A team of UK astronomers, led by postgraduate student Ed Hawkins, has made a decisive step toward resolving an argument that has rumbled on in the astronomical community for decades. The scientists from the University of Nottingham have been investigating the properties of quasars and nearby galaxies. As part of this study, they have overturned previous analyses which suggested that these two classes of object are physically associated, thus confirming the alternative, more widely-held view that quasars are some of the most distant objects in the Universe.
Quasars are star-like in appearance, but seem to be flying away from Earth at velocities comparable to the speed of light. The majority of astronomers believe that this high speed is a result of the expansion of the Universe, and that the quasars are traveling so fast because they are at enormous distances. However, a vociferous minority, including such notable figures as the great astronomer Fred Hoyle, has argued forcefully that quasars are much closer by. In particular, they have pointed to apparent associations between quasars and nearby galaxies, suggesting that the quasars have somehow been ejected from these galaxies in the recent past.
One of the pieces of evidence to support this idea was the tentative discovery that quasars only seem to move away from galaxies at particular speeds: for example, a surprisingly large number of quasars seem to be moving relative to neighbouring galaxies at speeds of 59% of the speed of light. If the quasars were actually on the far side of the Universe, how would they know to move at exactly 59% of the speed of light relative to a completely unrelated foreground galaxy?
Prof. Michael Merrifield | alfa
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27.07.2017 | Universität Innsbruck
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26.07.2017 | City College of New York
Physicists working with researcher Oriol Romero-Isart devised a new simple scheme to theoretically generate arbitrarily short and focused electromagnetic fields. This new tool could be used for precise sensing and in microscopy.
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Light-matter quasi-particles can be generated electrically in semiconducting carbon nanotubes. Material scientists and physicists from Heidelberg University...
Fraunhofer IPA has developed a proximity sensor made from silicone and carbon nanotubes (CNT) which detects objects and determines their position. The materials and printing process used mean that the sensor is extremely flexible, economical and can be used for large surfaces. Industry and research partners can use and further develop this innovation straight away.
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3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects
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Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.
For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...
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27.07.2017 | Life Sciences
27.07.2017 | Life Sciences
27.07.2017 | Health and Medicine