khuram

Archive for February, 2008

“Space-Time Four Dimensions” Vs. “Time is Not Absolute”:

Posted by khuram on February 24, 2008

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“Space-Time Four Dimensions” Vs. “Time is Not Absolute”:

Relativity Theory is often linked with the idea of space-time four dimensions. Meaning of space-time four dimensions is quite simple however. Just like we refer to a “point” in “space” using THREE coordinate references, we refer to an “event” using FOUR coordinate references of “space-time”, where three are the coordinates of space and the fourth is the time coordinate.

So far this concept of four dimensional “space-time” is quite simple. Actual confusion comes when both Special and General Theories of Relativity assert that Time is not absolute. According to these theories, since there is no absolute time, so two observers can record different time durations of a single event, even if they employ exact same type watches for recording the time duration.

Actually, General Relativity Theory provides that Time can move faster or slower at different locations of Universe. Speed of Time, according to this theory (i.e. experimentally proven) is normal (means fastest) in complete empty space where there is no effect of any force of gravitation at all.

But at those spots of universe, which are in the range of considerable force of gravitation, time slows down at those locations.

Secondly, Special Theory of Relativity says that time slows down in an object if that object is moving at very high speed i.e. comparable to the speed of light (i.e. “time dilation”). These two assertions of General Theory and Special Theory of Relativity have been resulted in famous “End of Time” in Black Holes (General Theory) and “Twin Paradox” (Special Theory) sort of things. These assertions also have been resulted in confusions regarding the concept of space-time four dimensions. Since there is no absolute time and since time can be different at different spots of spatial universe, so there comes the confusion as if ”time” is some “physical” part of “space” and that as if “space” has physical four dimensions, due to which time can be different at different points of space. Purpose of this article is just to show that these two assertions of General Theory and Special Theory of Relativity that time can be different in (i) gravitational fields and in (ii) high speed objects, have nothing to do with the simple concept of space-time four dimensions.

Let us take the assertion that time slows down in gravitational field (General Theory). Out of this primary assertion (empirically proven), what can be logically deduced is just that Speed of time is the characteristic property of any particular point of three-dimensional space.

But since this speed of time can very for high speed objects as well (Special Theory) … so speed of time can be considered to be a characteristic property of speed of objects as well.

To conclude Four physical dimensions of space or even space-time, out of these two assertions of General Relativity and Special Relativity is a whole misleading and just confused idea. Very ironically, science literature discusses the concept of space-time four dimensions and another quite different fact that time is not absolute, in a way that gives the sense that these two are representing a single concept … that space or space-time has physical four dimensions.  

Idea that “Time” is the 4th dimension of “space” is Totally Absurd – PROOF

Let us first assume that science in fact says that “time” is the fourth dimension of “space”. Actually science doesn’t say exact this thing, but we can proceed in following way to prove that “time” cannot be the fourth dimension of “space”:

If “science” is talking about “space” … then it should talk about only and only space. It means, “science” should talk about complete empty space.[Also see my article: Space as a form of ‘Nothingness’]

In a complete empty space … where there is no “matter” at all … Time cannot even exist in such complete empty space.

What is Time…???

Concept of time comes out of movement of material objects. Movement of material objects generates events.

What is Time…???

Time is actually the DURATION between those EVENTS.

In a complete empty space >>> there shall be no material objects >>> With no material objects >>> there shall be no movement of material objects >>> with no movement >>> there shall be no EVENTS >>> with no events >>> there shall be no DURATION between EVENTS >>> Means No Time at all…!!!

Time does not exist in empty space. So the idea that “time” is 4th dimension of space is Totally Absurd.

And as I have explained that Time does not exist in empty space. Here I want to add something to it.

The concept of time is wholly dependent on the movement of physical objects. Time does not reside in “space”. Time is there inside of physical objects. Because physical objects always remain in the state of motion. It is only and only physical objects and their mutual interactions that give us the “idea” of time. What has been empirically verified is just that movement of same nature “events” slows down with increase in the strength of Gravitational field. Gravitational field is Not the characteristic property of space itself. Gravitational field is the characteristic property of massive material objects in fact. Events occur only and only in material objects … Duration between events also has to do only with material objects … Slowing down of those events is also because of “mutual interactions” of those material objects.

Time, so, resides only in the “behavior” of “physical objects”. Time does not slow down because of some property of space itself. Time slows down only due to “mutual interactions” of material objects. Let’s at point ‘T’ of empty space, speed of time is ‘a’. Now we bring a massive material object near the point ‘T’. Now speed of time at point ‘T’ shall be slowed down because now this point would be within the range of a gravitational field. This slowing down of time has not happened due to any property of “space” whatsoever. It has happened just due to mutual interaction, or type of movement (in case of slowing down of time in high speed objects) of material objects.

Time has nothing to do with Space…!!!

Space has only three dimensions. We use three dimensions of space to locate a “point” in three dimensional space.

But we use four dimensions of “space-time” just with the view to locate an “event” in four dimensional space-time.

This simple idea of space-time four dimensions is not the direct or indirect result of the complicated idea of Theories of Relativity that time is not absolute and that time can be different in gravitational fields (General Relativity) or in high speed objects (Special Relativity).

But the fact that there is no absolute time in this universe does have its implication on the “structure” of space-time coordinates. In most simple words, the “time coordinate” of four dimensional “space-time” can be thought of having an “irregular scale”. Let us talk in terms of two different frames of references of two observers A and B. Observer A is stationary in space and is not subjected to varying strengths of surrounding gravitational fields (Suppose he is stationary in complete empty space outside the influence of any gravitational field). Observer B is moving in space with velocity v. As observer B is moving, he sometime moves from complete empty space and sometime goes through the fields of gravitation because of the presence of nearby massive bodies.

In this case, time coordinate scale of observer A has to be perfectly regular. Means his every second will be having a constant duration. But time coordinate scale of observer B will be irregular. Whenever he will pass by gravitational fields, the duration of his “seconds” will become greater because his time will slow down within the range of gravitational fields. He himself may not be able to take notice of irregularities of his time scale. But observer A will be able to take notice of irregularities of time scale of observer B. Suppose originally both observers kept exact same type watches. In the end, when observer B shall come to the location of observer A, then both observers’ clocks will show different passage of time. Observer B’s clock will show lesser passage of time than observer A’s clock because observer B was subjected to slowing down of his time at different spots of his journey. Observer B was also subjected to slowing down of his time because of his own velocity v.

It has been mentioned above that “irregularity” of the scale of time coordinate of observer B can be noticeable to only observer A. It is due to the fact that as clock of observer B becomes slow, so his all other movements in space also have to slow down. Meaning of slowing down of time is not confined to just slowing down of clock. Its complete meanings include slowing down of all the movements and events, including slowing down of clock and even “feeling” of passage of time as well as biological aging process, with same ratio. As every kind of movement in space has been slowed down, therefore for observer B, his distance traveled in space per unit time shall NOT be affected; because for him, his clock and his movement in space has been slowed down with exact same ratio. It means that observer B shall not be able to realize any decrease (or increase) in his “velocity” in space as a result of slowing down of his time.

Let us now talk only in terms of “time dilation” due to high velocity of observer B in space (i.e. Special Relativity). Suppose initially both observers A and B were at same location in space. Then observer B starts his journey in space at very high velocity i.e comparable to the speed of light. Suppose his destination was located at the distance of exact one hour with that much high velocity. Observer B has to reach his destination and has to come back at original location. For observer A, observer B should come back in exact two hours.

Now let us see what will happen due to the irregularity of the scale of time coordinate of observer B. As observer B will acquire high velocity, his time will be slowed down with reference to the time of observer A. Not only the clock of observer B, but his movement in space per unit time of observer A will also be slowed down. But as his movement in space will be slowed down in exact same ratio of his own clock timing, so neither observer B will be able to take notice of slowing down of his clock timing, nor he will be able to take notice of slowing down of his movement in space.  For him, he is still moving at the velocity that will take exact one hour to reach at the destination. In this way, he shall reach to the destination and will come back to original location in exact two hours.

But in the same “time”, observer A’s clock will show passage of far more time … may be 10 hours, 10 days, 10 years or like, depending on the velocity acquired by observer B. 

This is exactly what “Twin Paradox” tries to highlight. That there were two twin young brothers. One brother started journey in space at very high velocity. After few minutes when he came back, he saw that his twin brother was then an aged person!

Net result of this article is that space-time four dimensions is basically a simple concept. Idea of no absolute time does not mean that time is a “physical” dimension of space. Idea of no absolute time has the implication however that it suggests irregular scale of the time coordinate for an observer who is moving in four dimensional space-time with velocity v and/ or becomes subject to varying strengths of surrounding gravitational fields.

At the end, it is also important to point out that modern Physics also suggests more than three dimensions of “space” alone. It is said that higher dimensions of space are not perceivable to us because they reveal themselves only at particle levels and at very high energy states like in particle accelerators etc. Modern speculative theories like Strings Theory and M-Theory etc. have tried to construct models of universe in terms of higher than three dimensions of space.

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