The first version only used Earth's orbital speed (~30km/s), but the number moved too slowly. To get the "existential dread" feeling, I switched to using the Milky Way's velocity relative to the CMB (~600km/s). The math takes some liberties (using scalar sum instead of vector) to make the speed feel "fast," but it gets the point across.

Under the hood, it's a single HTML file with zero dependencies. No React, no build step. The main challenge was the canvas starfield—I had to pre-allocate the star objects to stop the garbage collector from causing stutters on mobile.

Let me know if the physics makes you angry or if the stars run smooth on your device.

It's interesting to see how little effect the orbit and rotation had on the straight line. A proposal is to align the numbers for the different movement categories so that it's easier to see the magnitudes of them.

It took me a couple of seconds to understand the concept, from the title I though it was going to be a planner to show gravity assists etc.

also there are some cursors with question marks but they don't espatially ;) call the FAQ, do they? firefox on win10