[raldi]

I don't follow. If we're communicating with aliens that we somehow know are made of matter, we tell them that right is the direction a horizontal wire carrying positive current away from us gets pushed by a vertical magnetic field.

[yorwba]

That just shifts the problem to specifying the direction of the magnetic field, and you can't use the concept of left vs. right in that definition without creating a circular dependency.

[pbhjpbhj]

Vertically up it's just too a higher local gravitational potential, no? Sure, we flip right-left when we look at things upside down, but that's a nuanced usage.

[yorwba]

How do you determine whether your magnetic field is pointing up and not down?

[goldenkey]

Closer and farther can be used to explain up and down.

[yorwba]

How do you use closer and farther to determine whether a magnetic field is pointing up or down? It's not like there are little arrows on magnetic field lines you can just look at.