Dimensions concern spatial or temporal dimensions- as we have 3 spatial and one temporal. But this multiverse quantum woo has no place in a physics classroom.
People also seem to misunderstand multiverses. There may not be a universe where hitler won or you and Emma Watson are together. The worlds defined by the many worlds hypothesis are supposedly created when quantum bits flip. So an alternate universe may be exactly the same. And this is a hypothesis, so when people go around stating as if it were unalterable truth, I'm not happy.
You can have only 3 mutually orthogonal geometric dimensions. But a dimension is just something that you can measure. Other dimensions could include, of course, time, but also: color, rotation, electrical charge, momentum, etc...
Color is a property of the electromagnetic force, electrical charge IS a force, momentum is a property of matter. Just because you can measure it does not mean it is a dimension. Also, there are no rules limiting the number of dimensions to 3 that physicists have found yet.
I'm looking at this more from a mathematics point of view. As in, you can make a multidimensional plot with axes defining different values and find ways of representing each value for each "point" on the plot. For example, if you wanted to plot a 5 dimensional function (one with 5 variables) you could use the 3 geometric dimensions, and for each point you could assign a hue to represent a 4th dimension, and a shade to represent the 5th.
You can only have 3 geometric axes, any geometric representation of higher dimensions is merely a projection of the actual object into 3-space.
I stayed up for a week thinking postulating and researching. there is another field of thought, that the compounding squares theory only works through until the 3rd. after that the temporal is a simple system, and the next is variably more complicated to explain. i forget the name of the book though.
You can only have 3 geometric axes, any geometric representation of higher dimensions is merely a projection of the actual object into 3-space.