Astronomers use galaxies to reckon a subatomic particles mass.
Astronomers surveyed regions outside our Galaxy to estimate neutrinos mass.
© R. Smith
The spread of galaxies reveals the smoothing effect of invisible neutrinos.
By mapping hundreds of thousands of galaxies, astronomers have estimated the mass of the neutrino. They have also calculated the contribution that this mysterious subatomic particle makes to the total mass of the Universe.
The neutrino weighs no more than one-billionth of the mass of a hydrogen atom, Ofer Lahav of the University of Cambridge told the annual UK National Astronomy Meeting in Bristol today. Yet despite being so small, neutrinos could account for a maximum of about 20% of the mass of the entire Universe.
Small but influential
Neutrinos are unimaginably tiny, carry no electrical charge and can pass through planets unperturbed. But their abundance makes them potentially major players in the Universe.
For a long time it was thought that neutrinos had no mass at all. Recent astronomical observations have suggested that they do, but working out the exact figure "is probably one of the hardest questions [in physics]", says theoretical physicist Stephen King of the University of Southampton, UK.
The new estimate "sounds like a reasonable number", King adds. It broadly agrees with, although does not confirm, other figures produced from studies of radioactive decay earlier this year.
One-billionth of a hydrogen atom is towards the lower end of current estimates. If this value stands up, it shows that neutrinos do not exert enough gravitational tug to have much influence over the evolution of the visible Universe, says King. "Its saying that neutrinos cant play an important part in galaxy formation."
Lahav and his colleagues conclusion is based on gauging the lumpiness of the Universe. Tiny wrinkles in the Big Bang led to matter forming into gigantic clumps - galaxies, and clusters of galaxies - as the Universe aged.
Yet only about 5% the Universes mass is in a visible form. The rest is in a variety of substances known as dark matter, of which neutrinos are one component.
Dark matter is betrayed by its influence on what we can see. Neutrinos, which whizz through space at close to the speed of light, smooth the Universe out by redistributing mass. The heavier neutrinos are, the less clumping we should see in todays Universe.
Lahavs team used a three-dimensional map of 160,000 galaxies that they constructed as part of an Anglo-Australian team. They worked out the mass of the neutrino that best fitted the spread of galaxies they saw.
JOHN WHITFIELD | © Nature News Service
DGIST develops 20 times faster biosensor
24.04.2017 | DGIST (Daegu Gyeongbuk Institute of Science and Technology)
New quantum liquid crystals may play role in future of computers
21.04.2017 | California Institute of Technology
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
20.04.2017 | Event News
18.04.2017 | Event News
03.04.2017 | Event News
25.04.2017 | Earth Sciences
25.04.2017 | Life Sciences
25.04.2017 | Earth Sciences