A binary star system is a pair of stars that orbit each other. They are very widespread – the majority of stars in the Milky Way are members of binary or multiple systems. Loners like our Sun are in the minority. The distance between stars in a binary system can vary hugely – some take millions of years to orbit each other, while others do it in just a few days. Astronomers find binaries very useful – the stars in these systems have spent their entire lives together, and were born at the same time from a shared cloud of gas and dust. What’s more, the way in which each star orbits can give away its relative mass, so it’s easy to compare how factors such as the mass of each star have affected their evolution and appearance as we see them today.
WHY DO TONGUE-TWISTERS TRIP US UP?
A recent study of three epilepsy patients has shed new light on this linguistic phenomenon. Electrodes implanted in the subjects’ brains in preparation for surgery allowed a team from the University of California, San Francisco, to record neural activity from the brain surface. The scans showed that sites in a region called the ventral sensory-motor cortex (vSMC) control different parts of the vocal tract to form each syllable. Stringing syllables together appears to require co-ordinating complex sequences of activity across vSMC sites, timed down to tens of milliseconds. Sounds that require similar vocal tract movements, such as ‘Sss’ and ‘Shh’, are especially tricky as their representations in the brain overlap. Tongue-twisters are likely tricky because they require a rapid sequence of overlapping neural patterns that simply overwhelms the brain.
WHY DO TONGUE-TWISTERS TRIP US UP?