Exploring the Origins: Can a Universe Emerge from Nothing?
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Chapter 1: The Fundamental Question of Existence
One of the most profound inquiries we can make with our current understanding of the cosmos is the origin of everything we observe. If our universe originated from some prior condition, we would seek to comprehend what that state entailed and the mechanism by which our universe was birthed. Conversely, if it emerged from a state of nothingness, we would be compelled to explore how we transitioned from absolute emptiness to the vast universe we inhabit and whether any causal factors were involved. This is precisely the question posed by our Patreon supporter, Charles Buchanan:
"I have a persistent query. I frequently encounter the idea of 'a universe from nothing' alongside the concept of negative gravity. In my studies of Newtonian physics, I learned that the gravitational potential's zero point can be positioned anywhere, with only differences being significant. However, Newtonian physics does not address scenarios where matter is created. Could you clarify this, ideally on a conceptual level with some calculations?"
Gravitation may appear to be a simple force, yet its myriad aspects can be quite counterintuitive. To delve deeper, let's examine the extensive scientific investigations into Einstein's general theory of relativity, which have tested this theory under some of the most stringent conditions known to humanity.
The first video, "A Universe From Nothing," by Lawrence Krauss, explores the philosophical and scientific implications of the universe emerging from a state of nothingness, challenging our understanding of gravity and existence.
Section 1.1: Understanding Gravity and Space
Einstein's initial solution applied to the weak-field limit around a solitary mass, like our Sun, yielded results that were remarkably successful when applied to our Solar System. We can visualize this as Earth (or any planet) in free-fall around the Sun, following a straight path in its frame of reference. In this framework, all masses and forms of energy contribute to the curvature of spacetime.
When two point masses exist some distance apart, they will experience an attractive force, pulling them toward one another. However, this perceived attraction is nuanced in the context of relativity, which presents two key considerations.
Subsection 1.1.1: The Nature of Space in Relativity
The first consideration is straightforward: while these masses will accelerate toward each other, whether they actually move closer depends entirely on the evolution of the space between them. Unlike the fixed nature of space in Newtonian gravity, in General Relativity, both matter and energy can change due to gravitational influences, and the very fabric of space itself is dynamic—capable of expanding, contracting, or flowing.
The second consideration is that the two masses are likely not the only forms of energy present. There will be other entities such as normal matter, dark matter, neutrinos, and various forms of radiation. Additionally, dark energy, a type of energy inherent to the fabric of space, plays a crucial role.
Section 1.2: The Complexity of Energy Density
Consider this scenario: what if the total energy contained within a given volume of space is less than the average energy density of the surrounding area?
The second video, "The Problem With Lawrence Krauss' A Universe From Nothing," critiques the ideas presented by Krauss and explores the challenges in reconciling the concept of a universe emerging from nothing with our understanding of physics.
In such cases, the mass with higher energy density will attract surrounding matter, while the one with lower energy density will struggle to retain its mass, leading to a scenario where these masses act as if they are repelling each other.
Chapter 2: Conceptualizing Nothingness
When discussing a universe arising from nothing, it's crucial to consider what 'nothing' truly means.
A common philosophical perspective equates nothingness with the total absence of everything: no matter, no energy, and a complete lack of curvature in space. However, if one begins to strip away space, time, and even the laws of physics, the ability to make predictions dissolves. This form of nothingness is what we term 'unphysical.'
In order to have a meaningful discourse about nothing in a physical context, we must retain certain elements, such as spacetime and physical laws. The quantum vacuum, for example, is not devoid of activity but is filled with energy fluctuations, suggesting that even empty space possesses a finite energy density.
The interplay of these factors culminates in the conclusion that empty space cannot be truly empty; instead, it is characterized by a zero-point energy that is greater than zero. This energy density, inherent to the very fabric of space, informs our understanding of the universe's expansion.
As we navigate the complexities of cosmology and gravity, it becomes evident that our intuitive notions may mislead us. By employing scientific principles, we can construct theoretical frameworks that accurately reflect the universe we observe, bridging the gap between the abstract concept of nothingness and the tangible reality of existence.
For any further inquiries or questions for "Ask Ethan," feel free to contact us at startswithabang at gmail dot com!
"Starts With A Bang" is also available on Forbes and Medium, thanks to the support of our patrons. Ethan is the author of "Beyond The Galaxy" and "Treknology: The Science of Star Trek from Tricorders to Warp Drive."