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Science Sunday #15

Posted by Don McLenaghen on September 25, 2011

– and on the seventh day we learn.
Each week I hope to give a synopsis of the interesting science stories I have heard on my plethora of science podcasts I listen to each week plus anything I pick up scanning the inter-web. This week’s top stories:

Words of the Week:

Neutrino – An electrically neutral, weakly interacting elementary subatomic particle[1] with a small but non-zero mass. Being electrically neutral, it is able to pass through ordinary matter almost unaffected, “like a bullet passing through a bank of fog”.
Neutrinos are similar to the more familiar electron, with one crucial difference: neutrinos do not carry electric charge, which means that they are not affected by the electromagnetic forces that act on electrons. Neutrinos are affected only by the weak sub-atomic force, of much shorter range than electromagnetism, and are therefore able to travel great distances through matter without being affected by it. Neutrinos also interact gravitationally with other particles..

Gamma-radiation – (also known as gamma rays) Electromagnetic radiation of high frequency (very short wavelength) above 10 exahertz (or >1019 Hz). Gamma rays are usually naturally produced on Earth by decay of high energy states in atomic nuclei (gamma decay). Some rare natural sources are lightning strike and terrestrial gamma-ray flashes, which produce high energy particles from natural high-energy voltages..

Stories:

 

FTL-R = Faster Than Light-Really? –

There have been a number of story on the news-o-sphere trumpeting the ‘discover’ of faster than light particles…something the theory of relativity states as impossible. Well to be pedantic, the theory only states that nothing accelerates beyond the speed of light, there is the theoretical possibly that something may be ‘born’ faster than light. That doesn’t make the possibility any more plausible because there is not known way for something to be ‘born’ at such a speed. Maybe some weird virtual particle, maybe parallel universe with alternative laws…but alas I am not a physicist, theoretical or otherwise so I will let the science take the lead on this one.

Letting the science take the lead on this is not something the ‘popular’ press is doing. The number of articles claiming the Einstein’s theory of relativity has been overturned is rushing things a bit…no a lot.

What the researches did was to fire neutrinos from an accelerator in Switzerland at a target in Italy. The scientists know to the centimeter (+/- 20 cm) the distance between the two points and have calibrated their clocks to within a billionth of a second (they used Cesium clocks accurate to 1 second in 30 million years). How this media storm was produced was when they checked the time it took the neutrinos to travel the distance (taking into account relativistic effects) the neutrinos arrived 60 nanoseconds too soon.

Why the storm? According to Einstein’s theory nothing can accelerate past the speed of light…it is regarded as the ultimate stop-sign of the universe. The reason you cannot accelerate is not arbitrary; according to the theory, as you accelerate you gain more mass…you also require more energy…both become infinite at the speed of light. Therefore, to accelerate beyond the speed of light would require infinite energy and the object would be infinitely heavy. If this observation is true, then the theory does not hold, something, at least, in the math is wrong.

Many have speculated that “Warp drives” or other faster than light starships are now possible but such is not the case. First, this is one experiment…there are some possibilities that these results are in error. For example, the exact time of ‘departure’ was note directly observed because the CERN lab (The shooting in our tale) does not have neutrino detectors so the departure times were indirectly calculated from the proton ‘blobs’ that created the neutrinos. Also there may be other ‘unknowns’ involved. Some have speculated that if this finding were true, then when a Supernova event occurs, we should expect to see the neutrinos significantly sooner than the photons (ie light). This was not observed during the 1987 supernova event (although technically, the neutrinos were seen first, the delay is explained by the fact that neutrinos don’t react much with matter so had a clear path away from the nova, whereas the light had to ‘burn’ its way out before making it way here).

Not the scientist presenting the research are not a bunch of ‘fringe’ elements. The reviews by other scientist of their work and more importantly the researchers attempts to illuminate possible alternative answers (ie faults in the experiment) have all be quite favorable. There are plans to upgrade the experimental equipment to ensure greater accuracy and to do what is most important to all science – replicate the results. IF they are successful at doing so, we may all be booking passage on the starships Enterprise someday (although not likely soon).

New Scientist

Eureka Alert

arXiv – Measurement of the neutrino velocity

Science Daily –  Neutrino Finding Puzzles Scientists

Science Daily – OPERA Experiment Reports Anomaly in Flight Time of Neutrinos

Scientific American –  Neutrino results challenge a cornerstone of Albert Einstein’s special theory of relativity

Bad Astronomy

 

Radiation may be good…for the joints –

A blast of gamma radiation could toughen up plastic prosthetic joints to make them strong enough to last for years, according to researchers in China writing in the current issue of the International Journal of Biomedical Engineering and Technology.

Whole joint replacement, such as hip and knee replacement, commonly use stainless steel, titanium alloys or ceramics to replace the damaged or diseased bone of the joint. Non-stick polymer or nylon is usually used to coat the artificial joint to simulate the cartilage. However, none of these materials are ideal as they produce debris within the body as the joint is used, which leads to inflammation, pain and other problems.

Maoquan Xue of the Changzhou Institute of Light Industry Technology, has investigated the effect of adding ceramic particles and fibers to two experimental materials for coating prosthetic joints, UHMWPE (ultra-high-molecular-weight polyethylene) and PEEK (polyether ether ketone). Alone neither UHMWPE nor PEEK is suitable as a prosthetic cartilage materials because both crack and fracture with the kind of everyday stresses that a hip or knee joint would exert on them. The problem is that the long polymer chains within the material can readily propagate applied forces causing tiny fractures to grow quickly and the material to fail.

Xue has now demonstrated that by adding ceramic particles to the polymers and then blasting the composite with a short burst of gamma-radiation it is possible to break the main polymer chains without disrupting the overall structure of the artificial cartilage. The resulting treated material is thus much tougher than the polymer alone and will not produce the problematic debris within a joint that might otherwise lead to inflammation and pain for the patient..

Eureka Alert

Science Daily

 

Same-Sex schools not good…bad! – 

While many parents chose to put their children in single-sex or same-sex schools and anecdotal evidence may show these schools perform excellently, there is no well-designed research that demonstrates that these schools improve student’s academic performance. There is, however, evidence that sex segregation increases gender stereotyping among children and teachers and legitimizes institutional sexism.

These findings are the focus of a new article that examines “The Pseudoscience of Single-Sex Schooling,” published in the Sept. 23, 2011, issue of the journal Science. Authored by researchers in ASU’s School of Social and Family Dynamics and social scientists from other universities, the article presents information for parents to consider when they are choosing an educational setting for their children.

“Though public sentiment may have strengthened in support of same-sex educational settings for improving the learning environment and outcomes for both boys and girls. Teaching boys and girls separately has become increasingly popular during recent years with at least 500 public school single-sex classrooms currently in the United States.

Fabes and the other co-authors cite evidence, including a U.S. Department of Education review comparing same-sex and coeducational outcomes, which concluded that results of both are equal. Similar large-scale reviews in Great Britain, Canada, Australia and New Zealand found little overall difference between single-sex and mixed-sex academic outcomes.

In addition, claims that boys and girls learn differently is not supported by brain research since neuroscientists have found few sex differences in children’s brains beyond the larger volume of boys’ brains and the earlier completion of girls’ brain growth, neither of which is known to relate to learning, the article states. Differences among the sexes can grow in sex-segregated environments, making positive interactions between boys and girls constrained, the social scientists write.

“Positive and cooperative interaction with members of other groups is an effective method for improving intergroup relationships,” according to the authors. There is evidence, however, that sex segregation increases gender divisions among children, according to the article. “Separating boys and girls in public school classrooms makes gender very salient, and this salience reinforces stereotypes and sexism,” Fabes said.

The social scientists noted that research shows that children exposed to environments where individuals are labeled and segregated along some characteristic — gender, eye color, or randomly assigned t-shirt groups — infer that the groups differ in important ways and develop biases in their individual groups. “Is it ever good to segregate on the basis of race, income or age? I think the answer is no,” Fabes said. “There is no good evidence that it is ever a good time to separate and segregate. Any form of segregation undermines rather than promotes equality.”

Science Daily – Single-Sex Schooling Does Not Improve Academic Performance

Science Daily – Sex Segregation in Schools Detrimental to Equality

Science – Pseudoscience of Single-Sex Schooling

Eureka Alert

 

Planet X may explain our solar system –

Astronomers have struggled for decades to explain the solar system’s current structure. In particular, Uranus and Neptune couldn’t have formed where they are today – the disc of gas that congealed into the planets would have been too thin at the edge of the solar system to account for the ice giants’ bulk.

A more likely scenario is that the planets were packed close together when they formed, and only spread out when the disc of gas and dust from which they formed was used up. But the great gravitational bullies of the solar system, Jupiter, Saturn, Uranus and Neptune, would not have gone quietly to their new homes. Previous simulations show that at least one planet, usually Uranus or Neptune, should have been ejected from the solar system in the shuffle.

Now Nesvorny proposes a solution: a sacrificial ice giant between Saturn and Uranus that takes the fall for its planetary siblings. “If you start with five gaseous planets, then you see again that you lose one planet,” he says. “In a large fraction of cases, you end up with a good solar system analogue.”

Nesvorny ran thousands of computer simulations for a planetary developmental period of 100 million years, long enough for the planets to settle into their final orbits. All but 10 per cent of the four-planet simulations wound up with only three left, he says. But in half the five-planet simulations, they ended with the four in a solar system that looks remarkably like our own.

The five-planet scenario solves a few other mysteries as well. For the inner rocky planets to survive intact while the outer gas giants jockeyed for position, some previous simulations show that Jupiter must have “jumped” from a position closer to the sun to its current orbit.

The reshuffling could also have disturbed the still-forming Kuiper belt and Oort cloud – reservoirs of proto-planets that lie beyond the current orbit of Neptune – flinging debris toward the inner solar system. That could explain the period of violence thought to have occurred 4 billion years ago, when the moon gained most of its craters. This is the period astronomers call the “late heavy bombardment”.

The long lost planet may still be out there. In May, astronomers in Japan announced that they had spotted lonely planets wandering through the dark space between stars. These lone wolfs may be even more common than star-bound worlds, the team reported. If the fifth gas giant is still out there, it will be one of the wandering exoplanets.

Today’s planets may have had other siblings as well. Previous researchers have suggested that a fifth rocky planet may have been ejected from an orbit between Mars and Jupiter, and that super-Earths may have been swallowed by Jupiter or Neptune.

New Scientist

aRxiv – Young Solar System’s Fifth Giant Planet?

 

New Theory Explains Collapse of World Trade Center’s Twin Towers – 

(Sorry for this one, but it’s an alternative idea that does not seem to rely on conspiracies or super-science)

According to a theory advanced by a SINTEF materials scientist, a mixture of water from sprinkler systems and molten aluminium from melted aircraft hulls created explosions that led to the collapse of the Twin Towers in Manhattan.

Just before the two New York skyscrapers collapsed on Sept. 11, 2001, powerful explosions within the building could be heard, leading many people to believe that overheated steel beams in the building were not the cause of the collapse.

The explosions fed the conspiracy theories that someone had placed explosives inside the towers.

Christian Simensen of SINTEF Materials and Chemistry, believes that it is overwhelmingly likely that the two aircraft were trapped inside an insulating layer of building debris within the skyscrapers. This leads him to believe that it was the aircraft hulls rather than the buildings themselves that absorbed most of the heat from the burning aircraft fuel.

The SINTEF scientist believes that the heat melted the aluminium of the aircraft hulls, and the core of his theory is that molten aluminium then found its way downwards within the buildings through staircases and gaps in the floor — and that the flowing aluminium underwent a chemical reaction with water from the sprinklers in the floors below.

Simensen continues: “I regard it as extremely likely that it was these explosions that made the skyscrapers collapse by tearing out part of the internal structure, and that this caused the uppermost floors of the buildings to fall and crush the lower parts. In other words, I believe that these were the explosions that were heard by people in the vicinity and that have since given life to the conspiracy theories that explosives had been placed in the skyscrapers.”

Okay, lets sidestep if this is true or not for the Twin Towers, is there anything useful to be gained from this speculation?

One lesson is that we could develop means of rapidly emptying sprinkler systems in the floors under the point of impact. Another possibility would be to fire in a rocket carrying a fire-retardant that would overlie the aircraft body and prevent the metal alloy from becoming overheated.

Science Daily

Popular Science

Live Science

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