One Thing Is Certain – When It Comes To Cosmology And The Universe Nothing Is Certain

The James Webb Space Telescope (JWST) tells us that the physics we trust to explain the Universe as we understand it is not quite right. The controversy begins with the Hubble Constant (HO), a calculation of the Universe’s expansion rate which we use to determine its age.

The H in HO represents Edwin Hubble who in 1929 was the first to observe the rate of expansion. The O equals zero, the present starting point. The calculation of HO uses different methods.

• Cosmic Microwave Background measurements yield a value of approximately 67 km/s/Mpc.
• The Hubble Space Telescope’s calculations yield a value of approximately 74 km/s/Mpc.
• The Red giant star method produces a value of approximately 69.8 km/s/Mpc.
• The JWST produces a value of approximately 69.96 km/s/Mpc.
• Gravitational lensing has been used to come up with a value of 75.4 km/s/Mpc.

So what’s the big deal between a measure of 67 and 75.4 km/s/Mpc? It turns out to be a very big deal when you consider a megaparsec is 3.26 million light-years, a huge distance. For a point of reference, the nearby Andromeda Galaxy, our Milky Way twin is currently 0.89 Mpcs distant or 2.9 million light-years and the two are converging at a rate from 110 to 300 km/s depending on who is making the calculations (again a huge discrepancy).

The difference in these calculations is referred to by physicists, mathematicians and cosmologists as the Hubble Tension. It challenges their fundamental understanding of the physics that governs the Universe. The discrepancies aren’t trivial. Differences in mathematical calculations have caused missions costing hundreds of millions of dollars to crash on places like the Moon and Mars.

To cause even more confusion, in 1998, two teams of astronomers discovered that the HO wasn’t a constant but rather was accelerating. The predominant explanation for this observation was a new force in the Universe called dark energy, a form of antigravity, that could explain why large objects like galaxies and galaxy clusters were moving further apart from each other at accelerating rates. Soon the dark energy explanation was joined by others including:

• The existence of the Metaverse suggests many other universes with regular collisions and mergers.
• Mathematicians in reviewing the equations behind Einstein’s General Relativity believe he predicted cosmic acceleration caused by the existing structure of the Universe itself.
• Some scientists argue the Universe is not homogeneous and different parts are expanding at different rates which can explain the current distribution of the galaxies.
• Some believe Einstein’s theory of general relativity is incomplete and needs a refresh to to understand the forces of gravity on a cosmic scale.
• Some argue that the speed of light hasn’t been a constant and that in the early Universe, it was different.
• Some propose that quantum gravity effects can have a larger influence than previously hypothesized when determining cosmic expansion.
• Some scientists propose a period of dark energy dominating the early Universe causing the birth of a multitude of bright and short-lived galaxies and spurring faster acceleration.

Today, based on the Hubble Space Telescope’s observations with JWST confirmations using the regular pulsations of Cepheid variable stars the current calculated age of the Universe is 13.8 billion years. That measure seems to be backed by a common consensus in the scientific community. But the Hubble Tension remains a conundrum.

Dark energy remains the leading contender in explaining the accelerated expansion. It is calculated as comprising almost 70% of the Universe’s total mass-energy, Einstein’s famous equation E = mc².

Dark energy, rather than existing in the earliest stages of the Universe, is seen as having come into force only halfway through its history. Its nature is unknown. It is not observable or measurable. Some cosmologists argue it is the energy of space itself.

What does its existence and effects imply? If the expansion of the Universe continues to accelerate all of the structures not gravitationally bound will eventually recede beyond our ability to see them. Our local galaxy cluster including Andromeda and others will remain visible to us billions of years in the future but the rest of space will become a black void.