Stewart's Site

General Info

Favourites

Germany 2003

Photos

The Olsen Twins

Travel Tips

Wierd Maths:  Pi The Infinitesimal

Henry II

The Black Rhinoceros

The Atomic Bomb

Home

The Infinitesimal

What is the smallest number? This question was once deemed unimportant, however now is puzzling many hunderds of mathematicians. Here there work is summed up. For further reading, consult New Scientist (26 Jan 2002) or go get a degree in pure mathematics.

How small is small?

• The 'infinitesimal' as it is known, is practically the opposite of infinity. If we use fractions:

  is quite small,  

is very very small,

so what must  equal???

• To put it another way, think of a circle. A circle is just like a triangle, or a hexagon, except it has an infinite number of sides. How long are these sides??

Archimedes was one of the first to think of this 'number'. He called it a fluxion. Newton also came across is when he formed The Calculus, and this concept of reducing a distance soooo small that it is practically zero, yet still can be used to divide, is fundemental to any high-school calculus.

BUT... If you have a number, can't you simply divide it in two to make a smaller number? In this case, the infinitesimal couldn't possibly exist, as you could always divide it.

HANG ON... Whoever said a number had to exist to be used? Scientists and matematicians currently think this weird number is an imaginary, or complex, number. This means it does not 'exist'. If you think of numbers as a line.... eg. -3   -2  -1   0   1    2   3  that goes on forever, then these imaginary numbers are not on this line, they are off to the side a bit. Weird, huh?

So there you have it - The infinitesimal. Do you think that it exists? If you come up with a solution, send it to a university - You will have solved one of the great holes in mathematics.