Issac Newton was sitting under an apple tree, an apple fell on his head and that inspired Newton to develop his theory of gravity.

Google Logo Animated for Newton’s Birthday
Today is the 366th birthday of Sir Isaac Newton and Google is celebrating it with an interesting logo on their homepage.
This is probably the first Google Doodle that’s animated but they haven’t used Flash or GIF animation for this logo – it’s a simple JavaScript.
Also see: How to Record Animated GIFs
<img width="384" height="138" border="0" onload="window.lol&&lol();setTimeout(function(){var h=0,v=1,f=document.getElementById('fall'),i=setInterval(function(){if(f){var r=parseInt(f.style.right)+h,b=parseInt(f.style.bottom)-v;f.style.right=r+'px';f.style.bottom=b+'px';if(b>-210){v+=2}else{h=(v>9)?v*0.1:0;v*=(v>9)?-0.3:0}}},25);google.rein&&google.rein.push(function(){clearInterval(i);h=0;v=1})},2000)" style="margin-top: -1.22em;" id="logo" title="Birthday of Sir Isaac Newton" alt="Birthday of Sir Isaac Newton" src="/logos/newton10-tree.jpg"/> 