Bang?
These theories were based on the hypothesis that all the matter in the universe was created in one big bang at a particular time in the remote past.
Sometimes a phrase is carefully crafted to describe a new phenomenon or idea. Other times, someone will casually throw a word or two out there, and that’s what sticks.
Fred Hoyle and the current best explanation for how the universe works were beneficiaries of this second type of phrase origination. Here’s how that happened.
Sir Fred Hoyle was a brilliant scientist because of his innovative and novel ways of looking at things. Unfortunately, this openness ultimately tarnished his legacy to a degree (more on that in a bit), but it also opened doors for some of the most important discoveries of the mid-20th century.
Hoyle’s most profound insight? The idea that all elements heavier than lithium were cooked inside of stars.
This was revolutionary, and it ran completely counter to the prevailing thought at the time: that all elements formed in the Big Bang. Together with Margaret Burbidge, Geoffrey Burbidge, and William Fowler, Hoyle published the seminal 1957 paper called B²FH. Physicists really love their name-based jokes.
Today, we understand this to be true. Hydrogen and helium (and some lithium) formed during those fist post-Bang moments, but every other element is formed in stars. Some heavier elements are only formed when stars blow up (go supernova).
Hoyle saw this very early on, and asserted it so that others would hear about this idea. If not for his contributions, we might not be so far along today.
Unfortunately, it’s probably fair to say: embedded in Hoyle’s greatest scientific contribution were the seeds of his greatest failure.
Hoyle chose a particular hill to die on, so to speak. While the Big Bang theory was able to explain some of the observations about how the universe worked, there was a great deal about which you could be dissatisfied. One of the things that really stuck in Fred Hoyle’s paw was that the early estimates of the age of the universe seemed to indicate that the Earth was actually older than the universe.
Hoyle had a point, didn’t he?!?
Of course the Earth couldn’t be older than the universe, and Big Bang cosmology ultimately answered this one with updated data—the Hubble constant, or the rate at which the universe is expanding, was updated in the ensuing decades. Today, our best guess is that the universe is about 13.8 billion years old, and the Earth is about 4.5 billion years old.
He went further, though, and here’s where I think Hoyle really started to veer off into speculative territory. Hoyle didn’t like the idea of the Big Bang theory. It just didn’t sit well with him on a philosophical basis to imagine that all all of the matter and energy could be concentrated into a single point, although modern astrophysicists don’t necessarily believe this today either.
In fact, it was Hoyle himself who ultimately coined the name “Big Bang” during a radio broadcast, where Hoyle was making fun of the implausibility of the theory, so that he could propagate his own competing theory: steady-state cosmology.
The steady-state model said that the universe was static and eternal—unchanging on large scales. It maintained a constant density even though it was expanding by constantly creating new matter.
And, expanding it certainly was. Hoyle (along with his colleagues Hermann Bondi and Thomas Gold) had to concede this based on overwhelming evidence and our ability to see farther.
This sidestepped the need for a “moment of creation”, at least according to Hoyle. The universe had always been here, and although it was expanding, new matter kept the state steady.
BBC radio debates showcased a passionate Hoyle defending the steady-state theory, and often engaging in debates with proponents of the Big Bang theory. This debate went on for decades.
The nail in the coffin for the steady-state theory was brought to us courtesy of pigeon poop, and you can read about that discovery a bit here if you’d like:
Pigeon Poop
Gradually, the scientific community shifted away from the steady-state model in favor of the Big Bang. Over and over again, the latter theory better accounted for observations.
It’s ironic that Hoyle’s greatest contribution—how heavy elements are formed inside of stars—came about because he hated the idea of the Big Bang theory. He was right because he was wrong, in a weird way.
I’ll leave you with an amazing conversation Hoyle had with Feynman:
“I don’t set any requirement that the answer be right”, Hoyle explains. Feynman’s response encapsulates everything: “I’m trying to find out not how nature could be, but how how nature is.”
Scientists (with a few notable exceptions) will do everything they possibly can to avoid thinking about the origin point of the universe, because it deals way too much with the ineffable where things get uncomfortably close to philosophy, poetry and theology. But the dilemma is, of course, that if they're not going to talk about an origin point, they have to talk about infinity, which makes them equally uncomfortable. Having an interest in theoretical physics, I've been watching this play out over the past decades. It's kind of delightful, watching them squirm.
I didn't know about the origin of the term until now; this explains a lot. There was a Calvin and Hobbes strip on the subject, in which Calvin argues that this particular theory should have a more evocative name than the Big Bang. Naturally Hobbes asks what he would call it, and Calvin answers, "the Horrendous Space Kablooie!"
I would actually prefer that, I think, and now I can't help wondering whether Hoyle would've liked that better or not. Probably not, under the circumstances.