A Treatise on the Physics and Psychology of Heavy Metal Music

Though the metal fan-base is largely young, white, male, and blue-collar, and that it has been often associated with "brutally aggressive music played mostly for minds clouded by drugs", I must confess that I am a devout heavy metal music fan and a typical headbanger. However, I seem to take as much interest in other genres of music as well, including classical Indian music, old Bengali songs as well.

But let me clear things a bit first. I am not a white, no longer in my youth, not a blue-collar and not a drug user. Yet the music just fills me with adrenaline rush, I feel energized and above all, the melodies just mesmerize me!

Perhaps you may argue that metal song lovers may have a 'low self esteem', as this study might suggest; but I have evidence to the contrary too! You certainly can't dismiss these young physicists doing their research in the 'high energy' domain of the giga-electron-volts at the LHC labs in CERN, Geneva, as mere dolts!  Here is a 'sonification' of some of their mathematical findings into music as they delve deep into the Heisenberg's Uncertainty of finding the 'God particle', the revered Higgs' Boson! They, kind of, selected their data from a chosen hexadecimal set and then converted them into the more familiar octave formats, compressed them and mixed them with some bass/drums to make the more metal friendly. The 4-lepton part of this song could even strike a chord between the pro-Christ and the anti-Christ theme of heavy metal in some dark corner of your psyche, as they reach toward a low entropy, in a very similar way matter and antimatter behave. [Sonification in the context of science isn't a new kid on the block. Proteins (amino acid sequences) have already been heard and listened].

Well, you guessed it right. I find a lot of physics and maths in it. Whereas most of you would disagree on the issue that hard rock had anything to do with any melody of any sort and would label it as high decibel noise, a very organized pattern of music can be discerned if one just judged it from a neutral and impartial standpoint. However, to be really be able to get into the heart of it, one ought to have a high musical processing power in 'real time', akin to having a faster CPU (Central Processing Unit) in computer jargon. What (musical tone) gets interpreted as a square wave to one's auditory cortex (or along the tonotopic pathway/basilar membrane), may actually turn out to be a composite of various other frequencies (their harmonics). This can be decoded in mathematical terms by the Fourier Transform. Thus what seems to you as a guitar belching out a harrowing 'noise' may actually be two or three guitars which differ slightly in phase, frequency or tune on careful scrutiny. It could be that I follow the music so well because I don't pay much attention to the lyrics or that English is not my first language that I can drift myself to the luxury and intricacy of the wafting melodies. Anyway, I must mention that some lyrics such as Iron Maiden's are so hard to overlook for they are so rich in Philosophy! Psychedelic drugs may enhance in understanding and following these artistic intricacies by inhibiting the dominant left hemisphere and thereby allowing the art-interpreting right half of the brain to be in charge.

Then the length tension relationship the guitar string has to follow a particular frequency (tune) is governed by physics as well. It's amazing how the performers manage to pluck the chords at exactly the same place and with the same displacement on the time scale so reproducibly well. Moreover, the two guitarists play the tune in unison ! Maybe the drummer gives some kind of 'global clock source' for synchronization or perhaps 'mirror neurons' might play a role. Well I don't care, who does?

Another aspect that baffles me is that how the 'disorganized' crowd synchronize themselves into the organized dancing movements at live concerts [see video:Lamb of God-Walk with me in hell; warning: explicit lyrics]. This might throw some light on herd behavior as well. This pattern of dancing is quite different from the "Mexican wave" that is observed especially in Football matches [see video]. In the latter case, the crowd performs the act consciously with inputs supposedly coming from the cerebral cortex, and the crowd is well organized. This behavior is also seen in honey bees as a means of communication, in their own language. And language of any kind is considered a higher function. In contrast, in the former case, the activity is more likely be originating from a lower CNS area, such as the locomotor pattern generator at the spinal cord level, (with assisted inputs from a higher region in the brain, perhaps) which appears more like a 'reflex' phenomenon than a well coordinated effort.

Then the faint and whispered insinuations seems to imprint a 'suggestion' in our psyche [see video, and watch out for the words "it's only getting worse": Lamb of God]. After all, music is about perception per se and not the mere analysis of mechanical vibrations. There are also cases of suicides arising out of the 'subliminal messages' contained within the lyrics, although they remain yet to be confirmed.

                                     Lamb of God 512 on Jimmy Kimmel live & Moshers                                                                                

Now, in a recent development, two doctoral students from Cornell University [don't miss the videos and the simulations in this website!] have found some deep similarities between crowd movement in mosh pits, which to them looked so fundamentally similar to randomly moving gas molecules bumping into each other. The moshers run, bash and bump into each other in a chaotic way. Schools of fish and flocks of birds show this type of behavior too. Needless to say, I am in full agreement with their research. Bear in mind, moshpits can be deadly and you might end up with a black eye!

Some interesting questions keep popping up. Why is the representation from black people into this genre of music so poor, despite many of them staying in the US or UK for generations? I hope you won't marginalize me alongside James Watson or Shockely, if I were to suggest that a genetic cause was more likely than an epigenetic one, because I feel that the latter would wear out with passage of time. A notable exception to this is the great vocalist Howard Jones of Killswitch Engage, who is black. Some women are also in the metal arena as well, including Lena of "Infected rain" and Leaves' Eyes' Liv Kristine, encroaching on this so called "masculine" bastion.

Some noteworthy words that convey their meaning in the way/effect they are pronounced, need mentioning. Judas Priest's "But there's always someone trying to put it down" gives you the 'Doppler'y feeling of 'down', Similarly, Dio's "You can be invisible" hammers deep inside your psychology to emphasize this invisiblity, Some music videos like this one by Metallica, which portrays a wonderfully inspired sci-fi theme is well worth watching too [Video:Metallica All Nightmare Long]. Heavy metal would be nowhere without the advancement in electronics technology and the guitar riffs.

That metal mania has carved its niche in the general populace can be exemplified by the ghastly terrorist attack in the Bataclan concert hall in Paris.

We can only pray "Heal the world, make it a better place, for you and for me and the entire human race." as Michael Jackson said.

Jesse L. Silverberg, Matthew Bierbaum, James P. Sethna, & Itai Cohen (2013). Collective Motion of Moshers at Heavy Metal Concerts 10.1103/PhysRevLett.110.228701 arXiv: 1302.1886v1



Last modified: June 30, 2018
Reference: hyper-links, unless specifically mentioned

Fourier Analysis: The Art and Science of Finding The Needle in a Haystack

Every time I listen to the heavy metal band Pantera my wife would invariably wonder aloud why I listen to all this ‘noise’. True, many music lovers would rather refer bands like Pantera as quintessential noise than music; there are persons like me who can dissect the melody from the apparent chaos of runaway frequencies of guitars, drums and so on. I can even analyze and follow individual instruments over time. This is what Fourier is about, or stated otherwise, my ear & brain can be said to be doing a Fourier transform on the said musical piece.

Joseph Fourier, a French mathematician, realized that all periodic waves could be ‘synthesized’ by mixing sine waves of right frequency, amplitude and phase. For example, a square wave could be prepared by ‘adding’ the fundamental frequency (the lowest frequency; say 70Hz) with an infinite number of its odd harmonics (e.g. 210Hz, 350Hz, 490Hz and so on. Harmonics are multiples of the fundamental frequency.) This is Fourier synthesis. Similarly, you could break down a periodic signal in which the amplitude varies over time into one of a frequency versus time graph. This is Fourier analysis, and it can be seen that here we are actually ‘decomposing’ the ‘signal’ into its frequency spectrum, over time. The process of decomposing a function into its constituent frequencies is known as Fourier transform. You can have a ‘hands on experience’ at what a square wave ‘looks’ or ‘sounds’ like and how a periodic wave is decomposed into its constituent parts here. Do experiment on the sine, cosine, triangle wave and square wave functions as well and turn on the sound of your PC while you are at this site!

While Fourier originally devised this to solve the problem of heat propagation, the impact of Fourier analysis can now be felt in almost every field of science, instrumentation, entertainment and telecommunications, and even arts. Whenever you use your audio graphic equalizer to suit a piece of musical performance to your taste, you are doing a Fourier. Here you are boosting some particular audio frequencies while suppressing others, obtained by a Fourier analysis of the audio signal. You are assigning relative weights to the frequencies by sliding those sliders. Likewise, when you compress a picture (graphic) file using software such as JPEG, an inbuilt program does a Fourier transform,--> eliminates the weaker components from the analysis and--> then saves the information in a compact way.

In Nuclear Magnetic Resonance Imaging (NMRI), the emitted radio frequency is Fourier transformed to give frequency versus time, throwing valuable information about nuclear spins. Fourier analysis may also be employed to remove mains AC hum frequencies, in mobile telephony and many other situations.

One day, we may expect, that Fourier analysis may be used to pick up the ‘right frequency’ in the brain EEG waves and may put the study of ‘mirror neuron’ and ‘thought controlled devices’ into a whole new domain.

Last modified: May15, 2013
Reference: Fourier analysis (Wikipedia),
Explained: The Discrete Fourier Transform

Of Twinkling Nanostars and the Possible Application of Stroboscopes in Biological Imaging

Imagine a strong crowd, as you see in a Manchester United versus Liverpool football match and you wished to concentrate on a particular person. How would you do it? Make him wear a fluorescent shirt and dye his hair (don’t do it in the middle of the crowd, I can’t guarantee your safety).

Purdue University researchers have been successful in focusing at the cell of interest among a background of equally noisy and boisterous biomolecules and other metabolically active cells. Currently, researchers use immunological techniques to create an antibody to a molecule and then visualize the ‘molecule of interest’ by tagging the antibody to a radioisotope or a fluorescent dye; and flow cytometry can sort out different types of cells.

The Purdue University team used gold coated nanoparticles with an iron oxide core that was impregnated in the cell they wished to see. They then subjected the specimen to a periodically changing magnetic field. The superparamagnetic cores (superparamagnetic nanoparticles have no net magnetization, but an external magnetic field can magnetize them) responded by rotating as the magnetic field rotated around them. The rotation could be seen in the ‘near infra-red’ light spectrum, as the incident light bounced off (scattered) the specially designed arms of the gold nanostar as it revolved. The rate (rpm) of this gyromagnetic (gyros means to rotate) twinkling could be externally controlled by varying the rate of the externally applied field. You now could identify the cell by its characteristic ‘twinkling’ (lighthouse type) effect.

I am tempted to go beyond what’s been achieved so far. Here I go. I guess you are all familiar what happens to the rotating ceiling fan blades when you turn on a fluorescent lamp. Don’t you see a momentary snapshot of the three blades (some have 4)? That’s what where stroboscope comes in. It consists of a Xenon lamp (ordinary fluorescent lamps could do, but incandescent lamps won’t work as the glowing filament takes time to extinguish) flashing at a controllable rate. The electronic circuitry may be had here.

Suppose that the fan is revolving at 1200 RPM and it is not changing. Set your stroboscope to flash at this rate. You’ll ‘see’ that the fan blades are absolutely not moving, which is certainly not true! But be there any mechanical defect in the fan, it will stand out as the centrifugal force widens it (provided that the fault is more or less tangential to the axis of rotation). Here also we are looking at our object of interest, aren’t we?

Now lets look what implication it might have in biological imaging. We now know that the gamma subunit of mitochondrial F type ATP Synthase ‘actually’ rotates when it is synthesizing ATP (reverse rotation occurs when ATP is hydrolyzed). There are other locomotive units within the cell as well. They comprise of actin and myosin based molecular motors. Could we study them using an externally adjustable stroboscope? The optical (electromagnetic) signals so obtained may then be similarly broken down into simpler trigonometric (sine and cosine) functions by Fourier analysis (Fourier transform) as was done in the ‘twinkling nanostars’ experiment. At least, we expect to get rid of some 'noise' and some good still photos. But if we wanted better resolution and used higher frequency (electromagnetic) for it, some extraneous error will be introduced. It's a trade-off!

Last modified: never
Reference: hyper-links, unless specifically mentioned
Principles of Biochemistry, Lehninger, 4th ed
http://en.wikipedia.org/wiki/ATP_synthase
Wei, Q., Song, H., Leonov, A., Hale, J., Oh, D., Ong, Q., Ritchie, K., & Wei, A. (2009). Gyromagnetic Imaging: Dynamic Optical Contrast Using Gold Nanostars with Magnetic Cores Journal of the American Chemical Society, 131 (28), 9728-9734 DOI: 10.1021/ja901562j