Hilary Boden shares the latest science news

 

Scientists Give Faster-Than-Light Neutrino Another Go

 The experiment which suggested that sub-atomic particles may be able to travel faster than the speed of light (and thus effectively re-write the laws of modern physics) is to be carried out again. Now, the physicists working at the Opera experiment intend to re-run the experiment in a different way, in order to discover or rule out some repeated systematic error which may have evaded detection.

The original experiment involved firing protons from Cern in Genevain a pulse of 10microseconds through the earth’s crust towards the Gran Sasso Laboratory in Italy, some 732km away. At the laboratory, neutrinos produced by the pulse were detected 60 nanoseconds earlier than light would have arrived over the same difference. However, because of the length of the pulse the researchers cannot know how long it took an individual neutrino to travel from Switzerland to Italy. The new experiment intends to address this issue by obtaining the time measurement more statistically, sending protons in a series of short bursts of one or two nanoseconds at 500 nanosecond intervals. The scientists can then repeatedly superimpose the neutrinos’ “arrival times” on the protons’ “departure times” before taking an average. This system allows for an unambiguous connection between each neutrino event at Gran Sasso and each pulse of protons produced at Cern. Professor Strassler of Rutgers University in New Jersey, said of the altered experiment “It’s like sending a series of loud and isolated clicks instead of a long blast on a horn; in the latter case you have to figure out exactly when the horn starts and stops, but in the former you just hear each click and then it’s already over.”

Opera’s altered neutrino experiment will conclude this November, and next year two other Gran Sasso experiments, titled ‘Borexino’ and ‘Icarus’, will begin to carry out independent cross-checks of Opera’s results.  So it seems that there will be a significant wait to see whether the speed of light has actually been broken.

Do Your Facebook Friends Reveal Something about Your Brain?

A recent study suggests that those people with large numbers of Facebook friends have denser grey matter in three regions of the brain associated with social skills than those who have fewer online connections. Leader of the study, Professor Geraint Rees, director of the Institute of Cognitive Neuroscience at UCL, explains the motivation behind the work: “A key question for debate in contemporary societies with online social networks is do people use them in the same way or are they enabling a completely different type of communication and interaction that was never before possible? People get worried about whether that is in some way affecting or changing our brains or the ways we interact with the world.”

Rees and his team asked 165 volunteers about details of their online and real-world friendships. MRI brain scans were then carried out on the participants.  It was found that the grey matter density of the superior temporal sulcus and the middle temporal gyrus (associated with the ability to perceive social cues from facial expressions) and the entorhinal cortex (associated with facial recognition) was higher for those who had more Facebook friends, but that there was no correlation to the number of real-world friends participants had.

Anthropologist Professor Robin Dunbar says of the results “The interesting question left unanswered is whether this is set in stone and those bits of your brain are hard-wired and determined by your genes, or whether if you bring people up in the right kind of social environment, those bits of the brain grow and therefore the number of people they can maintain as friends in adulthood increases.”

Ultimately, the findings do not reveal whether certain brain structures are more predisposed to social networking than others, or whether having many friends on Facebook in turn alters brain structure. But Rees asserts that studies using brain scans to investigate any changes to brain structures over time may help to indicate whether brain changes are a cause or effect of having large numbers of online social connections.

Hilary Boden

Image credit – Argonne National Laboratory