Saturday, July 12, 2008
The History of Science and Technology
Friday, July 11, 2008
Space: A Journey To Our Future
Highlights of “Space: A Journey to Our Future” include: the Lunar Base Camp where visitors can experience what it would be like to live on the moon; an up-close look at NASA’s Constellation Program and a model of the Orion, the spacecraft that will take human explorers back to the moon; an illustrated timeline of NASA’s 50 years of space exploration; and the multimedia 360-degree “Future Theatre.”
"Space: A Journey to Our Future" is a traveling exhibit developed by Evergreen Exhibitions presented at the National Air and Space Museum courtesy of NASA on its 50th anniversary.
This exhibition is made possible through the generous support of the National Aeronautics and Space Administration, General Motors, and Lockheed Martin.
Thursday, July 3, 2008
Reflections on the Blank Slate
Author and journalist, Matt Ridley was the host of a public discussion with author Steven Pinker as part of the University of Newcastle's public lecture programme. Pinker is Professor of Psychology at MIT.
Professor Pinker especially, has pushed the debate into the mainstream with his recent book 'The Blank Slate'. In it he argues that there are many myths operating in society that can be traced directly to a subtle but fervent belief in three discredited notions. He calls these a belief in the "Blank Slate", the "Noble Savage" and the "Ghost in the Machine". This website is as good an introduction as any which may pursuade you to read further.
Wednesday, June 25, 2008
Dispelling Some Common Myths about Science
Science is not a new kind of knowledge; it is not created only by a professional elite; and "The Scientific Method" is really many methods, including aspects of basic intelligence found in infants and animals.
Monday, June 16, 2008
Myths in Science
As an introduction to this disconcerting topic let me direct you to the TEN MYTHS OF SCIENCE as spelled out by William McComas of the School of Education, University of Southern California.
Monday, June 9, 2008
Brain Stem Cells Can Be Awakened, Say Scientists
An earlier paper (published in the May issue of Stem Cells) by the same scientists laid the foundation for the PNAS study findings by demonstrating that neural stem cells exist in every part of the brain, but are mostly kept silent by chemical signals from support cells known as astrocytes.
"The findings from both papers should have a far-reaching impact," says principal investigator, Dr. Dong Feng Chen, who is an associate scientist at Schepens Eye Research Institute and an assistant professor of ophthalmology at Harvard Medical School. Chen believes that tapping the brain's dormant, but intrinsic, ability to regenerate itself is the best hope for people suffering from brain-ravaging diseases such as Parkinson's or Alzheimer's disease or traumatic brain or spinal cord injuries.
Until these studies, which were conducted in the adult brains of mice, scientists assumed that only two parts of the brain contained neural stem cells and could turn them on to regenerate brain tissue-- the subgranular zone (SGZ) of the hippocampus and the subventricular zone (SVZ). The hippocampus is responsible for learning and memory, while the SVZ is a brain structure situated throughout the walls of lateral ventricles (part of the ventricular system in the brain) and are responsible for generating neurons reponible for smell. So scientists believed that when neurons died in other areas of the brain, they were lost forever along with their functions.
In the first study, Chen's team learned that stem cells existed everywhere in the brain by testing tissue from different parts of adult mice brains in cultures containing support cells (known as astrocytes) from the hippocampus, where stem cells do regenerate. In the cultures the stem cells from other brain regions came to life and turned into neurons.
When they compared the chemical makeup of the areas known to generate new neurons in the hippocampus with other parts of the brain, the team discovered that astrocytes in the hippocampus were sending one signal to the stem cells and that those from the rest of the brain were sending a different signal to stem cells.
In the second (PNAS) study, the team went on to discover the exact nature of those different chemical signals. They learned that in the areas where stem cells were sleeping, atrocytes were producing high levels of two related molecules--ephrin-A2 and ephrin-A3. They also found that removing these molecules (with a genetic tool) activated the sleeping stem cells.
The team also found that astrocytes in the hippocampus produce not only much lower levels of ephrin-A2 and ephrin-3, but also release a protein named sonic hodghoc that, when added in culture or injected into the brain, stimulates neural stem cells to divide and become new neurons.
"These findings identify a key pathway that controls neural stem cell growth in the adult brain and suggest that it may be possible to reactivate the dormant regenerative potential by adding sonic hedgehoc, or blocking ephrin-A2 or ephrin-A3," says Dr. Jianwei Jiao, the first author of the two papers,
The next step for the team will be to stimulate the sleeping stem cells in animals who are models of neurodegenerative disorders, such as Parkinson's disease, to see if the brains can repair themselves and restore their damaged functions.
Monday, May 26, 2008
Are Cell Phones Really So Dangerous?
The estimates of annual deaths reported in this week's article (2,600) may well be low. The number, for U.S. deaths related to drivers using cell phones, comes from a 2002 study by the Harvard Center for Risk Analysis (HCRA). Researchers then estimated that the use of cell phones by drivers caused approximately 2,600 deaths.
Because data on cell phone use by motorists are limited, the range of uncertainty is wide, those researchers said. The estimate of fatalities in that HCRA report ranged between 800 and 8,000.
Importantly, the researchers noted (in 2002) that increasing cell phone use could be expected to cause the annual death estimate to rise. The 2002 estimate, for example, was up from an estimate of 1,000 deaths in the year 2000. Logic suggests the number -- though just an estimate -- could be much higher in 2005.
The estimates are based largely on mathematical models, but they are not without basis. In 2001 in California, for example, "at least 4,699 reported accidents were blamed on drivers using cell phones, and those crashes killed 31 people and injured 2,786," according to an analysis by The Los Angeles Times. That number can expected to be low, because of the lack of formal procedures for noting cell phone use as a cause of a traffic accident.
The Times also noted a 1997 study of Canadian drivers "who agreed to have their cell phone records scrutinized found that the risk of an accident was four times greater while a driver was using the phone."
Each year, about 42,000 people die in U.S. auto accidents.
Here is how the new University of Utah simulations were conducted:
Participants in the simulator used dashboard instruments, steering wheel and brake and gas pedals from a Ford Crown Victoria sedan, surrounded by three screens showing freeway scenes and traffic, including a "pace car" that intermittently hit its brakes 32 times as it appeared to drive in front of study participants.
If a participant failed to hit their own brakes, they eventually would rear-end the pace car. Each participant drove four simulated 10-mile freeway trips lasting about 10 minutes each, talking on a cell phone with a research assistant during half the trips and driving without talking the other half. Only hands-free phones were used to eliminate any possible distraction from manipulating a hand-held cell phone.
Thirty times each second, the simulator measured the participants' driving speed, following distance and - if applicable - how long it took them to hit the brakes and how long it took them to regain speed.
Drivers on Cell Phones Kill Thousands........
Finally, empirical proof you can blame chatty 20-somethings for stop-and-go traffic on the way to work.
A new study confirms that the reaction time of cell phone users slows dramatically, increasing the risk of accidents and tying up traffic in general, and when young adults use cell phones while driving, they're as bad as sleepy septuagenarians.
"If you put a 20-year-old driver behind the wheel with a cell phone, their reaction times are the same as a 70-year-old driver who is not using a cell phone," said University of Utah psychology professor David Strayer. "It's like instantly aging a large number of drivers."
The study was announced today and is detailed in winter issue of the quarterly journal Human Factors.
Traffic jams and death
Cell phone distraction causes 2,600 deaths and 330,000 injuries in the United States every year, according to the journal's publisher, the Human Factors and Ergonomics Society.
The reason is now obvious:
Drivers talking on cell phones were 18 percent slower to react to brake lights, the new study found. In a minor bright note, they also kept a 12 percent greater following distance. But they also took 17 percent longer to regain the speed they lost when they braked. That frustrates everyone.
"Once drivers on cell phones hit the brakes, it takes them longer to get back into the normal flow of traffic," Strayer said. "The net result is they are impeding the overall flow of traffic."
Strayer and his colleagues have been down this road before. In 2001, they found that even hands-free cell phone use distracted drivers. In 2003 they revealed a reason: Drivers look but don't see, because they're distracted by the conversation. The scientists also found previously that chatty motorists are less adept than drunken drivers with blood alcohol levels exceeding 0.08.
Separate research last year at University of Illinois at Urbana-Champaign supported the conclusion that hands-free cell phone use causes driver distraction.
"With younger adults, everything got worse," said Arthur Kramer, who led the Illinois study. "Both young adults and older adults tended to show deficits in performance. They made more errors in detecting important changes and they took longer to react to the changes."
The impaired reactions involved seconds, not just fractions of a second, so stopping distances increased by car-lengths.
Older drivers more cautious
The latest study used high-tech simulators. It included people aged 18 to 25 and another group aged 65 to 74. Elderly drivers were slower to react when talking on the phone, too.
The simulations uncovered a twofold increase in the number of rear-end collisions by drivers using cell phones.
Older drivers seem to be more cautious overall, however.
"Older drivers were slightly less likely to get into accidents than younger drivers," Strayer said. "They tend to have a greater following distance. Their reactions are impaired, but they are driving so cautiously they were less likely to smash into somebody." But in real life, he added, older drivers are significantly more likely to be rear-ended because of their slow speed.
Other studies in the journal found:
- Telephone numbers presented by automated voice systems compete for drivers' attention to a far greater extent than when the driver sees the same information presented on a display.
- Interruptions to driving, such as answering a call, are likely to be more dangerous if they occur during maneuvers like merging to exit a freeway.
- Things could get worse. Wireless Internet, speech recognition systems and e-mail could all be even more distracting.
New Robot Walks Like You
A new robot that walks like humans is one of the most advanced of its kind.
Attempts to get robots moving like people typically result in very stilted gats and limited range of motion.
Human walking is "really very similar to falling forward in a controlled fashion," researchers at TU Delft in The Netherlands explained today in a statement. "Adopting this method replaces the cautious, rigid way in which robots walk with the more fluid, energy-efficient movement used by humans."
The new robot, Flame,weighs about 40 pounds (15 kg) and is 4 feet tall (1.3 meters). Its got several moving joints attenuated by springs. An inertia sensor (called an "organ of balance") helps keep the 'bot stable. Seven motors get it all going.
Flame can move at 1 mph (0.45 meters per second) and deal with steps down as long as they're not more than one-third of an inch (8 mm).
As it walks, swaying side-to-side like a flat-footed human, Flame uses its organ of balance to dictate how far apart its feet are placed, to prevent falls.
Project leader Daan Hobbelen gets his Ph.D. this week for all the work. Hobbelen said Flame is the most advanced walking robot in the world, at least in the category of robots which apply the human method of walking as a starting principle.
Research done to build the robot provides insight into how people walk, the researchers say, and this could lead to better training and rehabilitation equipment.