# Dimension in physics

I know this has been mulled over time and time again in different threads, so I will keep it short.

Which statement is more consistant with reality:

1. A dimension = all existing and non-existing points along an axis.
2. A dimension = all existing, but only existing points along an axis.

(change 'points' into 'events', 'interactions' or whatever else you prefer)

Thank you.

## Answers and Replies

ShayanJ
Gold Member
What you mean by existence?

Usually a dimension is assumed to be infinite (number 1) but it is typically a range of values for a unique characteristic of which limits of existence can be constraints in that range.

DennisN
Gold Member
I know this has been mulled over time and time again in different threads, so I will keep it short.

Which statement is more consistant with reality:

1. A dimension = all existing and non-existing points along an axis.
2. A dimension = all existing, but only existing points along an axis.

(change 'points' into 'events', 'interactions' or whatever else you prefer)

Thank you.

How large is a point? Please specify in e.g. meters1, meters2 or meters3, whatever you prefer.

My question is a trick question.

Okay, let's go with the flow.

What are the 'points' of the 4-dimensional universe around us? Are they the independant, fundamental elements? Like, maybe, photons, electrons, quarks?
Or is the 4-dimensional universe made up of collisions, interactions, relations between these elements?

Which is the basic stuff of reality?
(or to be fair: maybe both or neither, or you have some other answer)

Dale
Mentor
2021 Award
We stick to standard definitions here.