The geologic lifespan of Jon Bon Jovi

As a child of the 80’s, I grew up with a variety of ephemeral pop bands, who evolved from the primeval ooze, burst into an eruption of sound and video fury, only to fade into extinction. Occasionally, however, a rare artist would rise again from the depths of obscurity, a rock and roll coelacanth long after his contemporaries had lithified. After a recent sighting of one such musical living fossil, I began to wonder exactly how long this antiquated creature could reasonably be expected to survive. So in an exercise of Bon Jovichronology, I tried to deduce the musical lifetime of Bon Jovi using the principles of geochronology and some of his better known lyrics.

While the title of the song “Always” is obviously an unquantifiable hyperbole, there is a refrain from which we can attempt to derive an answer.

I’ll be there ‘till the stars don’t shine
‘till the heavens burst
And the words don’t rhyme

Thus, a Bon Jovi-eon is allegedly comparable to the lifetimes of stars, heavens, and rhyme. What are these in years?

The lifetime of the stars that shine is an astronomical question, not a geologic one. All of the stars we see right now are either
a. Short-lived massive stars,
b. Giant stars inflated by the last gasp of helium burning at the end of their lives
c. Sunlike stars that happen to be passing close to the sun right now.

Or some combination of the three. In any case, all of the stars that we can see today with the naked eye will either die out or move too far to see within millions to tens of millions of years. It is worth pointing out that the most common, longest lived M class stars are too dim to view unaided, even if they are very close. Of course, once the stars we see today disappear, they will be replaced by other, different stars. Sunlike stars are being born today, and they live for 10 billion years, so there will probably be something to be seen in the night sky for tens of billions of years, long after our sun runs out of hydrogen and swells up into a red giant, evaporating all the FM radio stations and record stores that may still exist on Earth. So this constraint is pretty open-ended.

It is hard to quantify when the heavens will burst, as heaven is a mythological/literary construct. Taken literally, this would presumably refer to Armageddon, which has a timescale of a few thousand years- orders of magnitude shorter than the stellar constraint.

So, what about the third constraint? While the timescale of rhyme is a linguistic question, we can derive a quantification from standard geochronological first principles. To do so, we will assume the following:
1. A rhyme is deemed to have decayed when the pronunciation of the words changes so that those which used to rhyme don’t anymore.
2. Like radionuclides, we will assume that the rhyme decay constant is invariant. It almost certainly isn’t, since audio recordings and dictionaries will probably effect it, but that doesn’t mean that we can’t pretend.
3. Rhyme decay is irreversible.
Using these assumptions, we can take an English language work of known age, and ratio the remaining rhymes to the original rhymes to determine the decay constant, lambda. The relevant equation is lamba = -ln(N/N₀)/t, where N is the remaining rhymes, N₀ is the original rhymes, and t is elapsed time. Lamba is related to the half life, as follows: T_1/2 = ln2/lamba. To calculate the English rhyme decay constant, I will use a subset of Shakespeare’s sonnets, published in 1609. Looking at every tenth sonnet, we see that out of a total of 210 rhymes, 12 have decayed, and 198 are intact. –ln(198/210)/400 gives us lamba=0.000147/yr, or a halflife of 4712 years. This is slightly shorter than the halflife of carbon-14.

A approximation is that after 10 halflives, 99.9% of a nuclide has decayed, and the original has generally dropped below detection limits. Applying this to Bon Jovi suggests that after 47,120 years, essentially all of the words that currently rhyme won’t.

For comparison, this is approximately the elapsed time since humans first arrived in Australia. Europe was still inhabited by the Neanderthal, and it would be 20,000 more years before Cro-Magnon people painted their caves. A similar period of time would have to elapse after that before this descendant of subsequent African emigrants invented rock and roll.

Of course, for the cynics among you, there is an alternative explanation.
Technically, shine and rhyme don’t rhyme right now. The heavens burst whenever it rains, and to the sea level observer, the stars stop shining just before sunrise.
So a jaded reader could interpret this as a one night stand song. This interpretation is irrelevant for two reasons.
Firstly, the known timescale of Bon Jovi’s success is 3-4 orders of magnitude longer than a single night.
More importantly, though, is the observation that during the 80’s, jaded cynics weren’t listening to Bon Jovi; they were playing records by the British black tee-shirt crowd instead. I should know. I was one of them.

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