Albert Einstein’s theory of general relativity was widely accepted when it was published in 1915, but it seemed to contradict observations made by astronomers who saw hints of an expanding universe. However, scientists soon realized that Einstein’s theory didn’t necessarily mean the universe had to be static; instead, it could support a dynamic and evolving model.
When we talk about expansion, we might think it means everything is getting bigger, which is true in some sense. But what’s more accurate is that everything is moving away from each other. This idea can be tricky because our brains are wired to separate space and time, but the universe exists as a single fabric called “space-time” where these two concepts are intertwined.
The concept of an expanding universe is subtle, and it’s easy to get it wrong with analogies like blowing up a balloon. While the analogy helps, it has its limitations. The problem lies in understanding how our brains intuitively think about space and time separately, but the universe doesn’t work that way.
A common question is “Where’s the center of the universe?” However, asking this question assumes there’s a fixed point or center to begin with. In reality, the universe doesn’t have a center because it exists as a four-dimensional fabric where every point has three dimensions in space and one dimension in time.
Understanding the expanding universe can be challenging due to its complex nature. Scientists are still working to understand what powers this expansion, but it’s clear that our intuition needs to be adjusted when thinking about space and time. By exploring these misconceptions and limitations, we gain a deeper appreciation for the beauty and complexity of our universe.
Source: https://www.space.com/astronomy/experts-ask-where-the-center-of-the-universe-is