If a simple 3-dimensonal sphere were displaced in a 4th spacial dimension, even slightly, it would disappear from 3-space instantly, but it would still have a location in 3-space, right?

840 views

Edit: Sorry for “spacial” instead of “spatial”. I always get that spelling wrong.

Let’s call the four spatial dimensions W,X,Y, and Z, where X,Y, and Z are the 3 familiar directions, and W is our fourth orthogonal direction.

Suppose a simple 3 dimensional sphere of radius 1 (size 0 in W) has the positional coordinates W0, X0, Y0, Z0.

If the sphere is moved to any non-zero coordinate along W, it disappears from 3-space instantly, as it has no size in W. By analogy, if we picked up a 2D disk into Z, it would disappear from the plane of 2-space.

Now nudge the sphere over to W1. The sphere no longer intersects 3-space, but retains the coordinates X0, Y0, Z0. Right?

So, while the sphere is still “outside 3-space” at W1, it can be moved to a new location in 3-space, say X5 Y5, or whatever, and then moved back to W0 and “reappeared” at the new location.

Am I thinking about that correctly?

A 3-space object can be moved “away” in the 4th, moved to a new location in 3-space without collisions, and then moved back to zero in the 4th at the new 3-space location?

What does it even mean to move an object in 3-space while it has no intersection or presence with said 3-space?

What would this action “look like” from the perspective of the 3-space object? I can’t form a reasonable mental image from the perspective of a 2-space object being lifted off the plane either, other than there suddenly being “nothing” to see edge-on, a feeling of acceleration, then deceleration, and then everything goes back to normal but at a new location. Maybe there would be a perception of other same-dimensional objects at the new extra-dimensional offset, if any were present, but otherwise, I can’t “see” it.

Edit: I guess the flatlander would see an edge of any 3-space objects around it while it was lifted, if any were present. It wouldn’t necessarily be “nothing”. Still thinking what a 3D object would be able to perceive while displaced into 4-space.

Bonus question: If mass distorts space into the 4th spatial dimension… I have no intuition for that, other than that C is constant and “time dilation” is just a longer or shorter path through 4-space…. eli5

In: 296

30 Answers

Anonymous 0 Comments

3-dimensional sphere is a ball on your table. 4th dimension is time. If you move the ball in time, say to tomorrow, the ball would disappear for one day and reappear tomorrow, in the same place on the table (that is, with the same 3D coordinates, but with a different T)

You are viewing 1 out of 30 answers, click here to view all answers.