**Gravity < electromagnetism < weak < strong.** There are 4 fundamental forces: gravity, electromagnetism, and the strong and weak nuclear forces. Gravity is the weakest and the strong force is the strongest. It holds the nucleus of atoms together. We are working on a combined theory that encompasses all of these forces. **** # More ## Source - [[A Briefer History of Time]] ## Related - [[The Standard Model (Quantum Mechanics)]]