R&D INSIGHT
Statistical analysis by an international research team, led by astronomers from the Max Planck Institute for Radio Astronomy, have been investigating an intriguing system that contains a pulsar that weighs twice as much as the sun and a white dwarf. Pulsars are highly magnetized, rotating
neutron stars that are formed in the aftermath of supernova explosions, and this particular one, catchily named PSR J0348+0432, is a truly extreme object. At its surface, the pulsar has a gravitational strength that is more than 300 billion times stronger than that of Earth. In its centre, more than one billion tons of matter is squeezed into a volume of a sugar cube. Not
only this, but the whole thing is also rotating faster than an industrial kitchen blender. The pulsar and white dwarf, which
are separated by just 830,000km, were discovered recently with the Green-Bank radio telescope. Due to their proximity to one another, the system is emitting a significant number of gravitational waves, and, according to the theory of general relativity, this close distance should make the orbital size and period shrink. To verify this, however, the mass of both of the objects must be known. This was done using the ESO’s Very Large Telescope by measuring changes in the light emitted from the white dwarf caused by its motion around
the pulsar. “After a quick analysis, I realized that the pulsar was a kind of heavyweight: a mass twice that of the Sun, making it the most massive neutron star we know about,” said John Antoniadis, a member of the research team.
With these masses, it is possible to calculate the amount of energy taken away from the system by gravitational waves, causing the orbital period to shrink. “Our radio observations with the Effelsberg and Arecibo telescopes were so precise that, by the end of 2012, we could already measure a change of 8 microseconds per year in the orbital period, exactly what Einstein’s theory had predicted.”
Microscopic tools provide new biopsy technique E 10
ngineers and physicians from John Hopkins University have devised a new way of performing biopsies using swarms of tiny,
untethered devices, each as small as a speck of dust. The devices, called ‘mu- grippers’, which require no batteries and are autonomously activated by body heat, could provide a more effective way of accessing narrow conduits in the body as well as detecting early signs of cancer and other diseases. The tiny devices can be retrieved through existing body openings via a magnetic catheter due to the magnetic material they contain. In a recent study, researchers described their use of the mu-grippers to collect
cells from the colon and oesophagus of a pig. One of the main advantages of the method is that it provides a much larger variety of samples than current techniques allow. “Based on a small sample, you can’t always draw accurate inferences,” explains physician Florin M. Selaru. “We could deploy hundreds or even thousands of these grippers to get more samples and a better idea of what kind of or whether a disease is present.” The new technique could lead to an
entirely new approach to conducting biopsies, and may be an important step towards the future goal of making surgical procedures non-invasive.
Insight Publishers | Projects
Massive pulsar proves Einstein correct
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