There are a number of models of the universe being proposed today. The most widely accepted is the ΛCDM Model. Λ designates Einstein’s Universal Constant or, more recently, Dark Energy or Vacuum Energy. CDM designates Cold Dark Matter. This model relies on gravity and one element of Einstein’s Field Equations to describe the way mass and energy interact with time and space.
BASIC ASSUMPTIONS
In this essay, a new model will be outlined, which I refer to as the MEK Model. The M designates Matter, the E designates Radiant Energy, and the K designates Kinetic Energy. These are the main acting components of the model. To make the model as general as possible, we need to limit the axioms that it is based on to as few concepts as possible.
So first we will outline four basic assumptions that will set the parameters by which the model will be restrained.
1. Basic Axiom : Conservation of Mass + Energy
2. Uniformity Axiom: Homogeneous and Isotropic Space and Time
3. Finite Universe Axiom: 1/0 = undefined in our finite universe
4. Operative Axiom: A photon of Electromagnetic Energy exists at All wavelengths
These axioms are discussed below.
1. Conservation of Mass + Energy
All this axiom is saying is that the total amount of mass + radiant energy + kinetic energy is not dependent on time. Although it is understood that energy can be converted to mass by Einstein’s relationship: e=mc2, and it is being converted constantly; and both energy and matter are constantly changing forms; the TOTAL amount of “stuff” is the same throughout the timeline.
Conservation of mass and conservation of energy are basic tools used by scientists and engineers to explain real-world situations. Most astronomers and physicists make these assumptions. However, some situations and processes, particularly in quantum physics, violate these rules. Under the MEK model, these violations will not be applicable.
In general, we will talk about the mass and energy being constant, neglecting the amount of mass being converted to energy and energy being converted to mass. This is, of course, a simplification; and when the amount being converted – such as during time periods at the two ends of the timeline – this generalization will have to be checked and compensated for.
The one big ramification of this axiom occurs at what is general referred to as the “beginning of time” when other models of the universe talk about there being empty space without any matter or energy in it. And then the physicist basically wave the arms is the air and say “voila now matter and energy exist”. The state of no mass/energy existence simply does not ever occur in the MEK Model. At ALL times the same amount of matter + energy is present.
2. Homogeneity and Isotropic of Space and Time
This assumption should not be controversial. Virtually all models of the universe assume that space is homogeneous and isotropic. This leads to a basic assumption referred to as the cosmological principle which allows astronomers to apply known processes to their observations, and reach conclusions about distance phenomena.
An important caveat must be made. And this should not be controversial either. The axiom should read: Space and Time are homogeneous and isotropic at all points, except as they are influenced by the presence of matter and energy. As we know (or generally assume) according to Einstein’s General Theory of Relativity space and time are warped by the presence of mass. And, we shall see that space/time is also affected by the presence of energy.
———————————————————–
First Aside: The Arrow of Time
In modeling the universe, it is generally assumed that space-time is a four dimensional existence with X, Y, Z, and T dimensions. And, whereas you can travel back and forth in the X, Y, and Z directions; Time always moves in the past to present to future direction. This violates the assumption that time is isotropic. For the MEK Model, we will always assume that any action or reaction that can be described in time, will be equally viable in both the past-present-future direction and in the future-present-past direction. The equations will just have opposite signs.
For example, a common justification for using a set arrow of time is the statement that entropy always increases. And this is true for the past-present-future direction. However, it could also be just as correctly stated that entropy always decreases, and all of the equations for entropy would then be written in the future-present-past direction.
Whether we call the distant past the beginning of time (tMINIMUM) or the distant future the beginning of time (tMINIMUM) and the distant past the end of time (tMAXIMUM) is completely arbitrary. That said, the human brain tends to think of the world working in the past-present-future direction. We observe and remember the past, and can only predict the future. This is a limitation of our brains. However since the choice of time direction is arbitrary, for the discussions that follows, we will create our model in the past-present-future time direction. Although we must always keep in mind that this is only a convenience and we could just as well have used a future-present-past arrow of time.
———————————————————–
3. Finite Universe Axiom
This assumption should not be controversial either. If Edwin Hubble and his colleagues at the Mount Wilson Observatory were correct, and the universe is internally expanding (in the past-present-future time direction); then the total universe cannot be infinite. This is due to the physical relationships between mass, energy, space and time; and due to some characteristics of the mathematics of infinity.
And if the universe is finite, then no values within the universe can be infinite. So, infinity does not exist. This fact adds some complications to our modeling of reality, but actually helps in some other ways. We will discus some of the complications later, but for now we will outline the reason an expanding universe cannot be infinite and discus a few important ramifications.
If the maximum extent of X, Y, and Z are infinite, then the size (volume) of the universe = ∞.
And we know from basic observations today that the densities:
ρ(matter) = n (a finite number)
ρ(electromagnetic energy) = m (a finite number)
ρ(kinetic energy) = r (a finite number)
Therefore Total values of mass and energy = (n,m,r) * volume (∞) = ∞.
And we can calculate densities ρ = total value / volume = ∞ / ∞ = 1 , and this is true for all time values. So, for a unit of space the energy densities never change, and therefore the space never expands.
Now, I know what that this seems like I am playing game with the arithmetic. First I multiplied the values to get one thing and then divided them to get something else. However, this is how mathematics works when applied to the concept of infinity. So, in a real-universe situation, unless the densities of matter, electromagnetic energy and kinetic energies are not constant, then infinity mathematics breaks down.
Conversely, we can say, as an axiom, that the densities are constant, but then mass and energy are constantly being created all throughout the universe. And that would negate the MEK Theory’s first premise.
4. Operative Axiom
At first glance, the idea that photons of energy exist at all wavelengths between the wavelength that they are created up to the maximum wavelength that can exist seems counterintuitive/crazy. How can a photon exist at different wavelengths at the same time?
The answer is pretty simple: It doesn’t. It simply elongates throughout time. In fact that is what time is: the measure of where any photon is on the wavelength/ frequency scale. Radiant energy (baryonic) creates the time/space relationship. As time increases in the past-present-future direction, radiant energy increases the space around itself. As the space increases in the y and z directions, the universe expands. As space increases in the x direction, the radiation red-shifts and expands the universe in that direction too.
Importantly, the expansion rate at any given time is directly related to the wavelength at that time. This is such that each photon doubles its wavelength (and halves its frequency) every 9,350,000,000 earth years. The number of photons does not increase, as per the Basic Axiom, but their effect on the expansion rate of space does. This is opposite to the Dark Energy Theory, which postulates that dark energy is constantly creating more of itself. And that dark energy, which only made up 0.2% of the matter+energy in the universe 13 billion years ago, now accounts for 70% (14 times the baryonic matter+energy) of what is in the universe today.