"C How a Revolution Happens"
The biggest revolution in cosmology since Einstein may be quietly brewing.
The speed of light may not be as rock-steady as it has been deemed to be. Rather, the value of this fundamental constant may be changing -- slowing down -- as time passes.
A number of observations made in recent years have pointed in this direction. If verified, we can bid goodbye to both the Inflationary Model of the early universe, and dispense with the idea of Dark Energy.
Neither theory would be necessary anymore to explain the smoothness of the universe on large scales and the apparent acceleration of the cosmic expansion.
Instead, all we would need to understand these characteristics of the universe is a simple equation:
GM = tc^3
Where G is the gravitational constant, M is the mass of the universe, and t is the age of the universe (time) times the speed of light cubed.
Because the mass of the universe (M) remains constant, flipping the equation to solve for c would be variable depending on the value t. In short, as time passes the speed of light (c ) would decrease.
But let's back up a bit. A bombshell of this magnitude requires a bit of back story, and some evidence.
Inflation Theory was proposed by Alan Guth in 1980. The theory is a cornerstone of modern cosmology because it solves a lot of the problems raised by a universe that is expanding -- which is known to be the case. One of these problems is why the universe is so smooth (the Cosmic Background Energy is virtually uniform) when different parts of the universe could not have been communicating with each other as they moved apart. Since energy cannot exceed the speed of light, as the universe grew the different parts could not exchange energy with increasingly remote parts of the universe, and so local blobs of matter should have dominated the picture.
In short, the universe should be pretty lumpy. Instead, on the biggest scales it is smooth. Inflation Theory posits that in the initial moments after the Big Bang, the universe expanded enormously -- time-space changed its metric much faster than the speed of light itself. This expansion overwhelmed such forces as gravity, and resulted in an initial configuration that was very smooth, and which only later began to agglomerate into structures such as galaxies.
For nearly 30 years now, numerous investigations have been made into the structure of the early universe, and on the surface these observations have largely fit with Inflation Theory.
But there are problems.
*Just what caused the massive inflation of time-space? The leading candidate is Dark Energy (or quintessence, the Fifth Force) that works like gravity, except it repels mass. Nobody has ever directly observed this putative force. It is implied to exist, but it doesn't fit with either Einstein's relativistic concept of gravity (space-time curvature) or the Quantum-mechanical conception (the force would need an associated particle, in this case an antigraviton).
*Inflation Theory violates the First Law of Thermodynamics (conservation of energy).
These are not trivial problems. Indeed, Inflation Theory has been compared to the Ptolemaic Model of the Universe by its detractors because, like that ancient geocentric model with its elaborate epicycles, it requires the existence of unobserved and inexplicable forces/particles in order to work.
In the last 28 years, Inflation Theory has become rather elaborate, as each new observation of the universe related to the theory has had to be accommodated.
Elaborate is actually a polite term. Some cosmologists and astronomers think its an overwrought edifice on a shaky foundation. This post is getting long, so I'll end here with a tease.
NEXT POST: The Earth is not drifting away from the Sun. It just looks that way.
Labels: speed of light