Time Is Not A Dimension

[MikeInfinity]

Time is not a dimension because it cannot stand independant of them. If time is a dimension then so is color and weight. Time cannot exsist without space. It takes a minimal of 3 points in space for time to become significant. From point a to point b takes an amount of time but with out a second motion to compare to the first, the time of the first motion from being at rest to point b would be yet undefined.

So from point b to point c would take an x amount of time as it is in relation to 1, the first movement.

Thus the third movement is pre-defined by the second as the pythagrian therom knows the third angle by knowing only two. The shape is now closed because 2 motions takes at least 3 points; Behold the triangle, 2D space is born along side with time.

[Keiji]

In some senses mass, force, charge and so on are dimensions. For example, ever heard of the phrase "dimensional analysis"? "Dimension" is pretty much a synonym for "unit".

The reason we talk of the universe as having three dimensions is because when you think of the universe you think of how big it is and that "size" happens to occur in three orthogonal spatial dimensions. Time is sometimes treated as a fourth dimension because one may be interested in how long the universe has existed or will exist in the future. If the universe was a cereal, sold "by weight mass, not by volume" then its important dimension would be its mass.

Conclusion: anything can be a dimension, depending on what's important in the context you're talking about.

[MikeInfinity]

Yes thank you Keiji

I find it good that all sciences use universal terminologies. The foundation of the very term "3D" implies that the "D" is understood as being spatial. So any reference to 4D is therefore cumulative and if used apart from its previous and primary contexts, confusion may occur.

Anything can be a dimension, I hope you can see why I titled this post "time is not a dimension". I think the term "4D" should exclusively be for spatial referencing. I say this because I was once confused by it. When people speak of time being the fourth dimension as a fact, as so many do, I find it a bit hasty. Nice reply Keiji.

[darthbeppo]

Perhaps we experience the fourth dimension as time, similar to the way a two dimensional character in a flip book experiences the third dimension as time.
We are experiencing a constantly changing realm.
Dimensions measure how far something goes.
something can be 1 inch long
or 4 meters wide
or 1 mile deep
or exist for 10 seconds
Things like mass and force don't measure dimensions. They can be better described as quantities.
When you talk about dimensions, you are more referring to how much area or space something takes up. When you talk about mass, you are talking about how much substance is there.
You can move in dimensions, not quantities.
You can move forward in the first dimension, or left in the second dimension, or up in the third dimension. We have no control over our movement in the fourth dimension, but we are constantly moving forward.
You cannot move forward in quantities. One would not say "I moved forward in weight." You gain more stuff -- the quantity increases, but the quantity already existed somewhere. It was simply moved.
The person above me gave an example with cereal. The way I'm reasoning is that the mass refers to how much cereal is there. The dimensions of the cereal refer to how big the cereal is. Now your mind kind of naturally tends to interpret volume as quantity, but a liter of hydrogen gas is not as much as a liter of cereal. The size is the same, but the actual quantity of matter is different.
I'm sorry for my difficulty in expressing my thoughts. I hope I make some sense.

[darthbeppo]

Okay, I figured out what I was trying to say!
Dimensions measure differences in position. Things like force, temperature, charge, or color measure quantities or qualities of an object.
Alright, so what about things like speed, or acceleration?
If I had to assimilate those into one of those existing categories, I'd say they're qualities. I think they're better described as rates. Speed is the rate at which an objects position in one, two, or three dimensions changes relative to its position in the fourth dimension. Because of this, they are also not dimensions.

[phoenix]

I think this thread should be titled "The Fourth Dimension Is Not [Necessarily] Time". Actually, it should be one of the rules here.

"So the fourth dimension-"
"Oh yeah that's time!"
"Very good! Anyway, so the fifth dimension..."
(repeat until desired result is achieved)

[wendy]

Time is, like length, a dimension of extent. That is, objects occupy bits of space and occupy time. In practice, they occupy bits of space over a bit of time, or in total, a bit of space-time. Like space, time gives a coordinate for objects to occupy: eg 'he was there yesterday' gives a space-time coordinate.

One can readily get around the question of 'fourth dimension', by realising that one can use 0 as a dimension coordinate, and use that for the temporal coordinate. For the linear dimensions, gravity and motion provide the first two coordinates, which after there are variations of 'across'.

Of space-time itself: this is just a graph. You can make an animation by putting down layers of x,y,z at t0, t1, t2, t3, .... Cartoons work like that. Galilean space-time has no conversion between space and time, because no velocity is absolute.

Electromagnetism provides that waves travel at a fixed velocity, and by galilean laws one could measure this against the 'etherfer'. Experiments by Michelson and Morsey failed to show this. This means that in order to keep this relative, one must allow a conversion between space and time (that, eg different observers travelling at different velocities, should see each others frames different to their own). In order to preserve momentum, energy and the velocity of light, one has to implement something like relativity. Likewise, to keep these relative to gravity, one has to implement a co-gravitional force, which behaves like magnetism.

Still, for the greatest part, these forces and effects are so faint that we choose to dismiss them out of hand.

Mass and charge are dimensions of quantity, colour and heat of quality, length and time are dimensions of extent.

When one reckons the dimensions, the proper order is 0 = time, 1 = height (gravity), 2 = forward (motion), 3 = width (across), 4 = width (across) &c. One normally counts to ignore 0 (ie space alone), or 0&1 (ie dimensions of the plane are usually forward and left/right, as of the maps.)

[gonegahgah]

I've been thinking of them lately as spatial dimensions are x,y,z which don't have any preferred orientation except to be 90deg to each other, relative movement dimension is time, and the reaction dimension is acceleration. Each dimension then has its own purpose and not all are spatial.