
BC 0800? Roman Numerals
 R
The Romans showed numbers into the thousands using these 7 symbols: I for 1, V for 5, X for 10, L for 50, C for 100, D for 500 and M for 1000.
http://qindex.info/d.php?c=4758#5038

/* Regular Expression
M{1,3}
((C{1,3})([^DM]$))(CD)(DC{0,3})(CM)
((X{1,3})([^LC]$))(XL)(LX{0,3})(XC)
((I{1,3})([^VX]$))(IV)(VI{0,3})(IX)
*/
// Javascript
function 2arabic(c) {
switch(c) {
case 'I': return 1; break;
case 'V': return 5; break;
case 'X': return 10; break;
case 'L': return 50; break;
case 'C': return 100; break;
case 'D': return 500; break;
case 'M': return 1000; break;
}
}
var roman = 'MCMLXVIII';
var arabic = 0;
var previous = 0;
var current = 0;
for(i=0; i<roman.length; i++) {
current
= 2arabic(roman.charAt(i));
if(previous && previous<current)
arabic = previous;
else arabic += previous;
previous = current;
}
arabic += current;


BC 0500? Hippasus
 R
According to Pythagoras theorem the diagonal length of a square with each side measuring one unit would be square root of two.
The assumption that square root of two could be expressed as a ratio of two integers deduces a contradiction.
http://qindex.info/d.php?c=4758#5026


1202 Leonardo Fibonacci
 R
Fibonacci asked himself how many pairs of rabbits originated from a single pair in one year. Each pair of rabbits will produce exactly one more pair of both sexes per month which in turn would be fertile from the second month after birth.
http://qindex.info/d.php?c=4758#4759


1643  1727 Isaac Newton
 R
Galileo had already discovered some years prior that the distance traveled by a falling object is represented by a function of time.
Newton wondered how one could calculate the velocity of the object at any particular instance during the fall.
http://qindex.info/d.php?c=4758#5035


Euclidian Geometry
 R
By stringing an infinite number of lines along a dimension perpendicular to the line, a twodimensional object called a plane can be obtained. And then if we string an infinite number of planes in either direction, we get three dimensional space.
http://qindex.info/d.php?c=4758#5031

