Thread: TIME EXPLAINED (v2.1)

1. TIME EXPLAINED

Time is very simple, once you get it. But “getting it” is very difficult. That’s because your current concept of time is so deeply ingrained. You form a mental map of the world using your senses and your brain. You use this mental map to think, and you are so immersed in it that you can’t see things the way they really are. You are locked into an irrational conviction that clocks run, that days pass, and that journeys take a length of time.

It takes an open mind, and logic to break out of this conditioning. First of all we need to look at your senses and the things you experience. Let’s start with sight. Look at the picture below or follow the link for a better image:

http://www.echalk.co.uk/amusements/O.../illusions.htm

The central portions of the two crosses are the same colour. You think the one on the left is grey and the one on the right is yellow. Not true. Tear a small hole in a piece of paper to make a peephole to mask out the context. Hold it up to one image after the other, and you realise that the central portion of the right-hand image really is grey. The yellow was the illusion. What does this tell you? It tells you that something you took for granted is not true. And it should remind you that a photon doesn’t have a colour. It has a wavelength, an oscillation, a motion.

Let’s move on to sound. Imagine a super-evolved alien bat with a large number of ears, like a fly’s eye. This bat would “see” using sound, and if it was sufficiently advanced it might even see in colour. But we know that sound is pressure waves, and when we look beyond this at the air molecules, we know that sound relies on motion.

Pressure is related to sound, and to touch. You feel it in your ears on a plane, or on your chest if you dive. You can feel it when I shake your hand. But you know you can’t measure the pressure of an atom, because pressure isn’t a fundamental property of the sub-atomic world. It’s a derived effect, and the Kinetic Theory of Gases tells us it’s derived from motion.

How about kinetic energy? A cannonball in space travelling at 1000m/s has kinetic energy. If it impacted your chest you would feel it. But apologies, my mistake. It isn't the cannonball doing 1000m/s. It's you. So where's the kinetic energy now? Can you feel it coursing through your veins? No. Because what’s really there is mass, and relative motion.

You can also feel heat. Touch that pretty stove and sizz, you feel heat. We talk about heat exchangers and heat flow as if there’s some magical mysterious fluid in there. And yet we know there isn’t. We know that heat is another derived effect of motion.

Taste is chemical in nature, and primitive. Most of your sense of taste is really your sense of smell. Do you know how smell works? Look up olfaction and you’ll learn about molecular shape. But the latest theory from a guy called Luca Turin says it’s all down to molecular vibration, not shape, because isomers smell the same. That’s motion again.

The point of all this is there’s a lot of motion out there, and most of your senses are motion detectors. But it never occurred to you because you’re accustomed to thinking about the world in terms of how you experience it, rather than the scientific, empirical, fundamental, ontological things that are there. And nowhere is this more so than with time.

So, what is time? Let’s start by looking up the definition of a second:

Under the International System of Units, the second is currently defined as the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium-133 atom. This definition refers to a caesium atom at rest at a temperature of 0K…

So, a second is nine billion periods of radiation. Now, what’s a period? We know that radiation is basically light, so let’s have a look at frequency:

Frequency = 1 / T and Frequency = v / λ

So frequency is the reciprocal of the period T, and also velocity v divided by wavelength λ. No problem. Flipping things around, we see that period T is wavelength λ divided by velocity v. We know that a wavelength is a distance, a thing like a metre:

The metre is the length of the path travelled by light in vacuum during a time interval of 1/299792458 of a second...

And we all know that velocity is a distance divided by a time. So a period is a distance divided by a distance divided by a time. The result is another period of time. This definition of time is circular and tells us nothing. How do we define it? Let’s look at frequency again:

Frequency is the measurement of the number of times that a repeated event occurs per unit of time.

So frequency is a number of events per second. And a second is a number of some other events. The interval between events is measured in terms of other events. And the interval between those events is measured in terms of other events. Until there are no events left, only intervals. And intervals are frozen timeless moments. For time is a measure of events, of change, measured by and against some other change. And for things to change, something, somewhere, somehow, has to have motion. You don’t need time to have motion. You need motion to have time.

We measured nine billion oscillation events and defined that as a second. We counted events. We counted motions. One, two, three, four, five… nine billion. Mark that down as a second. But you don’t have to count the motion in an atomic clock. You could count beans in a bucket. Ping, ping, ping, chuck them in, regular as clockwork.

You’re sitting there counting beans into the bucket, ping, ping, ping. Now, what is the direction of time? The only direction that is actually there, is the direction of the beans you’re throwing. “Fuller Bucket” is not the direction of time. “More Beans" is not the direction of time. The direction of your time is the direction of your counting, and I could have asked you to count them out of the bucket. There is no “Arrow of Beans”. There is no “Arrow of Time”. That’s just an illusion, as imaginary as the direction you take when you count along the set of integers.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 →

So why do we say things like Clocks slow down as if a clock is something that moves like a car? It isn't travelling. There's no slow or fast or up or down to it. We say the day went quickly but we know it didn’t go anywhere, and it didn’t go quickly at any speed at all. It isn’t travelling and there is no direction. The only directions that are there, are the directions of the motions that make the events that we use to measure the intervals between the other events. And they’re being counted, incremented, added up. We count regular atomic motion to use as a ratio against some other motion, be it of light, atoms, clocks, or brains. All of these things have motion, both internal motion and travelling motion. And all those motions are real, with real directions in space, ending in the sameness we call entropy. But the time direction isn't real. It's as imaginary as a trip to nine billion.

That's why the past is only in your head and your records. It isn’t a place you can travel to. It’s the places where things moved from. All those places are still here, now. And while the past is the integral of all nows, now lasts for no time at all. Because time needs events, and if there were only intervals and no events, there wouldn’t be any time. When you take away the events and the motion, you take away the time. A second isn’t some slice of spacetime, it’s just nine billion motions of a caesium atom. Accelerate to half the speed of light and a second is still nine billion motions of a caesium atom. But there's only half the local motion there used to be, because the other half is already doing the travelling motion through space. Imagine yourself as a metronome. Each tick is a thought in your head, a beat in your heart, a second of your time. If you’re motionless with respect to me I see you ticking like this |||. If you jet off in a spaceship, you tick like this /\/\/\. If you could reach c and we know you can’t, you wouldn’t tick at all. Your time would flatline like this ______ because any transverse motion would cause c to be exceeded. And you wouldn’t tick for anybody else in the universe. That’s the thing that’s out there, the thing we’re trying to learn about. This is what it’s like:

What can you see? What can you measure? Yes you can measure height. And width. And if it wasn't just a picture you could also measure depth. That's three Dimensions, with a capital D because we have freedom of movement in those dimensions. What else can you see? What else can you measure? You can see things moving, but you can’t see a fourth dimension. You might imagine a time dimension, with direction and length. But the picture comes from the wikipedia temperature page. The thing you should measure is temperature, which used to be considered a dimension, before the word changed from “measure” to “Dimension” under your feet. Temperature is an aspect of heat, that derived effect of motion. When you measure the temperature you are measuring motion, because that’s what’s there. You can call it a dimension, but there can be no motion in this dimension, because it’s a measure of motion. If you were one of those dots, immersed in temperature like we are immersed in time, you would not talk of climbing to a “high temperature”, because there is no height. Likewise we cannot travel a length of time, because there is no length, just as there is no height in temperature. So time is a dimension with a small d. It's a measure of change of place rather than a measure of place, and it has no absolute units, because you can only measure one change of place against another. The units are relative, which is what Special Relativity tells us.

Special Relativity tells us that your relative velocity alters your measurement of space and time compared to everybody else. You increase your relative velocity and space contracts while time dilates by a factor of √(1-v2/c2). If you travel at .99c, space contracts to one seventh of its former size. So your trip to a star seven light years away only takes you a year. But physics is about the universe, and in that universe it took you seven years. The space in the universe didn’t contract because you travelled through it. But your time did.

Einstein didn’t understand the full meaning of Special Relativity until later in life. In the early days he was influenced by Hermann Minkowski, a father-figure whose forename was the same as Einstein’s actual father. It was Minkowski who turned time into the fourth dimension:

The mathematics of his revolutionary paper on Special Relativity was relatively elementary, and at first he resisted its reformulation in terms of four-dimensional space-time by his former teacher Hermann Minkowski, complaining that “since the mathematicians pounced on relativity theory I no longer understand it myself”.

Later Einstein struggled with the Twins Paradox in 1918. He used acceleration from General Relativity as the explanation, but this explanation was erroneous and didn’t account for passing clocks. Look it up on wikipedia. A couple of years on in 1920 he gave an address at the University of Leyden about the dreaded ether:

..according to the general theory of relativity space is endowed with physical qualities; in this sense, therefore, there exists an ether. According to the general theory of relativity space without ether is unthinkable; for in such space there not only would be no propagation of light, but also no possibility of existence for standards of space and time (measuring-rods and clocks), nor therefore any space-time intervals in the physical sense. But this ether may not be thought of as endowed with the quality characteristic of ponderable inedia, as consisting of parts which may be tracked through time. The idea of motion may not be applied to it.

When you read the history you can see a slow evolution from the postulate that says the laws of physics are the same in all inertial frames of reference. The problem with reference frames is that all our observer velocities are zero, and if you don’t take care the sun goes round the earth. They don’t explain why the speed of light is always the same. It wasn’t until Einstein met Godel in Princeton that he realised the full impact of what Special Relativity really meant:

In his response to Godel's paper in the Schilpp volume, Einstein acknowledged that "the problem here disturbed me at the time of the building up of the general theory of relativity." This problem he described as follows: "Is what remains of temporal connection between world-points in the theory of relativity an asymmetrical relation (like time, intuitively understood, and unlike space), or would one be just as much justified to assert A is before B as to assert that A is after B? The issue could also be put this way: is relativistic space-time in essence a space or a time."

Godel didn’t “find a way to time travel” with his rotating universe. He merely used this conjecture to demonstrate that time could not have passed if you could visit the past. Einstein was with Godel on this, and understood full well the implications:

It is a widely known but insufficiently appreciated fact that Albert Einstein and Kurt Godel were best friends for the last decade and a half of Einstein's life. They walked home together from Princeton's Institute for Advanced Study every day; they shared ideas about physics, philosophy, politics, and the lost world of German-Austrian science in which they had grown up. What is not widely known is that in 1949 Godel made a remarkable discovery: there exist possible worlds described by the theory of relativity in which time, as we ordinarily understand it, does not exist. He added a philosophical argument that demonstrates, by Godel's lights, that as a consequence, time does not exist in our world either. If Godel is right, Einstein has not just explained time; he has explained it away...

That’s the true meaning of Special Relativity. The “speed of light” was always the problem. And it was always the problem because time was always the problem. Because at the speed of light there’s no time left for anything else to happen. It’s why c isn’t really a speed, because you run out of time trying to get there, and if there’s no time, there’s no speed because speed is distance over time. Velocity is prime. It defines your metres and your seconds. We should talk of it as a fraction of c like in the equations, or by degrees, but not by the things it itself defines. Because like temperature time is derived from motion, which is what is there. And c is the total motion, the rapidity of inductance from which we slice our immersive time, the inescapable property of oscillating photons and those electromagnetic things from which we’re made. From which the universe is made.

The universe is not a block universe, it is a world in motion. The worldlines are only in mathematical space, and in your head. There is no future, there is no past, only the now that is always now, the now of Presentism. We don’t travel in time at one second per second. We don't travel in time at all. Relativistic clocks don’t travel in time at different rates, they travel in space at different degrees of c, and when they collide, they collide at the same location and at the same time whatever their faces say is local time. Local time.

To travel backwards in time we'd need to unevent events, we’d need negative motion. But motion is motion whichever way it goes. You can’t have negative motion. So you can’t travel backwards in time. There are no time travel paradoxes, because there is no time travel, and there is no time travel because there is no travelling in time. And there never was. Time didn’t start fifteen billion years ago. Because time didn’t start in the first place. It was motion that started in the first place. And it was fifteen billion light years away by every light path you can track through timeless space. That’s how far we’ve come.

And now we can move on.

Acknowledgements:

Thanks to echalk and R Beau Lotto re colour perception, to Palle Yourgrau for “A World Without Time” re Einstein history, and to Julian Barbour (“The End of Time), Paul Davies (“About Time”) and Carlo Rovelli (various) for background reading. And thanks to all the forum fellas for all the feedback, wiki contributors, anybody who put up an image I’ve borrowed, and anybody else I’ve missed. And Albert Einstein

Thanks guys.

2.

3. This is a new improved version to take account of the feedback I've had so far. Thanks. And if you've got any more I'll be only too pleased to receive it.

4. Just because the only present is now does not mean that only now is present.

If yesterday suddenly began to move along a fifth dimension, a new world would appear that diverged from that day as if it never ended. Deep? Hope you can live with it. Zzzzzz.

See ya!

5. Originally Posted by LeavingQuietly
Just because the only present is now does not mean that only now is present. If yesterday suddenly began to move along a fifth dimension, a new world would appear that diverged from that day as if it never ended. Deep? Hope you can live with it. Zzzzzz. See ya!
Oh boy. If yesterday suddenly began to move along a fifth dimension.... I think somebody doesn't quite get it.

6. I see you have done your best to put this in laymans terms. But I am very stupid. Point blank. See if you can put this in "Stupid Laymans Terms" for me.

Time is not time, instead, it is just motion. A series of events that began - and - are still going. Is this correct? If so, does that mean that the first five or six events are still happening right now?

Help me out here. Try and use the best analogy you can find. And try, I know this may sound like a stretch, but try to explain it as if you were explaining it to a child.

Pride is of no concern to me.

7. Originally Posted by Kolt
I see you have done your best to put this in laymans terms. But I am very stupid. Point blank. See if you can put this in "Stupid Laymans Terms" for me.

Time is not time, instead, it is just motion. A series of events that began - and - are still going. Is this correct?
Not quite, Kolt. Time is how we compare the motion of our atoms and electrons and clocks against the motion we see in the world.

If so, does that mean that the first five or six events are still happening right now?
No. A motion starts, goes a distance, then ends. Then some other motion takes over, like a bullet hitting a sandbag setting sand grains moving and setting the atoms in the sand grains moving as heat.

Help me out here. Try and use the best analogy you can find. And try, I know this may sound like a stretch, but try to explain it as if you were explaining it to a child. Pride is of no concern to me.
Those first few events weren't fifteen billion years ago. They were fifteen billion light years a go-go. A light path distance. An amount of motion. And now is where we're at.

8. 'TIme' is a name we give to the passing of events, unlike light or sand, it cannot be measured, perceived, or held in your hand. What you count [and call time] is merely the number of swings of a pendulum, virbrations of a piezoelectric crystal or those tiny little things whizzing around in a caesium clock, an event happens and you cannot undo it. What you are doing when you 'time' an athlete sprinting 100 metres is to compare one motion [the runner] to another [the hands on a stopwatch]. It is convenient to classify events into time merely so that we are all 'synchronised'

THink of our 'time' units, they are all tied to the motion of the earth around the sun and are only 'valid' here on earth.

9. Originally Posted by Kolt
I see you have done your best to put this in laymans terms. But I am very stupid. Point blank. See if you can put this in "Stupid Laymans Terms" for me.

Time is not time, instead, it is just motion. A series of events that began - and - are still going. Is this correct? If so, does that mean that the first five or six events are still happening right now?

Help me out here. Try and use the best analogy you can find. And try, I know this may sound like a stretch, but try to explain it as if you were explaining it to a child.

Pride is of no concern to me.
Actually, the preservation of energy clearly states that the past cannot be ongoing at the same time as the present. But the information can, not to say must, remain, it's just that it have to be totally still. So supposedly if past time got an additional energy, in the same way present has one, the past would continue along this additional coordinate. And since the past does not change, it is still the same past even if it gets additional energy, hence the past in this case continue just like the present, and might develop differently then last time.

Does any of this make sense?

10. Megabrain: you've got it. Look out for usage of length or travel words associated with time. For example the word "passing" in your phrase "the passing of events". Also take care how you use past and future tense. After you practice this for a while, you really notice how illogical our language is and how much it shapes people's thinking.

Leavingquietly: Not to me I'm afraid. See ENERGY EXPLAINED. It's nothing mysterious. Just tension really.

11. Originally Posted by Farsight
Megabrain: you've got it. Look out for usage of length or travel words associated with time. For example the word "passing" in your phrase "the passing of events". Also take care how you use past and future tense. After you practice this for a while, you really notice how illogical our language is and how much it shapes people's thinking.

Leavingquietly: Not to me I'm afraid. See ENERGY EXPLAINED. It's nothing mysterious. Just tension really.
It has been my personal belief for many years that 'time' like 'numbers' do not exist, - however I have a practical world to live in, to share with people who have 'time' so engraved in them that to suggest it does not exist would be sheer lunacy other than in appropriate company. I use time in the accepted sense as I use numbers, there is no such thing as 'nine' or 'two' similar is time, it is convenient.

12. OK noted.

13. But i know simultaneous presents might be false. I've not really proven it yet. But it might be possible to prove it. Watch for such proofs.

14. Originally Posted by LeavingQuietly
But i know simultaneous presents might be false. I've not really proven it yet. But it might be possible to prove it. Watch for such proofs.
of course presents aren't simultaneous, but it doesn't have anything to do with energy.

15. How come?

16. Originally Posted by LeavingQuietly
How come?
presents are non simultaneous due to the limitations at which information can travel.

care to impart your knowledge of where energy comes into the picture?

17. The way I see it, the past might be some sort of position holder. That it is the past that kicks the present in the behind to create the future. That the future depends upon the present, depends upon the past etcetera. That the past might be present but emptied of energy. That so to speak, the identity of anything does not need energy, and that the information in the past does not need to be transfered to the future in order for it to exist. But what would happen if energy was added to the past from a fifth dimension? The fact that 2 objects moving in relation to eachother, both see the other system as moving slower in time, hence both objects are in different realities, or different positions along additional coordinates.

18. Originally Posted by Farsight
[Those first few events weren't fifteen billion years ago. They were fifteen billion light years a go-go. A light path distance. An amount of motion. And now is where we're at.

Okay so tell me if I'm any closer -

The univers began. "Boom!"....or I guess the official term is ..."Bang!" An explosion. Everything is moving away from each other, moing outward in all directions. As most of those things are moving they heat up or cool down, they break into pieces or they collect new pieces, they crash into each other creating or 'causing' new things. Cause and effect. A light-year is an amount of distance through space that is traveld by light. As you say, not fifteen billion years but fifteen billion light-years.

So.....Britney didn't kiss Madona three years ago, Britney kissed Madona....(Ahh fig-sticks! I wouldn't dare attempt to do the math)...but let's say, a small portion of a light-year ago?

I'm at the bus stop. I walk cross the street to the 7-Eleven to buy a hoagie and a pack of smokes. Now when I walk back to the bus stop I'm slimply moving through space in the opposite direction. Now when I first crossed the street everything happend a spacific way. Not just everything between the bus stop and the 7-Eleven but everything through out the entire univers. And I can't re-do that.

I can commit the same act but in this case the word "same" is relative. I can't acually go back to the bus stop and then cross the street the same exact way as I did the first time. In fact, I can't go back at all. Likewise, the concept of moving backwards through space is also relative. I'll never walk back to the bus stop, I'll always walk forward to the bus stop. No event can ever be undone or redone. I can't go back and eat the same exact hoagie as the first hoagie. That spacific hoagie was the only hoagie of it's kind. I can only continue forward and eat a new hoagie. Right?

I hope I'm not way off key here...

19. LeavingQuietly: interesting but i don't get what your saying.

Kolt: the light year is the distance through spacetime that light travels in a year.

as for the bus stop trips well lets put it this way.
moving from the bus stop to the 7-Eleven you travel a certain distance to get across the street, you travel a certain number of meters in a certain number of seconds. travelling back to the bus stop you have travelled twice the distance but since your back at the same place your displacement is zero meters, the distance travelled to the other side of the street minus the distance in the opposite direction. however when you travel across the street you are moving in the same direction through time so your displacement through time will be the amount of time it took you to get to the other side of the street and back.

so when you arrive back at the bus stop you will have displaced 0m in space but you will still have travelled a distance through time, so you'll kinda be in a different position.

20. Kolt: that's about right. Britney kissed Madonna three light years back.

wallaby: Sorry, nobody's travelled any distance through time. You travel distance through space. And while you do it you look at your atomic wristwatch which measures.. the distance travelled by light through space.

21. Originally Posted by Farsight
wallaby: Sorry, nobody's travelled any distance through time. You travel distance through space. And while you do it you look at your atomic wristwatch which measures.. the distance travelled by light through space.
valid point, however looking at your atomic wristwatch constitutes a measure of time, arbitrary measure of course but so is most measurement. the meter is an arbitrary measure defined as 1/299792458<sup>th</sup> the distance travelled by light per second measured by an atomic clock so both are equally arbitrary, would you then extend your arguement to nobody's travelled any distance through space?

if you measure a change in your position in space and a change in your position in time from an origin then you have travelled through spacetime, that is a distance through 4 dimensions and not just the 3 of space.

22. I think there's a big big difference between the time and the space. I can take a step through space and change my position in it. I just can't do that with time.

Sure I can travel fast in space so my clock runs slower than yours and my "travelling through time" is less than yours. but when I come back and tap you on the shoulder, we're both in the same position in time.

IMHO that fourth dimension isn't really there. It's just a relative measure of internal atomic motion versus travelling motion through the three dimensions that are.

23. Originally Posted by Farsight
I think there's a big big difference between the time and the space. I can take a step through space and change my position in it. I just can't do that with time.
big difference of course but just because your not steping through it doesn't mean your position remains static in it.

Originally Posted by Farsight
Sure I can travel fast in space so my clock runs slower than yours and my "travelling through time" is less than yours. but when I come back and tap you on the shoulder, we're both in the same position in time.
indeed we would be, so?

Originally Posted by Farsight
IMHO that fourth dimension isn't really there. It's just a relative measure of internal atomic motion versus travelling motion through the three dimensions that are.
and neither are the three spacial, there just a dimension is just a mathematical thing that we use to describe the universe. spatial motion is just a measure of your position, or change of, relative to a point. this is simply described by an internationally used standard, two marks on a platinum rod.

24. Originally Posted by wallaby
Originally Posted by Farsight
I think there's a big big difference between the time and the space. I can take a step through space and change my position in it. I just can't do that with time.
big difference of course but just because your not steping through it doesn't mean your position remains static in it.

Originally Posted by Farsight
Sure I can travel fast in space so my clock runs slower than yours and my "travelling through time" is less than yours. but when I come back and tap you on the shoulder, we're both in the same position in time.
indeed we would be, so?

Originally Posted by Farsight
IMHO that fourth dimension isn't really there. It's just a relative measure of internal atomic motion versus travelling motion through the three dimensions that are.
and neither are the three spacial, there just a dimension is just a mathematical thing that we use to describe the universe. spatial motion is just a measure of your position, or change of, relative to a point. this is simply described by an internationally used standard, two marks on a platinum rod.
Actually, most things are not in the same position in time. It is just that the time is infinitely thin, so different times can exist simultaneously, It's just that the last time is the final time. And we still have the problem "which one of you all is moving?" and it actually means that both are but not the other and hence the object you smashed away is not going to be in the same reality as you etc.

25. Originally Posted by LeavingQuietly
Actually, most things are not in the same position in time. It is just that the time is infinitely thin, so different times can exist simultaneously, It's just that the last time is the final time. And we still have the problem "which one of you all is moving?" and it actually means that both are but not the other and hence the object you smashed away is not going to be in the same reality as you etc.
thats because its relative to the observer. however one observer will still observe farsight tapping me on the shoulder at one point in time.

26. Yes, exactly, but different observers will all experience that they are older then the others. That cannot happen unless they are in different realities. Hypothenusically, that is. (kidding)

27. This is what the Universe is like. OK it's a just picture, so it's a flat version of the Universe, but use your imagination:

All those little dots are different observers with different motions. They're travelling through space at different speeds. So they all experience time at different rates. They don't agree about what time it is. All they do agree about is that whenever they bump into one another, the time for both of them is "now". Truth is, there isn't any time really, regardless of what anybody's clock says. A clock is just measuring motion and showing it to you so you've got something to measure some other motion against. The thing is, you're just another dot travelling through space, and the only time it ever is is now. There's nothing to travel through apart from space.

28. Originally Posted by Farsight
This is what the Universe is like. OK it's a just picture, so it's a flat version of the Universe, but use your imagination:

All those little dots are different observers with different motions. They're travelling through space at different speeds. So they all experience time at different rates. They don't agree about what time it is. All they do agree about is that whenever they bump into one another, the time for both of them is "now". Truth is, there isn't any time really, regardless of what anybody's clock says. A clock is just measuring motion and showing it to you so you've got something to measure some other motion against. The thing is, you're just another dot travelling through space, and the only time it ever is is now. There's nothing to travel through apart from space.
Then how do you explain that relativity clearly states that an object moving fast pass slower through time even though the speed in itself is relative and thereby passing slower in the other system that you were comparing to aswell, measured from the spaceship or train, whatever. So the astronaut experience that you move slower through time, but have you ever heard of an astronaut ageing faster then the earthlings that send it away? No. Because him is not us (speaking funny language) so even though he will experience that we are a bunch of younglings and he has aged twice as quick, we will experience that he is the youngling and we are the old guys. Hence the original astronaut is not the one we sent away. He is not in the same world. Everyone consider himself still in his own reference frame.

29. Originally Posted by LeavingQuietly
Then how do you explain that relativity clearly states that an object moving fast pass slower through time even though the speed in itself is relative and thereby passing slower in the other system that you were comparing to aswell, measured from the spaceship or train, whatever.
Relativity doesn't state that. It talks about experiencing less time. That's not the same as passing slower through time. Remember, Einstein was unhappy that Minkowski turned time into a fourth dimension.

So the astronaut experience that you move slower through time, but have you ever heard of an astronaut ageing faster then the earthlings that send it away? No. Because him is not us (speaking funny language) so even though he will experience that we are a bunch of younglings and he has aged twice as quick, we will experience that he is the youngling and we are the old guys. Hence the original astronaut is not the one we sent away. He is not in the same world. Everyone consider himself still in his own reference frame.
If you and I are separated by distance, you look small to me and I look small to you. It's just perspective.

If we're separated by velocity, your time looks small to me and my time looks small to you. It's another type of persepective.

If you then come back to me, you've travelled more distance than me so you've experienced less time than me. My atomic clock gizzards have been moving like this | while yours has been moving like this /\/\/\ and so suffering time dilation with respect to mine. See the wikipedia article on time dilation. The original Special Relativity used nothing more than Pythagoras' Theorem.

I'm not fond of "reference frames" because you could use them to insist that the Sun goes round the Earth. I think they make you think in terms of some particular perspective and make it harder to see the big picture.

30. Originally Posted by Farsight
Originally Posted by LeavingQuietly
Then how do you explain that relativity clearly states that an object moving fast pass slower through time even though the speed in itself is relative and thereby passing slower in the other system that you were comparing to aswell, measured from the spaceship or train, whatever.
Relativity doesn't state that. It talks about experiencing less time. That's not the same as passing slower through time. Remember, Einstein was unhappy that Minkowski turned time into a fourth dimension.
It has also been shown with a triangle experiment how time differ in the moving rocket compared to the earth. But it's not like the earth is the center of the universe, seen from the rockets comparative system, it is the earth that is moving, no matter how strange it might sound. So the astronout is younger and older at the same time. How do you explain that?
Originally Posted by Farsight
So the astronaut experience that you move slower through time, but have you ever heard of an astronaut ageing faster then the earthlings that send it away? No. Because him is not us (speaking funny language) so even though he will experience that we are a bunch of younglings and he has aged twice as quick, we will experience that he is the youngling and we are the old guys. Hence the original astronaut is not the one we sent away. He is not in the same world. Everyone consider himself still in his own reference frame.
If you and I are separated by distance, you look small to me and I look small to you. It's just perspective.

If we're separated by velocity, your time looks small to me and my time looks small to you. It's another type of persepective.
[b]You look older then me to me, and I look older then you to you. But when they meat, In every system, 1 is older then the other. So there have to be two systems the least.[b]
Originally Posted by Farsight
If you then come back to me, you've travelled more distance than me so you've experienced less time than me. My atomic clock gizzards have been moving like this | while yours has been moving like this /\/\/\ and so suffering time dilation with respect to mine. See the wikipedia article on time dilation. The original Special Relativity used nothing more than Pythagoras' Theorem.

I'm not fond of "reference frames" because you could use them to insist that the Sun goes round the Earth. I think they make you think in terms of some particular perspective and make it harder to see the big picture.

31. LeavingQuietly:

Not so. It's so much simpler than that.

Imagine we've got "light clocks" that work by bouncing light between parallel mirrors, and one of us is moving with respect to the other. Each of us sees our own clock ticking like this | and the other's clock ticking like this /\/\/\/\. The speed of light is the same for both of us, so I calculate that my tick involves a shorter lightpath distance than yours because mine is like this | and yours is like this / . I therefore calculate that your time is running slower than mine.

You do exactly the same.

The apparent contradiction isn't because there's two different worlds. It's because there isn't really any time! It's a subjective thing, not an objective thing that's actually out there. And how much of it you experience is related to how much you move compared to light.

We part at some "time" that we both agreed was "now" and we return at some other "time" that we again both agreed was "now", despite the different readings on our clocks. All the clocks have done is counted the number of times the light has crossed the gap between the parallel mirrors. The total lightpath distances for both our clocks is the same. When we meet up again, one of us, the one who travelled with respect to the other, has a lightpath that we agree looks like this:

-> /\/\/\/\/\/\/\/\/\
<- \/\/\/\/\/\/\/\/\/

The other has a lightpath that we agree looks like this |, which can be spread out like a deck of cards to look like this:

||||||||||||||||||||||||

The total line lengths are the same because the speed of light is the same. But the one who did the travelling had fewer ticks, because Pythagoras' Theorem says it has to be like that.

32. What you're actually saying is that time dilation is bogus. It can be proven that it isn't so it isn't

And you still have the problem that "both twins" will be older then the other. How exactly does "time does not exist" solve that?

33. Originally Posted by Farsight
The apparent contradiction isn't because there's two different worlds. It's because there isn't really any time! It's a subjective thing, not an objective thing that's actually out there. And how much of it you experience is related to how much you move compared to light..
No, it shows that there is no such thing as a global, universal time - the eternal beat newton imagined that the entire universe dances to. Time is a local thing, but it is an objective local thing - and there are very specific transformation rules to move one observers time frame to another observers frame of reference.

34. Can this have anything to do with the highthened energy release in microtechnology solar cells above the energy release of the photons? That a momentum can actually have cousins that joins the dance?

35. Originally Posted by LeavingQuietly
What you're actually saying is that time dilation is bogus. It can be proven that it isn't so it isn't.
Huh? No, it's not bogus. The twin who travelled experienced less time, and comes back younger than the other one.

And you still have the problem that "both twins" will be older then the other. How exactly does "time does not exist" solve that?
Read what I said again.

Can this have anything to do with the highthened energy release in microtechnology solar cells above the energy release of the photons? That a momentum can actually have cousins that joins the dance?
Nevermind.

36. For the other twin, the one that traveled, it is earth that moves and hence it is he that is old and you that are young, and hence 2 worlds are needed

37. river_rat: it isn't an objective thing. Invariant mass is an objective thing. Time experience is subject to the observer's motion compared to somebody else, his reference frame if you prefer. You might argue the same about distance but it's different. The Universe doesn't contract to a point because you and your buddies speed through it at all different angles and velocities. But when you meet up at some agreed location and velocity your time experiences are all different. Some have been out for 2 months, some 3, some 4. PS: local is the wrong word to describe one observer's time, because two colliding observers bring two different local times to the same location.

38. Originally Posted by Farsight
river_rat: it isn't an objective thing. Invariant mass is an objective thing. Time experience is subject to the observer's motion compared to somebody else, his reference frame if you prefer. You might argue the same about distance but it's different. The Universe doesn't contract to a point because you and your buddies speed through it at all different angles and velocities. But when you meet up at some agreed location and velocity your time experiences are all different. Some have been out for 2 months, some 3, some 4. PS: local is the wrong word to describe one observer's time, because two colliding observers bring two different local times to the same location.
Let's say we have 2 persons, A and B. They are at the same age. B goes to outerspace (yeey) in half light speed A experience that B is moving and that B age slower then A, hence A become older then B when a time has passed. That, moreover means that A has lived longer, that he will possibly die earlier and that he will be jelous on B because he is so young.

t(A) = t(B)/sqrt(1-(1/2)^2)

But in B's reference frame, B is still and A is moving in half light speed and since it can be proven that the exact same rules apply in this case in other words A age slower then B, hence B become older then A when a time has passed. That, moreover means that B has lived longer, that he will possibly die earlier and that he will be jelous on A because he is so young.

t(B) = t(A)/sqrt(1-(1/2)^2)

These statements:
{t(B) = t(A)/sqrt(1-(1/2)^2)
{t(A) = t(B)/sqrt(1-(1/2)^2)

Cannot be true in the same world, so A's reference frame is not in the same world as B's reference frame.

39. Originally Posted by Farsight
river_rat: it isn't an objective thing. Invariant mass is an objective thing. Time experience is subject to the observer's motion compared to somebody else, his reference frame if you prefer. You might argue the same about distance but it's different. The Universe doesn't contract to a point because you and your buddies speed through it at all different angles and velocities. But when you meet up at some agreed location and velocity your time experiences are all different. Some have been out for 2 months, some 3, some 4. PS: local is the wrong word to describe one observer's time, because two colliding observers bring two different local times to the same location.
I used local references so we can still talk about special relativity - it is only a local theory and it only makes sense locally around each observer provided they are not doing anything too strange. Do something strange and then general relativity rears its head.

Locations really don't make sense in SR, you need to talk about events. So two different observers bring different "times" to an event - so what. If i measure my time in second and you in minutes does it change anything? Should we throw away the notion of time, or just accept that we may need to transform between our different notions?

Where do you get that mass is invariant? Rest mass maybe, but you did not specify that. The universe does "contract", the effect is as real as gravity or any other physical effect - you still seem to be stuck to this grand background universe idea, which is not compatible with relativity. The time dilation is as real as the length contraction.

What is it about spacetime bothers you so much?

40. PS. How do you solve the paradox?

41. You need to analyze the problem properly - the trick is to realize that the space-ship bound twins notion of "back on earth now" changes dramatically when he turns the ship around. Nothing special happens to either one, except that huge shift in reference. The whole thing is not symmetric either, the one twin is always in an inertial reference frame (the earth bound twin) while the spaceship bound twin is in two different reference frames, the one on his ship traveling to the stars and the one on his ship traveling back. So the paradox is not really a paradox, the space cadet twin is really younger then his brother.

42. I believe timedilation is a different and existing phenomena to "he's over there, i know nothing about him now. Imagine a very long train. The same timedilation rules applies to the whole train seen from you, since it applies to a part, hence they will age slower on the train. Unless you have substancial proof, like for instance a proof that the acceleration kills the dilation or something remarkeable.

Note: I know that the twin comes home younger, doesn't mean there isn't 2 worlds.

43. Originally Posted by river_rat
Where do you get that mass is invariant? Rest mass maybe, but you did not specify that. The universe does "contract", the effect is as real as gravity or any other physical effect - you still seem to be stuck to this grand background universe idea, which is not compatible with relativity. The time dilation is as real as the length contraction. What is it about spacetime bothers you so much?
There's a lot of debate about mass. I don't think it's invariant myself. I can't recall where I got "invariant mass" from, but it gets bandied about enough. Here's what wikipedia says, not that it can always be trusted.

http://en.wikipedia.org/wiki/Rest_mass

Come on, the universe doesn't "contract". If you come at it from all sides it isn't a point. If you view two relativistic objects passing by ten miles away they are length-contracted but the space between them is not. What bothers me about spacetime is the same thing that bothered Einstein. That it's a space. Not a spacetime.

44. Originally Posted by LeavingQuietly
I believe timedilation is a different and existing phenomena to "he's over there, i know nothing about him now. Imagine a very long train. The same timedilation rules applies to the whole train seen from you, since it applies to a part, hence they will age slower on the train. Unless you have substancial proof, like for instance a proof that the acceleration kills the dilation or something remarkeable.

Note: I know that the twin comes home younger, doesn't mean there isn't 2 worlds.
All this crap about the twin comes home younger really mystifies me, he does NOT come home younger he comes home the SAME age, in the 'time' he has been 'away' the earth has been around the sun for 'x' times so he is the same age as his twin - that's how we essentially define age, 1 rotation of the earth atround the sun = 1 year. If they were born in 1960 spent 30 years apart and meet again in 2000 they are BOTH 40 years old, it's just that one of them has the appearance of a 10 year old - this is why Einstein [I think] postilated that the speed of light is the universal constant.

That time is not what we think of it or that it it does not 'exist' other than as a means of explaining events is a theory, I do not neccessarily agree with all the bells and whistles that go with it but I believe it is a theory with at least some credibility, and worth exploring.

45. Originally Posted by Megabrain
Originally Posted by LeavingQuietly
I believe timedilation is a different and existing phenomena to "he's over there, i know nothing about him now. Imagine a very long train. The same timedilation rules applies to the whole train seen from you, since it applies to a part, hence they will age slower on the train. Unless you have substancial proof, like for instance a proof that the acceleration kills the dilation or something remarkeable.

Note: I know that the twin comes home younger, doesn't mean there isn't 2 worlds.
All this crap about the twin comes home younger really mystifies me, he does NOT come home younger he comes home the SAME age, in the 'time' he has been 'away' the earth has been around the sun for 'x' times so he is the same age as his twin - that's how we essentially define age, 1 rotation of the earth atround the sun = 1 year. If they were born in 1960 spent 30 years apart and meet again in 2000 they are BOTH 40 years old, it's just that one of them has the appearance of a 10 year old - this is why Einstein [I think] postilated that the speed of light is the universal constant.

That time is not what we think of it or that it it does not 'exist' other than as a means of explaining events is a theory, I do not neccessarily agree with all the bells and whistles that go with it but I believe it is a theory with at least some credibility, and worth exploring.
But not the same local age. Both are older in local age but seen from eachothers planet (if they have one each), all the others are younger since they consider themselves still compared to themselves. So both planets look at eachother and experience that when having adjusted the measurements to distance, the other planets inhabitants age slower whilst they age quicker, and both cannot be right unless there are 2 worlds.

46. Originally Posted by LeavingQuietly
But not the same local age. Both are older in local age but seen from eachothers planet (if they have one each), all the others are younger since they consider themselves still compared to themselves. So both planets look at eachother and experience that when having adjusted the measurements to distance, the other planets inhabitants age slower whilst they age quicker, and both cannot be right unless there are 2 worlds.
considering two referance frames and comparing them with respect to the other you cannot distinguish which of the frames is undergoing contraction, without privilaging one referance frame over another, this is because the velocity of one observer with respect to the other is the same as the velocity of the other with respect to the original observer.

if you compared the two referance frames to a third then you have two velocities you can use to compare the first two.
ie. you need a third referance point.

EDIT: of course then the answer is dependant on the third referance frame, but i think thats the whole point isn't it. they'll only agree on the speed of light, so...ya.

if thats not right then i give up.

47. If we need a third reference point, that would suggest that a certain reference frame is still and none of the other 2 are. If there is a reference frame that is still, then time dilation would be compared to that system and einsteins SR would not be correct in our reference frame.

Through suggesting that every point is still, I get that if an object moves along the x, coordinate in for instance c/2 from the still reference frame, the z,y and x length is objective. In the objects reference frame, It cannot breach the speed of light in the same way that the still reference frame can't. The maximum speed the object can have seen from the (other) still reference frame that notes the objects speed, is c, no matter what coordinates this speed has. Hence the object cannot breach the speed
sqrt(c^2 - (c/2)^2) (since it is a triangle), z or y wise, seen from the other frames perspective. We get that both frames are equally objective. The recording frame will percieve that the moving objects perception of the length per second to get to velocity sqrt(c^2 - (c/2)^2) is c,
hence:
sqrt(c^2 - v(xz-plane)^2) = c(y(object))
This is likely, since we cannot breach the speed of light.
A moving train for instance, cannot dispatch a ray of light that has a horizontal vector, which together with its length wise vektor, breaches the speed of light. to the train inhabitants a beem straight out of the window, has merely the horizontal vector, hence the horisontal vektor is max lightspeed to them.

Also, if the object has the speed v = c/2 along x, the x-wise speed cannot breach c/2, hence c - v(x) = c(x) along the movement direction axis, there is no question about it, this is the equation along the x-axis. Unless every mass moves along time. The equation would then be:
[v(x),v(y),v(z),v(t)].^2 - v(tyz-plane)^2 = v_tot(x)^2.

From this point of view it seem clear to me that time would pass slower in moving reference frames, if it wasn't for that length is shorter hence events happen quicker. It seems clear, according to my analysis, that this is the case. Length contraction clearly happens along all coordinates, and not like my old science book showed, only along the direction of the object.

This would solve the "different world" problem.

Any comments are appreciated.

48. Originally Posted by LeavingQuietly
If we need a third reference point, that would suggest that a certain reference frame is still and none of the other 2 are. If there is a reference frame that is still, then time dilation would be compared to that system and einsteins SR would not be correct in our reference frame.
no.
every observer considers themselves to be stationary, even if they're observed to be moving relative to another observer. so the third observer will think that they are stationary and that the other two are in motion.

if everything is moving relative to something else then your going to have alot of fun nailing down your actuall veloctiy wouldn't you say?

A moving train for instance, cannot dispatch a ray of light that has a horizontal vector, which together with its length wise vektor, breaches the speed of light. to the train inhabitants a beem straight out of the window, has merely the horizontal vector, hence the horisontal vektor is max lightspeed to them.
EDIT:well since the speed of light is constant and since we can always see a train then one would have to suggest that you must add the velocities differently. see the velocity addition formula for special relativity.

can anyone tell me how thats derrived?

49. That's the point, isn't it?

50. ya it is... but relativity is valid for all observers. sorry can you tell this sleepy person what we're debating.

51. First I'm going to wish you a merry christmas (PS. that was it). Then we can talk.

We are discussing how things are relative, like Einstein did in special relativity.

Sometimes I'm wrong, and sometimes I'm right, you are here to figure it out.

52. merry christmas to you too.

as for relativity, i don't even know if i'm right or where i'm wrong so i'm way out of my league.

i'm going to go think about simpler things i can understand instead.

53. Me too. Right now it's Xmas-Chess http://www.mathsisfun.com/forum/viewtopic.php?id=5499

54. merry christmas to you all.

A very unscientific remark:

Is it strange to say (after reading all above comments) that time (or the sense of time) is a mental state? That could explain why the days were long, very long when I was a kid and went shorter and shorter as the years went by.....

55. Originally Posted by peter211
merry christmas to you all. A very unscientific remark:
Is it strange to say (after reading all above comments) that time (or the sense of time) is a mental state? That could explain why the days were long, very long when I was a kid and went shorter and shorter as the years went by.....
No. It isn't a mental state. You really do experience time, like you experience heat. The mental state is your concept of time. You talk about days being long like trains are long, and years going by like buses. You should examine the language you use here and ask yourself why you use it.

56. Time is what stops everything in the universe happening at once. Or maybe it did/does happen all at once, its just that in that brief fleeting moment of the universe's existence, life had the brain capacity to MAKE time, to seperate all pieces of information as it could not process everything at once. Take the humble house fly for instance, which makes a quick gettaway because it sees things in slow motion (what we percieve to be a slow motion) - Is out motion slow? no it isnt....but it is to the fly therefore it has time to re-act.

So maybe time is just a perception ?

57. Not just perception leo. Colour is just perception. But heat isn't. Heat burns. Time is like heat: a derived effect of motion.

58. I disagree.........

Heat is not a "real" thing. energy may-be, as infra-red.
I'm a chef and have been burned by heat so many times that it doesnt really bother me that much, but stick a new commis chef in the kitchen and he burns himself.....its going to be even more painful for him.

Heat is one of our perceptions of energy
Time is one of our perceptions of motion.

It is the MOTION that is the real thing. nothing else..

And how can you say that colour is just a perception but heat isnt ?? When thermal energy is carried by a specific wavelength of light; colour: (infra-red)

59. Um heat is a form of energy - circa Thompson and Joule.

I love how people try to separate motion and time here, when it is time that parametrizes motion

60. I wasnt trying to seperate time and motion; i know they go hand-in-hand. What I am saying is that time is our PERCEPTION of motion.

61. Originally Posted by leohopkins
I disagree.........

Heat is not a "real" thing. energy may-be, as infra-red.
I'm a chef and have been burned by heat so many times that it doesnt really bother me that much, but stick a new commis chef in the kitchen and he burns himself.....its going to be even more painful for him.

Heat is one of our perceptions of energy
Time is one of our perceptions of motion.

It is the MOTION that is the real thing. nothing else..

And how can you say that colour is just a perception but heat isnt ?? When thermal energy is carried by a specific wavelength of light; colour: (infra-red)
I agree that motion is the underlying thing that's there, leo. I'd say however that heat is the name we give to oscillatory atomic or molecular motion that can effect the same in some adjacent material. So you burn your hand. But colour is something different. Yes, it's a name we give to some other oscillatory motion, that of photons coming into our eyes. I might see something as green, but you might see it as brown because you're colour blind. The colour of something is totally in your head. The heat of it isn't. There's a difference.

62. I see what you are getting at. And i'd agree with what you are saying about colour. but the underlying factor in colour is the wavelength. We may not necessarily percieve the wavelength in the same way as the next person, but nevetheless the wavelength remains the same.

as it is for motion, you and i can percieve the motion of something, which is a real thing, however time is relative to the observer, as is the perception of colour. so time is really a perception.

63. We'll have to agree to differ on the fine detail there leo.

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