Twitter has gone from a microblogging service, to a source of news , a social platform and even a communication forum.

But the Twitter website and the Twitter interface is completely bird-brained when it comes to facilitating these unintended uses of their service. The solution ? TweetDeck.

TweetDeck is an Adobe AIR application (read “black and cross-platform”) that provides an intuitive and easy to use interface to Twitter right on your Desktop. Your replies, Direct messages and Tweets from friends are shown clearly in three panels (which can be customised). You can send Tweets with the click of a button. Your URLs can be shortened using one of many URL shortening services right in the menu and you can post images to Twitter.

And finally, as if that was not enough. TweetDeck will work offline too and queue your tweets to be updated seamlessly the next time you are connected to the Internet.

I think I can stop looking for better ways to access Twitter.

You can TweetDeck from Tweetdeck.com .

*Adobe AIR needs to be installed first (if you aren’t nerdy enough to have that done already).

A man condemned to be hanged was sentenced on Saturday. “The hanging will take place at noon,” said the judge to the prisoner, “on one of the seven days of next week. But you will not know which day it is until you are so informed on the morning of the day of the hanging.”

The judge was known to be a man who always kept his word. The prisoner, accompanied by his lawyer, went back to his cell. As soon as the two men were alone, the lawyer broke into a grin. “Don’t you see?” he exclaimed. “The judge’s sentence cannot possibly be carried out.”

“I don’t see,” said the prisoner.

“Let me explain They obviously can’t hang you next Saturday. Saturday is the last day of the week. On Friday afternoon you would still be alive and you would know with absolute certainty that the hanging would be on Saturday. You would know this before you were told so on Saturday morning. That would violate the judge’s decree.”

“True,” said the prisoner.

“Saturday, then is positively ruled out,” continued the lawyer. “This leaves Friday as the last day they can hang you. But they can’t hang you on Friday because by Thursday only two days would remain: Friday and Saturday. Since Saturday is not a possible day, the hanging would have to be on Friday. Your knowledge of that fact would violate the judge’s decree again. So Friday is out. This leaves Thursday as the last possible day. But Thursday is out because if you’re alive Wednesday afternoon, you’ll know that Thursday is to be the day.”

“I get it,” said the prisoner, who was beginning to feel much better. “In exactly the same way I can rule out Wednesday, Tuesday and Monday. That leaves only tomorrow. But they can’t hang me tomorrow because I know it today!”

… He is convinced, by what appears to be unimpeachable logic, that he cannot be hanged without contradicting the conditions specified in his sentence. Then on Thursday morning, to his great surprise, the hangman arrives. Clearly he did not expect him. 

And sure enough, he didn’t know he was going to be hanged, let alone known the day! 

XKCD does a search for phrases in the blogosphere.

[youtube=http://www.youtube.com/watch?v=pMfGY9cqTCI]

[youtube=http://www.youtube.com/watch?v=rUr4XMfqjlA]

Need I say more?

And this is no April Fool’s Joke !

The electrical properties of a new-found mineral could help to explain our planet’s wiggle.

Rachel Courtland
As the world turns: do conductive materials in the mantle interfere with its spin?As the world turns: do conductive materials in the mantle interfere with its spin?NASA

If a day seems to go by faster now than it did when you were younger, it might not just be your imagination. The speed of the Earth’s rotation is known to fluctuate slightly over decades. Now researchers have found a piece of the puzzle to explain this drift: a highly conductive mineral that could change the way the Earth spins.

A full day is almost never exactly 24 hours long. Early on in the Earth’s history, a day may once have been as short as five hours; tidal friction with the Moon has since made each successive day slightly longer. In any given year, earthquakes and seasonal ice melting change the Earth’s rotational speed by exerting subtle influences on how the planet’s mass is distributed. On the scale of decades, geophysicists see irregular millisecond-scale fluctuations in day length.

The exact cause of this decadal-scale variation is a bit of a mystery, but many have speculated that some process 2,900 kilometres down, at the boundary between the Earth’s core and mantle, may cause it. The Earth’s core and mantle spin somewhat independently; models show that if the bottom of the mantle contains a conductive layer, it may interact with the magnetic field coming from the core, putting a wiggle in the Earth’s spin that affects day length on this time frame.

But what could cause this conductance? A team led by Kei Hirose at the Tokyo Institute of Technology took a close look at a recently discovered mineral and say it could be at the root of the issue.
Under pressure

The team focused on post-perovskite, a high-pressure phase of a magnesium silicate mineral that was discovered in 2004 and is thought to exist in the mantle.

To investigate post-perovskite’s properties, the team recreated the conditions found at the bottom of the mantle, some 2,700 kilometres down, in the laboratory. They heated samples of post-perovskite to more than 2,700 °C and squeezed them to more than 1 million times surface pressure. “These are really challenging experiments,” says Raymond Jeanloz of the University of California, Berkeley.

The mineral is up to 100 times more conductive under these conditions than it is near the surface, the team reports in Science 1.

The team estimates that a 300-kilometre-thick layer of post-perovskite would create an electromagnetic interaction “strong enough to account for millisecond-order level change in length of a day,” says Hirose. Unfortunately no one yet knows if such a layer actually exists.
Alternative theories

The team also found the conductivity of post-perovskite was sensitive to the amount of iron present in the mineral. This sensitivity might explain geological measurements showing that the electrical conductivity of the mantle is higher at the bottom of the mantle underneath Africa and the Pacific than it is elsewhere. “People thought that the temperature is higher, but our data shows it’s more likely that the chemical composition is different, more iron-rich,” says Hirose.

But other structures might also be responsible for decadal-scale fluctuations in the length of day. A scant 200-meter layer of iron, for example, could also create the same sort of electromagnetic interaction as 300 kilometres of post-perovskite. “Iron is kind of the magic ingredient here,” says Quentin Williams of the University of California, Santa Cruz. “We’re not exactly sure what the detailed iron content is at the core-mantle boundary.”

Alternatively, it might not be down to interactions in electromagnetic fields at all: some propose that a rough boundary on the underside of the mantle might be what’s interacting with the Earth’s liquid outer core, creating a periodic sloshing that changes the Earth’s rotation.

*
References
1. Ohta, K., et al. Science. 320, 89-91. ([year]2008[/year]).

Conductive mineral could change day length : Nature News.

Feel free to flame me…