Riemann Zeta Function: 1 + 1/2^s + 1/3^s + 1/4^s + ... Riemann Hypothesis: All non-trivial zeros of the Riemann Zeta Function have real part 1/2. Card trick: Take a stack of poker cards. Slide the topmost card as far over the edge as it goes without tipping, this is 0.5 cardlength overhang. Then slide the two topmost cards over as far as they go without tipping. To find out how much more overhang this provides, consider the center of mass of the two-card system, which is halfway along the 1.5 length two-card system, which is 0.75, so sliding this to the edge gives an extra 0.25, making the total overhang 0.5+0.25=0.75. Now we can generalize using the formula for center of mass. Suppose we are on level N, then we have N-1 cards with their center of mass at x=0, where the origin is the point of overhang. But there is an additional card with its center of mass at x=1/2 in units of cardlength. So x_cm = 1/N * ((N-1)*0 + 1*(1/2)) = 1/(2N). Therefore the maximum total overhang for N cards is (1/2) Nth partial sum of the harmonic series. Since the harmonic series diverges, with an arbitrarily large stack of cards, one can achieve any desired amount of overhang, so you can have it so the top card is entirely past the edge of the bottom of the stack. How do we know the harmonic series diverges? Nicole d'Oresme pointed out that the elements between 2^n and 2^(n+1) always sum to greater than one half, and since all the terms are positive they may be rearranged in this order while preserving the value, and the sum of an infinte number of terms greater than 1/2 is divergent. The Basel Problem: Find a closed form for the infinite series of the inverses of the squares of the positive integers. Euler solved the problem: the answer is Pi^2/6 Gauss, Dirichlet, Riemann, and Dedekind were all at Gottingen simultaneous for a while. Gauss' big number theory book was Disquisitiones Arithmeticae Irish Philosopher George Berkeley said: "And what are these evanescent increments? They are neither finite quantities, nor quantities infinitely small, nor yet nothing. May we not call them the ghosts of departed quantities?" Chebyshev Bias - more primes =3(mod 4) than =1(mod 4) also more primes =2(mod 3) than =1(mod 3) these are violated, but yet very prominent Littlewood Violation - first one is when PI(x) exceeds Li(x) Littlewood's 1914 Result: Li(x) - PI(x) changes from positive to negative and back an infinite number of times - this is connected to the Chebyshev Bias Bays Hudson estimate of first Littlewood Violation: 1.39822*10^316 Van Koch's 1901 Result: If RH is true, then PI(x)=Li(x)+O(sqrt(x)log(x)) Big Oh Definition: Function f is big oh of function g iff for sufficiently large arguments, the value of f never exceeds some fixed multiple of g. 1/zeta(s) = sum(mu(n)/n^s,1,inf) = probability that s random integers have no proper factor in common The Merten function is defined as M(N)=sum(mu(n),1,N) If the Merten function is O(sqrt(x)) then the Riemann Hypothesis is true. Vis Viva Equation for Astronomy: v = sqrt(M(2/r - 1/a)) Random Matrices: Matrix with elements picked randomly from a Gaussian distribution Hermitian Matrix: every element is the complex conjugate of the corresponding element of its transpose (Note: this implies that the diagonal is real) Hilbert-Polya Conjecture: The non-trivial zeroes of the Riemann Zeta function correspond to the eigenvalues of some Hermitian operator. Riemann, defined a function J. Then he found PI in terms of J, and then J in terms of Zeta. This is the connection. The only well-defined of Hilbert's Problems not solved is the Riemann Hypothesis Estermann came up with the second proof that sqrt(2) is irrational. All zeros of the zeta function found so far have irrational complex component