What are friedmann equations?

The Friedmann equations are like recipes that tell us how the universe grows or shrinks over time.

Imagine you're blowing up a balloon, the more air you add, the bigger it gets. The Friedmann equations work the same way but for the whole universe! They help scientists understand if the universe is expanding, slowing down, speeding up, or even maybe starting to shrink again one day.

Think of the universe as a balloon with dots on it, each dot represents a galaxy. As you blow air into the balloon, all the dots move away from each other. That’s like how galaxies are moving apart in our real expanding universe. The Friedmann equations help scientists figure out how fast the balloon is growing and what might happen next, will it keep getting bigger forever or start to collapse?

These equations use things we can measure, like how much matter and energy are in the universe. It’s like a recipe that uses ingredients you already have on hand, flour, sugar, and eggs, to tell you what kind of cake you’ll make.

So, scientists use these Friedmann equations to explore the past, present, and future of our whole universe, just like we use recipes to bake the perfect cookie!