Charles Babbage on Acoustic Waves

Charles Babbage, who was born in 1791, the year after Ben Franklin died, wrote in the 1830s that, even if the sound of one's voice is hardly audible thirty feet away, that nevertheless, within twenty hours its effect has been felt by air molecules (particles he called them) over the entire earth.

The waves of air thus raised [by a voice], perambulate the earth . . . and in less than twenty hours every atom of its atmosphere [is affected].

Mr. Babbage wrote that in Chapter 9 of his 1837 book, "The Ninth Bridgewater Treatise." Chapter 9 is entitled "On the permanent Impression of our Words and Actions on the Globe we inhabit." In it he writes about the propagation of sound in air, water, solids. It was his view that sounds, any sounds, progress rapidly outward and diminish rapidly, but that, in effect, sound waves — those of falling water, spoken words, urban traffic, all sound waves — continue onwards, always diminishing but never ceasing to exist until the atmosphere itself ceased to exist.

Charles Babbage is best known for having tried to build a programmable mechanical computer in the 1840s. The Wikipedia article on Mr. Babbage describes him as "a mathematician, philosopher, inventor and mechanical engineer."

Regarding the planetary-scale effects of sound waves on "atoms of the atmosphere," he wrote:

A being possessed of unbounded knowledge of [the sciences of sound and acoustics], could trace even the minutest consequence of [any uttered word].

and

. . . he would distinctly foresee and might absolutely predict for any, even the remotest period of time, the circumstances and future history of every particle of that atmosphere.

I was probably in my teens when I had the idea that every little thing that happens in the world has an enduring effect on everything else in the world. Mr. Babbage is more specific, talking about "particles of air" interacting with each other over the whole planet within 20 hours — the effects being forever residual within the atmosphere.

Around that time I acquired the word "predestination," and I went around in the mode of thinking that every event in the world must be predestined. The word "predestination" might, however, have religious connotations relating to what God might know of the future, and somewhere I learned the term "determinism," which I'm pretty sure is a more proper label for my views when I was young. Had I at that time read Mr. Babbage's Chapter 9 on the permanent impressions of sound, he might well have become a life-long hero of mine, of the ilk of Ben Franklin and Richard Feynman.

Implicit in the 20 hours that Mr. Babbage cites as the interval over which the effect of each sound in the world comes to cover the entire earth is the speed of sound, or the speed of airborne acoustic signal propagation. The speed of light is another signal-propagation speed, one that Mr. Babbage doesn't mention, but plausibly he was aware of it; the speed of light in the 1830s was probably pretty close to the modern value; It seems likely that Mr. Babbage understood that the light of a lantern can reach the moon in less than a second, though he would have been challenged to tell how that light might interact with and thereby influence the moon. Regardless, he likely considered that every event "communicates" with every other event, everywhere, within an interval determined by signal propagation speed. These days we can in terms of photons from lanterns on earth interacting with electrons in lunar soil, and having an effect thereby.

Every atom, impressed with good and with ill, retains at once the motions which philosophers and sages have imparted to it. . . .

Implicit in Mr. Babbage's essay is that each spoken word of himself and, for that matter of Hitler, Buddha, Jesus, Ben Franklin and that young classmate you were attracted to in the fourth grade, is still present in each moment's speed and location of every single air molecule in the world and will continue so till the air no longer exists. Charles Babbage was one of those people who saw things in that way.

Such a view, that view, is called deterministic. It's strict cause and effect. It's plausible that educated and thoughtful people of the 18th and 19th centuries held to a deterministic view of events; determinism is, after all, the central element of Isaac Newton's three Laws of Motion, especially the Second Law, which is strictly determinstic: If a force does act on an object, than the object's change in motion - its acceleration - will always be proportional to the size of the force. By the time Charles Babbage, the Newton's Laws of Motion and their deterministic implications had pretty much seeped down to the masses of educated people — seeped in a way similar to how quantum mechanics is seeping into popular culture with increasing numbers of people learning about and thinking about the implications of quantum mechanics.

If the Second Law of Motion precisely describes what happens when forces act on objects, when photons interact with matter, if it effectively describes everything that is happening in the universe in this deterministic way, then what about free will? And how about God, which is spirit, and thus separate from the material world, how could God exert force upon the world? How did Isaac Newton, who was trained as part of the clergy, explain (if he had to or ever did) the actions of God in the world? And what might Charles Babbage had contemplated in relation of God and free will?

The Wikipedia article on the Ninth Bridgewater Treatise, which is another name for Babbage's book, "On the Power, Wisdom and Goodness of God," says that Babbage's view "can be described as a natural theology, in which God does not create the universe so much as set it going" — which is pretty much the "deism" attributed to the ilk of Jefferson, Franklin and presumably Babbage, a kind of gentleman's agreement by which a public person can assert a belief in God without arguing or implying that prayer can have any effect other than that of the placebo. As for Mr. Babbage's thoughts on free will, the last chapter of his book, Chapter 15, is entitled, "Reflections on Free Will," which is worth contemplating in all its 19th-century prose style.

The air itself is one vast library, on whose pages are for ever written all that man has ever said or woman whispered.

Bob

Global warming is the increase in the average temperature of Earth's near-surface air and oceans since the mid-20th century and its projected continuation -- Wikipedia.