Friday 24 August 2012
Why you should shut down your computer and not just press the off button
We just wondered if there is any harm in shutting down our computer by just pressing the power button for a few seconds, rather than going through the Windows shutdown procedure.
As far as people in concerned, the end result appears to be the same, the computer shuts down. In fact, from their point of view, holding the power button for a few seconds appears to shut down the computer immediately, whereas a proper Windows shutdown takes maybe 20 to 30 seconds. So is it a good idea to do this?
To get straight to the point, it is a very, very bad idea to shut down a computer by holding the power button.
In order to understand why this is such a bad idea, you need to understand a little about what a computer normally does during a standard Windows shutdown and why it needs to do these things.
During normal running,
- a computer hard disk is rotating thousands of times a minute
- the little arm that reads and writes data to the hard disk is moving backwards and forwards all the time
- Windows has many files open for reading and writing
- Windows may be reading and writing to the system registry
During a normal shutdown, (amongst doing many other things)
- Windows closes any files it was reading or writing
- Windows closes any access it has to the system registry
- the little hard disk arm is parked carefully at one side of the disk
So in comparison, what does holding the power button for a few seconds do?
Pressing the power button for a few seconds cuts power immediately to the whole computer.
What effect does this have?
Any files that Windows was writing to may now have incomplete or corrupt data, because you didn’t allow it to finish writing properly.
If Windows was writing to the registry, the system registry may now have incomplete or corrupt data because you didn’t allow it to finish writing.
The hard disk arm, not being allowed to park by the side of the disk, may scratch or damage the spinning disk, causing data to become corrupt.
Each of these things can cause hard disk data corruption. So what’s the big deal about that?
Well, for a long time you might get lucky and the data corruption may be in an area of the disk that you don’t notice, or a file that you can do without.
But one day, and it could be any day, you might find that one of your important programs no longer works because an important file is corrupt.
Or worse, Windows will no longer boot because the registry is corrupt.
Even worse again, the hard disk might have so many physical problems that it has to be replaced, potentially losing all your treasured photos, videos and documents that you always meant to backup but didn’t.
So please, for the sake of your data, and to avoid a costly repair, take a few seconds at the end of the day to shutdown Windows properly.
Tuesday 21 August 2012
10 causes of the Titanic tragedy
The "unsinkable" Titanic was sunk by an iceberg, but there are other reasons why the tragedy that occurred 100 years ago this month was as tragic as it was. Even a century later, the case of the Titanic illustrates how technological failures often result from a succession of omissions, missteps and bad luck rather than one big mess-up.
"No one thing sent the Titanic to the bottom of the North Atlantic," Richard Corfield writes in a Physics World retrospective on the disaster that caused 1,514 deaths on April 14-15, 1912. "Rather, the ship was ensnared by a perfect storm of circumstances that conspired her to her doom. Such a chain is familiar to those who study disasters — it is called an 'event cascade.'"
The iceberg that the Titanic struck on its way from Southampton to New York is No. 1 on a top-10 list of circumstances. Here are nine other suggested circumstances from Corfield's article and other sources :
Climate caused more icebergs : Weather conditions in the North Atlantic were particularly conducive for corralling icebergs at the intersection of the Labrador Current and the Gulf Stream, due to warmer-than-usual waters in the Gulf Stream, Richard Norris of the Scripps Institution of Oceanography told Physics World. "Oceanographically, the upshot of that was that icebergs, sea ice and growlers were concentrated in the very position where the collision happened," Norris said.
Tides sent icebergs southward : Last month, astronomers at Texas State University at San Marcos noted that the sun, the moon and Earth were aligned in such a way that could have led to unusually high tides in January 1912. They speculated that the tides could have dislodged icebergs that were stuck in the Labrador Sea, sending more of them toward the waters traversed by the Titanic a couple of months later.
The ship was going too fast : Many Titanicologists have said that the ship's captain, Edward J. Smith, was aiming to better the crossing time of the Olympic, the Titanic's older sibling in the White Star fleet. For some, the fact that the Titanic was sailing full speed ahead despite concerns about icebergs was Smith's biggest misstep. "Simply put, Titanic was traveling way too fast in an area known to contain ice; that's the bottom line," says Mark Nichol, webmaster for the Titanic and Other White Star Ships website.
Iceberg warnings went unheeded : The Titanic received multiple warnings about icefields in the North Atlantic over the wireless, but Corfield notes that the last and most specific warning was not passed along by senior radio operator Jack Phillips to Captain Smith, apparently because it didn't carry the prefix "MSG" (Masters' Service Gram). That would have required a personal acknowledgment from the captain. "Phillips interpreted it as non-urgent and returned to sending passenger messages to the receiver on shore at Cape Race, Newfoundland, before it went out of range," Corfield writes.
The binoculars were locked up : Corfield also says binoculars that could have been used by lookouts on the night of the collision were locked up aboard the ship — and the key was held by David Blair, an officer who was bumped from the crew before the ship's departure from Southampton. Some historians have speculated that the fatal iceberg might have been spotted earlier if the binoculars were in use, but others say it wouldn't have made a difference.
The steersman took a wrong turn : Did the Titanic's steersman turn the ship toward the iceberg, dooming the ship? That's the claim made in 2010 by Louise Patten, who said the story was passed down from her grandfather, the most senior ship officer to survive the disaster. After the iceberg was spotted, the command was issued to turn "hard a starboard," but as the command was passed down the line, it was misinterpreted as meaning "make the ship turn right" rather than "push the tiller right to make the ship head left," Patten said. She said the error was quickly discovered, but not quickly enough to avert the collision. She also speculated that if the ship had stopped where it was hit, seawater would not have pushed into one interior compartment after another as it did, and the ship might not have sunk as quickly.
Reverse thrust reduced the ship's maneuverability : Just before impact, first officer William McMaster Murdoch is said to have telegraphed the engine room to put the ship's engines into reverse. That would cause the left and right propeller to turn backward, but because of the configuration of the stern, the central propeller could only be halted, not reversed. Corfield said "the fact that the steering propeller was not rotating severely diminished the turning ability of the ship. It is one of the many bitter ironies of the Titanic tragedy that the ship might well have avoided the iceberg if Murdoch had not told the engine room to reduce and then reverse thrust."
The iron rivets were too weak : Metallurgists Tim Foecke and Jennifer Hooper McCarty looked into the materials used for the building of the Titanic at its Belfast shipyard and found that the steel plates toward the bow and the stern were held together with low-grade iron rivets. Those rivets may have been used because higher-grade rivets were in short supply, or because the better rivets couldn't be inserted in those areas using the shipyard's crane-mounted hydraulic equipment. The metallurgists said those low-grade rivets would have ripped apart more easily during the collision, causing the ship to sink more quickly that it would have if stronger rivets had been used. Other researchers have contested that claim, however.
There were too few lifeboats : Perhaps the biggest tragedy is that there were not enough lifeboats to accommodate all of the Titanic's more than 2,200 passengers and crew members. The lifeboats could accommodate only about 1,200 people — which was still in excess of the 1,060-person capacity that was the legal requirement for that time. "It seems that in 1912, in a way not dissimilar to our own box-ticking, responsibility-avoiding culture today, lack of effective oversight on the part of the authorities caused the consequences of the disaster to be much worse than they might have been," Corfield wrote.
"No one thing sent the Titanic to the bottom of the North Atlantic," Richard Corfield writes in a Physics World retrospective on the disaster that caused 1,514 deaths on April 14-15, 1912. "Rather, the ship was ensnared by a perfect storm of circumstances that conspired her to her doom. Such a chain is familiar to those who study disasters — it is called an 'event cascade.'"
The iceberg that the Titanic struck on its way from Southampton to New York is No. 1 on a top-10 list of circumstances. Here are nine other suggested circumstances from Corfield's article and other sources :
Climate caused more icebergs : Weather conditions in the North Atlantic were particularly conducive for corralling icebergs at the intersection of the Labrador Current and the Gulf Stream, due to warmer-than-usual waters in the Gulf Stream, Richard Norris of the Scripps Institution of Oceanography told Physics World. "Oceanographically, the upshot of that was that icebergs, sea ice and growlers were concentrated in the very position where the collision happened," Norris said.
Tides sent icebergs southward : Last month, astronomers at Texas State University at San Marcos noted that the sun, the moon and Earth were aligned in such a way that could have led to unusually high tides in January 1912. They speculated that the tides could have dislodged icebergs that were stuck in the Labrador Sea, sending more of them toward the waters traversed by the Titanic a couple of months later.
The ship was going too fast : Many Titanicologists have said that the ship's captain, Edward J. Smith, was aiming to better the crossing time of the Olympic, the Titanic's older sibling in the White Star fleet. For some, the fact that the Titanic was sailing full speed ahead despite concerns about icebergs was Smith's biggest misstep. "Simply put, Titanic was traveling way too fast in an area known to contain ice; that's the bottom line," says Mark Nichol, webmaster for the Titanic and Other White Star Ships website.
Iceberg warnings went unheeded : The Titanic received multiple warnings about icefields in the North Atlantic over the wireless, but Corfield notes that the last and most specific warning was not passed along by senior radio operator Jack Phillips to Captain Smith, apparently because it didn't carry the prefix "MSG" (Masters' Service Gram). That would have required a personal acknowledgment from the captain. "Phillips interpreted it as non-urgent and returned to sending passenger messages to the receiver on shore at Cape Race, Newfoundland, before it went out of range," Corfield writes.
The binoculars were locked up : Corfield also says binoculars that could have been used by lookouts on the night of the collision were locked up aboard the ship — and the key was held by David Blair, an officer who was bumped from the crew before the ship's departure from Southampton. Some historians have speculated that the fatal iceberg might have been spotted earlier if the binoculars were in use, but others say it wouldn't have made a difference.
The steersman took a wrong turn : Did the Titanic's steersman turn the ship toward the iceberg, dooming the ship? That's the claim made in 2010 by Louise Patten, who said the story was passed down from her grandfather, the most senior ship officer to survive the disaster. After the iceberg was spotted, the command was issued to turn "hard a starboard," but as the command was passed down the line, it was misinterpreted as meaning "make the ship turn right" rather than "push the tiller right to make the ship head left," Patten said. She said the error was quickly discovered, but not quickly enough to avert the collision. She also speculated that if the ship had stopped where it was hit, seawater would not have pushed into one interior compartment after another as it did, and the ship might not have sunk as quickly.
Reverse thrust reduced the ship's maneuverability : Just before impact, first officer William McMaster Murdoch is said to have telegraphed the engine room to put the ship's engines into reverse. That would cause the left and right propeller to turn backward, but because of the configuration of the stern, the central propeller could only be halted, not reversed. Corfield said "the fact that the steering propeller was not rotating severely diminished the turning ability of the ship. It is one of the many bitter ironies of the Titanic tragedy that the ship might well have avoided the iceberg if Murdoch had not told the engine room to reduce and then reverse thrust."
The iron rivets were too weak : Metallurgists Tim Foecke and Jennifer Hooper McCarty looked into the materials used for the building of the Titanic at its Belfast shipyard and found that the steel plates toward the bow and the stern were held together with low-grade iron rivets. Those rivets may have been used because higher-grade rivets were in short supply, or because the better rivets couldn't be inserted in those areas using the shipyard's crane-mounted hydraulic equipment. The metallurgists said those low-grade rivets would have ripped apart more easily during the collision, causing the ship to sink more quickly that it would have if stronger rivets had been used. Other researchers have contested that claim, however.
There were too few lifeboats : Perhaps the biggest tragedy is that there were not enough lifeboats to accommodate all of the Titanic's more than 2,200 passengers and crew members. The lifeboats could accommodate only about 1,200 people — which was still in excess of the 1,060-person capacity that was the legal requirement for that time. "It seems that in 1912, in a way not dissimilar to our own box-ticking, responsibility-avoiding culture today, lack of effective oversight on the part of the authorities caused the consequences of the disaster to be much worse than they might have been," Corfield wrote.
Sunday 12 August 2012
Best Place in Malaysia - Sipadan Island
The internationally famous island of Sipadan lies five degrees north of the equator in the Sulawesi Sea (Celebes Sea). Lying 35km south of Semporna, on Sabah’s mainland, like many tropical islands it is thickly forested and surrounded by sandy beaches. Sipadan is an oceanic island and was formed by living corals growing on top of an extinct undersea volcano, which rises 600m from the seabed.
The geographic position of Sipadan puts it in the centre of the richest marine habitat in the world, the heart of the Indo-Pacific basin. More than 3000 species of fish and hundreds of coral species have been classified in this richest of ecosystems. Sipadan is well known for its unusually large numbers of green and hawksbill turtles which gather there to mate and nest and it is not unusual for a diver to see more than 20 turtles on each dive. Another unique feature to divers visiting Sipadan is the turtle tomb, an underwater limestone cave with a labyrinth of tunnels and chambers that contain many skeletal remains of turtles that became disoriented and then drowned.
The geographic position of Sipadan puts it in the centre of the richest marine habitat in the world, the heart of the Indo-Pacific basin. More than 3000 species of fish and hundreds of coral species have been classified in this richest of ecosystems. Sipadan is well known for its unusually large numbers of green and hawksbill turtles which gather there to mate and nest and it is not unusual for a diver to see more than 20 turtles on each dive. Another unique feature to divers visiting Sipadan is the turtle tomb, an underwater limestone cave with a labyrinth of tunnels and chambers that contain many skeletal remains of turtles that became disoriented and then drowned.
The residential schooling barracuda and big-eye trevally, which often gather in thousands forming spectacular tornado-like formations, are one of the highlights of every diver’s wish-list. With the possibility of seeing pelagic species such as mantas, eagle rays, scalloped hammerhead sharks and whale sharks, each dive at Sipadan is a highly anticipated event.
It is not only the big fish that amaze divers coming to Sipadan, the macro life is equally mesmerizing. Garden eels, leaf scorpion fish, mantis shrimps, fire gobies, and various pipefish are guaranteed at various dive sites. The diversity and abundance of marine found at Sipadan gives it its reputation of being one of the ten best dive locations in the world.
Sipadan Island was established as a bird sanctuary in 1933 and in 2004, the Government of Malaysia has decided that all onsite dive resort operators are to move their operations out of Sipadan Island by 31st December 2004. The island is open for divers from 6am to 4pm - no night dives are allowed. The number of divers allowed to dive in Sipadan daily has also been limited to 120 pax in an effort to preserve the island’s pristine state.
Sipadan is a treasure which we want to save for the generations to come, before Sipadan can be saved, it must first be truly appreciated - hence the conservation efforts. Nevertheless, a treasure amounts to nothing if it cannot be enjoyed. Therefore, Sabah welcomes everyone to enjoy and appreciate Sipadan, and this appreciation will hopefully incite a bigger desire to save.
Sipadan Dive Sites
There a total of 12 dive sites in Sipadan Island namely the West Ridge, North Point, The Drop Off, Turtle Cavern, Barracuda Point, Coral Gardens, Whitetip Avenue, Mid Reef, Turtle Patch, South Point, Staghorn Crest, Lobster Lair, and the Hanging Gardens. The most popularly recommended dive sites are the Turtle Cavern, Barracuda Point, South Point and Hanging Gardens.
SIPADANS' SECRETS
The natural treasures of this island are its greatest assets. Here, you can still find wild deer in secluded coves. Dugongs, a cousin of the American manatees were known to swim the tides. Now they are hardly ever seen but are still held as one of Semporna's secrets.
Diving Sipadan's reefs, Jacques Cousteau was spellbound. "Go to Sipadan to see the schooling barracuda, to Mabul to see the seahorses and the erodes reefs of Kapalai to marvel at the detrius-like leaf fish" divers were told. Still today you will find turtles nesting under your beach hut on stilts and giant coconut crabs climbing the branches of a coconut palm. It has been said that the number of creatures on these reef surpass that of the tropical rainforest.
The coconut palm which grows in abundance here is precious to the people. The flesh and juice of a young fruit quenches the thirst. Sugar is made from the palm nectar and its wood is excellent for construction. Palms are thatched for roofing and leaves are weaved into baskets.
The natural glory of Sipadan remains. An arising awareness of the frailty of its natural wonders has rallied the defence of the island.
ATTRACTIONS
Barracuda Point
The Barracuda Point is located at the north Coast of Sipadan Island. Famous for its astounding vortex of barracudas (hence the name Barracuda Point), divers have also reported sightings of white tip sharks, grey reef sharks, eagle rays, turtles, as well as the bumphead parrotfish. A caveat: currents can get too strong, so don't go too deep!
Turtle Cavern
This site is famous for its population of green turtles and smaller hawksbill turtles. This cavern which lies 20 meters underwater is believed to be the final resting place of turtles. Divers are reminded to be extremely careful when exploring the caves as visibility can be drastically reduced to zero should the silt be disturbed.
South Point
South Point is one of the most likely sites for the rarer sharks such as the hammerheads and thresher sharks which are normally only seen around the 40-meter point. Divers are advised to be wary of the strong currents at this site.
Hanging Gardens
Named after the Hanging Gardens of Babylon, the topography of the Hanging Gardens consists of a 2-meter-deep reef that slopes down to a terrace at about 70 meters which subsequently plunges into an abyss. This is an excellent spot to view soft corals with dendronephthya alcyonarians in multifarious pastel colours encrusting the slope. Do keep an eye also for the diverse macro life.
Where to Stay
The Malaysian government has decided that all existing onsite dive resort operators were to move their operations out of the Sipadan Island by 31st December 2004. The move is aimed at conserving and maintaining a balanced marine and land ecosystem on Sipadan’s environments. However, Sipadan will remain as a dive site and divers are to be ferried by operators operating from the mainland or nearby islands other than Sipadan and Ligitan.
On an overnight trip to Sipadan, choose to stay in any one of these excellent resorts:
1-Borneo Divers & Sea Sports (Sabah) Sdn Bhd (KPL 1510)
2-Explore Asia Tours Sdn Bhd (Sipadan-Mabul Resort) (KPL 2941)
3-Seaventures Tours & Travel Sdn Bhd (KPL/LN 2639)
4-Sipadan Water Village Resort Sdn Bhd (KPL 3143)
* Resort rates may vary
Getting There
From Kota Kinabalu, take a 55-minute flight to Tawau and enjoy an hour’s drive to Semporna. From Semporna, Sipadan is another 40 minutes by speedboat. Be sure to pre-arrange transportation with your respective resort/dive operator.
More Information
For booking and enquiries, please refer to the list of Sabah Dive Operators
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