Scientists often use the analogy of quantum strings as being like instrument strings, under tension and vibrating through dimensions. But they never talk about the quantum strings themselves making a sound. This always seemed peculiar. If strings were isolated from the vacuum would they make a noise and could that noise be detected by us? What would such noises tell us? Strings give rise to photons with which we use to see and also to phonons from which we can use to hear and make sound. It would seem reasonable that if a string was isolated in some ideal environment and through experiment, one would be able to hear the string as it vibrated.
Vibrating strings create our elementary world, whether perceived as a force or as thermal or electromagnetic or gravimetric particles. The emergent sound from quantum strings into classical particles can be picked up by radio-telescopes and analysed for their identification and to give their origin. Hence we have the static-sound of the Cosmic Background Microwave radiation left over from the Big Bang and even the sound of the universe itself.
When particles collide in the cavernous tubes of the Large Hadron Collider would they conceivably clash in a crescendo of noise along with the light and energy they emit? Is there an inherent sound quality that emerges from strings into the classical world? Would strings hum, or crackle, pop, whine, drone, or hiss? Would a string be a pure solitary tone or a combined note assemblage? Would the pitch be high, low, or off our human-held scales? Would the frequency be long or short bursts or something completely random? Could string sounds be super partners of ‘normal’ classical sounds we humans hear? Perhaps, as with trying to physically detect strings, their sound would be far and away beyond our detection range. Noisy strings could reveal the rhythm of universe, the heartbeat of a dimension; quantum sounds in the cosmic darkness.
So, why is string noise important? Why can’t we hear them, if indeed they do squeak? What kind of frequencies would they emit at? And could string noise be formulated and used in equations? If physicists think about such things, here are a few proposed answers.
Why would string noise be important?
Each particle, dimension, universe might have its own vibrational frequency; hence its own sound and identification. Photons are strings that bring forth light and phonons (a quantum of vibrational energy in the acoustic vibrations of a crystal lattice) are strings that herald sound. Strings can be open or closed (the former represented by the weak nuclear, strong nuclear, and electromagnetic forces; the latter making up the proposed graviton). Knowing which sound characterised which string-type particle may preclude scientists from having to see the string, when they could just listen to it.
Why can’t we hear strings?
One theory could be related to the Heisenberg Uncertainty Principle in that even if we could see the strings we could not hear them due to the uncertainty of their probability in location or velocity. In trying to listen to the string we would alter the ability to detect it because of the act of interference of the measurement. As with pinpointing the position and momentum of atoms, or its direction of spin, we could do only one with certainty and thus with sound we could only measure certain aspects of it, an echo of it so to speak, if at all.
What kind of frequencies would strings emit at?
Strings may be transmitting sound through higher dimensions. Different strings may emit different sounds. Each higher dimensional and particle may have its own unique sound. We cannot see strings, but suppose we could hear them and use the sound to interpret the type of other universes or particles out there. In an analogy, suppose you were walking past a zoo with a large wall separating you from the menagerie on the other side. You could not see the animals, but on walking past you could hear trumpeting, roaring and tweeting. You would then interpret the sounds as elephants, lions, and birds. Further, you could theorise the type and size of those animals’ environments and maybe predict their behaviour. With strings, if they had sound and cosmologists could hear them, perhaps they could interpret the environment around the string and its properties.
How could string noise be formulated?
A whole new quantum mechanical discipline could take shape. Perhaps Quantum Audiodynamics (QAD) would be its designation. As sound can be musical and music ‘translated’ into mathematical formula, the underlying quantum structure of the universe may be more related to sound than we thought. What would a formula in Quantum Audiodynamics look like? Would such formulae be interconnected to current mathematical formulae? Are there mathematical formulae which describe the noise of strings? Such an emergent set of mathematical formulae could aid in the hunt for a Theory of Everything. Surely sound, as with light, energy, and mass would help fill out the fabric of the universe.
So, are strings noisy? We do not know. But it would be important to think that they are. String Theorists have come a long way by thinking out of the box. And in the cosmic symphony of theories and particles, string sounds could be another element of the Theory of Everything that strikes the right note.