Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

The Universe, seen under the Gran Sasso mountain, seems to be older than expected

14.05.2004


Some nuclear fusion reactions inside stars occur more slowly than we thought and, as a consequence, stars themselves, as well as galaxies and the entire universe are a bit older than expected. This is what comes out from the last results of Luna experiment (Laboratory for Underground Nuclear astrophysics), settled by National Laboratories of Gran Sasso and realized in cooperation by Infn and Ruhr University in Bochum (Germany). The study, that will be published on the review Physics Letters B next June 17, has been published today on the website of the review. A second article has been accepted by the review Astronomy and Astrophysics.



Luna’s aim is the production of some reactions that occur inside stars, in particular in the Sun, and the measure of their velocity. In Luna, protons (which means hydrogen nuclei) are made collide against nitrogen nuclei: a reaction that leads to the formation of an oxygen nucleus with the contemporary emission of energy. “The great part of the energy emitted by our star derives from fusion reactions of four hydrogen nuclei that lead directly to the formation of a helium nucleus. But there is another process in consequence of that helium nuclei are produced and this process passes through the so-called carbon-nitrogen-oxygen cycle. Cycle velocity is determined by the slowest of the reactions that form it, the one that leads to an oxygen nucleus as a result of the fusion between an azote nucleus and a proton. That is to say the reaction studied by Luna”, explains Carlo Broggini, Luna coordinator.

Producing fusion between the nitrogen nucleus and a proton is not difficult itself, but a difficulty lies in obtaining it at the same energy it occurs in stars: a relatively low energy, thanks to which the phenomena is quite slow, corresponding to a very few reactions a day (a lucky case for our planet, because if these phenomena occurred rapidly, the Sun would have burned up its ‘fuel’ in a few time and this would have made life –as we know it -impossible). “In an ordinary laboratory settled on surface, the effects of the reaction studied by Luna would be totally hidden by similar, but much more abundant effects due to reactions caused by the cosmic rays rain that crashes into our planet without interruption. The Gran Sasso Laboratories are on the contrary located under 1.400 meters of rocks, which constitute an impenetrable barrier for almost all the particles coming from Space. Thanks to these particular conditions we could carry out our experiment”, says Carlo Broggini.


The result has been surprising: the carbon–nitrogen –oxygen cycle occurs two times more slowly than expected. “The most fascinating aspect of this study is that another estimate of Universe age flows from it. Actually, the age of the most ancient stars, those that form the so-called globular star clusters, is calculated on the base of the light spectra they emit, supposing we know the carbon–nitrogen–oxygen cycle’s velocity As this last one seems to be slower than previewed, the age of the globular star clusters’ has also been newly calculated and grown-up of about one billion years. As a consequence, in the light of Luna’s new data, the age of our Universe passes from the previous estimate of about 13 billions years to that of about 14 billions years” explains Eugenio Coccia, director of Gran Sasso National Laboratories.

Luna’s results offer also another information: neutrinos provided with high energy produced by carbon – nitrogen – oxygen cycle are the half part of what expected, because this last one is responsible of only the 0,8% of the energy emitted by the Sun (and not the 1,6%, as believed). This data is of great interest for astroparticles physicists engaged in experiments that are specifically focused on neutrinos of relatively high energy, as it is for example the experiment Borexino, which is in preparation at Gran Sasso National Laboratories, or the Japanese Kamland.

Carlo Broggini | alfa
Further information:
http://www.sciencedirect.com/science/journal/03702693

More articles from Physics and Astronomy:

nachricht Hope to discover sure signs of life on Mars? New research says look for the element vanadium
22.09.2017 | University of Kansas

nachricht Calculating quietness
22.09.2017 | Forschungszentrum MATHEON ECMath

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Rainbow colors reveal cell history: Uncovering β-cell heterogeneity

22.09.2017 | Life Sciences

Penn first in world to treat patient with new radiation technology

22.09.2017 | Medical Engineering

Calculating quietness

22.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>