Tuesday, September 20, 2011

Dwarf galaxies suggest dark matter theory may be wrong - 16th Sept 2011

Scientists' predictions about the mysterious dark matter purported to make up most of the mass of the Universe may have to be revised.

Research on dwarf galaxies suggests they cannot form in the way they do if dark matter exists in the form that the most common model requires it to.

That may mean that the Large Hadron Collider will not be able to spot it.

Leading cosmologist Carlos Frenk spoke of the "disturbing" developments at the British Science Festival in Bradford.

The current theory holds that around 4% of the Universe is made up of normal matter - the stuff of stars, planets and people - and around 21% of it is dark matter.

The remainder is made up of what is known as dark energy, an even less understood hypothetical component of the Universe that would explain its ever-increasing expansion.

Scientists' best ideas for the formation and structure of the Universe form what is called the "cosmological standard model", or lambda-CDM - which predicts elementary particles in the form of cold dark matter (CDM).

These CDM particles are believed to have formed very early in the Universe's history, around one millionth of a second after the Big Bang, and they are "cold" in the sense that they are not hypothesised to be particularly fast-moving.

The existence of the particles has not yet been proven, as they are extremely difficult to detect - they cannot be "seen" in the traditional sense, and if they exist, they interact only very rarely with the matter we know. Read More