Cosmology, or really cosmogony, tries to answer one of the most fundamental questions of all: Where did the Universe come from? Cosmologists have no idea about the contents of this vast Universe. They speak of many unknowns—dark entities—used to make the standard ΛCDM (Lambda cold dark matter) big bang model fit the observational data. Dark energy and dark matter, which together allegedly make up 95% of the mass/energy content of the Universe, are total unknowns to experimental physics.
But these entities seem more like fudge factors to me than real science. Well, there is good reason for that feeling. They are fudge factors and now it seems like I am not the only one saying it.
In the following I excerpt (indented blue text) from an article titled “Cosmology is in crisis – but not for the reason you may think.” (link for full text) My emphases are in bold text.
We still have no idea what the vast majority of the universe is made of. We struggle to understand how the Big Bang could suddenly arise from nothing or where the energy for “inflation”, a very short period of rapid growth in the early universe, came from. But despite these gaps in knowledge, it is actually human nature – our tendency to interpret data to fit our beliefs – that is the biggest threat to modern cosmology.
But the dark energy problem is not the one that threatens to undermine cosmological experiments. In cognitive science, confirmation bias is the effect where people tend to unconsciously interpret information in a manner that leads to a selection of data that confirms their current beliefs. For cosmologists, this means the unconscious (or conscious) tuning of results such that the final cosmological interpretation tends to confirm what they already believe. This is particularly pernicious in cosmology because unlike laboratory-based experiments we cannot rerun our experiment many times to investigate statistical anomalies – we only have one universe.
A study that surveyed all the published cosmological literature between the years 1996 and 2008 showed that the statistics of the results were too good to be true. In fact, the statistical spread of the results was not consistent with what would be expected mathematically, which means cosmologists were in agreement with each other – but to a worrying degree. This meant that either results were being tuned somehow to reflect the status-quo, or that there may be some selection effect where only those papers that agreed with the status-quo were being accepted by journals.
Unfortunately the problem is only going to get more difficult to avoid as experiments get better. Ask most cosmologists what they think dark energy will be, and you will grudgingly receive the answer that it is probably a vacuum energy. Ask most cosmologists if they think Einstein’s theory is correct on cosmic scales, and you will grudgingly receive the answer that yes, it probably is correct. If these assertions turn out to be true, how can we convince the wider scientific community, and humanity, that any cosmological finding is not just the result of getting the answer we expected to get?
The author suggests three possible ways to overcome the problem:
- Blind analysis, and control samples, as are commonly and successfully used in experimental biology. There is only one universe, so we can’t know what are typical results, so why not introduce some fake data into some data sets that a researcher is working on without him knowing if it contains fake data or not.
- A systems engineering approach to experiment design. A list of requirements and result-independent tests are imposed that it must pass before it is used. If each sub-section of an analysis passes these tests then the entirety should produce unbiased results.
- Transparency. By publishing data and codes in an open way for anyone to download then there is no place to hide tuned parameters, and dodgy data.
He then suggests that with these three approaches—blinding, systems engineering and transparency—that the next generation of cosmology experiments (astronomical observations) should be in a position to convince the wider public that confirmation bias is not a limiting factor in our understanding of the cosmos.
I am not so circumspect. I believe the bias is so strong that there is an overriding belief that the ruling paradigm is correct and the dark entities are necessary or else we may end up with a situation where we have no viable cosmology. Of course, that is from a naturalist’s / materialist’s point of view, where he/she may consider keeping the theory that is considered ‘best in the field’ because the alternative, special creation by God, is intolerable.
The author finished his excellent analysis with:
Without them [his three approaches], by looking to the heavens, the most interesting thing we may find is ourselves.
- DOES THE CLAIMED ‘FIND’ OF DARK MATTER END THE ‘BIG BANG’ CRISIS?
- THE UNREALITY OF TIME
- DARK ENERGY AND THE ELUSIVE CHAMELEON—MORE DARKNESS FROM THE DARK SIDE
- ‘DARK PHOTONS’: ANOTHER COSMIC FUDGE FACTOR
- DEVELOPMENT OF AN “OLD” UNIVERSE IN SCIENCE
- ACCELERATING UNIVERSE: STANDARD ‘LIGHT BULBS’ NOT SO STANDARD
- COSMIC STORYTELLING
- WHY IS DARK MATTER EVERYWHERE IN THE COSMOS?
- DARK MATTER AND THE STANDARD MODEL OF PARTICLE PHYSICS—A SEARCH IN THE ‘DARK’
2 replies on “Is there a crisis in cosmology? It would seem so!”
My 5th grade son is studying astronomy in school, we are using an Apologia text book. One of the questions he had for me is what is the stuff in between galaxies. I’ve never pondered it before, so we typed it into good ol’ google, and dark matter is what came up. Can you give me a good answer for his question, if it is not dark matter? Thank you for your help!
Dark matter has become a “catch-all” for anything that is not understood. In the Intergalactic Medium (IGM) between the galaxies there is a lot of vacuum (empty space), and some hydrogen gas at very low density. Neutral, non-ionized hydrogen atoms are very hard to detect, i.e. hydrogen gas. When hydrogen molecules are dissociated to bare single neutral atoms, not ions, they can emit or absorb microwave radiation with 21 cm wavelength. These are commonly used to detect the presence of hydrogen but still it is very hard to find (often other gases like CO are used believing where you find CO you will find H2). But a lot of this normal matter is “missing” — that is, there seems to be much less than is expected from the standard big bang model. So, that is called the “missing baryon problem”. Baryons are normal matter particles, i.e. protons and neutrons etc. But dark matter is another matter (pun intended) all together. It may be claimed to exist in the IGM because of the measured dynamics of galaxies in the cluster. They move too fast, as measured by their redshifts or blueshifts within their clusters, that is, their intercluster motions. Because the clusters are believed to originate with the hydrogen atoms created in the big bang 13.8 billion years ago, and subsequently galaxies formed about 400 million to 1 billion years after the big bang, galaxy clusters are believed to be stable, in equilibrium, meaning they’ve been around for 10 billion years, and the high speeds of the individual galaxies then must mean (i.e. it follows from big bang thinking) that there must be more matter in the galaxies and in the IGM (up to 1000 times the visible matter in the clusters) than astronomers can see. So the dark matter is never observed there, only inferred from big bang assumptions.
Read WHY IS DARK MATTER EVERYWHERE IN THE COSMOS?