Unpacking the Expanding Universe: What Lies Beyond Our Horizon?
You might not think about it often, but the universe is constantly changing. Objects within it are not static, they are moving–and that movement contributes to a phenomenon that has baffled scientists for centuries: the expansion of the universe.
The Bread Dough Analogy
One way to grasp this concept is by imagining a loaf of bread in the oven. As the dough rises, it expands and fills the baking pan. Similarly, in the expanding universe, galaxies are like the raisins in the dough – they’re moving further apart as the fabric of space itself stretches.
However, the analogy has its limitations. Unlike a baking sheet, the universe doesn’t contain boundaries. It’s constantly expanding into itself, with no edge or fixed point of reference. This can be a mind-bending concept, especially when considering the vastness and seemingly infinite nature of space.
The expansion funnel visually shows how the universe’s rate of expansion has increased over time. At the left of the funnel is the Big Bang, and since then, the universe has expanded at a faster and faster rate.
Image credit: NASA
A Universe in Motion
Through observations of distant galaxies, scientists discovered that the universe is not static, but is expanding at an accelerating rate. This acceleration is attributed to a mysterious force known as dark energy
