Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists at Low Temperature Laboratory planning to model a black hole

16.04.2003


Academy Professor Matti Krusius and Antti Finne, M.Sc. (Eng.), were invited to a recent science breakfast, hosted by the Academy of Finland, to talk about their ongoing work to produce a first-ever laboratory simulation of a black hole. A black hole is created as a result of the most extreme concentration of matter.



Scientists have been arguing about the possible existence of black holes for an entire century. Today the existence of black holes is supported by various astrophysical phenomena. Experimental observations of their existence are necessarily indirect because not even light can escape from a black hole. However, indirect observations cannot explain the structure of a black hole and its surrounding event horizon.

Over the past couple of decades scientists have designed several experiments for the purpose of modelling the physics of the event horizon of a black hole, as based upon the theory of relativity, but all proposals have so far proven impracticable. However, work is now under way at the Helsinki University of Technology Low Temperature Laboratory, Finland, one of the Academy’s Centres of Excellence in Research, to set up the experiment and conduct the necessary measurements.


Simulation can help to unravel the mysteries of the universe

According to Academy Professor Matti Krusius, the advances that have been made over the past years in cosmological observations have revolutionised scientists’ understanding of the Universe. However, there remain many intriguing questions about the birth, structure, and future fate of the Universe that have so far not been answered by means of direct measurement. One of the ways to tackle these enigmas is by means of analogue models, i.e. by simulating the event in some other seemingly remote area of physics. This is exactly what scientists at the Low Temperature Laboratory are doing while attempting to simulate a black hole.

One of the world’s first successful cosmological analogue measurements was completed at the Low Temperature Laboratory in 1996. This experiment involved measuring the defects nucleated in the macroscopic structure of matter by a very rapid change of state, specifically the change of liquid helium from the normal to the superfluid phase. Scientists believe that the Early Universe, during its expansion and cooling in the aftermath of the Big Bang, went through a whole series of changes in state. It is presumed that the defects created in these processes are responsible for the inhomogeneous density of visible matter that is seen in the current Universe, clear proof of which is the uneven distribution of galaxies into long chains interspersed by vast empty spaces.

The 1996 analogue measurement did not provide a direct answer to the origin of the cosmic inhomogeneity, but the experiment did prove that the proposed mechanism via defect formation in rapid changes of state is physically sound. During the past two years measurements of the cosmic microwave background radiation have suggested that the so-called inflation model can provide a better explanation for the observed inhomogeneity in the distribution of matter.

Answers lie in superfluid interface oscillations

Professor William Unruh originally drew attention to the similarities between fluid dynamics and the theory of relativity as early as 1981. In his model the speed of fluid flow is increased beyond the speed of sound, thus creating an event horizon for the sound carried forward in the fluid. In practice, however, this is not physically possible for ordinary fluids.

A superfluid, on the other hand, can within certain limits flow without loss. The plans that scientists at the Low Temperature Laboratory have for modelling a black hole are based upon interface oscillations between two superfluids. The purpose is to create a situation where two fluids are moving at different speeds relative to each other. At some critical speed the interface will no longer remain stable, but begins to oscillate and forms surface waves. When the thickness of the superfluid layers is reduced to a sufficient extent, the equations describing the interface oscillations become similar to those giving rise to the event horizon of a black hole. Thus by varying the thickness of the fluid layers in the course of their measurements, the scientists will be able to observe whether it is indeed possible to create an analogue model of the black-hole event horizon.

Scientists at the Low Temperature Laboratory are now in the position that they can control the superfluid interface and produce interface oscillations. The next challenge is to study other intervening phenomena that need to be understood before it is possible to interpret the black-hole-like measurements and compare with the relativistic models. Although the experimental setup as well as the necessary measurement technology are already in place, it will still be another 2-3 years before the scientists will know the final answers from these simulation studies.

Jenni Järvelä | alfa
Further information:
http://www.aka.fi/modules/release/show_release.asp?

More articles from Physics and Astronomy:

nachricht Further Improvement of Qubit Lifetime for Quantum Computers
09.12.2016 | Forschungszentrum Jülich

nachricht Electron highway inside crystal
09.12.2016 | Julius-Maximilians-Universität Würzburg

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: Electron highway inside crystal

Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.

Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Researchers identify potentially druggable mutant p53 proteins that promote cancer growth

09.12.2016 | Life Sciences

Scientists produce a new roadmap for guiding development & conservation in the Amazon

09.12.2016 | Ecology, The Environment and Conservation

Satellites, airport visibility readings shed light on troops' exposure to air pollution

09.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>