Saltar para: Posts [1], Pesquisa e Arquivos [2]



Perdoem a pintarolice do desenho. Gostei muito da citação

30.11.11

Autoria e outros dados (tags, etc)

O Tempo não pula, passa.

30.11.11

 

 Lynds' solution to the Achilles and the tortoise paradox, submitted to Philosophy of Science, helped explain the work. A tortoise challenges Achilles, the swift Greek warrior, to a race, gets a 10m head start, and says Achilles can never pass him. When Achilles has run 10m, the tortoise has moved a further metre. When Achilles has covered that metre, the tortoise has moved 10cm...and so on. It is impossible for Achilles to pass him. The paradox is that in reality, Achilles would easily do so. A similar paradox, called the Dichotomy, stipulates that you can never reach your goal, as in order to get there, you must firstly travel half of the distance. But once you've done that, you must still traverse half the remaining distance, and half again, and so on. What's more, you can't even get started, as to travel a certain distance, you must firstly travel half of that distance, and so on.

According to both ancient and present day physics, objects in motion have determined relative positions. Indeed, the physics of motion from Zeno to Newton and through to today take this assumption as given. Lynds says that the paradoxes arose because people assumed wrongly that objects in motion had determined positions at any instant in time, thus freezing the bodies motion static at that instant and enabling the impossible situation of the paradoxes to be derived. "There's no such thing as an instant in time or present moment in nature. It's something entirely subjective that we project onto the world around us. That is, it's the outcome of brain function and consciousness."

(...)

According to Lynds, through the derivation of the rest of physics, the absence of an instant in time and determined relative position, and consequently also velocity, necessarily means the absence of all other precisely determined physical magnitudes and values at a time, including space and time itself. He comments, "Naturally the parameter and boundary of their respective position and magnitude are naturally determinable up to the limits of possible measurement as stated by the general quantum hypothesis and Heisenberg's uncertainty principle, but this indeterminacy in precise value is not a consequence of quantum uncertainty. What this illustrates is that in relation to indeterminacy in precise physical magnitude, the micro and macroscopic are inextricably linked, both being a part of the same parcel, rather than just a case of the former underlying and contributing to the latter."

Addressing the age old question of the reality of time, Lynds says the absence of an instant in time underlying a dynamical physical process also illustrates that there is no such thing as a physical progression or flow of time, as without a continuous progression through definite instants over an extended interval, there can be no progression. "This may seem somewhat counter-intuitive, but it's exactly what's required by nature to enable time (relative interval as indicated by a clock), motion and the continuity of a physical process to be possible." Intuition also seems to suggest that if there were not a physical progression of time, the entire universe would be frozen motionless at an instant, as though stuck on pause on a motion screen. 

(...)

Lynds continues that the cosmological proposal of imaginary time also isn't compatible with a consistent physical description, both as a consequence of this, and secondly, "because it's the relative order of events that's relevant, not the direction of time itself, as time doesn't go in any direction."

Autoria e outros dados (tags, etc)

Tags:

"Khazaria: A Forgotten Jewish Empire"

29.11.11

 

 "Yet historians, and medieval historians in particular, should be aware of the important existence of this powerful kingdom which played just as crucial a part in the stemming of the Arab advance into Europe as Charles Martel did at Tours at around the same time (i.e. the eighth century). However, this Khazar kingdom was neither Christian nor Muslim at the height of its power but Judaic, which makes study of it all the more interesting, since it places a powerful Judaic military presence amidst the power politics of the period in question."

(...)

"Both Byzantium and the Arab empire viewed the Khazars as a linchpin in the power-diplomacy game and an all-important factor in any balance of power considerations. Byzantium regarded Khazaria as more important than any Western kingdom, as can be seen from the Byzantine emperor Constantine Porphyrogenitus' De Cerimoniis, a treatise written on state protocol in the tenth century, where letters of correspondence to the Khaqan of the Khazars were to be given a gold seal worth three solidi, whereas those addressed to the pope in Rome or the 'Emperor in the West' were given a seal worth only two solidi. The importance placed on the power of the Khazars can also be seen in the practice adopted by the Persian king of having three golden thrones permanently placed in the royal palace, in addition to his own, representing the great powers of the day: one for the Khazar khaqan, one for the Byzantine emperor, and another for the emperor of China. As allies of the Byzantines the Khazars not only stemmed the Arab advance into Europe (from the seventh century onwards) but earlier helped to bring about the downfall of the Persian empire by supplying the Byzantine emperor, Heraclius, with 40,000 soldiers under the leadership of Ziebel in 627."

(...)

The story of the Khazar conversion, although largely fictional, contains revealing insights into the power-politics of the day and how religious considerations played a major part. According to the story the khaqan, on hearing the various arguments put forward by Christian, Muslim and Judaic missionaries, asked each in turn which of the other two religions was considered more acceptable after their own. As to what the Jewish representative replied is of no consequence since both the Christian and Muslim representatives (fearing each other) answered that after their own the Jewish faith would be the most acceptable – the consequences of a Khazar conversion to either Christianity or Islam could have been disastrous to the unsuccessful party. As things turned out the Khazars opted for a path which attracted least hostility, least obligation, and least cultural influence from any of the other major powers of the day."

Autoria e outros dados (tags, etc)

"I am the barely living son of a woman and man who barely made it but we’re making it taped together on borrowed crutches and new starts."

26.11.11

Autoria e outros dados (tags, etc)

Tags:

"But the water keeps rising"

26.11.11

Autoria e outros dados (tags, etc)

Tags:

Topicality

26.11.11

Autoria e outros dados (tags, etc)

The Sound and the Fury

26.11.11

 

Obrigado Feedback Loop

Autoria e outros dados (tags, etc)

Tags:

" time has imprisoned us in the order of our years,"

24.11.11

 

Por favor ignorem o título importado do Youtube. A músia chama-se "In the kingdom of the blind"

Autoria e outros dados (tags, etc)

Tags:

Words of wisdom

23.11.11

Autoria e outros dados (tags, etc)

Tags:

Pág. 1/4




Pesquisar

Pesquisar no Blog


subscrever feeds



Sitemeter