Exploring the Scale, Age, and Shape of the Observable Universe

While we estimate our universe to be approximately 14 billion years old since the last Big Bang, the true age and the boundaries of our known universe remain a mystery. This article delves into the expanding horizons of our cosmic understanding, exploring the shape, age, and the extent of what we can observe.

The Observable Universe and Its Boundaries

The term "universe" can encompass two distinct concepts. Primarily, it denotes the vast space that exists everywhere. Personally, I believe this infinite space has existed forever and has no end. However, the 'known universe' – the edge of all observable matter – has a defined boundary. Our observable universe is the sphere of matter and energy that lies within the cosmic horizon, where light has had time to reach us since the Big Bang.

The edge of our observable universe is expanding at the speed of light in all directions. Therefore, the shape of the observable universe is a sphere, with the edge continually moving away from us. As light continues to stretch and the universe expands, the distance our observable universe extends is continually increasing, moving further and further away from us at the speed of light.

The Limits and Expansion of Our Observable Horizon

Our current knowledge is limited by the light that has already reached us. Beyond the cosmic horizon, there is still matter and energy, but light has not had time to reach us from beyond this boundary. Thus, our observable universe is a sphere centered on our position in space, with a finite age due to the finite speed of light and the age of the universe.

The universe’s expansion is a significant factor in our understanding. From the Big Bang, the observable universe has expanded significantly, and it continues to do so. The rate of this expansion is accelerating, making the universe's true size and shape subjects of ongoing study and speculation.

Theories and Speculations About the Start of the Universe

There are various theories about the start of the universe, with the Big Bang theory being the most widely accepted. The concept of the Big Bang was first proposed by Georges Lema?tre in the 1930s, and the term "Big Bang" was coined by Fred Hoyle in 1949. However, many aspects of the Big Bang theory remain speculative and are still subject to debate.

According to one speculative theory, the universe as we know it is a part of an infinite space. Approximately 14 billion years ago, the existing matter in our part of the universe collapsed into a massive black hole or white hole. This transformational beginning contained the majority of the matter in the universe and expelled it at an incredible velocity, setting in motion the cosmic expansion that we observe today.

This speculative theory suggests that the Big Bang was a "reset" of the existing matter in the universe, leading to a universe where new stars, planets, and moons formed, filling it with the cosmic structures we see today. This theory does not conflict with scientific understanding and aligns with the concept of a universe where gravity may eventually take over and cause another collapse, leading to a new Big Bang in the distant future.

Some descriptions of the Big Bang mention a "singularity" or "infinitely dense point," which some may argue is necessary for the universe's creation. However, a black hole the size of our sun or even our entire solar system can still be considered a "small point" in the vastness of the infinite universe, making it plausible.

Conclusion

The observable universe, as we know it, is a fascinating and expanding frontier of knowledge. The boundaries of matter and energy that we can observe and the endless mysteries beyond them continue to captivate scientists and laypeople alike. As our technology and understanding advance, we hope to unravel more about the true shape, age, and size of the universe, and the role of events like the Big Bang in its creation and evolution.