This page is for experimenting with SVG animations. It is not useful in general.
Animated rectangle
World lines
The following is a manually edited animation of the world lines in the Earth’s reference frame which I have elsewhere on this site. It plots out how the \(x\)-axis for the traveling twin’s reference frame changes as the twin travels.
Editing SVG by hand for all the SVG animations I would like to create is not something I could do regularly. However, I used this to confirm whether an idea I have for generating SVG animation from a series of SVG images could work.