Universe expansion ‘is speeding up’

Astronomers have claimed that the expansion of the universe is accelerating, after studying thousands of galaxies using the Hubble Space Telescope. In its research, an international team has analysed nearly 446,000 galaxies to map the matter distribution and the expansion history of the universe, proving again that Albert Einstein’s theory of relativity is indeed correct. And the astronomers clearly found that the universe was indeed growing faster and faster with time, as predicted by Einstein.

“Our results confirmed that there is an unknown source of energy in universe which is causing the cosmic expansion to speed up, stretching the dark matter further apart exactly as predicted by Einstein’s theory,” lead astronomer Ludovic Van Waerbeke of Leiden University in the Netherlands said.

Einstein’s theory of general relativity predicts that space and time is a soft geometrical structure of which the shape and evolution are entirely determined by the matter within it.

According to the astronomers, the universe is composed of dark matter and normal matter with third constituent called “dark energy”, which over the past two billion years has been the force behind the accelerated expansion of the universe. “The data from our study are consistent with these predictions and show no deviation from Einstein’s theories,” Van Waerbeke said.

How Google results are filtered in China ?

Type “Falun Gong” in Chinese into Google’s search engine from Beijing, and the Web browser suddenly becomes unresponsive for about a minute.

Make the same search from Hong Kong, and you’ll get plenty of links to the spiritual movement banned by the Chinese government.

Internet users in mainland China and Hong Kong now share the same Google search site, but their experiences continue to widely differ, particularly on topics deemed sensitive by China’s Communist leaders. The difference is that the government, rather than Google Inc, is now doing the censoring.

The findings in a recent Associated Press test offer insights into the sophistication with which China uses its complex “Great Firewall” to filter its citizens’ online view of the world.

Recent searches for taboo topics from Beijing generally produced “page cannot be displayed” errors. The user’s browser stops working for about a minute, longer if one tries to access forbidden sites in quick succession. In other words, it’s not just the links to those sites that don’t work; the results don’t come back at all.

Yet the filters aren’t exact, and English-language sites have a greater chance of slipping through, partly because the government is more concerned about the vast majority of citizens who speak only Chinese. And even as the Great Firewall blocks Twitter and sensitive blog postings, excerpts do show up on Google’s search results page.

The findings illustrate how China’s vast government-run network of Web filters works. When a user enters a sensitive term in a search, it triggers a brief blockage that affects subsequent searches — even those on innocuous topics — by that user or anyone else at the same numeric Internet address. That can be one computer or an entire cybercafe.

Chinese-language searches for missing Chinese activist lawyer Gao Zhisheng, jailed Chinese dissident Liu Xiaobo, Chinese President Hu Jintao and “June 4 incident” — known elsewhere as the 1989 Tiananmen Square crackdown — all led to the Web browser in Beijing hanging for a minute or longer.

Before Google killed its mainland search service Monday and redirected “Google.cn” traffic to its existing Hong Kong-based site, Google returned censored results with a note explaining that some items had been removed. Google needed to comply with Chinese laws, but it wanted users to know about the omissions in hopes they would pressure their government to lift restraints.

But Google announced January 12 that it was no longer willing to censor those results after it discovered it was the target of hacking attacks originating from China. Unable to reach agreement with the ruling party on running an uncensored search service, Google decided to send mainland users to Hong Kong, a Chinese territory that is semi-autonomous because of its past as a British colony.

Some Google searches produce the same results whether from Beijing or Hong Kong. Among them: “Michael Jackson” and “March 14 incident,” which refers to the 2008 anti-Chinese riots in the Tibetan capital, Lhasa. “Taiwan” also produced no difference in search results, despite tensions with a region that China considers its own.

In other cases, results appear the same, but the text ads alongside them differ. A recent search for “iPhone” in Hong Kong produced two sponsored links, for the Apple store in Hong Kong and for Vodafone, while the one in Beijing led to the mainland version of Apple’s home page. In most cases, though, the mainland version of the search produced more ads than in Hong Kong.

Google routinely uses a computer’s numeric Internet address to determine the visitor’s location and adjust search results and ads accordingly. Visiting the US-focused Google.com site from Geneva, for instance, often takes you automatically to the Swiss version of the site at Google.ch. Even within the United States, sites for some local businesses may show up higher or lower in the results depending on where you are.

Thus, despite Google’s decision to give mainland users the Hong Kong site, at Google.com.hk, visitors from Beijing still see differences having nothing to do with China’s filters.

With the change, Hong Kong’s site began displaying search results in the simplified Chinese characters that are used in mainland China, but Hong Kong visitors still get a page in the traditional Chinese script, with links to versions for English or simplified Chinese.

Beijing visitors get the simplified version first, and their Hong Kong page looks much like the old Google.cn, with colorful, animated icons offering quick links to video, shopping and other popular features.

The Google-owned online video leader YouTube is typically blocked on the mainland. In Beijing, searches on a separate Google video service are directed to a Google.cn site where the company is still censoring results. Video, music and maps are among the features that Google continues to operate in China. In Hong Kong, however, video searches go to the Hong Kong site, where results are not censored.

Meanwhile, Hong Kong users can reach a China-only music service, but unless you’re on the mainland, you get this advisory when you try to listen to a song: “Music streaming/download services are not available in your region.”

Despite the pervasive reach of the Great Firewall, mainland Chinese can use Google’s Hong Kong site for a glimpse of material that is usually blocked.

Consider a search for “Obama.” One recent search from Beijing produced a page leading with news stories about the US president, but the results page also included recent posts by people on Twitter, a social-messaging service that is blocked in China.

In a Chinese-language search for “Tibet,” Google includes excerpts from such blogs as Invisible Tibet, which is written by the well-known Tibetan poet and activist Woeser and is usually blocked in China.

Not surprisingly, attempts to access the blog from the search page failed. By comparison, a search for Woeser’s blog on the Chinese search site Baidu.com produced one line: “The search results could involve content that fails to comply with the relevant laws, regulation and policies, and are not displayed.”

Meanwhile, a search for “Tibet” in English shows links to Free Tibet, the International Campaign for Tibet and other activist sites.

The Great Firewall isn’t an exact science, but it’s meant to keep most of the sensitive content from most of the citizens most of the time.

Near field communication: What it is and how it works ?

For the layperson, how does NFC work?

NFC is basically a form of radio communication, but it uses very low-power radios. It’s related to radio-frequency identification (RFID) as well.

In its simplest form, you have two electronic devices. Each has a battery, a radio, and a processor on-board. One sends a stream of data to the other, and the other responds. They transmit with such low power that the signal is lost after only a few inches. So in order for them to communicate, you have to basically touch them together.

RFID can also be classified as Near Field Communication, though not all forms of RFID use the same data protocols as NFC devices. RFID comes in two flavors: active and passive.

Active RFID works just as NFC does: two powered devices, two radios, and a transmission between them. The range doesn’t need to be short; it can be as long as you have power to transmit. The EZ-Pass system you see on toll roads is a good example of active RFID — it can cover several meters.

Passive RFID, on the other hand, is generally very short range, because there is only one powered device. The RFID reader sends out a radio signal. When an RFID tag is in range, it receives the signal, and uses the energy of the radio transmission to power itself. The amount of energy isn’t great, so the RFID tag can only power itself long enough to send a signal back to the reader, then it shuts down.

How significant will NFC technology be in the coming years?

NFC, coupled with RFID tags, creates a really cool channel for devices and objects to talk to one another. Tom and I have done lots of freaky projects with BluetoothXBee/ZigBeeWi-Fi — all things that communicate over a reasonable distance. But NFC and RFID give us the ability to have objects that are close to one another talk to each other. And one thing I love is that the RFID side of the equation lets un-powered objects — anything you can embed a tag in — play in this game of networked objects.

That, to me, is the starting point for all this. I don’t want to worry about whether NFC payments are going to take off, or if NFC will replace the business card. What I love about this is that it gives us another way for objects to participate in the “Internet of things.”

Are there any impressive or unique ways that NFC is being used right now?

There’s one story that seems to dominate the headlines, and that’s about using NFC for payments. But for me, the more interesting application is replacing QR codes. Imagine you’re standing outside a restaurant, and there’s a sticker in the window with a QR code that takes you somewhere for reviews. How long does that take? Half a minute to fire up your QR code scanner, two minutes of cursing because there’s not enough light or there’s glare on the glass, and when you eventually get it working, your friends have already searched for it on Google and read the reviews. And that’s assuming you’re enough of a power user to already have an app like Barcode Scanner or Red Laser installed.

Compare that to NFC. I can tap the sign with my Nexus S, and it will fire up the built-in Tags app (see video below), and take me right to the URL. It’s really fast. Tap your phone to the thing you want to create a relationship with, and you’re done.

NFC security is a concern for some. How well is this issue being addressed?

When people ask that question, I find that they haven’t done enough research to know why they should be concerned. Why are you not worried about Wi-Fi security? Or mobile phone security? Both of them use the same technology: radio transmission. Yet no one raises concerns about those.

I think the confusion stems from the fact that people think an RFID tag or an NFC device actually contains secret data about them. In fact, most of the time the only data on an RFID tag or NFC device is a serial number. In order for that number to mean anything, it has to be associated with other data in a database, and the database has to be attached to an RFID reader. The same is true of magnetic stripe credit cards — the data is not on the card. It’s a serial number that associates that card with your record in the database. It’s possible to record more than just the serial number on your card, but in order to extract that information, a more complex transaction involving encryption and passkeys has to happen.

Unlike mag-stripe cards, however, you don’t need to swipe an RFID or NFC card through a reader in order to read it. You merely need to bring it within a few centimeters of your reader. So people often ask, “Does that mean you can read my card in my wallet or my purse?” Sure, if you touch your wallet or purse to my reader. But if I get that close to you, I might as well just steal your whole wallet!

Practically speaking, it’s as difficult — or more so — to steal your credit card number off your RFID-enabled credit card as it is off your traditional credit card, assuming you handle your card with the same amount of basic caution. Practice some common sense, and you’re not in danger.

What are the most significant obstacles NFC faces?

The biggest issues at this point are compatibility — there are several different protocols that are incompatible with each other — and documenting the technologies in such a way that industrial designers know how to make them work best. Timo Arnall, Einar Martinussen, and the folks at BERG studios have done some good work on this at nearfield.org.

If you were to implement a solution today using RFID, you’d have some good choices at your disposal for secure solutions. However, there are insecure, first-generation — and probably second-generation and beyond — systems still in use that should be replaced.

Source: O’Reilly

Why are wedding rings worn on the ring finger ?

Of our ten fingers, the fourth finger on the left hand is generally known as the ring finger, or the wedding finger. This is where most brides wear their wedding rings. Though it is not always the case. In some countries, wedding rings are worn on the fourth finger of the right hand. This was the custom in England until the end of the sixteenth century and lasted among Roman Catholics until much later.

There is a practical reason for wearing wedding rings on the fourth finger of the left hand. It is well protected from accidental damage in everyday activities. There is also a more romantic one. An old belief holds that a small artery runs directly from this finger to the heart – and as any love song will tell you, the heart has a big part to play in marriage.

How does Teddy Bear gets its name ?

Teddy bears have been around since 1902. That was the year they first appeared in both the USA & Germany. No one knows for sure which country was first with the bear.

There is a question mark over the name ‘Teddy Bear’ too. The likeliest explanation seems to be that it is named after the American president at the time. He was Theodore Roosevelt and his nickname was Teddy. He liked bear hunting. But he also respected bears and once refused to shoot a captive bear cub. This story appeared in a cartoon in November 1902 and the Teddy Bear was born.

Why is Friday the Thirteenth thought to be unlucky ?

There are several reasons why Friday has been considered the most unlucky day of the week. Jesus Christ was crucified on a Friday. Friday was traditionally the day when criminals were executed. According to one superstition, if you cut your nails on a Friday, witches would pick up the pieces and turn you into a witch yourself.

Friday was also known as ‘Tip Tod’s Day’, meaning the Devil’s Day. In earlier times, sailors didnt like putting to sea on Friday. And it was also said that work started on a Friday was never finished ( which sounds like a good excuse for taking Friday easy 😛 ).

Then there is thirteen. This has been an unlucky number in the Christian world ever since thirteen sat down to eat at the Last Supper on the night before Jesus Christ was crucified.

How can horses sleep while standing up ?

Most of us need eight hours of sleep a night. Horses can get by with only half the amount & unlike us, they are able to fall asleep standing up, without falling over.

In the wild, horses are prey to wolves and other animals. Lying down, they are much more vulnerable than they are standing up. So over millions of years, their bodies have developed a way of staying upright even when they are asleep. Although most horses no longer live in the wild, they can still fall asleep as their ancestors used to.

The reason they are able to do this is a unique system of ligaments – the chords which bind bones together. A horse’s ligaments act like a sling over its whole body. These can lock its joints into a fixed position, so it can stand upright without any coscious muscular effort while sleeps.

It is a pity that human beings have not developed a way of doing this. It could be very handy for long queues or travelling on crowded trains!

Why is a hat trick a hat trick ?

Almost anything we manage to do three times in a row is called a hat trick today. The one thing you can be fairly sure of is that it seldom, if ever, involves a hat. However, a hundred years ago a hat gave rise to the expression. In those days, hat tricks only occurred in game of cricket.

Back in the 1880s, a bowler who took three wickets with three balls bowled one after the other was given a new hat by his club. The feat became known as a hat trick and, as it caught on, people began applying the term to all sorts of other sports & activities.

Why do clocks run clockwise ?

Mechanical clocks were invented in the northern hemisphere, the half of the world north of the Equator. Before they existed, people used sundials to tell the time. In a sundial, it is the shadow cast by the bit in the centre that actually indicates the time of day. In the northern hemisphere, this moves in what we now call a clockwise direction. So when the first mechanical clocks were invented, their faces and hands were built to follow the same direction.

If clocks had been invented in the southern hemisphere, everything would have been reversed. The shadow on the sundial mover in the opposite direction, and presumably clocks would have been built to run that way too.

Mystery #2

Why doesn’t Tarzan have a beard?

Why do banks charge a fee on ‘insufficient funds’ when they know there is not enough?

What is the speed of darkness?

Why is it that people say they ‘slept like a baby’ when babies wake up every two hours?

If the temperature is zero outside today and it’s going to be twice as cold tomorrow, how cold will it be?

Do married people live longer than single ones or does it only seem longer?

How is it that we put man on the moon before we figured out it would be a good idea to put wheels on luggage?

Why do people pay to go up tall buildings and then put money in binoculars to look at things on the ground?

Did you ever stop and wonder…

Who was the first person to look at a cow and say, ‘I think I’ll squeeze these pink dangly things here, and drink whatever comes out?’

Who was the first person to say, ‘See that chicken there… I’m gonna eat the next thing that comes outta its bum.’

Why do toasters always have a setting so high that could burn the toast to a horrible crisp, which no decent human being would eat?

Why is there a light in the fridge and not in the freezer?

Why do people point to their wrist when asking for the time, but don’t point to their bum when they ask where the bathroom is?

Why does Goofy stand erect while Pluto remains on all fours? They’re both dogs!

If quizzes are quizzical, what are tests?

If electricity comes from electrons, does morality come from morons?

Why do the Alphabet Song and Twinkle Twinkle Little Star have the same tune?

Does pushing the elevator button more than once make it arrive faster?