cosmic strings

Cosmic strings are hypothetical, extremely thin and dense filaments thought to have formed in the early universe during phase transitions, similar to cracks forming as ice freezes. They are incredibly long—possibly spanning vast cosmic distances—and possess immense mass and energy. While they haven't been observed, cosmic strings could influence the universe’s structure and generate detectable signals like gravitational waves. They are a fascinating theoretical concept that could help us understand the universe's history and the fundamental physics governing its evolution.