“A good scientific theory is one that allows us to calculate the results of many observations from few assumptions.”
— Physicist Sabine Hossenfelder
Hossenfelder’s concise statement explains why the Genesis account — Earth and Heavens created out of nothing in six days — has no appeal for scientists looking to understand the cosmos. And why most cosmologists today favor the current top contender for the deep history of the universe, the Concordance Model, due to its simplicity. In a nutshell, this model, also known as Lambda-Cold Dark Matter (ΛCDM), says that the universe started out tiny some 14 billion years ago and has been expanding ever since.
The beauty of ΛCDM is that it requires a minimum of assumptions to (mostly) explain why the universe looks the way it does today, while a biblical 6,000-year-old universe requires a hugely complicated initial state, including fossils artfully planted to bamboozle paleontologists. In contrast, all the ΛCDM model needs is to start with a super hot and dense “plasma” (a smooth soup of elementary particles) which evolves in accordance with Einstein’s general relativity, and 14 billion years later, Bam! Here we are, out there are the galaxies. And here’s the evidence:
The cosmic microwave background radiation (CMBR), discovered by accident in 1964, fits nicely with the idea of light traveling through an expanding universe ever since the initial hot plasma had cooled sufficiently to allow photons to escape. The average temperature of the CMBR and its anisotropies (fluctuations) add weight to the ΛCDM model. See the accompanying illustration.
ΛCDM can handily explain the relative abundance of elements in the early universe: 75 percent hydrogen, 25 percent helium, with a dab of lithium.
The observed large-scale distribution of galaxies is consistent with the ΛCDM model, assuming the plasma soup wasn’t 100 percent smooth. Here and there, slightly denser places grew yet denser thanks to gravity. Small clumps evolved into bigger clumps which, given half a billion years, evolved into the first galaxies.
The model explains the accelerating expansion of the universe, per measurements of distant galaxies and supernovae.
While the ΛCDM model fits well with many observations, it leaves a lot unexplained, in particular what’s responsible for the overall makeup of the universe. At our current level of knowledge, only 5 percent of the universe consists of the stuff we know and love — atoms and molecules, aka “ordinary matter” — while 26 percent is invisible “dark matter,” known to us only by apparent anomalies in the rotation of galaxies. The rest, 69 percent, is “dark energy,” the unknown force responsible for the accelerated expansion of the universe.
So where does the Big Bang fit into all this? Short answer: It doesn’t. Cosmologists can theorize using the ΛCDM model back to a fraction of a second after a hypothetical Big Bang, but before then, it’s anyone’s guess, now and likely ever. The farther we go back, the hotter and denser the plasma “soup” becomes, until it’s many orders of magnitude beyond anything we can mimic (at CERN, for example) or observe in stars.
Lack of data hasn’t stopped physicists from speculating, of course. Whether our universe emerged out of nothing at all from what cosmologists call a “quantum fluctuation,” or from a gas of “superstrings,” or whether it bounced into existence from a previous universe, or began according to a hundred other proposals, the answer’s the same: We lack the data. Hossenfelder, quoted above, has this gloomy assessment: “It’s hard to conceive of any evidence that could settle the debate regarding which [hypothesis] is correct, because they are all so flexible they can plausibly be made to accommodate any data thrown at them.” l
Barry Evans (he/him, barryevans9@yahoo.com, planethumboldt.substack.com) gives a nod to Belgian Catholic priest and theoretical physicist Georges Lemaître who, in 1927, was the first to argue for an expanding universe and consequently (what we now know as) the Big Bang theory.
This article appears in 2026 Pet Photo Contest.