(creationism, pseudoscience) The conflict between Young Earth creationism (asserting that the universe is thousands of years old) and the starlight-related measurements that show the universe to be billions of years old.

(number theory) The problem of whether each natural number k has an associated positive integer s such that every natural number is the sum of at most s natural numbers raised to the power k.

plural of Gettier problem

(mathematics, UK, Canada) The problem in combinatorial optimization in which, given a number of cities and the costs of travelling from one to the other, it is required to determine the cheapest route that visits each city once and then returns to the initial city.

the millennium bug

A proposal that does not solve any problem or provide any value; or one that is intended to fill a need which does not really exist.

plural of solution in search of a problem

(graph theory) The problem of finding the shortest closed path or circuit that visits every edge of a (connected) undirected graph.

plural of Chinese postman problem

(mathematics) A mathematical problem where one must determine how many grains of wheat are on a chessboard, assuming one grain of wheat is placed on the first square, and each subsequent square having twice as many grains of wheat as the previous square.