Why do people think of time when they consider the fourth dimension?

Question

I'm not asking what the fourth dimension is, I already know. I'm simply curious as to why an overwhelming number of people believe it to be time.

Time is a construct of the third dimension. Time is based on our planetary orbit and our axial rotation. All of these planetary and geometrical phenomena are within three dimensions, so time itself is a three dimensional construct. How then did this misnomer originate?

Answer 1

To my knowledge, there is no global scientific consensus on what the 4th dimension is. In the absence of a proven 4th dimension, time becomes the obvious choice to tout as the "4th Dimension"

What are dimensions if not merely a method of measurement within our physical realm. Height, Width, and Depth are 3 of these easily distinguishable qualities of physical matter and space to measure. Time is yet another distinguishable quality of space and matter and their interaction between each other.

While I wouldn't call it the "4th dimension" Time is most certainly a dimension in the same sense as Height Width and Depth. It's designation as the "4th" by many people is simply done out of lack of knowledge of another measurable dimension

Answer 2

First of all, time as an abstract concept is completely independent of the spatial dimensions, it's not a construct of the third dimension. It's just that we use periodic events in three dimensions as a convenient way to measure time.

Now, to understand how time is the fourth dimension is somewhat complicated, but bear with me. Time is fundamentally different from the three spatial dimensions. However, it is often useful to treat time as another dimension, albeit of a different type. For example, in Einstein's Special Theory of Relativity the time and distance between two events are entirely dependent on the frame of reference of the observer. However, there is a quantity called the "spacetime interval" between those two events that is the same no matter what the frame of reference of the observer. It's giving by:
(delta(s))^2=(c(delta(t)))^2-(delta(x))^2-(delta(y))^2-(delta(z))^2
Where (delta(s)) is the spacetime interval, c is the speed of light, and delta(t);delta(x);delta(y);delta(z) are the changes in time and the spatial coordinates between two events. To help you understand, think as the spacetime interval to be analogous to the distance between two events in space time, and is similar to the use of the Pythagorean Theorem to find the distance between two points in a plane.

I know that may have been somewhat technical, but I hope that it helps you understand why time is considered the fourth dimension, and sorry about the mess, but yahoo isn't very conducive for writing equations.

Answer 3

Space without time, would have no purpuse. Immagine it! There would be no need for space without time...
Immagine a space of 2 dimention (like on the surface of a piece of paper) without time you would'nt be able to move either. Now if we lived on that surface of paper (in 2D) and allow time to be the third dimention. We could go everywhere on that surface but we would not have any idea what up and down is... We would m,ove sideways do all kind of geometrical moves in 2 D. Now immagine someone rolls that piece of paper and glues it like a cylender, you would go from a certain point on that cylender and go straight ahead to find yourself at the same place where you left!
Everyone would wonder why...
All the scientists in that universe would be facinated at such a phenomena and perhaps a great genius would interpretate it with all kinds of variables that belongs in that universe...
Time can exist in a one dimention spatial universe also. Like on a string.
Immagine a space of 4 dimentions where you can goin 2 directions at the same time...Now time would have taken another dimention wich we cant relate to...The only thing we can immagine is based on our perception of time as we know it...We might think that in that kind of universe we can leave tommorow and get here and there today. Or vice versa or as many situations that we can immagine given the perception we have in this 3 space 1 time dimentional universe.
So you see space without time has no purpuse...Why would it be then?

Answer 4

Most modern scientists consider the fourth dimension to be time. This is standard practice in Relativistic physics (that came straight from a physicist to me).

Answer 5

I think it's just become part of popular culture and understanding that time is the fourth dimension. And it makes it possible to think about time-travel, which sounds interesting ...

Answer 6

What are the first three dimensions? See you learn something new every day.