Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

The search for dark matter and dark energy in the Universe

17.09.2003


Philosophical transactions a November issue

Organised and edited by Carlos Frenk, George Kalmus, Nigel Smith and Simon White

What is the universe made of? How is it expanding? What is the origin of galaxies and other cosmic large-scale structures? These questions and some tentative answers were the focus of the discussion meeting on The search for dark matter and dark energy in the Universe, held at The Royal Society on 22-23 January 2003.



Astronomers have known for many years that the predominant form of mass in the universe is dark matter, that is, matter that does not emit detectable electromagnetic radiation at any wavelength. Only recently, however, has it become possible to measure how much dark matter there is. These measurements are based on surveys of unprecedented numbers of galaxies combined with careful studies of tiny irregularities in the residual heat left over from the Big Bang, the cosmic microwave background radiation. These irregularities are imprints left in the radiation by the precursors of today’s galaxies. By contrasting the properties of the primeval irregularities with the large-scale distribution of galaxies, physicists can infer the amount of dark matter in the universe. The surprising result is that the density of dark matter falls short, by about a factor of three, from the critical value required to ensure that the cosmic expansion would eventually come to a halt.

Although we now know how much dark matter there is, its identity is still unknown. It is clear, however, that the dark matter cannot be the same sort of matter that we see in stars, planets and people. Such ordinary matter makes up only about 10 percent of the total. The search for the remaining 90 percent of the cosmic mass is intense and is taking place deep underground in well shielded laboratories around the world.

The combination of microwave background and galaxy data has recently produced another, perhaps even more perplexing result: our universe must contain not only dark matter but also a new form of energy which, in the absence of a better name, is often called ``dark energy.’ This gives rise to a cosmic repulsive force which counteracts the effect of gravity. Dark energy has dominated the overall evolution of the universe for the past 8 billion years or so, causing it to expand at an ever increasing rate. The origin of the dark energy is a profound mystery.

The Royal Society Discussion meeting brought together foremost world experts in cosmology and particle physics. They discussed the evidence for dark matter and dark energy, their effect on the expansion of the universe and on the properties of galaxies, speculate on the origin of the dark energy and describe experimental searches for the dark matter particles using ultra-high-technology devices. The meeting was pervaded by the certain knowledge that these are really exciting times in the quest for understanding the origin of our universe.

Rebecca Humphreys | Royal Society
Further information:
http://www.pubs.royalsoc.ac.uk
http://www.catchword.com/rsl/1364503X/previews/contp1-1.htm
http://www.lbl.gov/Science-Articles/Archive/Phys-HST-supernovae.html

More articles from Physics and Astronomy:

nachricht The taming of the light screw
22.03.2019 | Max-Planck-Institut für Struktur und Dynamik der Materie

nachricht Magnetic micro-boats
21.03.2019 | Max-Planck-Institut für Polymerforschung

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: The taming of the light screw

DESY and MPSD scientists create high-order harmonics from solids with controlled polarization states, taking advantage of both crystal symmetry and attosecond electronic dynamics. The newly demonstrated technique might find intriguing applications in petahertz electronics and for spectroscopic studies of novel quantum materials.

The nonlinear process of high-order harmonic generation (HHG) in gases is one of the cornerstones of attosecond science (an attosecond is a billionth of a...

Im Focus: Magnetic micro-boats

Nano- and microtechnology are promising candidates not only for medical applications such as drug delivery but also for the creation of little robots or flexible integrated sensors. Scientists from the Max Planck Institute for Polymer Research (MPI-P) have created magnetic microparticles, with a newly developed method, that could pave the way for building micro-motors or guiding drugs in the human body to a target, like a tumor. The preparation of such structures as well as their remote-control can be regulated using magnetic fields and therefore can find application in an array of domains.

The magnetic properties of a material control how this material responds to the presence of a magnetic field. Iron oxide is the main component of rust but also...

Im Focus: Self-healing coating made of corn starch makes small scratches disappear through heat

Due to the special arrangement of its molecules, a new coating made of corn starch is able to repair small scratches by itself through heat: The cross-linking via ring-shaped molecules makes the material mobile, so that it compensates for the scratches and these disappear again.

Superficial micro-scratches on the car body or on other high-gloss surfaces are harmless, but annoying. Especially in the luxury segment such surfaces are...

Im Focus: Stellar cartography

The Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI) at the Large Binocular Telescope (LBT) in Arizona released its first image of the surface magnetic field of another star. In a paper in the European journal Astronomy & Astrophysics, the PEPSI team presents a Zeeman- Doppler-Image of the surface of the magnetically active star II Pegasi.

A special technique allows astronomers to resolve the surfaces of faraway stars. Those are otherwise only seen as point sources, even in the largest telescopes...

Im Focus: Heading towards a tsunami of light

Researchers at Chalmers University of Technology and the University of Gothenburg, Sweden, have proposed a way to create a completely new source of radiation. Ultra-intense light pulses consist of the motion of a single wave and can be described as a tsunami of light. The strong wave can be used to study interactions between matter and light in a unique way. Their research is now published in the scientific journal Physical Review Letters.

"This source of radiation lets us look at reality through a new angle - it is like twisting a mirror and discovering something completely different," says...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

International Modelica Conference with 330 visitors from 21 countries at OTH Regensburg

11.03.2019 | Event News

Selection Completed: 580 Young Scientists from 88 Countries at the Lindau Nobel Laureate Meeting

01.03.2019 | Event News

LightMAT 2019 – 3rd International Conference on Light Materials – Science and Technology

28.02.2019 | Event News

 
Latest News

Solving the efficiency of Gram-negative bacteria

22.03.2019 | Life Sciences

Bacteria bide their time when antibiotics attack

22.03.2019 | Life Sciences

Open source software helps researchers extract key insights from huge sensor datasets

22.03.2019 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>