Friedmann–Lemaître–Robertson–Walker metric
Okay kiddo, have you ever played with a globe or a ball? Let's pretend the universe is a ball. The Friedmann-Lemaitre-Robertson-Walker (or FLRW) metric is a way to measure the shape of this ball and how it's expanding over time. Just like how we measure the distance between two points on a globe using latitude and longitude, we use different measurements to study the universe.
The FLRW metric tells us how long it takes light to travel through the universe, how dense different parts of the universe are, and how it's expanding. It's like a "map" of the universe that astronomers use to explore the big questions about space and time.
Let's break it down even simpler: FLRW is a tool that helps scientists understand how the universe works by looking at things like how fast it's growing and how much stuff is in it. It's like a giant puzzle that scientists are trying to solve, and FLRW is one of the tools they use to do it.
The FLRW metric tells us how long it takes light to travel through the universe, how dense different parts of the universe are, and how it's expanding. It's like a "map" of the universe that astronomers use to explore the big questions about space and time.
Let's break it down even simpler: FLRW is a tool that helps scientists understand how the universe works by looking at things like how fast it's growing and how much stuff is in it. It's like a giant puzzle that scientists are trying to solve, and FLRW is one of the tools they use to do it.