Exploring the boundaries of our cosmos.
The idea of space continuing indefinitely is perplexing, not least because our minds aren’t built to deal with notions like infinity. But isn’t it possible that it just looks to be limitless because it’s always expanding? This is one idea proposed by physicists and planetary scientists.
Our universe is about 13.8 to 14 billion years old, yet because of its continual expansion, humans can see for 46 million light-years in all directions. So, if you could freeze time and so stop the expansion of the universe, it would have a reachable end point or edge. As a teacher, presenter, and planetary scientist Dr. Sheila Kanani says, one way to visualize this notion is to think about a balloon. Consider yourself inside this balloon, living in a two-dimensional realm on its inside surface. As more air is pushed into the balloon, the space or surface area of the cosmos expands, and every point on its surface gets further and further away. The balloon represents the universe, and as more air is pumped into it, the universe’s space or surface area expands, and every spot on its surface becomes increasingly far from one another.
This raises the question of what will actually happen to our universe if the expansion slows down.
According to New Scientist, many theoretical physicists predict the universe will end in 2.8 to 22 billion years, meaning we won’t be there to see it. A ‘Big Crunch,’ as described on the website HowStuffWorks, is one of the numerous conceivable outcomes for our universe. In a reverse of the Big Bang, a Big Crunch may force matter and space-time to collapse in on itself, generating a singularity – an endlessly dense point identical to where the universe began.
This notion has been linked to the possible existence of multiverses, or many worlds. Perhaps our own universe will grow and then shrink into a massive crunch. That will result in a new Big Bang and the birth of a new universe. Consider a glass of bubbly water – there’s nothing in it but the water, but then a bubble forms. The bubble explodes, and other bubbles in the water form and vanish at the same time. Each bubble is generated with a bang and vanishes with a crunch. So suppose our universe and other universes are really not formed from and expanding into nothing in space. But rather something else exists in which universes are formed, and we just haven’t discovered it yet. Do you have a whirlwind of thoughts going through your mind?
These principles are difficult for humans to grasp, which is why many scientists use analogies such as balloons and fizzy water to explain them. And, like those bubbles in the water, as soon as we answer one question, it leads to a slew of others that we have yet to address. The universe may continue to expand indefinitely, but surely our questions about it will not.
Let us know your opinions in the comments.