How Can the Universe Be Flat?

The video explores how matter distorts spacetime, a concept central to Einstein's general relativity. It discusses the universe's geometry, which can be flat, positively curved, or negatively curved, and how this is determined by the universe's matter and energy content. The video explains the critical density needed for a flat universe and how current measurements suggest our universe is flat. It also delves into the universe's potential fates, influenced by dark energy, including scenarios like the big crunch or big bounce.

What role does dark energy play in the expansion of the universe?

What is critical density and why is it important for understanding the universe's geometry?

What are the potential fates of the universe based on its curvature and the presence of dark energy?