How Does Space Keep Getting Bigger and What Does It Mean for Us

Have you ever wondered what it really means when scientists say the universe is expanding? It sounds like something out of a sci-fi movie, but it’s actually one of the coolest ideas in astronomy. Imagine space itself stretching, making everything in the universe move away from each other. It feels weird to imagine space itself stretching, but that’s exactly what’s happening.

What Does It Mean That the Universe Is Expanding?

When scientists say the universe is expanding, they don’t mean that galaxies are flying through space like rockets. Instead, the space between galaxies is getting bigger. Think of it like dots on a balloon. When you blow up the balloon, the dots move farther apart, not because they are moving on the balloon’s surface, but because the balloon itself is stretching. That’s how space works too.

Galaxies Moving Away Because Space Is Stretching

Galaxies aren’t zooming away from each other on their own. Instead, the fabric of space between them is stretching, pushing them apart. This means the farther away a galaxy is, the faster it seems to be moving away from us. It’s like the dots on the balloon moving faster the farther they are from each other.

Galaxies moving apart as space expands

Edwin Hubble’s Big Discovery

Back in the 1920s, a scientist named Edwin Hubble made a huge discovery. He noticed that distant galaxies were moving away from us, and the farther they were, the faster they moved. This was the first strong evidence that the universe is expanding. Before Hubble, many people thought the universe was static and unchanging. His discovery changed everything.

What Is Redshift and Why Does It Matter?

One way astronomers know galaxies are moving away is through something called redshift. It’s a bit like when an ambulance siren changes pitch as it drives past you, but with light. When a galaxy moves away, the light it sends out stretches to longer, redder wavelengths. This shift toward red light tells us the galaxy is moving away. The more redshift, the faster the galaxy is receding.

The Big Bang Started It All

The expansion of space started with the Big Bang about 13.8 billion years ago. At that moment, the universe was tiny, hot, and dense. Since then, space has been stretching out, and it hasn’t stopped. It’s like the universe is still growing up, getting bigger every second.

Dark Energy Speeds Up the Expansion

Here’s a wild fact: the expansion of the universe isn’t slowing down. Instead, it’s speeding up. Scientists think this is because of something called dark energy. We don’t really know what dark energy is, but it acts like a mysterious force pushing space to stretch faster. It’s one of the biggest puzzles in astronomy today.

Galaxies Aren’t Growing Bigger