Not sure if this is possible in light of physical limits on computer hardware or electrons but does there exist a practical way in any programming language to call a function every nanosecond? What limits exist?
For example in javascript trying this does not go over as expected:
<html>
<head>
<script type="text/javascript">
var numb = 1;
function addNum(){
numb=numb+1;
document.getElementById('thing').innerHTML = numb;
}
</script>
</head>
// try to do addNum every nanosecond
<body onload='setInterval("addNum()", 0.000001)'>
<div id="thing"></div>
</body>
</html>