Don't know if this belongs in this topic but can someone please explain what is meant by dimensions as in when Einstein referred to dimensions.

Hi beginner1,

A simple answer without mathematics here. Dimension is more than just a measurement along an axis. The axes of a dimensional space can be placed anywhere inside that space. You may or may not define an origin to that coordinate system. In normal parlance we talk about the x, y and z axis if it is a three dimensional space. This is usually referred to as "euclidean" space. This space is a very simple concept. In Einsteins Special Relativity space is indivisible from time and this is called Minkowski Space-time. They are all interconnected with a set of rules. Under normal velocities and such you will not notice any difference to euclidean space but as you near the speed of light you will begin to see some of the effects.

There is a dimensional "space" which is the volume of space over which the dimension ranges. In mathematics this can be an infinite space. In reality it may be restricted. These spaces can be "open" or "closed". If open... space just goes on forever. If closed... the space is curved internally such that you go round and round and you cannot find any way out of it. Sort of like a bug on a two dimensional space of the surface of a balloon. The bug can walk as far as it wants but it will never find a barrier to stop it, yet it is confined to a rather small space. If course the bug could fly away but that would mean the bug can operate in more than those two dimensions. We operate in three spatial dimensions and we cant just get out of then by "jumping up". Our Universe is finite closed space of three dimensions and time. A minkowski space-time. There may be more dimensions but we cannot see them because we are restricted to only the three spatial and one temporal dimensions.

In the General Theory of Gravitation space-time is curved by gravity as well and this also affects time in a slightly different way to Special Relativity. Dimensions are no longer simply related to a set of axes and depends on our state of motion. The shortest distance between two points is no longer always a straight line. Gravity is equated with ordinary Acceleration and this is what is causing space-time curvature. You can see space-time curvature by going into the park and throwing a ball. The curve the ball is executing is a straight line in an inertial (unaccelerated) frame of reference. This is the same as a freely falling frame of reference. If you were freely falling near that ball you would see it travel in a straight line. It is gravity that causes us to see the curve of the ball in space. We are accelerated (not the ball).

Cheers

Hello Good Elf,
These dimensions, other than the few that we are aware of, are these theoretical dimensions? Are they mathematically conjured up or are they real, the kind of real that affects us.
I'm looking at that bug walking on that balloon and although he isn't aware of that outer dimension, there could be something that comes from that dimension and burst his balloon. So what I'm asking is, in your opinion, can these other dimensions or something that lives in them, affect us?
PS - I'm not a scientist or a product of higher education. I ask this question for conversational purposes only. Just kickin it around a bit.