infinity

قبل 11 سنةdiscuss

How about time travellers from the Imperium Romanum?

قبل 11 سنةdiscuss

"it's a good rule never to leave documentary evidence if you can help it, because you don't know when it may be put in."

    - from Great Expectations by Charles Dickens

infinity

قبل 11 سنةdiscuss

The argument does not state that Bertie really sees a green object in the sense that light with green wave lengths enters the eye and triggers biochemical reactions.

The argument talks about the experience of "greenness" as the after-image of a red object:

  Suppose Bertie is experiencing a green after-image
  as a result of seeing a red flash bulb go off;
  the greenness of the after-image is the quale.

Indeed, there is no green object outside or inside of Bertie. The light bulb was red, the memories or patterns in the brain are not green.

  Sensory qualities pose a serious problem for materialist
  theories of the mind. For where, ontologically speaking,
  are they located?

The argument is about materialist theories of the mind. After the argument, which seems to me a valid argument against oldschool hardcore materialism (a material location for the greenness is needed), the following paragraph mentions a more modern development, namely the modern representational theory of sensory qualities, sometimes as an attempt to resolve the foregoing dilemma compatibly with materialism.

infinity

قبل 11 سنةdiscuss

Somebody has added the year of the first publication of the article (2000) to the title. More interesting is the fact that this article has gone through a substantive revision and has been updated yesterday. For example, it now includes references to literature published after 2000. The year 2000 in the link title suggests that this is a 15 year old article that has not been changed ever since.

infinity

قبل 11 سنةdiscuss

Alternatively, if you don't want to read the original story, you can read a plot summary from wikipedia:

http://en.wikipedia.org/wiki/%22—And_He_Built_a_Crooked_Hous...

infinity

قبل 11 سنةdiscuss

The german newspaper FAZ (Frankfurter Allgemeine Zeitung) claims that there is an inititiative to block cat images from the web due to excessive bandwidth consumption (article in german):

http://www.faz.net/aktuell/feuilleton/debatten/die-digital-d...

The other content to be blocked are 'theses concerning the future of journalism' ...

infinity

قبل 11 سنةdiscuss

Johann Wolfgang von Goethe

  Der Zauberlehrling

  Hat der alte Hexenmeister 
  Sich doch einmal wegbegeben! 
  Und nun sollen seine Geister 
  Auch nach meinem Willen leben. 
  Seine Wort´ und Werke 
  Merkt ich und den Brauch, 
  Und mit Geistesstärke 
  Tu ich Wunder auch. 

  Walle! walle 
  Manche Strecke, 
  Daß, zum Zwecke, 
  Wasser fließe 
  Und mit reichem, vollem Schwalle 
  Zu dem Bade sich ergieße. 

  Und nun komm, du alter Besen! 
  Nimm die schlechten Lumpenhüllen; 
  Bist schon lange Knecht gewesen: 
  Nun erfülle meinen Willen! 
  Auf zwei Beinen stehe, 
  Oben sei ein Kopf, 
  Eile nun und gehe 
  Mit dem Wassertopf! 

  Walle! walle 
  Manche Strecke, 
  Daß, zum Zwecke, 
  Wasser fließe 
  Und mit reichem, vollem Schwalle 
  Zu dem Bade sich ergieße. 

  Seht, er läuft zum Ufer nieder, 
  Wahrlich! ist schon an dem Flusse, 
  Und mit Blitzesschnelle wieder 
  Ist er hier mit raschem Gusse. 
  Schon zum zweiten Male! 
  Wie das Becken schwillt! 
  Wie sich jede Schale 
  Voll mit Wasser füllt! 

  Stehe! stehe! 
  Denn wir haben 
  Deiner Gaben 
  Vollgemessen! - 
  Ach, ich merk es! Wehe! wehe! 
  Hab ich doch das Wort vergessen! 

  Ach, das Wort, worauf am Ende 
  Er das wird, was er gewesen. 
  Ach, er läuft und bringt behende! 
  Wärst du doch der alte Besen! 
  Immer neue Güsse 
  Bringt er schnell herein, 
  Ach! und hundert Flüsse 
  Stürzen auf mich ein. 

  Nein, nicht länger 
  Kann ichs lassen; 
  Will ihn fassen. 
  Das ist Tücke! 
  Ach! nun wird mir immer bänger! 
  Welche Miene! welche Blicke! 

  O, du Ausgeburt der Hölle! 
  Soll das ganze Haus ersaufen? 
  Seh ich über jede Schwelle 
  Doch schon Wasserströme laufen. 
  Ein verruchter Besen, 
  Der nicht hören will! 
  Stock, der du gewesen, 
  Steh doch wieder still! 

  Willsts am Ende 
  Gar nicht lassen? 
  Will dich fassen, 
  Will dich halten 
  Und das alte Holz behende 
  Mit dem scharfen Beile spalten. 

  Seht, da kommt er schleppend wieder! 
  Wie ich mich nur auf dich werfe, 
  Gleich, o Kobold, liegst du nieder; 
  Krachend trifft die glatte Schärfe. 
  Wahrlich! brav getroffen! 
  Seht, er ist entzwei! 
  Und nun kann ich hoffen, 
  Und ich atme frei! 

  Wehe! wehe! 
  Beide Teile 
  Stehn in Eile 
  Schon als Knechte 
  Völlig fertig in die Höhe! 
  Helft mir, ach! ihr hohen Mächte! 

  Und sie laufen! Naß und nässer. 
  Wirds im Saal und auf den Stufen. 
  Welch entsetzliches Gewässer! 
  Herr und Meister! hör mich rufen! - 
  Ach, da kommt der Meister! 
  Herr, die Not ist groß! 
  Die ich rief, die Geister 
  Werd ich nun nicht los. 

  "In die Ecke, 
  Besen! Besen! 
  Seids gewesen. 
  Denn als Geister 
  Ruft euch nur, zu seinem Zwecke, 
  Erst hervor der alte Meister."

infinity

قبل 11 سنةdiscuss

In a far distant future an interstellar scientific exploration vessel will approach the lifeless remains of the solar system and discover, stashed away in a big artificial moon, one very huge data archive consisting entirely of harsh noise. They will be so happy.

infinity

قبل 11 سنةdiscuss

>> I also learned that most professional mathematicians

>> consider it uncool to get really good at doing integrals:

>> it's just one step up from memorizing digits of pi.

I consider it cool to get really good at anything.

infinity

قبل 11 سنةdiscuss

Because they are so complicated, they are unlikely to have evolved twice.

This reminds me of the beginning of the babel fish argument for the non-existence of god by Douglas Adams:

Now it is such a bizarrely improbable coincidence that anything so mindbogglingly useful could have evolved purely by chance ...

infinity

قبل 12 سنةdiscuss

One way to approach your wishes to learn "mathematics from first principles" is to see modern mathematics as the study and application of formal systems:

http://en.wikipedia.org/wiki/Formal_system

A formal system has several components:

An alphabet of symbols from which sequences or strings of symbols are constructed. Some of these strings of symbols can be well-formed according to some formal grammar, which is the next component.

Next we have a collection of basic assumptions, called axioms, which are supposed to reflect the obvious truths about whatever we want to formalize in the formal system.

And then we have some rules of inference. They allow us to derive conclusions from premises. An example would be the rule of modus ponens: If we have "If A then B" and "A", we can conclude "B".

An example of a formal system is ZFC set theory which can be regarded as a formalization of one concept, the concept of a set:

We take "classical predicate logic" as a background formal system, it already has logical symbols, like symbols for AND, OR and "IF ... THEN ..." and quantifiers "FOR ALL ..." and "THERE EXISTS ...".

We enhance this logic with one non-logical symbol, the binary element-of-symbol ∈. With it we want to express the idea that something is an element of something, for example x ∈ y is supposed to mean that x is an element of y.

Of course this is a bit simplified, but now we can build expressions (with symbols from the alphabet, according to the grammar for logical formulas plus the element symbol) which talk about the element-of-relationship between individuals.

Next, we sit together at a round table and discuss which properties about sets and element-of or membership of a set we see as self-evident - there is room for discussion and there can be many different intuitions.

For example, as in ZFC set theory, we may want to have some existence axioms. They guarantee us that in this formal system certain objects do exist. An example is the axiom of the empty set: There exists a set which has no elements. This statement can be written in our formal language.

Other axioms may have a more constructive meaning. Instead of telling us that something exists, they say that given the existence of some objects we know the existence of further objects. An example would be the axiom of set unions: Given some arbitrary sets A and B, there exists a set C, which contains all the members of A and all the members of B as its elements. Another axiom asserts the existence of an unordered pair of any two given sets, from this we can define the concept of an ordered pair, which is very important.

ZFC is one example of a set theory, there are many different set theories. You could exchange classical logic with intuitionistic logic and arrive at some formal system for intuitionistic or constructive set theory. You can drop certain axioms, because maybe they do not appear as self-evident to you (for example the axiom of choice, which contributes the "C" in ZFC, is not accepted by some people). You may add further axioms to arrive at a possibly stronger theory.

One interesting aspect about set theory is that the concept of set is very powerful and expressive, because many concepts from modern mathematics can be build up from sets: natural numbers 0,1,2,3,... can be constructed from the empty set, functions can be represented through ordered pairs of sets. Sometimes set theory is regarded as "the foundation of all mathematics", but feel free to disagree! Just because natural numbers can be modelled as sets it is not certain that natural numbers are indeed sets.

The basic pattern above is the formalization of an intuitive or natural concept, something from everyday life. We try to capture the essentials of this concept within a formal system. And then we can use the deductive power of the formal system to arrive at new and hopefully interesting conclusions about whatever we wanted to formalize. These conclusions are theorems. Not all theorems are interesting, some are even confusing, paradox and disppointing. Formalization is used to arrive at new insights about the original concept. Interesting in this context is Carnap and his idea of explication of inexact prescientific concepts:

http://en.wikipedia.org/wiki/Explication

What I want to express with this is that it is really possible to start your journey into mathematics at a beginning.

infinity

قبل 12 سنةdiscuss

L'Arbre du Ténéré was once considered the most isolated tree on Earth, the only one for over 400 kilometres ... it was killed in 1973 by a drunk truck driver:

http://en.wikipedia.org/wiki/Arbre_du_Ténéré

http://knowledgenuts.com/2013/09/30/a-drunk-driver-killed-th...

infinity

قبل 12 سنةdiscuss

So far it has always been a good policy for me to take these lines literally:

>> Google’s mission is to organize the world’s information

>> and make it universally accessible ...

http://www.google.com/about/company/

infinity

قبل 12 سنةdiscuss

Did you tell them about this? Or did you just go full disclosure? There are alternatives ...

http://en.wikipedia.org/wiki/Responsible_disclosure

infinity

قبل 12 سنةdiscuss

Ok, I have successfully submitted one quote. But if there is already one quote by the same author (for example Oscar Wilde) and I try to submit another quote it doesn't seem to work.

infinity

قبل 12 سنةdiscuss

I have created an account, but the quotes which I have submitted do not show up.

infinity

قبل 12 سنةdiscuss

Finally, at 2:26 a.m. I was successful with a score of 21000 ... that was fun, thank you!

infinity

قبل 12 سنةdiscuss

A big part of the GeoCities content has been available as a torrent file from a group called the Archive Team and maybe you can still download it:

http://archiveteam.org/index.php?title=GeoCities

The file was huge, about several hundred gigabyte. I didn't download it, because I don't have enough space and downloading it would take ages with my slow connection.

On http://reocities.com/ you can browse through some of the old pages and sites, but many things are broken now, missing images.

infinity

قبل 13 سنةdiscuss

The really huge Google Matrix from the world of Information Retrieval: http://en.wikipedia.org/wiki/Google_matrix

infinity

قبل 13 سنةdiscuss

This article is written by Gareth Heyes. He has a blog about JavaScript weirdness and hacking:

http://www.thespanner.co.uk/

Submissions

Information theft attacks abusing browser's XSS filter

The Hole Argument

CokeSpeak

Non-Deductive Methods in Mathematics

The Definition of Lying and Deception

Representational Theories of Consciousness (2000)

The Experience and Perception of Time

x86 Disassembly

–And He Built a Crooked House– By Robert A. Heinlein [pdf]

A Guide to Debug.exe

Codename: Cloudy Viper

Associationist Theories of Thought

Attribution is hard

Connectionism

The life of a Marine Biologist

The Problem of the Many

Lakes of Wada

Game Theory

Skolem's Paradox

Arrow's Theorem

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