The Big Bang Theory Is True. Deal With It.
This fencing along the Hudson evokes the grids with which cosmologists simulate the universe. The padlocks represent… Oh, hell, I don’t know, you decide.
September 17, 2023. There’s something comical about cosmology. A field that tries to explain the whole universe? Give me a break! We don’t even know how a brain makes a thought! But that’s what I love about cosmology, too--the contrast between this grand scientific endeavor and our benighted, mortal selves.*
And over the last century, cosmology has given us a mind-blowing insight into our existence, which anyone can grasp: Our universe exploded into being billions of years ago and is still hurtling outward.
I love telling my students the tale of this discovery. Just over a century ago, our universe consisted of the Milky Way, the swirl of stars that houses our solar system. Then telescopes got big enough to spot other galaxies far, far beyond the borders of our own. The light from these galaxies tends to be redder in proportion to their distance from us.
A fellow named Hubble concluded, based on galaxies’ red shifts, that they are receding from us. Theorists extrapolated the universe backward in time to an extremely small, dense fireball that fused primordial hydrogen into helium and other light elements. Astronomers detected light elements in the predicted proportions, corroborating so-called big-bang nucleosynthesis.
The clinching evidence emerged in 1964. Researchers at Bell Laboratories, right here in northern Jersey where I teach, detected a faint microwave signal coming from all points of the sky. Theorists had proposed the big bang would leave behind this microwave afterglow.
Come on, I enthuse to my students after recounting them this scientific creation story, isn’t that amazing?
In my 1996 book The End of Science, I call the big bang one of the greatest discoveries ever. The theory will surely be tweaked and extended, but it will never be overturned, because it is true, just as heliocentrism and evolution by natural selection are true. So I claim.
But wait. What about a recent New York Times essay, “The Story of Our Universe May Be Starting to Unravel,” by astrophysicists Adam Frank and Marcelo Gleiser? The James Webb Telescope, they report, reveals that galaxies formed “far earlier than should have been possible according to the so-called standard model of cosmology.” This standard model is a souped-up version of the big bang.
Frank and Gleiser disclose other problems with the standard model. To match observations, modelers must assume the existence of undetectable, “dark” forms of matter and energy. To solve other cosmic puzzles, theorists allege that the universe underwent an enormous growth spurt, called inflation, shortly after its birth; inflation implies that our universe is just one of many in a “multiverse.”
The evidence for dark matter, dark energy, inflation and the multiverse is circumstantial, at best; they should be seen not as discoveries but as inventions, theoretical conveniences. Skeptics are justified in questioning the validity of a model that incorporates such dubious hypotheses. Or so Frank and Gleiser suggest.
They propose various solutions to the “crisis in cosmology.” Maybe physicists should rethink their basic assumptions about space and time. Maybe gravity and other forces, far from being constant, “change over time.” Maybe our observations of reality alter it, as physicist John Wheeler speculated. Maybe, maybe, maybe.
Pardon my eye-rolling, but Frank and Gleiser are reprising, pretty much exactly, arguments I heard at a cosmology symposium in 1990. Thirty-three years ago! Attendees included Stephen Hawking, Frank Wilczek, James Peebles, Martin Rees, Michael Turner, Alan Guth, Sidney Coleman and Andrei Linde.
As I recount in The End of Science, these superstars of cosmology spent six days fretting over mismatches between theory and observation. They debated the validity of inflation, the multiverse, dark matter and dark energy (although that phrase hadn’t been coined yet). Not to mention superstrings, cosmic strings, wormholes and other exotica.
Some attendees claimed that cosmology is undergoing a crisis and needs radical new ideas. Dave Schramm, a barrel-chested, irrepressibly optimistic physicist who specialized in big-bang nucleosynthesis, rejected this view. The red-shift, microwave and nucleosynthesis data provide a rock-solid foundation for the big bang, Schramm insisted.
Yes, the theory poses puzzles, such as how galaxies formed, not to mention how the big bang happened in the first place. Yes, inflation and dark matter might turn out to be wrong. But Schramm assured me that the basic big bang “framework” is in “fantastic shape.” “Just because you can’t predict tornadoes,” he said, “doesn’t mean the earth isn’t round.”
Schramm’s confidence has been borne out. Since that 1990 meeting, cosmologists have made one genuinely surprising discovery, that the expansion of the universe is speeding up. But this finding, which dates back to the late 1990s, hasn’t overturned the big bang; it just adds an intriguing twist, which fuels the current enthusiasm for dark energy.
That’s the view that emerges from a new book on cosmology, Simulating the Cosmos, that I just reviewed for The Wall Street Journal. Author Romeel Davé, who works on cosmic computer simulations, says cosmology has matured in recent decades “from a science of rampant speculation into one of statistical precision.” The big bang paradigm is so well-supported, Davé asserts, that “there are no viable competing models.” Just as Dave Schramm (who died in 1997) predicted.
So why do Frank and Gleiser proclaim in The New York Times that cosmology is “starting to unravel”? They probably hope cosmology is unraveling, because they think it’s getting boring. Although scientists can be conservative, many yearn to be revolutionaries, toppling old paradigms and erecting new ones. They aren’t thrilled by the prospect of adding more “statistical precision” (as Romeel Davé puts it) to a century-old theory like the big bang.
Would-be scientific revolutionaries, aided by journalists, keep pointing to puzzles unresolved by well-established paradigms like the big bang or evolutionary theory. These ambitious rebels indulge in hype, proclaiming that this field or that is in “crisis,” and that breakthroughs like those that transformed physics a century ago are imminent.
They wish. I wish. I yearn for a genuine revolution too! Maybe quantum computing will catalyze such a revolution. Maybe not. If you believe science actually discovers reality, and achieves truth, you must consider the possibility that the era of truly profound, revolutionary insights into nature is over.
*To emphasize how comical cosmology is, I originally titled this column “Is the Big Bang Just a Fart in the Wind?”
Further Reading:
The desperation of physicists and journalists for non-boring results can lead them to abandon their critical faculties. For a recent example, see “Physicists Teleport Bullshit Through ‘Wormhole’!
Huge Study Confirms Science Ending! (Sort Of)
Sabine Hossenfelder, The End of Science and My Quantum Experiment
Physicist John Wheeler and the “It from Bit”
See “About Cross-Check” for a list of all the free, un-paywalled columns I’ve posted on this site.