- #1
wvguy8258
- 50
- 0
I'm familiar with space and time together being 4 dimensions and that mass causes a curvature in this spacetime.
When I consider a line that is curved, I can view the curvature because the line is drawn on a 2D surface (plane). So, it seems an additional dimension is required for a curvature to take place. I don't believe that you could curve a line in only one dimension, but I could be wrong (especially if curved could be thought of as moving backward and forward only, but this does not represent what we mean by a curved line when speaking commonly).
So, this brings me back to spacetime. Do the entire 4 dimensions curve? Or is it like my (perhaps nonsensical) line example where fewer than 4 dimenions curve and use the remaining dimension to move within? Or is it better to view each dimension as curving within another dimension, so that no extra dimension is needed to curve within? For instance, I could draw a cross (represents a 2D coordinate system) and move the lines around (x-axis curves using y-axis by moving up or down in a wavy way) on the paper but not lift them (as this would require adding a 3rd dimension to the scheme).
I'm likely confused by the common rubber sheet examples of spacetime, where an additional dimension is needed. This representation always left me wondering whether the space dimensions (if they can be thought of separately with any coherency) were curving within the time dimension, and is now making me question what it even means to curve.
Any help to sort this out is appreciated. -seth
When I consider a line that is curved, I can view the curvature because the line is drawn on a 2D surface (plane). So, it seems an additional dimension is required for a curvature to take place. I don't believe that you could curve a line in only one dimension, but I could be wrong (especially if curved could be thought of as moving backward and forward only, but this does not represent what we mean by a curved line when speaking commonly).
So, this brings me back to spacetime. Do the entire 4 dimensions curve? Or is it like my (perhaps nonsensical) line example where fewer than 4 dimenions curve and use the remaining dimension to move within? Or is it better to view each dimension as curving within another dimension, so that no extra dimension is needed to curve within? For instance, I could draw a cross (represents a 2D coordinate system) and move the lines around (x-axis curves using y-axis by moving up or down in a wavy way) on the paper but not lift them (as this would require adding a 3rd dimension to the scheme).
I'm likely confused by the common rubber sheet examples of spacetime, where an additional dimension is needed. This representation always left me wondering whether the space dimensions (if they can be thought of separately with any coherency) were curving within the time dimension, and is now making me question what it even means to curve.
Any help to sort this out is appreciated. -seth