Do ghosts really exist? Well, if scientists are to be believed, they do but "in the mind" only.
The researchers at the University College in London have found that that when people gaze around in a poorly lit context, it can fool their brains into seeing things that are not really there.
"The context surrounding what we see is all important -- sometimes overriding the evidence gathered by our eyes and even causing us to imagine things.
"Illusionists have been alive to this phenomenon for years. When you see them throw a ball into the air, followed by a second ball, and then a third ball which 'magically' disappears, you wonder how they did it.
"In truth, there's often no third ball -- it's just our brain being deceived by the context, telling us that we really did see three balls launched into the air, one after the other."
"This could also be why monsters tend to lurk in the shadows. In shadows many things are seen vaguely (rather than clearly), thus tending to trigger the filling in," 'The Daily Telegraph' quoted lead researcher Prof Li Zhaoping as saying.
In their study, 18 observers were asked by the team to concentrate on the centre of a black computer screen.
Every time a buzzer sounded they pressed one of two buttons to record whether or not they had just seen a small, dim, grey "target" rectangle in the middle of the screen. It didn't appear every time, but when it did it was displayed for just 80 milliseconds (80 one thousandths of a second).
"People saw the target much more often if it appeared in the middle of a vertical line of similar looking, grey rectangles, compared to when it appeared in the middle of a pattern of bright, white rectangles. They even registered 'seeing' the target when it wasn't actually there.
"This is because people are mentally better prepared to see something vague when the surrounding context is vague. "It made sense for them to see it -- so that's what happened. When the target didn't match the expectations set by the surrounding context, they saw it much less often," said Prof Zhaoping.
The results of the study have been published in the 'PLoS Computational Biology' journal.
Saturday, February 23, 2008
Friday, February 15, 2008
Flash drives ready to jump in capacity
In the wake of a series of technical announcements from flash memory supplier SanDisk, larger-capacity solid-state drives are on the way.
SanDisk 72GB solid state drive(Credit: SanDisk)
Flash memory is gaining as a replacement for hard drives in ultra-thin, ultra-small notebooks such as the MacBook Air and Asus Eee PC. Why? Flash uses less power, generates less heat, and has faster access times than hard drives. The Air, for example, offers a 64GB flash-based SSD as an option while the Eee PC is sold standard with flash storage.
There is a big catch, though. High-capacity SSDs are expensive. Prohibitively so. The flash drive in the pricier $3,098 Air is the main culprit in the gaping $1,300 price difference with the lower-cost hard-drive model ($1,799). Update: SSDs also have limited write cycles. That is, flash drives can eventually "wear out" after hundreds of thousands of write cycles. File systems that spread the write over the device can extend the life cycle but it's still an issue.
The low power and high speed, however, make a flash drive almost irresistible for some users. A SanDisk SSD 1.8-inch drive achieves a sustained read rate of 66MB/sec and a random read rate of over 7,000 inputs/outputs per second for a 512-byte transfer, many times the speed of a hard drive--which must move an arm across a spinning platter to find data, the so-called seek time of a hard drive.
SanDisk will not discuss future pricing but as larger-capacity SSDs hit the market, prices are certain to fall. And eventually these will be steep price drops. For example, an 8GB SanDisk flash card now sells for about $80 at resellers. A few years ago consumers would have paid this much (or more) for a 1GB drive. (And a 1GB card was originally priced at $500 in 2004!)
SanDisk and Toshiba will start making flash memory on a new 43-nanometer manufacturing process that will result in SSDs later this year with capacities that should approach those of today's mainstream 2.5-inch hard drives, ranging between 120GB and 160GB.
The two companies recently achieved 32-gigabit (Gb) density, according to Khandker N. Quader, SanDisk's senior vice president of flash memory design and product development. The 32Gb die combined with multilevel cell (MLC) technology--which uses multiple levels per cell to allow more bits to be stored--"doubles the SSD capacity points," Quader said in a written response to questions.
Flash based on "X3" technology is another new development, Quader said. "This is an important milestone (and) allows us to do 3bits/cell as opposed to 2bits/cell thereby providing improved manufacturing efficiency," he said. "So a combination of technology scaling (i.e., 56nm to 43nm) and the bit scaling (i.e. 2bits/cell to 3bits/cell) is extremely powerful for manufacturing efficiency and for increasing capacities of flash memories."
But there are challenges. Moving to X3 can affect performance. "One very important point to take into consideration is that X3 is not a simple memory to manage," Quader said. "This is the first generation X3. We expect this to evolve in 2008."
SanDisk has also developed a 43nm 16Gb MLC for MicroSD, according to Quader. MicroSD is a tiny flash chip used in mobile phones. The new technology will double the capacity of current 8GB MicroSD, he said.
SanDisk 72GB solid state drive(Credit: SanDisk)
Flash memory is gaining as a replacement for hard drives in ultra-thin, ultra-small notebooks such as the MacBook Air and Asus Eee PC. Why? Flash uses less power, generates less heat, and has faster access times than hard drives. The Air, for example, offers a 64GB flash-based SSD as an option while the Eee PC is sold standard with flash storage.
There is a big catch, though. High-capacity SSDs are expensive. Prohibitively so. The flash drive in the pricier $3,098 Air is the main culprit in the gaping $1,300 price difference with the lower-cost hard-drive model ($1,799). Update: SSDs also have limited write cycles. That is, flash drives can eventually "wear out" after hundreds of thousands of write cycles. File systems that spread the write over the device can extend the life cycle but it's still an issue.
The low power and high speed, however, make a flash drive almost irresistible for some users. A SanDisk SSD 1.8-inch drive achieves a sustained read rate of 66MB/sec and a random read rate of over 7,000 inputs/outputs per second for a 512-byte transfer, many times the speed of a hard drive--which must move an arm across a spinning platter to find data, the so-called seek time of a hard drive.
SanDisk will not discuss future pricing but as larger-capacity SSDs hit the market, prices are certain to fall. And eventually these will be steep price drops. For example, an 8GB SanDisk flash card now sells for about $80 at resellers. A few years ago consumers would have paid this much (or more) for a 1GB drive. (And a 1GB card was originally priced at $500 in 2004!)
SanDisk and Toshiba will start making flash memory on a new 43-nanometer manufacturing process that will result in SSDs later this year with capacities that should approach those of today's mainstream 2.5-inch hard drives, ranging between 120GB and 160GB.
The two companies recently achieved 32-gigabit (Gb) density, according to Khandker N. Quader, SanDisk's senior vice president of flash memory design and product development. The 32Gb die combined with multilevel cell (MLC) technology--which uses multiple levels per cell to allow more bits to be stored--"doubles the SSD capacity points," Quader said in a written response to questions.
Flash based on "X3" technology is another new development, Quader said. "This is an important milestone (and) allows us to do 3bits/cell as opposed to 2bits/cell thereby providing improved manufacturing efficiency," he said. "So a combination of technology scaling (i.e., 56nm to 43nm) and the bit scaling (i.e. 2bits/cell to 3bits/cell) is extremely powerful for manufacturing efficiency and for increasing capacities of flash memories."
But there are challenges. Moving to X3 can affect performance. "One very important point to take into consideration is that X3 is not a simple memory to manage," Quader said. "This is the first generation X3. We expect this to evolve in 2008."
SanDisk has also developed a 43nm 16Gb MLC for MicroSD, according to Quader. MicroSD is a tiny flash chip used in mobile phones. The new technology will double the capacity of current 8GB MicroSD, he said.
Friday, February 01, 2008
Orkut turns four; aims to outgrow rivals
Internationally popular social networking website Orkut, which celebrated its fourth birthday, sees a long journey ahead and does not have any threat perception from rivals like LinkedIn and Facebook.
"Each of us has a different target userbase, we, at Orkut, aim casual and leisure exchanges between family and friends, as compared to a LinkedIn, which targets professional exchanges between individuals," Google India Country Head, Products, Vinay Goel said.
Orkut, with a strong India following, started as a plain vanilla exchange platform, but has now moved to the next level as a mature user now wants newer features.
So, as compared to the early structure where anyone could visit any person's account and get to know the personal details and conversations taking place between individuals there, one has now the option to restrict visitors.
"This new feature is increasingly becoming popular, and more so amongst women," Goel said.
Answering on Orkut platform playing the pivotal role in the murder of 16-year-old Mumbai boy Adnan Patrawala, he said "Adnan's case was very unfortunate." "It is hard to rectify each user registering on the website in India, but we do work in close contact with law and order departments over them," Goel said.
99.9 per cent use it for the right purposes as a platform of self expression. Also, we try to educate them on etiquettes of being a part of a social networking sites through the privacy and security centre.
"Each of us has a different target userbase, we, at Orkut, aim casual and leisure exchanges between family and friends, as compared to a LinkedIn, which targets professional exchanges between individuals," Google India Country Head, Products, Vinay Goel said.
Orkut, with a strong India following, started as a plain vanilla exchange platform, but has now moved to the next level as a mature user now wants newer features.
So, as compared to the early structure where anyone could visit any person's account and get to know the personal details and conversations taking place between individuals there, one has now the option to restrict visitors.
"This new feature is increasingly becoming popular, and more so amongst women," Goel said.
Answering on Orkut platform playing the pivotal role in the murder of 16-year-old Mumbai boy Adnan Patrawala, he said "Adnan's case was very unfortunate." "It is hard to rectify each user registering on the website in India, but we do work in close contact with law and order departments over them," Goel said.
99.9 per cent use it for the right purposes as a platform of self expression. Also, we try to educate them on etiquettes of being a part of a social networking sites through the privacy and security centre.
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