takes forever for something to fall into a black hole, anything ever falls into a black hole? I would think that once you reach the point of singularity, your black hole would never gain any more mass and would eventually evaporate.
I'm trying to teach myself to set people on fire with my mind... Is it hot in here?
What? Light from 3 co-planar axis? If the planes and light beams aren't moving with respect to the mechanism itself, there will be NO phase distrotion, no matter how fast or which direction the detector is moving. That is THE principle of special relativity. We could measure acceleration with this device however.
Black holes are where the Matrix raised SIGFPE
Actually, that was all very convincing. Not 100%, but something more to chew on than 80% of the comments posted. IF time travel were possible, the man is right, their'd be a temporal race of epic porportions and we probably wouldn't just enounter just ourselves, but multiple other factions and species warring over the same fulcrums in time. Maybe there would be police that would "put things right", but if you use any form of law enforcement as an example, it's nowhere near 100% effective. Time would be majorly screwed up. Surely we'd be finding pulse rifles and tacheon cannons fossilized in the ground or something.
But...
Just because we haven't see anything doesn't mean it can't or hasn't happened. I'm assuming a war like this would be highly destructive and create multiple paradoxes during the length of the war (assuming there was one). Obviously, time continues to trek regardless. I would think that when a paradox is created, enough random chance exists in the universe to where the events that cause the paradox are eventially (after a couple billion timeline recycles) circumvented. Maybe through a change in the species evolution, or maybe they didn't carry the two when building their time machine. Don't know, but perhapse the timeline would naturally heal through random chance.
In the end, I'm inclined to agree with the parent. Either it's never going to happen, or it already has and we'll never know about it.
You need a FREE iPod Nano
[did i get first post?] no, but perhaps someday you can go back in time and get it.
Just post last, and then reverse time.
Table-ized A.I.
I wonder what programming languages would look like if time was not assumed to flow just forward. Instead of Brainfuck, somebody please invent Timefuck. Instead of "goto", will it have "camefrom" statements, or something yet weirder?
(Cicso can perhaps sell it to the wormhole aliens.)
Table-ized A.I.
The closest quote I could find on the net to "if it is possible it will happen. If it is impossible it will just take a little longer." was "Things are only impossible until they're not" by the distinguished captain, Jean-Luc Picard.
Anyone else come up with a better match?
- It is (theoretically) impossible to accelerate to the speed of light, because it would require an infinite amount of energy to do so, so the best we can do is approach the speed of light.
- The closer you get to the speed of light, the harder it is to accelerate, because of said energy requirement.
Wouldn't time distortion then simply occur because things simply could not happen as fast? Your aging, your blood flow, the chemicals flowing between your synapses (this altering preception), the rate at which something burns, the rate electricity moves at, etc. all happen slower than they would if the object where traveling at a lesser speed, because the whole process takes more energy, correct?If this is true, what happens when an object comes to a complete halt in space, the absolute zero of velocity, if you will. Could that make a black hole or something?
IADNAP.
CAn'T CompreHend SARcaSm?
Something that has always perplexed me about the possibility of time travel is apparent contradictions with the law of conservations of mass/energy. If an object (say a person) were to travel into the past, wouldn't his/her matter be lost? Correspondingly we would have to surmise that there are three possibilites:
1: Something of equal mass would have to come from the past or be created in the universe simultaneously.
2: Massive amounts of energy would be released when the mass "went back" in time, to compensate for the matter lost. This would make time travel an interesting source or energy, sending useless objects back in time and harnessing the energy released.
3: Law of conservation of mass/energy would have to be adapted in some way to apply to some form of mass/energy integrated over time so that there is a constant amount throughout the life-span of the universe. This would have interesting ramifications if theories of time forking were to prove true, ie which alternate time lines would this time:mass/energy integration be applied?
These are just some idle thoughts I've had... Anyone with some more ideas let me know what you think!
-- Mr. E Gecko
Snarfle.
Here, since no one seems to be putting theories forward, here goes.
I think of time like a flashlight shining on a wall.
There is only one point shining at any one time. It may be possible to 'see' into the future, or travel there, but not backwards, namely because the Langoliers have eaten it.
It certainly is possible to travel faster than light, and will not result in time-travel. As time has shown again and again, there are no limits. Sound, Light, Warp 10, etc. So, this should tell you all one thing...
NEVER speak in infinitives. You will ALWAYS be proven wrong.
Slashdot gets worse every day... Pipedot: News for nerds, without the corporate slant
All of these arguments that the lack of time travelers is evidence that there is no backwards time travel got me thinking: Maybe there are time travelers, but we've given them no reason to show themselves publicly. So...
We need to prepare if we want to find out if backwards time travel is possible.
Here what we to do. We set up a well publicized botique for time travelers, a place that sells tee shirts that says "My parents went backwards in time and all I got was this lousy tee shirt!" If anyone buys the tee shirt then we know that time travel is happening.
Rocky J. Squirrel
I am not sure that I implied that nothing can travel faster than light (since I am quite certain some things, eg. X-Rays, can, at least practically if not theoretically :) ), and I would agree with your assessment.
Note that, in this case, by approaching the speed of light, your gravitational "depth" increases. Also note that such speed is relative, but really only the important relative component is to your initial speed to which the speed of light is measured, and the celesital objects to which you have affinity.
no... non-coplanar beams :) because of the compression of the waves because light has a fixed speed, you could measure the velocity. You can measure acceleration with a plane old gyro :) You should get three components with which you can measure mutualy orthagonal components of motion, though you couldn't express those in any standard way (x,y,z just doesn't make sence :) and neither does r,theta, ioyota(I wish I could make greek letters here, because I don't know their names :))) There are some nobel gasses that make light very very accurate in terms of wavelength that you could do it with.
:) This is all assuming that the actual speed of light isn't infinite. If it is infinite, then the theory of relativity doesn't make a whole lot of sence :)
You might have to use a cesium chamber if that doesn't work it ensure that the photon is traveling straight... then you can measure how long it takes to get to the other side
Karma Clown
That's X-L-N-tay!
Thanks, epine. If I had mod points to award, and could award them to just a portion of a post, I'd rate that sentence a "5".
But I don't and I can't.
Time flies like an arrow...
fruit flies like a banana
--Groucho Marx
If we ever was to be able to build a time machine, shouldnt we then at some point have had visitors from the future? As far as I know, we still havent so I believe it's very unlikely that a time machine ever will be built...
Just think, it would be one heck of a plus to send the solution back in time with a quick hint to post it on "/.". Perhaps it is because it didn't happen and the usual trolls got there, that we can say that time-travel doesn't exist.
Good way of making money quickly. Of coursem your time machine probably breaks SEC insider-trading rules.
It has been shown that X-Rays escape black holes, and by doing so "must" travel faster than light. There are other plausible explanations (wherein "must" is "could"), but this one serves my statement with some peer-reviewed merit.
I was quite sure that X-Rays did escape the event horizon. However:q /black_hol e/bhole-38.html
http://chandra.harvard.edu/resources/fa
indicates otherwise. I have seen and agreed with theories that support my assertion of a not-so-infalliable event horizon, but it is not so easy to find a reference now, and it is probably an outdated notion or just out of style in the colloquial peer-review discourse.
I don't have any evidence or reference to back up my assertion aside from said heresay, so I highly suggest you extend the waiver that comes with a Slashdot Poll to my comments on X-Rays escaping a black hole.
Your reference to "quantum tunneling" is the closest thing I could find to what I was thinking of, too. It was not under this name that I thought of it. I do recall discussing it as if it were common knowledge, though. Perhaps it was just colloqial knowledge.
Nevertheless it is good to know that my assertion may not have been a figment of my imagination, or worse - an assumption. It has left me with a bit of an enigma.
Thanks for the Quantum Tunneling reference.
Time slows down relative to the things around you, not just in general. Speed is also relative to the things around you. If you had two objects travelling the same velocity (magnitude and direction), both fractionally close to the speed of light, they would observe the same measurement of time.
Also, if you had one object moving away from another object, you could view this as:
1) #1 is moving at velocity V away from #2
2) #2 is moving at velocity V away from #1
3) #1 has velocity V1, and #2 has velocity V2 such that V1+V2=V (note that one of V1 and V2 would be negative).
"Still" is also relative to the surrounding objects. You have to pick points of reference with which you must remain the same distance from under any given definition of still (for Cartesian modeling of the universe, which is what humans generally use, you need THREE points of reference). Meeting this definition is quite possible.
Hopefully this has increased your understanding of introductory physics.
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