The major contributions to science that Galileo brought to the world are well known. But putting these discoveries in the musical context could turn out to be more relevant that one would think.

The origin of Western science is linked to the study of harmony. As it was understood, Harmonia comes to be in all respect out of contraries; for Harmonia is the unity of multiplicity, and the agreement of things that disagree (the fitting together of extremes).

The Pythagorean school of philosophy sought to integrate scientific inquiry into the nature of Number and a mythical awareness of the musicality of universal law. In particular, the harmonic series consisted of whole numbers: 2/1, 3/2, 4/3, 5/4…and so on.

The instrument that was used to investigate numbers was the monochord (see my previous blog post on the subject), which is used to measure the relationship or ratios between harmonics of a root note (the fundamental).

In fact, some historians of science contend that the division of the monochord strings is possibly one of the earliest scientific-empirical experiments ever to be carried out with mathematical rigor.

Throughout the whole of history, right up to the eighteenth century, the monochord was associated with cosmic concerns…the stretched string stood for the universe, with the various harmonics representing the planets in the solar system. Music, mathematics, and astronomy were inexorably linked in the monochord. The universe was thought to obey musical laws; therefore, the study of the monochord yielded information considered relevant to the other sciences, the humanities, and religion. Keeping with this harmonic-based cosmology, Kepler discovered a numerical relationship, his third law of planetary motion where the major semi-axis of the orbits of planets and their periods are proportionately related. He called it the “Harmonic Law”, and like all the philosophers of the time, he studied the ancient world of Pythagorus and Plato (Kepler also attempted to fit all the orbits of the 6 planets in nested Platonic solids).

Ancient cultures, before the invention of the printing press and the proliferation of books, were far more sonically oriented than visually focussed. That made them more receptive of the subtleties of the nature of pure tones.

Galileo was born into a musical family, and his father Vincenzio, beside being an excellent lutenist, was also a music theorist, and was investigating tuning. There was at the time a controversy about which form of tuning was best: on one side was the ‘natural’ tuning based on the harmonics of the monochord, and on the other side a more “tempered” tuning, which sounded more pleasing to the ears, in particular the major third- which sounded a bit harsh in the ’natural’ tuning. Also, the pure tuning limited the number of keys the instruments could play in. Galileo, who also played the lute, helped his father in his research. This research involved weighted strings which were set up similar to monochords.

There are several examples of how Galileo would have used music in his research:

In order to keep time while conducting his studies of the motion of bodies and their rate of fall, he used a ball rolling on an incline, by spacing frets at increasing distances from one another in order to hear a steady beat. If the frets were spaced evenly the ball would hit them at an increasing rate. At the time there was no clock precise enough to measure this. The obvious solution was music. Sing a song and the beat will be steady. This was first suggested in 1973 by Stillman Drake, a leading Galileo expert. 

After Galileo discovered the moons of Jupiter, he spent a long time figuring out their periods, in an unsuccessful attempt to use their orbits as a clock to help navigators establish their position at sea, since the first three moons- Io, Europa and Ganymede, were locked in a harmonic ratio of 4:2:1 at one octave from each other.

I think it makes sense to mention that during the experiment at the Tower of Pisa (if it ever happened), the sound of the two objects hitting the hard surface of the ground would have been much more accurately measured by the sound made than by looking at them. The rate at which our ears can distinguish singular events from one another is four times more precise as the one our eyes can.

So thinking about Galileo and the work he did assisting his father with tuning, I am sure his inquisitive mind must have stretched the boundaries of these investigations, and I dare to come up with the following insight:

Coming back to the experiment at the Tower of Pisa, I started to wonder if there was not some connection with the “weighted string experiment” which is how some monochords are set up: by hanging weights at the end of strings. And trying to understand what would be the common phenomena of the falling object and the production of the tones on the strings put into tension by the weights. It dawned on me that there could be a direct connection:

• the weight (let us say they are stones), initially are at rest, and have potential energy, each linked to their mass
• this energy is unlocked when put in motion, either when released from the top of the tower or from being hung from the strings they are attached to. None of the phenomenon in these configurations – the falling of the stones or the tones emitted by the strings in tension from the weights – are possible without gravity.
• as the weight of the stones’ sizes differ, the tension on the string varies.
• in order to reveal their tension, we have to pluck them, which gives them energy (the same goes for the stones- we have to nudge them over the tower’s edge to use gravity to put them in motion)
• as it is apparent in the stones’ varying sizes, each string produces a tone that is proportional to the size (in that case inversely proportional, the smaller stone giving the lowest tone) of the stone
• the energy given to the string manifested in its tension is equivalent to the energy produced by the gravity acting on the stone, both directly related to their potential.
• you could assume that if you pluck two strings together, they should not reach our ears at the same time, as the lower frequency (being of a lower energy tied to the lighter stone) would take longer to travel in the air than the one with the higher frequency (tied to the heavier stone) as you would assume that the lighter weight would fall at a slower rate. But they don’t, they reach our ears at the exact same time (we never question this because it is so obvious). 
• but both phenomena, the plucking and the falling, are merely a translation (or to use a musical term, a transposition) of the same initial fact: the size of the stones, and both are a form of motion. The only difference is that one (the sound waves) do not have friction (actually traveling through the medium of the air). So if we remove the friction on the stones, you should end up with the same result and they would hit the ground at the same time, as demonstrated by cosmonaut David Scott of Apollo XV on the Moon – as the different notes reach our ears at the same time.

So it could have been that this correlation was revealed to Galileo during the experimentations he performed with his father, and the root of these physics could very well be music. it seems to me that we have the same initial state give rise to a similar effect, demonstrated by two phenomena, connected through the bridge of the Monochord acting as a phase transition acting on the energy of the stone. 

The various stones fall at the same rate and the various sound waves travel at the same rate.

Of course these are conjectures; it might not be the way his train of thought worked out. But I think there is a chance, and it is an interesting proposition, and it shows that the Law of moving bodies can be deduced with this old instrument, the monochord.

To close, it is interesting to know that in the past ten years the relationship between science and music has been revived and has revealed to us elements in our data set that would not be so easy to discern if the information was offered to us visually only. There are many examples – from exoplanet systems, asteroseismology, gravity waves, and so on. (View my previous posts)

When you listen to the music of Galileo’s time, it is important to try to imagine what was the acoustic environment in which it was conceived and performed. It clearly illustrates the unique position he held in the history of human knowledge with one foot in the ancient world and the other in the modern world. He was, to use a trendy word, an inflection point not possible without the past but enabling the future.