source The Inflationary Universe: A Possible Solution To The Horizon And Flatness Problems (Guth, 1980)
Questions I still have # DONEWHY#1: why is that approximation unstable? # See Flatness Problem
Abstract # The initial conditions defined in the Standard Model present two problems:
The early universe is defined to be homogeneous despite the massive distances between regions (causal disconnect) The Hubble constant must be set very finely to produce a flat universe (like ours) These problems could disappear if the universe (in its early stages) cooled to temperatures twenty-eight or more orders of magnitude below the critical temperature for “some phase transition”.
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Articles # Black Holes as Primordial Dark Matter Papers # The Inflationary Universe (Guth, 1980) Concepts # Configuration Space Cosmic Inflation Equations of Motion Galilean Transformation Generalized Coordinates Homogeneous Inertial Frames Isotropy Newtonian Spacetime Newtons Laws of Motion Principle of Relativity Problems # Flatness Problem Olber’s Paradox Black Hole Information Paradox
Articles # Phosphine, Life, and Venus
Source: Phosphine, Life, and Venus
Regarding the released report that Venus was found to “possibly harbor life” (see this Nature article)
What’s Phosphine? # A chemical compound found in small amounts in Earth’s atmosphere Used in: electronics fabrication, rodenticide On Earth it’s primarily found in its oxidized form, generally thought to be the result of lightning strikes, where the required amount of electrons would be present. But, it’s also been noticed in anaerobic environments (low/no oxygen).
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A type of chemical reaction in which electrons are lost
The Problem # People used to believe that the Universe was infinite (in age and size) and static. If this were true
Why is the night sky not as bright as day?
That is to say, if the universe is infinite as are the stars, and the universe is not undergoing any sort of evolution, we should expect every point of the night sky to be filled with the light from any one of its inifnite stars.
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Denoted H_0 (subscript 0)
The position that there is no relationship among two measured phenomenon or among groups. The central task of science is to prove that a relationship may exist between entities, implying that the null hypothesis is false.
Thus, centrally, science attempts to disprove the null hypothesis for a given field of questioning. This hypothesis is the default stance when approaching a statistical/scientific problem; i.e. the null hypothesis begins as true and it is up to the investigator to prove otherwise.
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I # In an intertial frame of reference (i.e. a frame of reference undergoing zero acceleration), an object at rest stays at rest (or, similarly, keeps its initial velocity) unless acted upon by an outside force.
\begin{equation} \sum \mathbf{F} = 0 \Leftrightarrow \frac{d\mathbf{v}}{dt} = 0 \end{equation}
II # In the simplest of terms:
\begin{equation} \mathbf{F} = m\mathbf{a} \end{equation}
which states that
The vector sum of the forces on an object is equal to that objects mass times the acceleration
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Overview # In the Big Bang model there are multiple parameters which appear to be “fine tuned” in that, small changes to a given parameter have massive effects on the evolution of the universe as a whole.
Wrt the flatness problem itself, the questionable parameter is the Density Parameter (\(\Omega\)), which is defined as
\begin{equation} \Omega \equiv \frac{\rho}{\rho_{c}}\tag{1} \end{equation}
where the subscript \(c\) is in reference to the “critical value” of density (\(\rho\)).
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Inflation # Inflation (Cosmic) is a theory put forth (originally, by Alan Guth in his 1980 paper) to explain why, if the universe is full of mass, is it not curved in some way? Instead, it’s flat (see: Curvature).
This isotropy in its temperature/geometry seems to contradict Thermodynamics in that we should see varying pockets of temperature around us since it would take time for the heat to dissipate throughout the universe.
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