good point and you are right. it's fast, but only on short distance. the animation within the article and the text explains this further.
Edit: I found it, but it's a very small part of the article. The guidelines ask to submit here using the same title as the article. https://news.ycombinator.com/newsguidelines.html
Otherwise yes, the animation is under the chapter: Virology 101: Get to know the COVID-19 transmission risk levels