Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

How to merge two black holes in a simple way

26.09.2016

The merger of two black holes, such as the one which produced the gravitational waves discovered by the LIGO Observatory, is considered an extremely complex process that can only be simulated by the world's most powerful supercomputers. However, two theoretical physicists from the University of Barcelona (Spain) have demonstrated that what occurs on the space-time boundary of the two merging objects can be explained using simple equations, at least when a giant black hole collides with a tiny black hole.

If we had to choose the most important and newsworthy piece of science news for 2016, the discovery of gravitational waves would have every chance of winning first prize.


The merger of two black holes, where one is so large that only a portion of it –nearly flat– is shown, while the other, smaller black hole falls into and is absorbed by the larger one. / Credit: Roberto Emparan & Marina Martínez


The complete sequence

The two signals that have been produced so far came from the collision and merger of two black holes in some remote part of the universe. The first detection was announced in February and the second in June, both by scientists from the Laser Interferometer Gravitational-Wave Observatory (LIGO) in the United States.

To determine the patterns of these waves and simulate how those mysterious fusions take place -a phenomenon characteristic of Einstein's general theory of relativity- scientists use the best supercomputers, such as the MareNostrum from Barcelona, Spain's most powerful supercomputer; however, there could be other, less complicated ways.

Physicists Roberto Emparan and Marina Martínez from the University of Barcelona have found a simple and exact way to approach the subject of the event horizon of two merging black holes, where one is much smaller than the other.

The joining together of horizons
The event horizon is the boundary that characterises a black hole; whereas the events inside the event horizon cannot affect an observer on the outside, the opposite can occur. When two black holes merge together, their event horizons join together to become one.

"Surprisingly, the ideas and techniques used in our work are elemental and allow us to thoroughly study the properties of the horizon at the moment both black holes join together to form one", points out Emparan, who along with his colleague has published the results in the journal 'Classical and Quantum Gravity'.

The equations utilised to solve the problem are based on the physicists' basic knowledge, such as the definition of an event horizon and the so-called equivalence principle, which is part of the foundation of Einstein's theory of gravity.

According to this idea, an observer cannot tell the difference between free falling in a gravitational field and floating in deep space.

This is something we are familiar with because of pictures of astronauts on the International Space Station. Their noticeable weightlessness is not a result of their distance from Earth -gravity at the altitude of the station is 90% that of the gravity on Earth's surface- but is rather due to the fact that the orbiting station and the astronauts inside are freely moving through Earth's gravitational field.

A universal behaviour of two black holes that make contact

Likewise, in this study the small black hole that falls into a much larger one cannot tell this fall apart from another situation in which it is floating alone in space, thus allowing the description of the phenomenon to be greatly simplified.

Emparan and Martínez have utilised geometric elements in their study in order to describe the event horizon. Specifically, the horizon is obtained by plotting null geodesic lines on the so-called Schwarzschild metric, the solution to the field equations posed by Einstein for describing the gravitation field of a black hole.

According to the authors, these results make it easy to identify many geometric properties of the event horizon at the moment the two black holes join together. More importantly, "[the results] indicate the existence of a universal, general behaviour that occurs when two black holes come into contact with each other in any part of the universe".

  • Full bibliographic informationRoberto Emparan, Marina Martínez. "Exact Event Horizon of a Black Hole Merger". Classical and Quantum Gravity 33. Number 15, 2016. DOI: 10.1088/0264-9381/33/15/155003

For further information, please contact:

Enrique Sacristan

enrique.sacristan@fecyt.es

Notes for editors

Para contactar con los investigadores:
Roberto Emparan and Marina Martínez. Universidad de Barcelona
Emails: emparan@ub.edu y marinamartinez@ub.edu
Tlf.: +34 934034818

Enrique Sacristán López
Redactor Agencia SINC
www.agenciasinc.es
Fundación Española para la Ciencia y la Tecnología
Edificio Museo Nacional de Ciencia y Tecnología
C/ Pintor Velázquez, 5 - 28100 Alcobendas (Madrid)
Tfno: 91 425 09 09 ext. 3251 - Fax: 91 571 21 72

Enrique Sacristan | AlphaGalileo

More articles from Physics and Astronomy:

nachricht Breaking the optical bandwidth record of stable pulsed lasers
24.01.2017 | Institut national de la recherche scientifique - INRS

nachricht European XFEL prepares for user operation: Researchers can hand in first proposals for experiments
24.01.2017 | European XFEL GmbH

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 spin artificial silk from whey protein

X-ray study throws light on key process for production

A Swedish-German team of researchers has cleared up a key process for the artificial production of silk. With the help of the intense X-rays from DESY's...

Im Focus: Quantum optical sensor for the first time tested in space – with a laser system from Berlin

For the first time ever, a cloud of ultra-cold atoms has been successfully created in space on board of a sounding rocket. The MAIUS mission demonstrates that quantum optical sensors can be operated even in harsh environments like space – a prerequi-site for finding answers to the most challenging questions of fundamental physics and an important innovation driver for everyday applications.

According to Albert Einstein's Equivalence Principle, all bodies are accelerated at the same rate by the Earth's gravity, regardless of their properties. This...

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Breaking the optical bandwidth record of stable pulsed lasers

24.01.2017 | Physics and Astronomy

Choreographing the microRNA-target dance

24.01.2017 | Life Sciences

Spanish scientists create a 3-D bioprinter to print human skin

24.01.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>