Archives for Cosmology
Vacuum energy of particle antiparticle pairs may be responsible for the value of cosmological constant?
In short, No. There is an enormous discrepancy. However, this did not strictly disprove the idea that vacuum energy contributes to the cosmological constant. It showed that the simplest quantum-field-theory…
The unconnected manifold versus the affine connected manifold – describe what these are. Densities, Derivatives, Integrals, Invariant Derivatives in particular
This is a deep and beautiful distinction—one that sits right at the boundary between pure geometry and physics-ready geometry. Let’s build it cleanly and intuitively, then connect it to densities,…
Perfect Gas with Dipole Moments – what can it model?
Can a Perfect Gas of Dipolar Molecules Model Stars or Planets? Short answer: No — a “perfect gas with N molecules each having a dipole moment p” is not…
Universal Expansion Clock: Why the Big Bang Was Infinitely Long Ago
Milne’s Expansion Clock: Why the Big Bang Is “Infinitely Long Ago” This explains how, in Milne’s kinematic relativity, using the rate of expansion (or its integral) as the universal clock…
How the Arrow of Time Emerges from the Big Bang
How the Arrow of Time Emerges from the Big Bang Why do we experience time flowing in one direction — from past to future — when the laws of physics…
Why Entropy Increases After the Big Bang
Why Entropy Increases After the Big Bang The universe began in a very special, low-entropy state — a smooth, nearly homogeneous high-energy configuration. But why does entropy increase from there?…
The Big Bang — Pencil on its Tip
The Big Bang — Pencil on its Tip Was the Big Bang more like a pendulum or like a pencil balanced on its tip? Many physicists believe that the early…
Understanding Rindler Space
Understanding Rindler Space 1. What is Rindler Space? Rindler space describes the spacetime experienced by an observer undergoing constant acceleration in special relativity. It is useful for understanding: Uniformly accelerated…
Understanding the Event Horizon
Understanding the Event Horizon 1. The Event Horizon as a Global Concept The event horizon is not a physical surface but a mathematical boundary beyond which nothing can escape. Its…
Neutron Stars and Pulsars – Mathematical Differences
Mathematical Difference: Neutron Star vs Pulsar Neutron Star A neutron star is a highly dense remnant of a massive star after a supernova explosion. It is characterized by: Mass: \(…