Claude Elwood Shannon 1916-2001

November 14, 2010 at 2:41 pm (1, ΔΙΑΦΟΡΑ, ΡΗΤΑ)

I visualize a time when we will be to robots what dogs are to humans. And I am rooting for the machines.

Omni Magazine 1987

Οραματίζομαι την εποχή που θα είμαστε για τα ρομπότ αυτό που είναι τα σκυλιά για τους ανθρώπους, και τάσσομαι υπέρ των μηχανών.

Permalink Leave a Comment

15 Οκτωβρίου 1844 γέννηση Φρειδερίκου Νίτσε

October 15, 2010 at 12:29 pm (ΔΙΑΦΟΡΑ)

ΑΝ ΚΑΠΟΙΟΣ ΠΑΡΕΙ ΑΠΟ ΤΟΝ ΚΑΜΠΟΥΡΗ ΤΗΝ ΚΑΜΠΟΥΡΑ ΤΟΥ ΕΙΝΑΙ ΣΑΝ ΝΑ ΤΟΥ ΠΑΙΡΝΕΙ ΤΟ ΠΝΕΥΜΑ ΤΟΥ. ΝΙΤΣΕ

Permalink Leave a Comment

ΠΙΣΤΗ

September 16, 2010 at 9:15 pm (MOTIVATIONAL) ()

Permalink Leave a Comment

Ancient Greeks spotted Halley’s comet

September 12, 2010 at 7:42 pm (ΔΙΑΦΟΡΑ, ΕΠΙΣΤΗΜΟΝΙΚΑ ΝΕΑ) ()

http://www.newscientist.com/article/mg20727774.400-ancient-greeks-spotted-halleys-comet.html

A CELESTIAL event in the 5th century BC could be the earliest documented sighting of Halley’s comet – and it marked a turning point in the history of astronomy.

According to ancient authors, from Aristotle onwards, a meteorite the size of a “wagonload” crashed into northern Greece sometime between 466 and 468 BC. The impact shocked the local population and the rock became a tourist attraction for 500 years.

The accounts describe a comet in the sky when the meteorite fell. This has received little attention, but the timing corresponds to an expected pass of Halley’s comet, which is visible from Earth every 75 years or so.

Philosopher Daniel Graham and astronomer Eric Hintz of Brigham Young University in Provo, Utah, modelled the path that Halley’s comet would have taken, and compared this with ancient descriptions of the comet (Journal of Cosmology, vol 9, p 3030). For example, the comet was said to be visible for 75 days, accompanied by winds and shooting stars, and in the western sky when the meteorite fell.

The researchers show that Halley’s comet would have been visible for a maximum of 82 days between 4 June and 25 August 466 BC. From 18 July onwards, a time of year characterised in this region by strong winds, it was in the western sky. At around this time, the Earth was moving under the comet’s tail, so its debris field would have made shooting stars.

None of this proves the comet’s identity, but Graham says such major comet sightings are rare, so Halley must be a “strong contender”. Previously, the earliest known sighting of Halley was made by Chinese astronomers in 240 BC. If Graham and Hintz are correct, the Greeks saw it three orbits and more than two centuries earlier.

The researchers’ analysis reveals this moment to be a crucial turning point in the history of astronomy. Plutarch wrote in the 1st century AD that a young astronomer called Anaxagoras predicted the meteorite’s fall to Earth, which has puzzled historians because such events are essentially random occurrences.

After studying what was said about Anaxagoras, Graham concludes that he should be recognised as “the star of early Greek astronomy”. Rather than predicting a particular meteorite, he reckons Anaxagoras made a general statement that rocks might fall from the sky.

At this time, says Graham, everyone thought that celestial bodies such as the moon and planets were fiery, lighter-than-air objects. But after observing a solar eclipse in 478 BC, Anaxagoras concluded that they were heavy, rocky lumps, held aloft by a centrifugal force. This implied that solar eclipses occurred when the moon blocked the light from the sun. It also meant that if knocked from position, such a rock might crash to Earth.

“When the meteorite fell, no one could deny it,” says Graham. “The headline was ‘Anaxagoras was right’.”

Did Halley’s comet play a role? It is always possible that the comet might have nudged a near-Earth asteroid from its course and sent it hurtling towards northern Greece. From that point on, the idea of rocks in the sky was accepted, and the Greeks had a new understanding of the cosmos.

Permalink Leave a Comment

GOD

September 12, 2010 at 6:55 pm (MOTIVATIONAL)


Permalink Leave a Comment

ΕΠΙΚΤΗΤΟΣ ΚΑΙ CRISIS I

September 12, 2010 at 6:42 pm (ΡΗΤΑ) ()

ΚΡΕΙΣΣΟΝ ΓΑΡ ΛΙΜΩ ΑΠΟΘΑΝΕΙΝ ΑΛΥΠΟΝ ΚΑΙ ΑΦΟΒΟΝ
ΓΕΝΟΜΕΝΟΝ, Ή ΖΗΝ ΕΝ ΑΦΘΟΝΟΙΣ ΤΑΡΑΣΣΟΜΕΝΟΝ.

ΜΕΤΑΦΡΑΣΗ:

Είναι προτιμότερο να πεθάνεις από την πείνα χωρίς λύπη και φόβο

παρά να ζεις μέσα στην πολυτέλεια και την αφθονία όλο άγχος και φόβο.

ΕΠΙΚΤΗΤΟΣ “ΕΓΧΕΙΡΙΔΙΟΝ”

Permalink Leave a Comment

ΣΠΑΡΤΗ ΚΑΙ CRISIS 2

August 16, 2010 at 3:06 pm (ΡΗΤΑ) ()

ΠΛΟΥΤΑΡΧΟΣ “ΛΑΚΩΝΙΚΑ ΑΠΟΦΘΕΓΜΑΤΑ” – ΑΓΗΣΙΛΑΟΣ Ο ΜΕΓΑΣ

ΚΑΤΑ ΔΕΝ ΤΟΝ <ΑΠ’> ΑΙΓΥΠΤΟΥ ΑΠΟΠΛΟΥΝ ΑΠΟΘΝΗΣΚΩΝ ΕΝΕΤΕΛΕΙΛΑΤΟ ΤΟΙΣ ΠΕΡΙ ΑΥΤΟΝ ΜΗΤΕ ΠΛΑΣΤΑΝ ΜΗΤΕ ΜΙΜΗΛΑΝ ΤΟΥ ΣΩΜΑΤΟΣ ΕΙΚΟΝΑ ΠΟΙΗΣΑΣΘΑΙ. ΕΙ ΓΑΡ ΤΙ ΚΑΛΟΝ ΕΡΓΟΝ ΠΕΠΟΙΗΚΑ, ΤΟΥΤΟ ΜΟΥ ΜΝΗΜΕΙΟΝ ΕΣΤΑΙ. ΕΙ ΔΕ ΜΗ, ΟΥΔ’ ΟΙ ΠΑΝΤΕΣ ΑΝΔΡΙΑΝΤΕΣ ΒΑΝΑΥΣΩΝ ΚΑΙ ΟΥΔΕΝΟΣ ΑΞΙΩΝ ΕΡΓΑ ΟΝΤΕΣ.

Στην επιστροφή του από την Αίγυπτο, σχεδόν ετοιμοθάνατος, άφησε εντολή στη συνοδεία του να μην του κάνουν ούτε άγαλμα ούτε ζωγραφιά ούτε καμιά άλλη απομίμηση της μορφής του. “Αν έχω πετύχει κάποιο αξιόλογο έργο, αυτό θα είναι το μνημείο μου. Αλλιώς, ούτε όλοι οι ανδριάντες, που είναι έργο ανδρών που ασχολούνται με χειρωνακτικές εργασίες και που δεν αξίζουν τίποτα”.

Permalink Leave a Comment

Σέξπιρ και crisis I

August 15, 2010 at 3:59 pm (ΔΙΑΦΟΡΑ) ()

ΒΑΣΙΛΙΑΣ ΛΗΡ, ΠΡΑΞΗ Γ’

…….όταν φόρα θα μετράνε τα λεφτά οι καταχραστές

και θα χτίζουν οι ρουφιάνοι κι οι πουτάνες εκκλησιές,

τότε στο βασίλειο της Αλβιόνας

θα γενεί μεγάλος κυκεώνας.

Permalink Leave a Comment

ΑΠΟΔΕΙΧΘΗΚΕ ΟΤΙ P!=NP

August 11, 2010 at 6:43 pm (ΕΠΙΣΤΗΜΟΝΙΚΑ ΝΕΑ)

http://cacm.acm.org/news/97397-p-%E2%89%A0-np-its-bad-news-for-the-power-of-computing/fulltext

ACM News

P ≠ NP? It’s Bad News for the Power of Computing

New Scientist

August 11, 2010

Has the biggest question in computer science been solved? On 6 August, Vinay Deolalikar External Link, a mathematician at Hewlett-Packard Labs in Palo Alto, California, sent out draft copies of a paper External Link titled simply “P ≠ NP”

This terse assertion could have profound implications for the ability of computers to solve many kinds of problem. It also answers one of the Clay Mathematics Institute’s seven Millennium Prize problems, so if it turns out to be correct Deolalikar will have earned himself a prize of $1 million.

The P versus NP question External Link concerns the speed at which a computer can accomplish a task such as factorising a number. Some tasks can be completed reasonably quickly—in technical terms, the running time is proportional to a polynomial function of the input size—and these tasks are in class P.

If the answer to a task can be checked quickly then it is in class NP.

So if P = NP, every problem that can be checked quickly can also be completed quickly. That outcome would have huge repercussions for Internet security, where the difficulty of factorising very large numbers is the primary means by which our data is kept safe from hackers.

Permalink 1 Comment

ΣΠΑΡΤΗ ΚΑΙ CRISIS Ι

August 11, 2010 at 6:19 pm (ΔΙΑΦΟΡΑ, ΡΗΤΑ)

ΠΛΟΥΤΑΡΧΟΣ “ΛΑΚΩΝΙΚΑ ΑΠΟΦΘΕΓΜΑΤΑ” – ΕΚΔΟΣΕΙΣ ΖΗΤΡΟΣ

“ΑΓΙΔΟΣ ΓΟΥΝ ΜΕΤΑ ΠΟΛΥ ΧΡΟΝΟΝ ΤΟΥ ΒΑΣΙΛΕΩΣ ΕΠΑΝΕΛΘΟΝΤΟΣ ΑΠΟΣ ΣΤΡΑΤΕΙΑΣ – ΚΑΤΑΠΕΠΟΛΕΜΗΚΕΝ Δ’ ΑΘΗΝΑΙΟΥΣ- ΒΟΥΛΟΜΕΝΟΣ ΠΑΡΑ ΤΗ ΓΥΝΑΙΚΙ ΜΙΑ ΗΜΕΡΑ ΔΕΙΠΝΗΣΑΙ ΚΑΙ ΜΕΤΑΠΕΜΠΟΜΕΝΟΥ ΤΑΣ ΜΕΡΙΔΑΣ, ΟΥΚ ΕΠΕΜΨΑΝ ΟΙ ΠΟΛΕΜΑΡΧΟΙ. ΜΕΘ’  ΗΜΕΡΑΝ ΔΕ ΦΑΝΕΡΟΥ ΓΕΝΟΜΕΝΟΥ ΤΟΙΣ ΕΦΟΡΟΙΣ, ΕΖΗΜΙΩΘΗ ΥΠ’ ΑΥΤΟΝ”

ΜΕΤΑΦΡΑΣΗ:

Όταν ο Βασιλιάς Άγης μετά από πολλά χρόνια γύρισε από μια εκστρατεία – είχε νικήσει μάλιστα τους Αθηναίους- και θέλησε να δειπνήσει κοντά στη γυναίκα του μια μέρα και ζήτησε να του στείλουν τις μερίδες του φαγητού του στο σπίτι, οι πολέμαρχοι δεν τις έστειλαν. Την επόμενη μέρα αναφέρθηκε αυτό στους εφόρους και του επιβλήθηκε από αυτούς πρόστιμο.

Permalink Leave a Comment

Next page »

Follow

Get every new post delivered to your Inbox.