Thread: Time?

Originally posted by issaiah1332
K, so I understand sring theory, relativity, quantum mechanics, the concept of time travel, ECT. But what I do not get is how time can be physical, and how time is perpetual, as in how the past can still be their to travel back to.

I didnt think traveling back in time was possible . When you say time can be physical do you mean that it is within the dimension of space ? Time is supposed to be the 4th dimension . But time and space are co-existant , they are interwoven . As space streches from differing gravity intensities so does time .

Im not sure what you mean by time being perpetual . It is everywhere that space is , and since space is everywhere , so is time (duh? ) Time if not infinite if thats what you mean . Time had a definite beggining , around 13.7Billion years ago supposedly , at the big bang . The instant before the big bang , all matter in the universe was compressed into a so called singularity and space and time were non existant . I suppose matter was non existant too , as matter surely cant exist without space . So this singularity decided to explode and spew out all the matter in the universe , and create time and space with it .

Will time ever end ? Well i suppose that depends on which big bang camp your into . If you believe in the big crunch then time may end for the instant the singularity is again produced in the crunch , then it would created the big bang all over again . Or the universe may continue to expand , and space and time will be streched infinately thin du to gravity getting weaker and weaker . But then theres dark energy which supposedly accelerates the expansion .

To be honest , after i started looking into it all i just got more and more confused . Maybe you could enlighted me more than i can you , since you understand string theory , relativity, quantum mechanics, the concept of time travel etc .

But time is a tough nut to crack . Im interested in what you think about time .

Where does time fit into the equation if you put it in correlation to the impossible question.
How can there be an end to the universe. and how can there be a beginning. They are the same thing. The beginning and the end. Where does time fit into that?

What do the great minds think of this. what kind of poposterious theory can anyone come up with ti the answer to what is behind the end. And what was before the beginning?

Originally posted by issaiah1332
K, so I understand sring theory, relativity, quantum mechanics, the concept of time travel, ECT. But what I do not get is how time can be physical, and how time is perpetual, as in how the past can still be their to travel back to.

If man could reach the speed of light the theory is that time would stand still. From the observers point.
So what would be ten minutes to you could be ten years on earth. So in that sense you are going back in time.
But to truly go back to past events the only way I know of that possibility is via our memories.
I suppose if you could catch an image so far out there that contains an image of the past, that too would be considered going back in time. But not physically. Just as a witness.

[quote]Where does time fit into the equation if you put it in correlation to the impossible question.
How can there be an end to the universe. and how can there be a beginning. They are the same thing. The beginning and the end. Where does time fit into that?

What do the great minds think of this. what kind of poposterious theory can anyone come up with ti the answer to what is behind the end. And what was before the beginning?



If man could reach the speed of light the theory is that time would stand still. From the observers point.
So what would be ten minutes to you could be ten years on earth. So in that sense you are going back in time.
But to truly go back to past events the only way I know of that possibility is via our memories.
I suppose if you could catch an image so far out there that contains an image of the past, that too would be considered going back in time. But not physically. Just as a witness.

No one can or will know what is after or before the beginning or end , its pointless even trying to think , becasue even if theres something , its still nothing . When time ends so does our existance . Cos time is space , and we exist in space so were caput without time .

The example of relativity you gave doesnt sound quite correct . For the observer , his time would be the same , but if the guy going C had a clock , when he came back , the clock would be slower now . So i suppose you could say the observer would see(if he had a really good telescope) the clock slowing down as the traveller sped away from him .

Its not that your going back in time , just that the time is slowed down when looking at the traveller .

But im not scientist and ive never studied relativity so i might be wrong .

Turning back time is freaking impossible. That's a fact. Einstein proves it, as does everyday logic. However, besides in personal perpective, slowing down time and speeding up time is possible. Travel at high speed allready made the atom clock on board a space shutte run 0.001 slower then the one on earth.

The reason time travel to the past is considered a possibility by some scientists is that the equations used to describe the physical universe, relativistic and otherwise, are symmetrical with respect to time (i.e. you can run them backwards or forwards to calculate past or future states). Mathematically, time travel is not forbidden by the laws of physics, and if you study quantum mechanics, causality and the relationship between past and future diverges sharply from our own macroscopic, everyday perceptions. However, just because the mathematical formulation of physical laws does not expressly forbid time travel does not mean that it is, in fact, possible. When I speak of "time travel" here, I am specifically talking about travel backwards through time, since travel forwards through time, as has already been mentioned, is easily accomplished (well, relatively ) via the effects of time dilation. In fact, these effects have been measured multiple times by comparing clocks on earth to those aboard the ISS and orbiting spacecraft. But just traveling forward through time is not all that practical. The same thing could be accomplished by cryogenically freezing oneself (although that technology is not yet available) and waking up at some predetermined time in the future. It’s not the type of future travel you see in the movies where you could run into your future self as an old man or woman. What you and almost everybody else mean when they say "time travel" is being able to jump to a specific time in the future or past, since it would require the capacity for both in order to travel and then return home. The last article I read about time travel to the past was probably 7 years ago and so somewhat dated, but it stated that the most likely mechanism for backwards travel would be a wormhole opened with one terminus located at spacetime coordinate in our past (when the wormhole was created) and one in our present. However, the tricky thing is that according to the mathematics (at least at the time this article was written), maintaining a stable macroscopic wormhole would require a negative energy density. Now, if you can figure out how to have a negative energy density, you’ll likely be eligible for the Nobel Prize. Unfortunately, the fact that such a requirement seems so nonsensical and likely a mathematical artifact could lead one to doubt that such wormhole-based time travel is possible.

As to where the past is located? You’ve got me. Where are the landscapes and vistas of your dreams located? Intuitively, I don't think there is some physical location, like a hard drive address, where every interval progression of the Plank time is saved. I can't explain or justify that physically - it just seems ridiculous to think that the state of every single subatomic particle in the universe throughout the entire history of time is captured freeze-frame in 10^-43 second intervals and that those states are then stored like a child's flip book at some physical location. But maybe that's just me.

The fact is that time travel to the future is far easier to accept and understand, because the future is something that unfolds naturally – all you’re doing with forward time travel is speeding that process up to your own perception. You’re not actually “going” anywhere. You’re letting nature take its course. Travel to the past, however, is trickier. According to our everyday experience, backwards time travel is against the natural progression of things. So, is it physically possible, or just a mathematical artifact? That is certainly the matter of some debate.

I do not understand how all of you guys think that travelling back in time is impossible. I have never heard of einstein proving this either, he himself was surprised at the fact that his theory supported time travel. Think time flows and eventually curls back onto itself, hence black holes, since it curls onto itself it is going backwards upon itself, making time flow backwards. Please elaborate on what you mean by travelling into the past being impossible.

Well I read somewhere like to years ago, that some cientist(dont remember there name) where working on this laser wormhole witch they had allready opened, its on somo sort of lab, it is supose to bring things from the future, something like if I turn it on today, today will be the recieving day always if it is always turned on on the same place, and in future years I could send my self something throug it wich I will recieve when I turned it on, Now what I see of this, is that for it to work, you have to be in the future, meaning making the future, since when this scientis turned it on(and I suppouse it is still on) nothing came to them, this meaning the future has yet to happen. I doubt this machine will work, but the idea seems very interesting and cool, could be used for health technology and to prevent war(well it depends on whos hands it is). Personaly I don't believe in time, as how it is described

Originally posted by issaiah1332
I do not understand how all of you guys think that travelling back in time is impossible. I *have never heard of einstein proving this either, he himself was surprised at the fact that his theory supported time travel. Think time flows and eventually curls back onto itself, hence black holes, since it curls onto itself it is going backwards upon itself, making time flow backwards. Please elaborate on what you mean by travelling into the past being impossible.

I dont think black holes have anything to do with time travel . Infact , in a black hole , there is a thing called a singularity , where the laws of physics cease to exist time , space matter dont exist . They are simply stored in there as a value . But matter is constantly being spewed out of the black hole , in the form of radiation .

#1 Time travel to the past is not possible. If it were, we'd already have the technology. Think about it... Somebody from the future would've come back and told us about it.

#2 Supposing the people of a time-travel-embracing culture of the future are governed by a "prime directive," kind of like in Star Trek, someone would've broken the prime directive and altered the past. People are corrupt.

#3 The simplest of all: time is not a dimension. We've yet to discover any "temporal rays" or any physical evidence of time. Time is merely a sense of perception, created by beings unable to come to terms with the idea of "endlessness."

#4 I don't see how a black hole could affect time. Let's suppose that time is a physical dimension. Current theories place a black hole at the center of our galaxy (that's what makes it spital). So, in that case, the stars located deeper within the galaxy would be at a different state of decay (be it faster or slower). That, however is not the case.

[quote]#1 Time travel to the past is not possible. If it were, we'd already have the technology. Think about it... Somebody from the future would've come back and told us about it.

Well if i created a time machine , i definately wouldnt go back in time and give previous foolish generations power to alter the arrangement of time . Time is something i dont think man should mess with , its nice to fantisize about it , but if someone managed to go back in time and later something , then we would all pay dearly for it in whatever way . But then one has to think , if you went back in time would it still be to our universe or would it create a parralel time line ? Ahh i dunno ive gotto read Stephen Hawkings book a brief history of time .

#2 Supposing the people of a time-travel-embracing culture of the future are governed by a "prime directive," kind of like in Star Trek, someone would've broken the prime directive and altered the past. People are corrupt.

Not sure what this prime directive is you speak of , but i assume its some law to govern what can and cant be done in the past such as timeline altering events .

#3 The simplest of all: time is not a dimension. We've yet to discover any "temporal rays" or any physical evidence of time. Time is merely a sense of perception, created by beings unable to come to terms with the idea of "endlessness."

Well i think time is something , and what better place for time to be bound to than a dimension . Time certainly does exist , you cant explain time dialation without having an actual time that can be manipulated by speed close to light . Although that is a percepted time difference , so i dunno .

What exactly does the speed of light have to do with time?

Why can't it be just another speed? Kind of like the speed of sound?

Originally posted by vystral
What exactly does the speed of light have to do with time?

Why can't it be just another speed? Kind of like the speed of sound?

Ya know..That is a damn good question?
Maybe it has something to do with it is blaaah I don't know what I am talking about.

I will ask Peregrinus

Time travel into the past is possible, Michio Kaku, along with many other scientists have said so. The reason they have said this is due to the recent developements in string theory, and quantum mechanics. Scientists now think that it is possible due to parallel universes, you would not alter this universe but another.

New model 'permits time travel'
By Julianna Kettlewell
BBC News science reporter



The concept of time-travel is laden with uncomfortable paradoxes
If you went back in time and met your teenage parents, you could not split them up and prevent your birth - even if you wanted to, a new quantum model has stated.



Researchers speculate that time travel can occur within a kind of feedback loop where backwards movement is possible, but only in a way that is "complementary" to the present.

In other words, you can pop back in time and have a look around, but you cannot do anything that will alter the present you left behind.

The new model, which uses the laws of quantum mechanics, gets rid of the famous paradox surrounding time travel.

Paradox explained

Although the laws of physics seem to permit temporal gymnastics, the concept is laden with uncomfortable contradictions.

The main headache stems from the idea that if you went back in time you could, theoretically, do something to change the present; and that possibility messes up the whole theory of time travel.

Clearly, the present never is changed by mischievous time-travellers: people don't suddenly fade into the ether because a rerun of events has prevented their births - that much is obvious.

You go back to kill your father, but you'd arrive after he'd left the room, you wouldn't find him, or you'd change your mind

Professor Dan Greenberger, City University, New York
So either time travel is not possible, or something is actually acting to prevent any backward movement from changing the present.

For most of us, the former option might seem most likely, but Einstein's general theory of relativity leads some physicists to suspect the latter.

According to Einstein, space-time can curve back on itself, theoretically allowing travellers to double back and meet younger versions of themselves.

And now a team of physicists from the US and Austria says this situation can only be the case if there are physical constraints acting to protect the present from changes in the past.

New model 'permits time travel'
By Julianna Kettlewell
BBC News science reporter



The concept of time-travel is laden with uncomfortable paradoxes
If you went back in time and met your teenage parents, you could not split them up and prevent your birth - even if you wanted to, a new quantum model has stated.



Researchers speculate that time travel can occur within a kind of feedback loop where backwards movement is possible, but only in a way that is "complementary" to the present.

In other words, you can pop back in time and have a look around, but you cannot do anything that will alter the present you left behind.

The new model, which uses the laws of quantum mechanics, gets rid of the famous paradox surrounding time travel.

Paradox explained

Although the laws of physics seem to permit temporal gymnastics, the concept is laden with uncomfortable contradictions.

The main headache stems from the idea that if you went back in time you could, theoretically, do something to change the present; and that possibility messes up the whole theory of time travel.

Clearly, the present never is changed by mischievous time-travellers: people don't suddenly fade into the ether because a rerun of events has prevented their births - that much is obvious.

You go back to kill your father, but you'd arrive after he'd left the room, you wouldn't find him, or you'd change your mind

Professor Dan Greenberger, City University, New York
So either time travel is not possible, or something is actually acting to prevent any backward movement from changing the present.

For most of us, the former option might seem most likely, but Einstein's general theory of relativity leads some physicists to suspect the latter.

According to Einstein, space-time can curve back on itself, theoretically allowing travellers to double back and meet younger versions of themselves.

And now a team of physicists from the US and Austria says this situation can only be the case if there are physical constraints acting to protect the present from changes in the past.

Originally posted by Peregrinus
As to why the speed of light is what it is: no one knows. It's just one of those physical constants of the universe, born when space and time were born at the moment of the Big Bang. Science can't answer why - just what and how.

The speed of light is related to time through Einstein's theory of general relativity. The faster you perceive an object's velocity to be, the slower its flow of time will appear to you. For example: Imagine you're on a space ship in the middle of empty space and see another space ship speed by you at close to the speed of light. If you could look inside the windows of that other space craft, you'd see all of their clocks running slow. The astronauts would be waving in slow-motion. Their mouths would be moving like TV characters put on slow-mo replay. All of the chemical reactions on that ship would appear slow to you. However - and here's the part that will just mess with your head - as long as you are both in inertial reference frames (constant velocity - not accelerating- and away from any strong gravitational fields - not near any planets, stars, moons, etc), you will appear to be moving in slow-mo to the astronauts on the other ship.

That's the \"relative\" part of relativity - there is no preferred inertial reference frame. The astronauts on the other ship have just as much right to say that their ship is floating still in the void and you are zooming by as you have to say that you are still and they're the ones bookin' it across space. (Think of being in a train and seeing the scenery fly by out your window - is it the train that's moving forward across the earth or the earth that's moving backwards beneath the wheels of the train?) So long as neither of you feel any acceleration (either due to gravity or to a change in velocity) both of you are correct. So to you, their clocks are moving slow. And to them, your clocks are moving slow. So both think that the other person is in slow-mo and each is perfectly correct in that perception. Try to wrap your mind around that. Smile I always have a fun time trying.

Ok, so time travel backwards is either being prevented or is impossible. I'd prefer to think that it's impossible. Then again, let's say someone went back and erased George W Bush from history (i volunteer). We'd never know it happened because he would be ERASED FROM HISTORY. Our lives would go on like he never existed. Who is to say that I wasn't a billionaire somewhere before someone changed the timeline and now the world exists as if I were a poor college student. In that respect, I hope time travel backwards is not possible.

Originally posted by vystral
Ok, so time travel backwards is either being prevented or is impossible. I'd prefer to think that it's impossible. Then again, let's say someone went back and erased George W Bush from history (i volunteer). We'd never know it happened because he would be ERASED FROM HISTORY. Our lives would go on like he never existed. Who is to say that I wasn't a billionaire somewhere before someone changed the timeline and now the world exists as if I were a poor college student. In that respect, I hope time travel backwards is not possible.

What if multiple times existed all at the same time? Then changing a future would be not necisarilly changing this one

Also if you could view this, put a democrat in office then see how bad of a job they would be doing, the world could prove that who is holding office is the correct one..... No no. Democrats never say they are wrong. Even if you could show them proof.

I don't want to get into a political discussion right now, but I'm with you on the alternate "times" idea.

What if with every change in this universe a new one is created. Every time and every possibility would exist at the same time.

And time is so relative. Objectively there isn't really time. A second is a human term with a human meaning. If there would be a supreme power that was completely objective everything would be, instead of happening.

Originally posted by Neruo
What if with every change in this universe a new one is created. Every time and every possibility would exist at the same time.

And time is so relative. Objectively there isn't really time. A second is a human term with a human meaning. If there would be a supreme power that was completely objective everything would be, instead of happening.

If there were multiple universes then each time would exist on its own. Multiple times, as apposed to the same time, wouldn't that be the case?

Even if time has humanistic traits attached to it, like a name and lengths, there are signs of changing that are physical which indicates signals of time and it changing.

[quote]

If there were multiple universes then each time would exist on its own. Multiple times, as apposed to the same time, wouldn't that be the case?

Even if time has humanistic traits attached to it, like a name and lengths, there are signs of changing that are physical which indicates signals of time and it changing.

Hmmm I have no idea what you mean. But what I am saying is that time is so relavtive everything is. Instead of everything is happening. The amount of matter and the amount of energy in the univserse allways adds up.

Like a box of matches in your pocket. They will allways be there. Just shake around abit.

ok maybe not

Then about dimensions. The 3D shit really raped the 'demensions'. What is so 3d about this world? The universe, the matter+energy we are in That is One demension. Time is a different factor, a way more relative one, maybe only existant within our own demension.

A different universe/demension is a different 'place'. But it might be a totally different place, or it might be the same place however with different 'parameters'. Like a different way the matches are located in the box.

I think new terms should be invented to differ the dimensions. I now see universes and demensions as the same. For I do ragard our world as one and time as not a demension.

I might be talking crap. And I can't reallt explain it. But since we can never know or see maybe it is allways right, or wrong, or not, or maybe it's just a different way of seening it.

My point is: There are an infinite amount of demensions of our universe. And there might be more universes, but on other levels of demension.

universes/dementions are fun. We really can never understand Just talk about it endlessly.

[quote]

If there were multiple universes then each time would exist on its own. Multiple times, as apposed to the same time, wouldn't that be the case?

Even if time has humanistic traits attached to it, like a name and lengths, there are signs of changing that are physical which indicates signals of time and it changing.

Hmmm I have no idea what you mean. But what I am saying is that time is so relavtive everything is. Instead of everything is happening. The amount of matter and the amount of energy in the univserse allways adds up.

Like a box of matches in your pocket. They will allways be there. Just shake around abit. ok maybe not

I have no idea what I meant either!?
I thought that matter & energy does NOT match up. Leading them to believe that there is dark matter?

In some recent theories they suspect that space time could be a kind of fluid.
The basic principle is that sound waves in a fluid behave uncannily like waves in space.
Black holes even have acoustic counter parts.
The question being could space time be a type of fluid, like the ether of pre einstien physics.
From what I derive from the article is that Stephen Hawkins is kind of taking of where Einstein left off. Except rather than focusing of relativity he is trying to correspond the two worlds of relativity and the Quintam realm.
Scinetific american (echoes of black holes) 12/25/05