Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Experiment could reveal ’extra dimensions’, exotic forces

30.10.2002


Physicists have devised a new experiment that will be used in the quest for exotic forces in nature and "additional spatial dimensions."

The researchers have demonstrated an innovative way to measure a phenomenon known as the Casimir effect – findings that also could have implications for the design of microscopic machines that contain tiny parts on the size scale of nanometers – or billionths of a meter.

The scientists are taking their theoretical findings a step further by conducting an experiment to prove that the theory works, said Ephraim Fischbach, a professor of physics at Purdue University.



A paper that describes the theory for the experiment will appear in the Nov. 4 issue of Physical Review Letters, a journal published by the American Physical Society. The paper was written by Fischbach and Dennis E. Krause, a professor of physics at Wabash College, in Crawfordsville, Ind.

The Casimir effect, predicted in 1948 by Dutch physicist Hendrick Casimir, is a force that pushes together two plates of metal placed near each other in empty space – or a vacuum. The closer the plates are to each other, the stronger the force.

What may be thought of as empty space is actually teeming with fleeting particles and electromagnetic fields. However, because the plates are so close to each other, many of the particles and fields cannot get between the plates. That means the space surrounding the plates contains more particles and energy than the space between the plates. The more energy-dense space surrounding the plates exerts a force on the metal, pushing the plates together.

The strength of the Casimir effect depends on the number of electrons in the metal out of which the plates are made. For that reason, the Purdue physicists will test the effect using plates made of isotopes of the same metal. Isotopes are elements that contain the same number of electrons but different numbers of neutrons in the atom’s nucleus.

One portion of the experiment will use plates made out of nickel 58, an isotope of nickel that contains 28 protons and 30 neutrons in its nucleus. A second portion of the experiment will use plates made of nickel 64, which contains 28 protons and 36 neutrons.

Because the plates made of nickel 58 and 64 have the same number of electrons, the Casimir forces acting on both sets of plates will be nearly identical. That means any measurable difference in force between the two sets of plates must be attributed to some entirely new, as-yet undiscovered force acting on the respective nuclei.

Such knowledge could prove critical in the design of future devices containing tiny gears and motors that are measured in nanometers. Because these devices will contain moving parts placed extremely close to one another, they may be subjected to exotic forces that do not affect the parts inside large-scale machines.

"When you actually make little gears, for example, they may stick together in funny ways," Fischbach said. "You can’t just make a microscopic version of your car’s transmission and expect it to work. Suddenly, on such small size scales, when moving parts are very close to one another, a lot of funny things happen.

"In order to go from fundamental physics to applied nanotechnology, you really will have to understand the laws that govern what happens at a very small scale. This research helps to bridge the gap between very fundamental physics and really applied physics."

The discovery of new forces, could, in turn, provide evidence for the existence of additional dimensions beyond the three spatial dimensions of length, width and height.

"A new kind of gravity-like force would be the fingerprint of the fact that we may really live in a world that is more than three spatial dimensions," Fischbach said. "You wouldn’t see this force over large distances, but you could see it over small distances."

However, scientists must first devise a way to confidently measure the Casimir force.

"Physicists know that the Casimir force exists," Fischbach said. "But we have to now understand it sufficiently well that we can say, ’I know when I line up the plates exactly like this, that I should see a certain force, which I can measure, and if I see something different, then there might be a new force on top of the Casimir force.’"

Because nickel 58 and 64 have the same number of electrons but different nuclei, any difference in forces observed between the two sets of plates could provide evidence that those nuclei were interacting with "extra dimensions" that exist side-by-side with the known three dimensions, Fischbach said.

Scientists have proven the existence of four fundamental forces of nature: gravity; electromagnetism; the strong force, which holds the nucleus of the atom together; and the weak force, which governs the energy production in stars and is responsible for some forms of radioactivity.

Researchers have theorized that the universe contains additional dimensions beyond the three spatial dimensions observed in the everyday world. Theory also has suggested that, of the four known fundamental forces of nature, all but one – gravity – are confined to three dimensions. This could help to explain why gravity is weaker than the other forces.

"In a sense, gravity gets dissipated by being spread out over more dimensions, and that’s why gravity looks weak compared to the other forces," Fischbach said. "Gravity might sense and interact with these extra dimensions in such a way as to reveal their presence.

"The point is that gravity actually penetrates these other dimensions."

Previous research by Fischbach has suggested the existence of a so-called "fifth force" of nature. If other dimensions do exist, a gravity-like "fifth force" might be used to study and communicate with those dimensions, Fischbach said.

Fischbach and Krause have worked recently with Ron Reifenberger, a Purdue professor of physics, and Stephen W. Howell, a postdoctoral research associate in the Department of Physics. They are now collaborating with two experimentalists, Ricardo Decca, a professor of physics at Indiana University-Purdue University Indianapolis, and Daniel Lopez, a scientist who is a member of the Nanofabrication Research Lab at Lucent Technologies.

The experiment currently being designed by the team will use nanofabrication techniques to replace one of the plates in the above experiment with a tiny sphere. The remaining plate with the nickel coatings will be attached to a "microelectromechanical torsion oscillator," a setup that could be likened to a nanometer-scale version of a record player in which the record player’s needle is the sphere. The device will record the force between the sphere and the plates, searching for a difference in the forces on the two nickel isotopes.

The research has been funded by the U.S. Department of Energy.

NOTE TO JOURNALISTS: An electronic or paper copy of the research paper is available from Emil Venere, (765) 494-4709, venere@purdue.edu.

Writer: Emil Venere, (765) 494-4709, venere@purdue.edu

Source: Ephraim Fischbach, (765) 494-5506, ephraim@physics.purdue.edu

Emil Venere | EurekAlert!
Further information:
http://www.aps.org/
http://www.purdue.edu/

More articles from Physics and Astronomy:

nachricht Halfway mark for NOEMA, the super-telescope under construction
20.09.2018 | Max-Planck-Institut für Radioastronomie

nachricht What even Einstein didn't know
20.09.2018 | Technische Universität München

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: Scientists present new observations to understand the phase transition in quantum chromodynamics

The building blocks of matter in our universe were formed in the first 10 microseconds of its existence, according to the currently accepted scientific picture. After the Big Bang about 13.7 billion years ago, matter consisted mainly of quarks and gluons, two types of elementary particles whose interactions are governed by quantum chromodynamics (QCD), the theory of strong interaction. In the early universe, these particles moved (nearly) freely in a quark-gluon plasma.

This is a joint press release of University Muenster and Heidelberg as well as the GSI Helmholtzzentrum für Schwerionenforschung in Darmstadt.

Then, in a phase transition, they combined and formed hadrons, among them the building blocks of atomic nuclei, protons and neutrons. In the current issue of...

Im Focus: Patented nanostructure for solar cells: Rough optics, smooth surface

Thin-film solar cells made of crystalline silicon are inexpensive and achieve efficiencies of a good 14 percent. However, they could do even better if their shiny surfaces reflected less light. A team led by Prof. Christiane Becker from the Helmholtz-Zentrum Berlin (HZB) has now patented a sophisticated new solution to this problem.

"It is not enough simply to bring more light into the cell," says Christiane Becker. Such surface structures can even ultimately reduce the efficiency by...

Im Focus: New soft coral species discovered in Panama

A study in the journal Bulletin of Marine Science describes a new, blood-red species of octocoral found in Panama. The species in the genus Thesea was discovered in the threatened low-light reef environment on Hannibal Bank, 60 kilometers off mainland Pacific Panama, by researchers at the Smithsonian Tropical Research Institute in Panama (STRI) and the Centro de Investigación en Ciencias del Mar y Limnología (CIMAR) at the University of Costa Rica.

Scientists established the new species, Thesea dalioi, by comparing its physical traits, such as branch thickness and the bright red colony color, with the...

Im Focus: New devices based on rust could reduce excess heat in computers

Physicists explore long-distance information transmission in antiferromagnetic iron oxide

Scientists have succeeded in observing the first long-distance transfer of information in a magnetic group of materials known as antiferromagnets.

Im Focus: Finding Nemo's genes

An international team of researchers has mapped Nemo's genome

An international team of researchers has mapped Nemo's genome, providing the research community with an invaluable resource to decode the response of fish to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

One of the world’s most prominent strategic forums for global health held in Berlin in October 2018

03.09.2018 | Event News

4th Intelligent Materials - European Symposium on Intelligent Materials

27.08.2018 | Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

 
Latest News

Fraunhofer ISE with over 60 Contributions at the European PV Solar Energy Conference and Exhibition

21.09.2018 | Trade Fair News

558 million-year-old fat reveals earliest known animal

21.09.2018 | Earth Sciences

Neutrons produce first direct 3D maps of water during cell membrane fusion

21.09.2018 | Health and Medicine

VideoLinks
Science & Research
Overview of more VideoLinks >>>