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
Mars 2020 mission to use smart methods to seek signs of past life
17.08.2017 | Goldschmidt Conference
Gold shines through properties of nano biosensors
17.08.2017 | American Institute of Physics
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
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17.08.2017 | Physics and Astronomy
17.08.2017 | Earth Sciences
17.08.2017 | Physics and Astronomy