{"type":"rich","version":"1.0","title":"Zero reference point for gravitational potential energy","html":"<span class=\"wb-embed wb-embed-math\" data-latex=\"U(r=\\infty)=0\">U(r=\\infty)=0</span><footer><cite class=\"wb-embed-author\">Rong Martin-Siebler ZHOU</cite></footer>","width":640,"height":320}