Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Carbon, Carbon, Everywhere; But Not from the Big Bang

13.05.2011
As Star Trek is so fond of reminding us, we’re carbon-based life forms. But the event that jump-started the universe, the Big Bang, didn’t actually produce any carbon, so where the heck did it – and we – come from? An NC State researcher has helped create supercomputer simulations that demonstrate how carbon is produced in stars, proving an old theory correct.

More than 50 years ago, an astronomer named Fred Hoyle deduced that when three helium nuclei – or alpha particles – come together inside the core of a star, they have difficulty combining to form carbon-12, the stuff we’re made of.

So he predicted a new state of carbon-12, one with an energy tuned just right to make the formation of carbon possible in stars. This new state is now known as the Hoyle state. Later experimentation demonstrated that the theory was correct, but no one had ever been able to reproduce the Hoyle state from scratch, starting from the known interactions of protons and neutrons. If the Hoyle state didn’t show up in those calculations, then the calculations must be incorrect or incomplete.

NC State physicist Dean Lee, along with German colleagues Evgeny Epelbaum, Hermann Krebs, and Ulf-G. Meissner, had previously developed a new method for describing all the possible ways that protons and neutrons can bind with one another inside nuclei. This “effective field theory” is formulated on a complex numerical lattice that allows the researchers to run simulations that show how particles interact. When the researchers put six protons and six neutrons on the lattice, the Hoyle state appeared together with other observed states of carbon-12, proving the theory correct from first principles.

... more about:
»Big Bang »Carbon »Physic »Physical »alpha particles

“We’ve had simple models of the Hoyle state using three alpha particles for a long time, but the first principles calculations weren’t giving anything close,” Lee says. “Our method places the particles into a simulation with certain space and time parameters, then allows them to do what they want to do. Within those simulations, the Hoyle state shows up.”

Their research appears in the May 13 issue of Physical Review Letters.

Lee adds, “This work is valuable because it gives us a much better idea of the kind of ‘fine-tuning’ nature has to do in order to produce carbon in stars.”

The Department of Physics is part of NC State’s College of Physical and Mathematical Sciences.

-peake-

Note to editors: An abstract of the paper follows.
“Ab initio calculation of the Hoyle state”
Authors: Dean Lee, North Carolina State University; Evgeny Epelbaum and Hermann Krebs, Institut fur Theoretische Physik II, Ruhr-Universitat Bochum, Germany; Ulf-G. Meissner, Helmholtz-Institut fur Strahlen-und Kernphysik and Bethe Center for Theoretical Physics, Universitat Bonn, Germany
Published: in Physical Review Letters
Abstract:
The Hoyle state plays a crucial role in the helium burning of stars heavier than our sun and in

the production of carbon and other elements necessary for life. This excited state of the carbon-12 nucleus was postulated by Hoyle as a necessary ingredient for the fusion of three alpha particles to produce carbon at stellar temperatures. Although the Hoyle state was seen experimentally more than a half century ago nuclear theorists have not yet uncovered the nature of this state from first principles. In this letter we report the first ab initio calculation of the low-lying states of carbon-12 using supercomputer lattice simulations and a theoretical framework known as effective field theory. In addition to the ground state and excited spin-2 state, we find a resonance at −85(3) MeV with all of the properties of the Hoyle state and in agreement with the experimentally observed energy.

Tracey Peake | Newswise Science News
Further information:
http://www.ncsu.edu

Further reports about: Big Bang Carbon Physic Physical alpha particles

More articles from Earth Sciences:

nachricht Multi-year submarine-canyon study challenges textbook theories about turbidity currents
12.12.2017 | Monterey Bay Aquarium Research Institute

nachricht How do megacities impact coastal seas? Searching for evidence in Chinese marginal seas
11.12.2017 | Leibniz-Institut für Ostseeforschung Warnemünde

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: First-of-its-kind chemical oscillator offers new level of molecular control

DNA molecules that follow specific instructions could offer more precise molecular control of synthetic chemical systems, a discovery that opens the door for engineers to create molecular machines with new and complex behaviors.

Researchers have created chemical amplifiers and a chemical oscillator using a systematic method that has the potential to embed sophisticated circuit...

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

New technique could make captured carbon more valuable

15.12.2017 | Life Sciences

First-of-its-kind chemical oscillator offers new level of molecular control

15.12.2017 | Life Sciences

A chip for environmental and health monitoring

15.12.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>