Did you know that, unless you’re ON the equator, you have to constantly turn a little bit to walk due east or due west? Play around with this interactive globe and map to get a sense of what I mean. Double-click to drop a marker anywhere on the globe. This tool also allows you to draw a great circle from that marker starting in any direction (N, NE, E, and so on). You can also draw a latitude circle from the same marker. Notice how different these circles look on the Mercator projection map next to the globe. You can toggle the globe's transparency to see through it, and add a diameter connecting each marker to its antipode to help build your 3D sense of things.

When you traverse a sphere (I know the Earth is technically an oblate spheroid, don’t come at me) in a straight line, you always follow a great circle. This path will go around the globe to the antipode of your starting point (the point exactly opposite your marker)before coming back. If you start out at 90 degrees (east) or 270 degrees (west), you’ll begin tangent to the latitude circle of your starting point but will follow a great circle. You can use this to see just how much you need to turn to stay at the same latitude while traveling due east (or west). The farther away from the equator, the smaller the radius of the latitude circle.

*This tool was vibe-coded (poorly) by me. As such, it only really works on desktop. If you’re a developer and want to review the code and make suggestions, let me know by submitting the contact form.