Search This Blog

Monday, 20 September 2021

Buddhism: a brief history.

 Buddhism (/ˈbʊdɪzəm/, US/ˈbd-/)[1][2] is an Indian religion based on a series of original teachings attributed to Gautama Buddha. It originated in ancient India as a Sramana tradition sometime between the 6th and 4th centuries BCE, spreading through much of Asia. It is the world's fourth-largest religion[3][4] with over 520 million followers, or over 7% of the global population, known as Buddhists.[5][6] Buddhism encompasses a variety of traditions, beliefs and spiritual practices largely based on the Buddha's teachings (born Siddhārtha Gautama in the 5th or 4th century BCE) and resulting interpreted philosophies.

As expressed in the Buddha's Four Noble Truths, the goal of Buddhism is to overcome suffering (duḥkha) caused by desire and ignorance of reality's true nature, including impermanence (anicca) and the non-existence of the self (anattā).[7] Most Buddhist traditions emphasize transcending the individual self through the attainment of Nirvana or by following the path of Buddhahood, ending the cycle of death and rebirth.[8][9][10] Buddhist schools vary in their interpretation of the path to liberation, the relative importance and canonicity assigned to the various Buddhist texts, and their specific teachings and practices.[11][12] Widely observed practices include meditation, observance of moral preceptsmonasticism, taking refuge in the Buddha, the Dharma and the Sangha, and the cultivation of the Paramitas (perfections, or virtues).

Two major extant branches of Buddhism are generally recognized by scholars: Theravāda (Pali: "The School of the Elders") and Mahāyāna (Sanskrit: "The Great Vehicle"). Theravada has a widespread following in Sri Lanka and Southeast Asia such as CambodiaLaosMyanmar and Thailand. Mahayana, which includes the traditions of ZenPure LandNichiren BuddhismTiantai Buddhism (Tendai), and Shingon, is practiced prominently in NepalMalaysiaBhutanChinaJapanKoreaVietnam, and TaiwanVajrayana, a body of teachings attributed to Indian adepts, may be viewed as a separate branch or as an aspect of Mahayana Buddhism.[13] Tibetan Buddhism, which preserves the Vajrayana teachings of eighth-century India, is practised in the countries of the Himalayan regionMongolia,[14] and Kalmykia.[15] Historically, until the early 2nd millennium, Buddhism was also widely practised in Afghanistan and Pakistan; it also had a foothold to some extent in other places including the Philippines, the Maldives, and Uzbekistan.

In defence of the argument from anology re:design.

  Basically the argument is based on our universal experience accross our entire history re:the source of sophisticated engineering (for that matter even unsophisticated engineering).Its presupposition is simply that an item would require at least as much expertise to engineer as to reverse engineer,this conclusion is based on our observations ,without exception, accross our entire history. Now, engineering expertise is not something that grows on trees but is always the product of a mind of some kind,whether subhuman,human (superhuman?). Some though, are uncomfortable with the idea of the existence of superhuman intelligences (for them man must remain at the top of the food chain) and have arbitrarily ruled that science cannot be allowed enquire into the possible existence of such,thus they seek to find fault with the argument from analogy claiming e.g that living things and the ecosystems that support them are too dissimilar from any device or structure engineered by humans to be regarded as truly analogous. Of course items compared in analogies are almost never totally similar. They merely need to have in common that quality about which one is attempting to make ones point. And then not necessarily to a comparable degree,the point design advocates are seeking to highlight would be ease ,or lack thereof,of reverse engineering. 

Manmade structures and devices are not so dissimilar from living things, that no comparison can be made re:ease of reverse engineering,indeed the very differences that opponents of the argument from analogy tend to highlight such as growth , reproduction,capacity for self repair etc.seem to be making design advocates' point. Imagine if you will, the kinds of accolades that would be heaped upon the technologist who invented a device that can even crudely mimic such qualities.

The French revolution: a brief history.

 The French Revolution was a period of radical political and societal change in France that began with the Estates General of 1789 and ended with the formation of the French Consulate in November 1799. Many of its ideas are considered fundamental principles of liberal democracy, while phrases like Liberté, égalité, fraternité reappeared in other revolts, such as the 1917 Russian Revolution, and inspired campaigns for the abolition of slavery and universal suffrage. Its values and the institutions it created dominate French politics to this day.


The causes are generally agreed to be a combination of social, political and economic factors, which the existing regime proved unable to manage. In May 1789, widespread social distress led to the convocation of the Estates-General, which was converted into a National Assembly in June. The Assembly passed a series of radical measures, including the abolition of feudalism, state control of the Catholic Church and extending the right to vote.

The next three years were dominated by the struggle for political control, exacerbated by economic depression and social unrest. External powers like AustriaBritain and Prussia viewed the Revolution as a threat, leading to the outbreak of the French Revolutionary Wars in April 1792. Disillusionment with Louis XVI led to the establishment of the First French Republic on 22 September 1792, followed by his execution in January 1793. In June, an uprising in Paris replaced the Girondins who dominated the National Assembly with the Committee of Public Safety, headed by Maximilien Robespierre.

This sparked the Reign of Terror, an attempt to eradicate alleged "counter-revolutionaries"; by the time it ended in July 1794, over 16,600 had been executed in Paris and the provinces. As well as external enemies, the Republic faced a series of internal Royalist and Jacobin revolts; in order to deal with these, the French Directory took power in November 1795. Despite a series of military victories, the war caused economic stagnation and political divisions; in November 1799, the Directory was replaced by the Consulate, which is generally seen as the end of the Revolutionary period.

Thursday, 16 September 2021

Darwinism; a whisker away from deconstruction?

 

Rats! Another Code Found in Whiskers

Evolution News DiscoveryCSC

Saying “Rats!” does not represent what design advocates are thinking. It represents a plausible reaction of evolutionists at accumulating evidence of complex specified information — codes — throughout biology. Here is another stunning example.

Nicholas Bush, Sara Solla and Mitra Hartmann, writing in PNASpublished results of experiments on the information that rats and other animals receive from their whiskers. The title indicates the information is in code: “Continuous, multidimensional coding of 3D complex tactile stimuli by primary sensory neurons of the vibrissal system.”

An animal’s primary sensory neurons (PSNs) translate information about the environment into neural signals that allow perception and action. While much is known about visual and auditory PSN responses to complex stimuli, somatosensory neurons have been characterized with simplified and repeatable stimuli. Thus, knowledge of somatosensory PSN representational capacity remains incomplete. We used the rodent whisker system to examine how tactile mechanical information is represented in PSNs of the trigeminal ganglion (Vg) when the whiskers receive complex three-dimensional stimulation. In contrast to proposed codes in which subpopulations of Vg neurons encode select stimulus features, our results show that individual Vg neurons represent multiple stimulus features in a tiled and continuous manner, thus encoding large regions of a complex sensory space. [Emphasis added.]

An “Information Bottleneck” 

All senses confront an “information bottleneck” from their inputs: photons in eyes, pressure waves in ears, chemicals noses, and so forth, which must filter the flood of inputs into optimal amounts of information. Encoding by eyes and ears has described in research for many years, but less is known about tactile information sensed by vibrissal systems (i.e., whiskers). The team at Northwestern brought expertise in neuroscience, physics, physiology and engineering to the problem. What their research indicates is that whiskers code their information differently than other sensory organs. The sensory space of a whisker is extensive, continuous, and multidimensional in scope. How does a neuron encode such dynamic and wide-ranging information?

The results show that individual Vg neurons simultaneously represent multiple mechanical features of a stimulus, do not preferentially encode principal components of the stimuli, and represent continuous and tiled variations of all available mechanical information. These results directly contrast with proposed codes in which subpopulations of Vg neurons encode select stimulus features. Instead, individual Vg neurons likely overcome the information bottleneck by encoding large regions of a complex sensory space. This proposed tiled and multidimensional representation at the Vg directly constrains the computations performed by more central neurons of the vibrissotrigeminal pathway.

The team expanded on simpler methods that measured only one-dimensional or 2-D tests into more realistic 3-D measurements. What they found is that far more information comes in than realized, much more than a simple on/off response to touch.

When characterized through the expanded naturalistic stimulus set employed here, the response properties of Vg neurons reveal a fundamentally different encoding structure than generally appreciated. We find that Vg neurons are broadly tuned across multiple stimulus features, including force, bending moment, and rotation, as well as stimulation direction.

The “information bottleneck” problem becomes correspondingly more acute in a set of whiskers distributed across the face. In vision, photons project onto a curve; additional information is gained from binocular vision. In hearing, pressure waves converge onto the oval window, then undergo frequency analysis within the cochlea; two ears add stereo information. With touch, though, there is more information at the source: data about position, force, texture, rotation, and direction. The sensory neurons in whiskers have to be able to sort this all out before sending coded signals to the brain. 

Neurons must translate continuous analogue information at the source (e.g., arclength and direction) into digitized representations (i.e., neuron firings). The team measured higher frequency of neuron firings as a whisker was deflected. That’s one way an analogue signal can be digitized, but it is insufficient to sense all the information at the source. Their measurements led to

an underappreciated characteristic of Vg responses: when direction and arclength covary continuously and simultaneously, as during natural contact, Vg firing rate is governed jointly by both parameters. These results suggest that a single neuron’s response cannot unambiguously encode either of these two stimulus features and that a population readout is required to disambiguate.

That is what having a population of whiskers provides: the ability to disambiguate (disentangle) features that overlap. Adjacent whiskers will be firing at different rates, supplying additional information for disambiguation.

As in hearing, tactile neurons can experience “adaptation” to sources that are not varying, so as not to flood the brain with constant, unhelpful chatter. Also, like in cochlear hair cells, some vibrissal neurons adapt quickly and others slowly. This team found less of a discrete categorization between rapidly adapting (RA) or slowly adapting (SA) neurons in whiskers; they found more intermediate “adaptation categories” across the spectrum.

16-Dimensional Stimulus Space

Their 3-D measurements were unable to characterize the full sensory capacity of whisker neurons. They did establish that “Vg neurons encode multiple stimulus features and that stimulus features themselves are strongly correlated.” 

The one- and two-dimensional tuning maps of Fig. 4 A and B provide intuition for the neural representation of select stimulus features but fall short of describing the full neural response to the presented stimuli. A full description would require knowing the average firing rate in response to any arbitrary point in the stimulus space and thus fitting a tuning histogram such as those in Fig. 4A to the full 16-dimensional stimulus space. This goal cannot be achieved by systematic and exhaustive exploration and requires a modeling approach.

Did you know that a rat’s tactile sense requires analyzing a 16-dimensional stimulus space? How does that computation fit into a rat’s brain? Trying to simplify in a model what goes on in rat whiskers quickly gets deep into mathematical weeds. Their “generalized linear models” that analyzed pairs of covarying features showed some success. Nevertheless, they admit they have only (so to speak) scratched the surface.

Coding properties of Vg neurons can be fully quantified only if the stimuli employed span the extent of the full stimulus space. Without claiming to have achieved complete presentation of a naturalistic stimulus space that incorporates the full spatial and temporal structure of natural objects available to an awake animal, the present work takes a significant step toward a more complete understanding of vibrissotactile encoding by relating neural activity to whisker motion in three spatial dimensions.

It’s clear now (at least) that “individual Vg neurons simultaneously encode multiple features of the stimulus” and that “features are represented across a population and may be extracted by more central neurons that integrate information across many Vg neurons.” 

A Touch-Screen Phone

The motion of a single whisker is felt in the follicle of the whisker. In touch-screen phone, there are variations in finger position, speed, repeated taps, and force that affect the application through pre-programmed codes. Similarly, the base of a whisker in the follicle can sense multiple pieces of information simultaneously. This gives them “broad and diffuse tuning to mechanical features,” the authors say. But they only measured responses of passive whiskers. What other information is encoded by the live animal that actively samples its tactile space?

In the present study, neural responses are likely dominated by rotations of the whisker–follicle complex because the muscles holding the whiskers are relaxed as the animal is anesthetized. During active whisking, the muscles contract around the follicle, resisting passive rotation within the skin and causing the whisker to bend rather than rotate. In addition, increases in blood pressure in awake animals will tend to stiffen the follicle near the ring sinus, increasing the effects of the whisker’s deformation.

The researchers considered the possibility that rat whiskers represent their tactile space via “a dense or nearly dense code.” A dense code, which represents the most information with the least possible bits at the source, would have several advantages, such as robustness against noise and neuron loss. The population of whiskers, each one sensitive to many kinds of stimuli, could additionally “tile” the information to the brain without overwhelming it. “In this way,” they say, “the Vg population could represent arbitrary stimuli in the space of all possible stimuli” giving the central neurons the job of extracting the most useful information at the source before sending it to the brain.

A Challenge for Darwinism

One can appreciate what scientists are up against trying to understand such an information-rich system:

Vg neurons must represent a large range of mechanical stimuli in multiple behavioral contexts, including active and passive touch, texture discrimination, collisions with objects, noncontact whisking, and airflow exploration. Although it is not possible to sample all whisker velocities and vibration patterns, the present work leverages manual stimulation and stereo videography techniques to explore and quantify a vastly larger stimulus set than previously reported.

All this for a few rats in a Northwestern University lab! Consider what a challenge this is for Darwinism: very disparate animals have systems like this, including lobsters (arthropods, which are invertebrates), rodents, rabbits, cats, dogs, sea lions and more. None of the three authors needed Darwinism for this work. They needed a physicist, an engineer, and a neuroscientist. Think of what design-friendly engineers, physicists, computer scientists and information theorists, untethered from evolutionary materialism, could bring to one of their ending challenges: “Future studies may investigate how the encoding properties described here coexist with Vg neurons’ ability to encode texture and self-motion.”

For more on this theme at Evolution News, see, “By a Whisker: Scientists Discover Predictive Coding in a Surprising Place.”

The sexual revolution: a brief history.

 The sexual revolution, also known as a time of sexual liberation, was a social movement that challenged traditional codes of behavior related to sexuality and interpersonal relationships throughout the United States and the developed world from the 1960s to the 1980s. Sexual liberation included increased acceptance of sex outside of traditional heterosexual, monogamous relationships (primarily marriage). The normalization of contraception and the pillpublic nuditypornographypremarital sexhomosexualitymasturbation, alternative forms of sexuality, and the legalization of abortion all followed.

Tuesday, 14 September 2021

Oumuamua: a brief history.

 ʻOumuamua is the first known interstellar object detected passing through the Solar SystemFormally designated 1I/2017 U1, it was discovered by Robert Weryk using the Pan-STARRS telescope at Haleakalā ObservatoryHawaii, on 19 October 2017, approximately 40 days after it passed its closest point to the Sun on 9 September. When it was first observed, it was about 33 million km (21 million mi; 0.22 AU) from Earth (about 85 times as far away as the Moon), and already heading away from the Sun.


ʻOumuamua is a small object estimated to be between 100 and 1,000 metres (300 and 3,000 ft) long, with its width and thickness both estimated to range between 35 and 167 metres (115 and 548 ft). It has a red color, similar to objects in the outer Solar System. Despite its close approach to the Sun, ʻOumuamua showed no signs of having a coma, but it did exhibit non‑gravitational acceleration. Nonetheless, the object could be a remnant of a disintegrated rogue comet (or exocomet), according to astronomer Zdenek Sekanina. The object has a rotation rate similar to the average spin rate seen in Solar System asteroids, but many valid models permit it to be more elongated than all but a few other natural bodies. While an unconsolidated object (rubble pile) would require it to be of a density similar to rocky asteroids, a small amount of internal strength similar to icy comets would allow a relatively low density. ʻOumuamua's light curve, assuming little systematic error, presents its motion as "tumbling", rather than "spinning", and moving sufficiently fast relative to the Sun that it is likely of an extrasolar origin. Extrapolated and without further deceleration, ʻOumuamua's path cannot be captured into a solar orbit, so it would eventually leave the Solar System and continue into interstellar space. ʻOumuamua's planetary system of origin and the age of its excursion are unknown.

In July 2019, astronomers concluded that ʻOumuamua is most likely a natural object. A small number of astronomers suggested that ʻOumuamua could be a product of alien technology, but evidence in support of this hypothesis is weak. In March 2021, scientists presented a theory based on nitrogen ice that ʻOumuamua may be a piece of an exoplanet similar to Pluto, from beyond our solar system.