Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

1,2,3, Many - How Few Particles Turn into a ‘Heap’

25.10.2013
Heidelberg physicists observe the formation of a many-body system in experiment

How large does a group of particles have to be to render moot its exact number of particles?

In experiments using ultracold atoms, Heidelberg physicists succeeded in observing the transition to a many-body system well described by an infinite number of particles. In philosophy, this problem is known as the sorites paradox. The essential question is when a collection of elements forms a "heap".

The experiments were conducted by researchers of Heidelberg University under the direction of Prof. Dr. Selim Jochim at the Max Planck Institute for Nuclear Physics. The results of the research were published in "Science".

"Systems comprising many particles are generally extremely difficult to describe in a microscopically exact way. Hence researchers tend to work with effective theories that look not at the individual particles, such as gas molecules in the air, but at macroscopic values such as pressure or temperature," explains Jochim. The Heidelberg researchers prepared the systems so small they could still be described microscopically. Starting with a single atom, the scientists increased the number of particles one by one.

The energy of the entire system was measured with each added particle. The experiments ultimately showed that for the system under study very few atoms were needed to apply the theory derived for an infinitely large system. "We can identify this as the direct transition from a few-body system into a many-body system. Simply put, in our system it takes only about four atoms to form a 'heap' in the sense of the sorites paradox," continues the Heidelberg physicist.

Two years ago Jochim's team was able to reproducibly control the system used for the current experiments in all of its properties, including the exact number of particles, their state of motion and their interaction. "To date we are the only research team in the world able to prepare such systems," Prof. Jochim points out. "For the first time, these results realise our vision to gain a much deeper insight into the nature of fundamental few-body systems by these experiments.

Original publication:
A. N. Wenz, G. Zürn, S. Murmann, I. Brouzos, T. Lompe, S. Jochim: From Few to Many: Observing the Formation of a Fermi Sea One Atom at a Time. Science, Vol. 342 no. 6157 pp. 457-460, 25 October 2013, doi: 10.1126/science.1240516
Note to Newsrooms:
An infographic is available from the Press Office.
Contact:
Prof. Dr. Selim Jochim
Institute for Physics
Phone: (06221) 54-19472
jochim@uni-heidelberg.de
Communications and Marketing
Press Office
Phone: +49 6221 54-2311
presse@rektorat.uni-heidelberg.de

Marietta Fuhrmann-Koch | idw
Further information:
http://www.uni-heidelberg.de

More articles from Physics and Astronomy:

nachricht Tangled magnetic fields power cosmic particle accelerators
14.12.2018 | DOE/SLAC National Accelerator Laboratory

nachricht In search of missing worlds, Hubble finds a fast evaporating exoplanet
14.12.2018 | NASA/Goddard Space Flight Center

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: Data use draining your battery? Tiny device to speed up memory while also saving power

The more objects we make "smart," from watches to entire buildings, the greater the need for these devices to store and retrieve massive amounts of data quickly without consuming too much power.

Millions of new memory cells could be part of a computer chip and provide that speed and energy savings, thanks to the discovery of a previously unobserved...

Im Focus: An energy-efficient way to stay warm: Sew high-tech heating patches to your clothes

Personal patches could reduce energy waste in buildings, Rutgers-led study says

What if, instead of turning up the thermostat, you could warm up with high-tech, flexible patches sewn into your clothes - while significantly reducing your...

Im Focus: Lethal combination: Drug cocktail turns off the juice to cancer cells

A widely used diabetes medication combined with an antihypertensive drug specifically inhibits tumor growth – this was discovered by researchers from the University of Basel’s Biozentrum two years ago. In a follow-up study, recently published in “Cell Reports”, the scientists report that this drug cocktail induces cancer cell death by switching off their energy supply.

The widely used anti-diabetes drug metformin not only reduces blood sugar but also has an anti-cancer effect. However, the metformin dose commonly used in the...

Im Focus: New Foldable Drone Flies through Narrow Holes in Rescue Missions

A research team from the University of Zurich has developed a new drone that can retract its propeller arms in flight and make itself small to fit through narrow gaps and holes. This is particularly useful when searching for victims of natural disasters.

Inspecting a damaged building after an earthquake or during a fire is exactly the kind of job that human rescuers would like drones to do for them. A flying...

Im Focus: Topological material switched off and on for the first time

Key advance for future topological transistors

Over the last decade, there has been much excitement about the discovery, recognised by the Nobel Prize in Physics only two years ago, that there are two types...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

ICTM Conference 2019: Digitization emerges as an engineering trend for turbomachinery construction

12.12.2018 | Event News

New Plastics Economy Investor Forum - Meeting Point for Innovations

10.12.2018 | Event News

EGU 2019 meeting: Media registration now open

06.12.2018 | Event News

 
Latest News

Data use draining your battery? Tiny device to speed up memory while also saving power

14.12.2018 | Power and Electrical Engineering

Tangled magnetic fields power cosmic particle accelerators

14.12.2018 | Physics and Astronomy

In search of missing worlds, Hubble finds a fast evaporating exoplanet

14.12.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>