Filipe Barroso > House of Ideas

Friday, March 26, 2010

The Red Harlequin

A friend of mine just brought me this story:

The room was completely wrapped up in darkness, except for a small portion of Mr. M’s working desk, over which a stain of moonlight lied quietly, like a spotlight coming from the moon itself and making its way into the room through the window. Mr. M found that rather odd, for he always leaves his chair between the desk and the window, so that the sunlight would not discolor his precious paintings and printings. His mind, as usual, wandered away and he started thinking about the problems of aging, such as memory loss, when suddenly a squeak brought him back from his thoughts. He turned his head to the left and saw his chair, near the cabinet, turning around and watched a dark figure rising from it.

‘Mr. M…?’, asked the figure. It was a dark, sexy woman’s voice, warm and harsh like burning ashes. Even though she was standing on the other side of the room, he could smell the lovely chords of her French perfume and hear the satin of her dress slowly rubbing her body as she would move.

‘Who wishes to know?’, replied Mr. M, confused by the situation. What was that lady doing in his office?

‘Names do not matter for this affair’, she said, and continued slowly ‘but, if you wish name my existence in your mind, you can use White Kitten to do so.’

He could feel a voluptuous smile blooming from her mouth as she spoke, and felt curious about that mysterious woman. However, for no reason, as he started to acknowledge her presence, he began to create a mental picture of her perfect silhouette.

‘White Kitten?’, he inquired.

‘Yes.’, she answered. As she walked towards him, the moonlight’s subtle shine began to reveal that feline physiognomy and appearance; short, wavy fair hair appearing from underneath a dark veil, which did not allowed any soul to see any part of her face. Despite the grim feeling one would get by this sight, her satin dress held the most heavenly shade of pearl ever seen.

‘Us, felines’, she proceeded, ‘don’t like our identities to be revealed. It’s a matter of… exclusivity. An exposed feline is a dead feline’

‘So you just came here to elucidate me about cat’s rules?’, mocked Mr. M ‘you could have simply sent me a letter, that would have spared you the effort of coming here!’

The pleasant halo which surrounded the feline suddenly vanished, giving place to a heavy, intense feeling of anger and indignation.

‘You want to cut to the chase? Fine. We know about the Red Harlequin.’

Mr. M, still stunned by the White Kitten’s sudden change of mood, felt his knees trembling and his throat collapsing. His pale complexion became even more translucent and, from his dark hair, thick drops of sweat began to weep.

‘The…the…the…Red Harlequin?’, stutter him, struggling to stay on his feet. Even though the White Kitten’s face remained hidden to his eyes, he could feel her sarcastic smile taking over her expression.

‘Yes, the Red Harlequin. You were the one who painted it, isn’t it so? Did you ever think for a mere second that we would not find out about it? You are not the smooth criminal your minions make you believe you are…’. She turned away from the window and the darkness which consumed that room swallowed her slim figure again. She then proceeded. ‘And don’t you dare to even dream that we are not aware of that painting’s purpose!’

Mr. M shivered one more time. His mind wandered away again, and his thoughts were filled with the consequences and traumas which his hunger for revolution had brought upon his spirit. That would be his final attempt, he had sworn, that would be his final silent cry. Harlequins, as many might not know, were his personal symbols of chaos, and that fateful painting reflected his inner rebellion, inherent to every artist who claims to be so. However, despite his stress and discomfort, he fought the guilt and remained undaunted.

‘It’s just a painting, White Kitten…an innocent painting. So, I like harlequins. Some people like razor blades, but I don’t see you bugging them.’

The feline eyes lit up and her voice became harsher.

‘Insolent maggot!’ She then lowered her tone. ‘You know the Boss does not care much for rebels and revolutionaries…’

And, hidden by the darkness of the room, the Kitten vengefully attacked Mr. M. The last thing that damned painter gazed at, in his miserable life, was reflection of the moonlight produced upon two ruthless fangs.
M. P

Saturday, January 02, 2010

Lambdoma

Pythagoras’s most important discovery was the system of arithmetical relationships that make intervals recognizable by humans.
The most simple ratios (2:1 , 3:2) are immediately recognizable by most human beings. Plato introduced the essence of Pythagora’s ratios into the Greek world and it eventually became standard in the entire civilization of Western thought.

Tuesday, December 29, 2009

This is the season!

Ha! Time for simple pleasures.
Play with Pixels:3d.
A walk on the ocean .

Monday, October 26, 2009

But how well does it heal?

Well then. For those who dig skepticism (itself a valuable attitude) we will do it very slightly.
We dont’t really need music for this one; perhaps just sound.
Ah, but what a sound we will be rewarded with. The technically minded, al least. There are a lot of ways of doing this of course; you may find a tone producing device (such as a synthesizer) handy.
For this kind of experience I woud rather use a pair of my trusty Hartley/Colpitts oscillators (once part of the tunning system of my [long defunct] Elka organ). Since their frequency can be tuned using a screw driver in the little bottle with the two mutual inductors (one of which is tapped), I will lower one of them until both tones are similar in frequency. Once the tones begin to match, you get a most curious feeling. The oscillators have a rich harmonic output; if you manage to capture the sawtooths, you wil notice a very pleasing, low sweep due to phase-canceling.
The beauty of this approcah is that the tones won’t sync, because they are not coupled (different boards). Also, a true sawtooth has a series on infinite harmonics; the interaction between the two waves is so different from what you get from bandwidth-limited digital emulations. I bet you will be tied to the latter, at best. (On the analogue side you may achieve a similar temporary result with a couple of NE566s - just study the data sheet).
Some people will argue you cannot hear the difference, so why bother with old tech stuff when you can do it with your laptop. Don’t believe them! Do the experience yourself. And no you cannot properly sample it because of nasty Nyquist artifacts, even with the best 96k system. Plug an oscilloscope in xy mode, if available, and compare the sound sweep with the varying image. You will understand what this is about instantly. Perhaps our timbre perception is not confined to spectrum, but reads waveshape as well. Ever heard of ‘chorus’ effect? A faible attempt to reproduce this phenomenon.
Now extend the concept and… happy relaxing!

Sunday, October 18, 2009

The speed of Vibrations

The Pythagoreans noticed that the speed of vibrations and the size of the body that produced the sound were musical factors arithmetically regulated.
An up-to-date modern example would be a bass guitar tuned to the lowest notes due to its size.
The sound was conceived to be generated by striking followed by a vibration in the air, which was then received by the ear and sent, in Plato’s words, “to the brain and the blood and transmitted to the soul”.
The underlying theory was that the frequency of vibration of a stretched string is inversely proportional to its length.
Although the Pythagoreans had no opportunity to accurately measure the frequency sound vibrations, their statement laid the foundation for an important branch of physics - the science of acoustics.
The study of harmony in terms of numbers raised a lot of resistance, as in those days musical perception was though to be a pure mater of taste.

Saturday, October 10, 2009

Music of The Spheres: Stability and Resonance

While investigating interval ratios in music - an interval is the space and the relationship between two notes- , Pythagoras used the lyre and the monochord.
The monochord was a one-stringed instrument which featured frets on the fingerboard at various lengths. When stopping the string at the halfway point, he produced an octave, or a ratio of 1:2. When dividing the string into several other lengths, intervals of the fourth and fifth were produced, and so on. Pythagoras and his followers thought of the universe as an enormous lyre, with each planet, vibrating at a certain pitch, in relationships similar to the stopping of the monochord’s string, harmonized with other heavenly bodies to create a “music of the spheres,” a concept which remained plausible for centuries. Even such strict science men as the late C. Sagan made references to this theory; it has an irresistible appeal that goes beyond music, science and even science fiction.
Although the theory was too simplistic, it serves to give us a picture which was later developed by philosophers and, in contemporary times, by scientists working with quantum relationships.

http://www.aquarianage.org/lore/holst.html

Monday, October 05, 2009

Modal Temperament

According to tradition, a young man who had been abandoned by his lover prepared to flame the house of both; Pythagoras noted the fact and found that the youngster was under the influence of a particular musical mode (scale).
He suggested that he change his tone and employ a melody based on a replacement scale.
Pythagoras was thus able to restore calm to the young. Whether the story is true or not, Pythagoras was one of the first musicians to recognize the therapeutic role of music. His work with the properties and relations of musical intervals convinced him that the human body would react in various ways to these relationships; for the Pythagoreans, both music and the soul would share a basis in number.

Sunday, September 06, 2009

The Art of Time

The Pythagoreans considered all mathematical sciences to be divided into four parts: one half they marked off as concerned with quantity, the other half with magnitude; and each of these they posited as twofold. A quantity can be considered in regard to its character by itself or in its relation to another quantity, magnitudes as either stationary or in motion. Arithmetic, then, studies quantities as such, music the relations between quantities, geometry magnitude at rest, spherics (astronomy) magnitude inherently moving.

Sunday, April 20, 2008

Water

From the Pixel3d Forum, 2001. 

It has been a while since I began trying to emulate water wave movement with 3d software. Short after I read a nice article by Jimy Arndt (“Undulations”, P.I.U.) I revisited Curtis’ online post (do not miss it) on the subject, I decided to put together some notes I have been taking now and then. After seeing a lot of effort by several developers, I remain unconvinced with the results [by the way, the best (ocean) wave representation I have seen was made with Tsunami for A.E.].
Realistic 3d ocean waves, whether done in mesh displacement or shader emulation, are heavy on the CPU. That is because only in some special cases they can be represented accurately by the sinusoidal function. I will try to point out the main concepts in a brief discussion.
Any regular, oscillating disturbance which spreads through a medium may be called a wave. In a transverse wave, the particles of the medium move to and from at right angles to the direction in which the wave is travelling. Ripples on a pond (I have seen good ones made with Pixels) are an example of transverse wave motion; the direction of propagation is horizontal, and a small particle floating on the surface moves up and down but is ultimately left in its original position after the passage of the wave. It is essentially the disturbance, which moves forwards, not the water (as long as the wave does not break, there is no wind and the friction with the ground is negligible).
In longitudinal waves, the particles of the propagating medium oscillate forwards and backwards in the direction of the wave motion, but here too their mean position does not change. Sound is an example of longitudinal compression wave. The particles of the medium compress and rarefact and these regions advance, not the medium.
The essential parameters of a wave are its wavelength (L), its amplitude (a) or wave height (H = 2a), and its period (T), which is the time interval between successive crests passing a fixed point.
The number of waves which pass a fixed point in unit time is the wave frequency (f) and is equal to 1/T.
The speed at which the wave is moving ( c ) is thus given by:

C=L/T.

Wave steepness is defined rather arbitrarily as H/L.
The passage of wave produces a displacement (ro). This is frequently considered as a function of distance (x) at a fixed time, or as a function of time (t) as a fixed distance. If the wave is assumed to have sinusoidal profile these are simply harmonic functions,

ro = a*sin [(2*pi*x)/L],

ro = a*sin [(2*pi*t)/T].

However, if you are in charge of a boat in a middle of high waves, even in a river, you will better know that the front part of your boat must face the wind, because waves wont’t behave according to sinusoidal. Even if they all propagate in the same direction, which is highly rare, they will tend to have logarithmic attack and exponential decay. Furthermore, they will break and form spirals.
Other rather interesting alternate profiles describe steep waves as trochoidal functions. A trochoidal curve is the path traced by a point on a circular disc as the disc rolls along a straight line. If you ask a child to draw an ocean wave, it is higlhy probable that he/she will draw either triangular or trochoidal-like waves. (Children tend to draw what they see, before they are misguided by narrow-minded teachers).

It can be shown that the speed c of an individual sinusoidal gravity wave
c = sqroot [(g*L/2*pi) * tanh (2*pi*d/L)]

where d is the depth of water. But I digress. The point is ripples, wavelets, waves with or without foam crests and spray are mainly cause by wind and/or tidal movement. The actual mechanism by which waves are generated is still poorly understood. Empirical studies show that when wind blows at constant speed, it generates a wave field which stems from the superimposition of a wide variety of simple wave trains with different directions, periods and lenghts.

Friday, February 15, 2008

Schnecken

Snails have obvious limitations but watching ( in situ ) a swimming Aplysia is such a wonderful experience.

http://www.youtube.com/watch?v=Jlbu7BjFK6s&NR=1

Snails move by rhythmic contractions of the muscular foot.
Glands in the foot secrete a layer of mucus on which they slide.
Slugs do not have shells but are protected by a layer of mucus instead, so they must live in moist places.
Their tegument (skin-like) bas relief together with the mucus reflective and refractive properties are impossible to emulate in 3d, right?
Well someone has consitently proven it is not so.