I missed this aside the other day; do go on.
Without posting equations (which I will most certainly not understand), explain what is fascinating about this fellow.
Well, without posting
too many equations, what Galois was trying to do is actually quite simple. You're probably at least familiar with quadratics (of form ax^2+bx+c, which we all know from our Algebra I classes), and cubics, (ax^3+bx^2+cx+d), and you may recall that there are formulas available that will always find the solutions to those equations (
quadratic formula) (
less well-known and certainly more complicated cubic formula). Anyway, mathematicians in the olden days naturally wondered if such formulas could be found for polynomials of higher degrees than 2, 3, and 4. There is actually a formula for degree 4 polynomials similar to the quadratic and cubic formulas, but it is so large that to put it all in one equation, so to speak, you would need a posterboard. Galois was able to show that in fact, no formula exists for solving a polynomial of degree 5 or higher by
developing an entirely new branch of mathematics starting at the tender age of 18. He also made enormous contributions to number theory (he literally changed the course of mathematical thinking in this field).
Since he wasn't able to express his ideas in the most clear manner, though, his papers were generally rejected or even lost. He was known for having a temper, which led to erratic behavior at times (more on this later), and he was actually a republican activist during the French Revolution - which led to his arrest and imprisonment, during which he worked on his mathematical contributions. Due to his political activism, he wound up getting expelled from the university he was studying at, which probably contributed further to his depression. He tried to submit some papers during this time, but they were rejected because they were incomprehensible to the mathematicians reviewing his work; he took this rejection pretty hard. About a month after this happened, he was involved in a duel (allegedly over a failed love affair) and died at the age of 20. Eventually, someone (a guy named Liouville) ended up reviewing his work and declaring it sound, and so Galois' work actually partly kickstarted a whole new branch of mathematics known as abstract algebra.
In short, his stuff isn't really useful to the layman, but it has been invaluable in proving certain theorems in mathematics. He led a much more interesting life than the typical mathematician. I just find it really interesting and inspiring that he did all of this at the age of 20. Guy had a full life in those 20 years.