Moore's Law's Demise: Moore's Law, which states that the number of transistors on a microchip doubles approximately every two years, is slowing down. The challenges of maintaining this exponential growth in computing power have profound implications for the future of hardware development.

Quantum Computing Uncertainty: While the promise of quantum computing is exciting, building practical and scalable quantum computers is extremely challenging. The field is still in its infancy, and there are uncertainties about when we'll have reliable and powerful quantum computers.

P vs NP Problem: It remains unknown whether every problem that can be verified quickly (in polynomial time) can also be solved quickly (in polynomial time). This is one of the most important open problems in computer science and mathematics.

The Two Generals' Problem: In distributed computing, there is a theoretical problem called the Two Generals' Problem, which explores the difficulty of coordinating actions between two entities that can only communicate through an unreliable channel.

Rice's Theorem: This theorem, named after mathematical logician Henry Gordon Rice, states that all non-trivial properties about the behavior of a program are undecidable. In other words, it's impossible to write a general algorithm that can decide all interesting properties of computer programs.