Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


International collaboration replicates amplification of cosmic magnetic fields


Astrophysicists have established that cosmic turbulence could have amplified magnetic fields to the strengths observed in interstellar space.

"Magnetic fields are ubiquitous in the universe," said Don Lamb, the Robert A. Millikan Distinguished Service Professor in Astronomy & Astrophysics at the University of Chicago. "We're pretty sure that the fields didn't exist at the beginning, at the Big Bang. So there's this fundamental question: how did magnetic fields arise?"

This video simulation shows how a laser that illuminates a small carbon rod launches a complex flow, consisting of supersonic shocks and turbulent flow. When the grid is present, turbulence becomes dominant and the self-generated magnetic field is significantly amplified. The top half of the simulation illustrates gas density per cubic centimeter, while the bottom half depicts strength of magnetic field.

Credit: University of Chicago Flash Center

Helping to answer that question, which is of fundamental importance to understanding the universe, were millions of hours of supercomputer simulations at Argonne National Laboratory. Lamb and his collaborators, led by scientists at the University of Oxford, report their findings in an article published in the June 1 issue of Nature Physics.

The paper describes experiments at the Vulcan laser facility of the United Kingdom's Rutherford Appleton Laboratory that recreates a supernova (exploding star) with beams 60,000 billion times more powerful than a laser pointer. The research was inspired by the detection of magnetic fields in Cassiopeia A, a supernova remnant, which are approximately 100 times stronger than those in adjacent interstellar space.

Physics at multiple scales

"It may sound surprising that a tabletop laboratory experiment that fits inside an average room can be used to study astrophysical objects that are light years across," said Gianluca Gregori, professor of physics at Oxford. "In reality, the laws of physics are the same everywhere, and physical processes can be scaled from one to the other in the same way that waves in a bucket are comparable to waves in the ocean. So our experiments can complement observations of events such as the Cassiopeia A supernova."

Making the advance possible was the extraordinarily close cooperation between Lamb's team at UChicago's Flash Center for Computational Science and Gregori's team of experimentalists.

"Because of the complexity of what's going on here, the simulations were absolutely vital to inferring exactly what's going on and therefore confirming that these mechanisms are happening and that they are behaving in the way that theory predicts," said Jena Meinecke, graduate student in physics at Oxford and lead author of the Nature Physics paper.

Magnetic fields range from quadrillionths of a gauss in the cosmic voids of the universe, to several microgauss in galaxies and galaxy clusters (ordinary refrigerator magnets have magnetic fields of approximately 50 gauss). Stars like the sun measure thousands of gauss. Neutron stars, which are the extremely compact, burned out cores of dead stars, exhibit the largest magnetic fields of all, ones exceeding quadrillions of gauss.

In 2012, Gregori's team successfully created small magnetic fields, called "seed fields," in the laboratory via an often-invoked effect called the Biermann battery mechanism. But how could seed fields grow to gigantic sizes in interstellar space? Building on their earlier findings, Gregori and his collaborators at 11 institutions worldwide now have demonstrated the amplification of magnetic fields by turbulence.

In their experiment, the scientists focused laser beams onto a small carbon rod sitting in a chamber filled with a low-density gas. The lasers, generating temperatures of a few million degrees, caused the rod to explode, creating a blast that expanded throughout the gas.

"The experiment demonstrated that as the blast of the explosion passes through the grid it becomes irregular and turbulent, just like the images from Cassiopeia," Gregori said.

Experimental variables

"The experimentalists knew all the physical variables at a given point. They knew exactly the temperature, the density, the velocities," said UChicago research scientist Petros Tzeferacos, a study co-author. Tzeferacos and his colleagues incorporated that data into their FLASH simulations.

"This allows us to benchmark the code against something that we can see," Tzeferacos said. Such benchmarking—called validation—shows that the simulations can reproduce the experimental data. The simulations consumed 20 million processing hours on both the Mira and Intrepid supercomputers at Argonne. Mira, which can perform 10 quadrillion calculations per second, is 20 times faster than Intrepid.

With validation in hand, all members of the collaboration could return repeatedly to the simulations to get answers to new questions regarding the physics they saw. "We could look at the velocity instead of the density of the magnetic field, or we might look at the pressure," Lamb said. "This simulation is a treasure trove of information about what's really going on. It's actually critical to understanding correctly what's really happening."


The magnetic field simulations were made possible by the addition of capabilities to the FLASH Code in recent years, funded by the Office of Advanced Simulation and Computing in the Department of Energy's National Nuclear Security Agency. Originally designed to support computer simulations of exploding stars, FLASH Code also now supports high-energy density physics simulations to better understand the properties of matter at high densities and high temperatures.


"Turbulent amplification of magnetic fields in laboratory laser-produced shock waves," by J. Meinecke and 26 others, Nature Physics, June 1, 2014.


U.S. Department of Energy through the Innovative and Novel Computational Impact on Theory and Experiment (INCITE) program.

Steve Koppes | Eurek Alert!

Further reports about: Cassiopeia Computational Magnetic Nature Oxford amplification interstellar physics waves

More articles from Physics and Astronomy:

nachricht 4D imaging with liquid crystal microlenses
20.11.2019 | American Chemical Society

nachricht Outback telescope captures Milky Way center, discovers remnants of dead stars
20.11.2019 | International Centre for Radio Astronomy Research

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: Small particles, big effects: How graphene nanoparticles improve the resolution of microscopes

Conventional light microscopes cannot distinguish structures when they are separated by a distance smaller than, roughly, the wavelength of light. Superresolution microscopy, developed since the 1980s, lifts this limitation, using fluorescent moieties. Scientists at the Max Planck Institute for Polymer Research have now discovered that graphene nano-molecules can be used to improve this microscopy technique. These graphene nano-molecules offer a number of substantial advantages over the materials previously used, making superresolution microscopy even more versatile.

Microscopy is an important investigation method, in physics, biology, medicine, and many other sciences. However, it has one disadvantage: its resolution is...

Im Focus: Atoms don't like jumping rope

Nanooptical traps are a promising building block for quantum technologies. Austrian and German scientists have now removed an important obstacle to their practical use. They were able to show that a special form of mechanical vibration heats trapped particles in a very short time and knocks them out of the trap.

By controlling individual atoms, quantum properties can be investigated and made usable for technological applications. For about ten years, physicists have...

Im Focus: Images from NJIT's big bear solar observatory peel away layers of a stellar mystery

An international team of scientists, including three researchers from New Jersey Institute of Technology (NJIT), has shed new light on one of the central mysteries of solar physics: how energy from the Sun is transferred to the star's upper atmosphere, heating it to 1 million degrees Fahrenheit and higher in some regions, temperatures that are vastly hotter than the Sun's surface.

With new images from NJIT's Big Bear Solar Observatory (BBSO), the researchers have revealed in groundbreaking, granular detail what appears to be a likely...

Im Focus: New opportunities in additive manufacturing presented

Fraunhofer IFAM Dresden demonstrates manufacturing of copper components

The Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM in Dresden has succeeded in using Selective Electron Beam Melting (SEBM) to...

Im Focus: New Pitt research finds carbon nanotubes show a love/hate relationship with water

Carbon nanotubes (CNTs) are valuable for a wide variety of applications. Made of graphene sheets rolled into tubes 10,000 times smaller than a human hair, CNTs have an exceptional strength-to-mass ratio and excellent thermal and electrical properties. These features make them ideal for a range of applications, including supercapacitors, interconnects, adhesives, particle trapping and structural color.

New research reveals even more potential for CNTs: as a coating, they can both repel and hold water in place, a useful property for applications like printing,...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

First International Conference on Agrophotovoltaics in August 2020

15.11.2019 | Event News

Laser Symposium on Electromobility in Aachen: trends for the mobility revolution

15.11.2019 | Event News

High entropy alloys for hot turbines and tireless metal-forming presses

05.11.2019 | Event News

Latest News

The neocortex is critical for learning and memory

20.11.2019 | Life Sciences

4D imaging with liquid crystal microlenses

20.11.2019 | Physics and Astronomy

Walking Changes Vision

20.11.2019 | Health and Medicine

Science & Research
Overview of more VideoLinks >>>