# THE forth Dimension

by bayan
Tags: dimension
 P: 202 HI. I was wondering if anyone can tell me a bit about the forth dimension? Any comment is welcome
 PF Patron Sci Advisor P: 2,188 Time is often called the fourth dimension, but be careful as it is not a dimension of space, it is a dimension of spacetime which has four dimensions (usually by convention it is actually the zeroth dimension of spacetime, but this is only a convention), the other three being the normal three spatial dimensions. In spacetime each 'point' is known as an event and is specified by four coordinates: (t,x,y,z). The reason why choose to describe physics using spacetime comes from special relativty. In special relativty how someone views space and time is dependent on their motion (I'm sure that you have heard of the phenoumna of time dialtion and length contraction in special relativty), however evryone views spacetime pretty much the same (a different veelocity is equivalent to a different coordinate system in spacetime). This means that spacetime is a powerful tool for describing the world around us using relativty.
 P: 315 I agree that the 4th dimension is considered to be time in relativity. Like the gentleman before, he states that time is not an isolated dimension but entwined with the trhee spatial dimensions. The 5th dimension is the age of aquarius. If you are not familiar with 60s music you will not understand my joke. The astrophysicist Paul davies once asked if mathematics is built into nature or if it is just an abstraction of human thought. With this in mind you must ask if geometry (which is what dimensions are) really exist or is just a concept of man. Does our mathematical and geometric constructions accurately describe the universe or is geometry a depiction of reality, like a photograph of your family. Is geometry and mathematics just a depiction of nature, like a topographical map of the Earth (such as a globe)? I believe there are no dimensions to the universe. Time and space are illusions. Physicist David Bohm (along with many others) believe the holographic model of the universe, which is caused by wave interference. If you take a picture of an apple on a piece of holographic film, you can cut the piece of film in half. If you expose that half piece of a picture of the apple to a laser, you still get a whole picture of the apple but the size of the apple will be reduced by 50%. What this says in general is that all parts of the film has information about the whole (if you were to keep cutting the picture of the apple into smaller and smaller pieces the image would become very distored and unrecognizable). From the perspective of a holographic model, in a sense the whole universe is contained in every part of the universe. The whole universe is contained in each subatomic particle if one subscribes to a holographic model. RAD
P: 202

## THE forth Dimension

that was a very nice ending. lol
P: 2,059
 Quote by RAD4921 I agree that the 4th dimension is considered to be time in relativity. Like the gentleman before, he states that time is not an isolated dimension but entwined with the trhee spatial dimensions. The 5th dimension is the age of aquarius. If you are not familiar with 60s music you will not understand my joke. The astrophysicist Paul davies once asked if mathematics is built into nature or if it is just an abstraction of human thought. With this in mind you must ask if geometry (which is what dimensions are) really exist or is just a concept of man. Does our mathematical and geometric constructions accurately describe the universe or is geometry a depiction of reality, like a photograph of your family. Is geometry and mathematics just a depiction of nature, like a topographical map of the Earth (such as a globe)? I believe there are no dimensions to the universe. Time and space are illusions. Physicist David Bohm (along with many others) believe the holographic model of the universe, which is caused by wave interference. If you take a picture of an apple on a piece of holographic film, you can cut the piece of film in half. If you expose that half piece of a picture of the apple to a laser, you still get a whole picture of the apple but the size of the apple will be reduced by 50%. What this says in general is that all parts of the film has information about the whole (if you were to keep cutting the picture of the apple into smaller and smaller pieces the image would become very distored and unrecognizable). From the perspective of a holographic model, in a sense the whole universe is contained in every part of the universe. The whole universe is contained in each subatomic particle if one subscribes to a holographic model. RAD
That's pretty cool.

 Quote by kokain Space-time consists of three spactial dimensions (x,y,z) and one temporal dimension (time). These four dimensions are warped within another special dimension (hyperspace) which is perpendicular to the three perpendicular x,y,z dimensions. The warping occurs around anything with mass, the higher the mass the more the warping. Time is bound to the three dimensional space-time. Walking on the ground in a straight line is a one-dimensional motion. If a post is in your way, you stop. If you evolve to “see” two dimensions, you may now step to the side and pass the post. And in effect disappear as seen by everyone else. If you now come to a wall (here is where time comes into play) you may walk around the wall with everyone else, but if you evolve to “see” three dimensions, you may now jump over the wall and save the time it takes everyone else to walk around. Being the only one who can jump, you move faster than time. By that I mean, time has to flow around the wall as nothing is able to jump over it. To everyone else you disappear, then reappear later. Now since we can all step around and jump, so can time. So we must do what time cannot. Step or jump, “upsilon,” around or over the obstacles that time cannot pass. These obstacles are the warps in space-time. If we go through a massive obstacle we will move faster than time, which has to move around the obstacle. Lets say John is walking past a building, and I am next to him. If the sidewalk is exactly straight (to him) he will walk exactly straight. But he is actually walking some portion of the “diameter?” of a hyper-sphere that goes around the building. (Very little warpage, I know, but warpage nonetheless) Now if I am capable of moving in a direction that combines x,y,z and hyperspace, I can walk a straighter line than John. I will move through the four dimensional void left by the warp and arrive at our destination before John. He will see me disappear and then reappear further along than himself.

If you were a 4 spatialy dimensional being you would be God to 3 dimensionalers.

 Quote by Michio Kaku "Imagine being able to walk through walls. You wouldn't have to bother with opening doors; you could pass right through them" "Imagine being able to disappear or reapperar at will. Instead of driving to work you could just vanish and rematerialize in your classroom or office." "Imgine being able to reach into an object without opening it. You could extract the sections from an orage without peeling or cutting it. You would be hailed as master surgeon, with the ability to repair the internal organs of patients without ever cutting the skin, thereby greatly reducing pain and the risk of infection." "Imagine what a criminal could do with these powers. He could enter the most heavily guarded bank. He could see through the massive doors of the vault for the valuables and cash and reach inside and pull thm out. He could then stroll outside as the bullets from the guards passed right through him. With these powers, no prison could hold a criminal."
But of course you wouldn't need money...

What sorts of things would happen if they were to try and attack you? Would you feel pain? Only the two dimensional parts of the atoms touching the ground would be hit?
 HW Helper Sci Advisor P: 3,149 Most of the folklore about the fourth dimension is due to Abbott who wrote a cute and whimsical story years ago called Flatland. It was a fantasy but has contributed to the misguided view many mathematicians and physicists have of "the fourth dimension." There just one problem with it. If there are hidden dimensions (i.e. we 3-D people can't see into the fourth dimension) then there is absolutely no reason to believe that it's not reciprocal (i.e. those 4-D people shouldn't be able to see into OUR 3-D world!) If there are extra degrees of freedom out there then certainly some components of either "universe" would have taken advantage of them.
 PF Patron Sci Advisor P: 8,903 Time is a necessary component of a universe that submits to being described by physics.
P: 2,059
 Quote by Tide Most of the folklore about the fourth dimension is due to Abbott who wrote a cute and whimsical story years ago called Flatland. It was a fantasy but has contributed to the misguided view many mathematicians and physicists have of "the fourth dimension." There just one problem with it. If there are hidden dimensions (i.e. we 3-D people can't see into the fourth dimension) then there is absolutely no reason to believe that it's not reciprocal (i.e. those 4-D people shouldn't be able to see into OUR 3-D world!
We can't see in 3D? I think not.

 Quote by Tide If there are extra degrees of freedom out there then certainly some components of either "universe" would have taken advantage of them.
You could take several sides:

We wouldn't know if they did, they'd do it so often that it would be normal.

Besides why would they want to tinker with inferior us?

Maybe they got tired with us, that's why God doesn't intervine all the time, like in the bible...

Maybe no creatures exist in higher dimensions?

What about the tea garden-carp-scientist-hyperspace analogy?
 P: 197 Bayan: Almost everyone has tried to make the fourth dimension strange and mysterious. In mathematics multiple dimensions have no strange properties. All dimensions are the same. If all dimensions are the same then the difference between the three spatial dimensions and the time dimension must be what is going on in the time dimension. The only thing you can do in a dimension is move, or transition. We therefore perceive time because we are transitioning in the time dimension. We know that time is perpendicular to all the spatial dimensions because we are able to plot movement in the spatial dimension against time. We find that time is always perpendicular to motion in any direction. This is called velocity. It is also only possible to plot this function up to the speed of light. At this point we run out of time base. You run out of time base if you are moving at the same rate as the time base. We must therefore be moving in the time dimension at a rate equal to the speed of light. As you can see it is all very simple.
HW Helper