perception is never a di­­rect window onto an objective reality

colors do not exist out there in the world

Colors are a clever trick that evolution has hit on to help the brain keep track of surfaces under changing lighting conditions.

The reality we experience—the way things seem—is not a direct reflection of what is actually out there.

It is a clever construction by the brain, for the brain.

Plato’s Allegory of the Cave

Kant’s term “nou­men­on” refers to a “thing in itself”—Ding an sich—an objective reality that will always be inaccessible to human perception.

the brain is a kind of prediction machine and that perception of the world—and of the self within it—is a process of brain-based predictions about the causes of sensory signals.

It forms these best guesses by combining prior expectations or “beliefs” about the world, together with incoming sensory data, in a way that takes into account how reliable the sensory signals are.

The differences between predicted and actual sensory signals give rise to so-called prediction errors, which are used by the brain to update its predictions, readying it for the next round of sensory inputs.

the brain implements approximate Bayesian in­­ference, and the resulting Bayesian best guess is what we perceive.

our perceptions come from the inside out just as much as, if not more than, from the outside in.

perception emerges as a process of active construction—a controlled hallucination, as it has come to be known.

normal perception is a controlled form of hallucination.

“primary” and “secondary” qualities. Primary qualities of an object, such as solidity and oc­­­cu­pan­cy of space, exist independently of a perceiver. Secondary qualities, in contrast, exist only in relation to a perceiver

All that has changed are your brain’s predictions about the causes of these sensory signals.

being hallucination-prone went along with perceptual priors having a stronger effect on perception.

is possible to have people experience an unreal environment as being fully real

A popular explanation for the differing perceptions of the garment holds that people who spend most of their waking hours in daylight see it as white and gold; night owls, who are mainly exposed to artificial light, see it as blue and black.

even if these differences start out small, they can become entrenched and reinforced as we proceed to harvest information differently, selecting sensory data that are best aligned with our individual emerging models of the world and then updating our perceptual models based on these biased data.

the experience of being a self is itself a perception

once we can appreciate the diversity of experienced realities scattered among the billions of perceiving brains on this planet, we will find new platforms on which to build a shared understanding and a better future

"Mi papá invitó a Rudy Kalman a dar una conferencia en Ames, y cuando lo hizo, papá tuvo una epifanía", explicó el joven Schmidt. Kalman había escrito un artículo sobre una solución teórica 'lineal' para estimar la ubicación y la velocidad de un vehículo.

"Mi padre luego desarrolló las ecuaciones para resolver este problema no lineal, una extensión importante del trabajo de Kalman"

las contribuciones de Stanley Schmidt convirtieron una teoría en algo esencial para el éxito de Apolo.

The Apollo primary guidance, navigation, and control system (PGNCS, pronounced pings) was a self-contained inertial guidance system that allowed Apollo spacecraft to carry out their missions

PGNCS was developed by the MIT Instrumentation Laboratory under the direction of Charles Stark Draper

PGNCS consisted of the following components: an inertial measurement unit (IMU) the Apollo Guidance Computer (AGC) resolvers to convert inertial platform angles to signals usable for servo control

The onboard guidance software used a Kalman filter to merge new data with past position measurements to produce an optimal position estimate for the spacecraft.

A brief biography of R.E. Kalman is presented

The most important facts concerned with the creation of the celebrated Kalman filter are briefly outlined

Se relata la secuencia de acontecimientos que llevaron a los investigadores del Centro de Investigación Ames al descubrimiento temprano del filtro de Kalman poco después de su introducción en la literatura.

Se describen los avances científicos y las reformulaciones que fueron necesarias para transformar el trabajo de Kalman en una herramienta útil para una aplicación aeroespacial específica.

Some tutorials, references, and research related to the Kalman filter.

Este artículo trata sobre el período previo al trabajo de Kalman, los descubrimientos clave en el desarrollo y la maduración del filtro, una muestra de sus muchas aplicaciones en la industria aeroespacial y el reconocimiento de algunos que desempeñaron un papel clave en esa historia.