The Mystery of the Universe Expanding
This week, I look at one of the biggest astronomy questions that I’ve always wondered, why is the universe expanding? At the beginning, I picture space as a cold, empty voice, but it turns out that the universe is anything but that. The universe is stretching, growing, and changing every minute. The fact solely opens up a lot of questions.
- How do we know the universe is expanding?
- What does this actually mean for the future?
- And, really, how big is the universe?
How Do We Really Know The Universe is Expanding?
For most people, they thought the universe was everlasing and constant. But this idea was changed in the 1920s when Edwin Hubble an astronomer came into the picutre.
Evidence That the Earth is Stretching?
What is RedShift?
Picture a person honking their car horn as they drive away, the sound the honk makes stretched out and the sound drops. This happens with light, when a galaxy departs, its light stretches, shifting towards the red end of the spectrum, this is called redshift.
The Big Bang Theory & The Cosmic Microwave Background
If space is stretching, it must have started from a single point. This is where the Big Bang Theory comes in. Approximately 13.8 years ago, everything, such as space, time, matter, blow up from unbelieve hot and a dense point.
As the universe cooled off, it let go of the first light ever, a dim light called Cosmic Microwave Background. This light is still traveling across the universe today. How cool is this?
How Big Is the Universe, Really?
Here’s the mind-blowing part:
- The observable universe is around 93 billion light-years
- But it may be much bigger, we just haven’t see the rest of it yet
- Because the universe expands quicker than light can travel, some galaxies are permanently out of reach, and their lights will never get to us
- Cool Tool
A Look Back In Time
The new James Webb Space Telescope gives us a time machine that looks into the past. It’s a powerful camera that captures light from galaxies that were formed billions of years ago, which was not long after Big Bang Theory.
The pictures and video let scientists explore how fast the universe has actually been growing, and what the universe looks like in its cosmic childhood.
What I Learned This Week
The universe isn’t entirely expanding, it’s running outward, faster than we can picture. What started as a tiny spark is now a sprawling cosmic web crossing billions of light-years. It’s beautiful, and it’s just the star of what we can explore.