Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Penn astrophysicist outlines a multi-pronged approach in the hunt for dark energy

21.02.2005


For the last few years evidence that we are living on a very "weird" universe has been growing: the expansion of the universe is accelerating, and one theory proposed to account for this acceleration is what has been termed "dark energy."

In order to find out what this mysterious energy really is, astronomers need to compare astrophysical observations that are at first sight completely unrelated. At a session on dark energy at the Annual Meeting of the American Association for the Advancement of Science today, University of Pennsylvania astrophysicist Licia Verde outlines how the hunt for dark energy will draw on the avalanche of recent and forthcoming data on surveys of objects throughout the universe.

"We were just coming to grips with ’dark matter’ when, out of the blue, observations tells us that something is propelling the universe apart and that this something comprises about 73 percent of existence," said Verde, an assistant professor in Penn’s Department of Physics and Astronomy. "Unlike dark matter, which, as mysterious as it may be, is still matter, dark energy is ’dark’ only because astronomers simply do not know what it is. At the heart of the dilemma, however, hides the answer to just what all this universe stuff is made from anyway."



For example, some clues to the nature of dark energy have been obtained by comparing the state of the universe at its birth – as depicted in the Cosmic Microwave Background experiments – with how it exists today, using data taken from galaxy surveys. One of the first sources of data will come from the ongoing series of surveys that look at the state of galaxies today and other celestial objects which we see as they were few billion years ago.

These observations become even more powerful in combination with observations of the Cosmic Microwave Background, which provide a look at the young universe by measuring the residue of the Big Bang itself. If dark energy changes the way the universe expands, the distance between galaxies and the CMB and the time elapsed between the CMB and the era of galaxies must carry some clues about dark energy, left behind like fingerprints on space-time.

"If you think of the universe as a great sea, where space is water, over time gravity, like the wind, made ripples in that water that turned into waves. That’s the universe today, a surfer’s paradise," Verde said. "Of course, a surfer would end up in a different place if you changed the composition of water or if you let the wind blow longer. Likewise, the position and the properties of the galaxies today tell us something about how they surfed there and the composition of the universe that took them there.

"We’re drawing on data compiled from astronomers across the globe in surveys of galaxies, supernovae, clusters of galaxies and other objects in space from as many different viewpoints as possible," Verde said. "Part of the difficulty studying dark energy is that we are still not sure what we are looking for, so we are looking to seemingly unrelated sources that might tell us something about the properties of dark energy.

According to Verde, if these approaches fail, it could mean that the current mode of thinking about the universe is wrong. If it turns out that dark energy does not exist after all, it would be the cause of a basic re-thinking of our understanding of astrophysics. "Finding out about the nature of dark energy will have consequences for both astronomy and fundamental physics," Verde said. "In other words, the question of dark energy cannot be answered without connecting the cosmological properties of the universe to the fundamental properties of matter on the subatomic level – from the infinitely small to the infinitely big."

Greg Lester | EurekAlert!
Further information:
http://www.upenn.edu

More articles from Physics and Astronomy:

nachricht Shape matters when light meets atom
05.12.2016 | Centre for Quantum Technologies at the National University of Singapore

nachricht Climate cycles may explain how running water carved Mars' surface features
02.12.2016 | Penn State

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: 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...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

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

IHP presents the fastest silicon-based transistor in the world

05.12.2016 | Power and Electrical Engineering

InLight study: insights into chemical processes using light

05.12.2016 | Materials Sciences

High-precision magnetic field sensing

05.12.2016 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>