> I don't know why the title was changed.

The HN guidelines ask submitters not to change titles except when they are misleading or linkbait. Accordingly, we often change an edited title back to language used by the article itself—usually the original title, sometimes a subtitle or other heading. One reason for this is that we can't judge the accuracy of most edits.

HN titles also tend not to include the names of authors or speakers. We learned years ago that the site works better when the focus is on content, not personalities.

(Submitted title was "SpaceX's GPU-Powered Combustion Simulation – Adam Lichtl and Stephen Jones")