Quotes About Observation

One purpose of these notebooks was to record interesting scenes, especially those involving people and emotions. "As you go about town," he wrote in one of them, "constantly observe, note, and consider the circumstances and behavior of men as they talk and quarrel, or laugh, or come to blows."1 For that purpose, he kept a small notebook hanging from his belt. According to the poet Giovanni Battista Giraldi, whose father knew Leonardo:

If you stand far enough away from a picture, even a large one, the problem of the edges being at a different distance from you diminishes. Leonardo determined that a proper vantage point for a large picture should be ten to twenty times its width or height. "Stand back until your eye is at least twenty times as far off as the greatest height and width of your work

His eyes are looking far away. He is part of the scene but detached from it, an observer and commentator who is immersed but marginalized. He is, like Leonardo, of this world but apart from it.

The front of the white lectern has a slight blue tinge, since it is lit mainly by the refracted light of the sky rather than the yellowish direct glow of the setting sun.59 "Shadows will vary," Leonardo explained in his notebooks. "The side of an object that receives a reflected light from the azure of the air will be tinged with that hue, and this is particularly observable in white objects. That side that receives the light from the sun will partake of that color.

In other words, there is no single underlying reality that is independent of our observations. "It is wrong to think that the task of physics is to find out how nature is," Bohr declared. "Physics concerns what we can say about nature."62 This

look carefully and separately at each detail. He compared it to looking at the page of a book, which is meaningless when taken in as a whole and instead needs to be looked at word by word. Deep observation must be done in steps: "If you wish to have a sound knowledge of the forms of objects, begin with the details of them, and do not go on to the second step until you have the first well fixed in memory."23

It should not be hard for you to look at stains on walls, or the ashes of a fire, or the clouds, or mud, and if you consider them well you will find marvelous new ideas, because the mind is stimulated to new inventions by obscure things.9

In collecting such a medley of ideas, Leonardo was following a practice that had become popular in Renaissance Italy of keeping a commonplace and sketch book, known as a zibaldone. But in their content, Leonardo's were like nothing the world had ever, or has ever, seen. His notebooks have been rightly called "the most astonishing testament to the powers of human observation and imagination ever set down on paper."3

His notebooks have been rightly called "the most astonishing testament to the powers of human observation and imagination ever set down on paper.

Skill without imagination is barren. Leonardo knew how to marry observation and imagination, which made him history's consummate innovator.

Leonardo was experimenting with the trick known as anamorphosis, in which some elements of a work may look distorted when viewed straight on but appear accurate when viewed from another angle. Leonardo occasionally made sketches of the technique in his notebooks.

All of the other muscles he studied acted by pulling rather than pushing a body part, but the tongue seemed to be an exception. This was true in humans and in other animals. The most notable example is the tongue of the woodpecker. Nobody had drawn or fully written about it before, but Leonardo with his acute ability to observe objects in motion knew that there was something to be learned from it.

Leonardo was not content merely to measure every aspect of every body part. In addition, he felt compelled to record what occurs when each of these parts moves.

Every part will be drawn, using all means of demonstrations, from three different points of view; for when you have seen a limb from the front, with any muscles, sinews, or veins which take their rise from the opposite side, the same limb will be shown to you in a side view or from behind, exactly as if you had that same limb in your hand and were turning it from side to side until you had acquired a full comprehension of all you wished to know.

I studied the relationship of their motions to their emotions. When I saw the hint of a smile come across someone's lips, I tried to fathom her inner mysteries.

His curiosity was aided by the sharpness of his eye, which focused on things that the rest of us glance over.

Oddest of all, there is this entry: "Go every Saturday to the hot bath where you will see naked men."10 We can imagine Leonardo wanting to do

Algunas teorías científicas dependen primordialmente de la inducción, es decir, de analizar un montón de hallazgos experimentales y luego encontrar teorías que expliquen las pautas empíricas.

Electrical fluid is attracted by points. We do not know whether this property is in lightning. But since they agree in all particulars wherein we can already compare them, is it not probable they agree likewise in this?" To which he added a momentous rallying cry: "Let the experiment be made.

Todo conocimiento de la realidad parte de la experiencia y acaba en ella.

Two events which, viewed from a system of coordinates, are simultaneous, can no longer be looked upon as simultaneous events when envisaged from a system which is in motion relative to that system.

En su madurez, Einstein creía más firmemente que había una realidad «objetiva» que existía con independencia de que nosotros pudiésemos observarla o no. La creencia en un mundo externo independiente de la persona que lo observaba —diría repetidamente— era la base de toda ciencia.

There's a time to wink as well as to see 

For time to pass it would have to go somewhere, and where would that be? Time sits. We move, it sits. Sometimes it trembles slightly, but that's all.