Space

The lighter side of dark matter

The lighter side of dark matte...
Scientists have proposed a new form of particle in dark matter theory (Photo: Abell 1689, a galaxy affected by gravitational lensing theorized to be amplified by dark matter. NASA JPL/Caltech and STScI)
Scientists have proposed a new form of particle in dark matter theory (Photo: Abell 1689, a galaxy affected by gravitational lensing theorized to be amplified by dark matter. NASA JPL/Caltech and STScI)
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Scientists have proposed a new form of particle in dark matter theory (Photo: Abell 1689, a galaxy affected by gravitational lensing theorized to be amplified by dark matter. NASA JPL/Caltech and STScI)
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Scientists have proposed a new form of particle in dark matter theory (Photo: Abell 1689, a galaxy affected by gravitational lensing theorized to be amplified by dark matter. NASA JPL/Caltech and STScI)

In spite of substantial scientific investigation and convincing indirect evidence, dark matter still eludes direct detection and its existence essentially remains a tantalizing, but unproven, hypothesis. Notwithstanding this, nearly 85 percent of the predicted mass of the universe remains unaccounted for, and dark matter theory is still the prime contender to explain where it may be. Researchers at the University of Southampton have theorized the existence of a new "lighter" dark matter particle in an effort to help unravel the mystery.

Physicists believe that dark matter exists because of a number of tell-tale pieces of evidence gathered over the years that tend to fit with the theory. These include observed gravitational effects on stars and galaxies – including the phenomenon of gravitational lensing where light rays are bent around large unseen masses in space – and apparent evidence of anistropic patterns in the Cosmic Microwave Background, which alludes to its existence.

Many scientists believe that dark matter particles have a very large mass, similar to that of heavy atoms. The idea of lighter dark matter particles has not been considered likely on the basis of current observed astrophysical properties of space particles.

However, when researchers from a number of diverse physics disciplines at the University of Southampton were tasked with investigating the light dark matter theory a previously unknown opening in the science appeared. It was found that such an idea could exist and (along with some quite general arguments from particle physics) the researchers arrived at some surprising results.

"This work brings together some very different areas of physics: theoretical particle physics, observational x-ray astronomy, and experimental quantum optics," said Doctor James Bateman, from Physics and Astronomy at the University of Southampton. "Our candidate particle sounds crazy, but currently there seem to be no experiments or observations which could rule it out. Dark Matter is one of the most important unsolved problems in modern physics, and we hope that our suggestion will inspire others to develop detailed particle theory and even experimental tests."

The theoretical particle that would fit the new hypothesis suggested by the interdisciplinary teams would have a mass of around 100eV/c2 (1.78266184 × 10-34 kilograms), which is approximately 0.02 per cent of the mass of an electron. This newly-supposed (and yet un-named) fundamental particle apparently would not interact with light but would strongly interact with normal matter. And, unlike other proposed dark matter candidates, it may not even be able to penetrate Earth’s atmosphere due to its infinitesimally small mass.

As a result, the team suggests that Earth-based detection of the particle would not be likely, so they intend to piggyback on searches being proposed for an experiment in space involving a Macroscopic Quantum Resonator (MAQRO) that aims to explore untested parameters of quantum physics by observing the decoherence of superpositions of macroscopic objects.

Put simply, the MAQRO experiment intends to use the incredibly low temperatures and ultra-high vacuum of space combined with an optical trap to explore the quantum-mechanical concept of superposition for massive particles. As the new light matter particle has been defined by the team as a nanoparticle, it is envisaged that the MAQRO experiment will help expand the understanding of the quantum behavior of similar objects in space.

The researchers believe that the new nanoparticle would be found suspended in space and be part of the direct flow of dark matter, thereby being pushed along by the mass. Subsequent detection and monitoring of this particle’s position is then expected to reveal evidence about the nature of this dark matter particle, provided that it actually exists.

"At the moment, experiments on Dark Matter do not point into a clear direction and, given that also the Large Hadron Collider at CERN has not found any signs of new physics yet, it may be time that we shift our paradigm towards alternative candidates for Dark Matter," said Doctor Alexander Merle from the Max Planck Institute, and co-collaborator on the research. "More and more particle physicists seem to think this way, and our proposal seems to be a serious competitor on the market."

The research is published in the Nature journal Scientific Reports

Source: University of Southampton

8 comments
David Carlson
What we've got is an endless stream of new particle candidates from technicians with PhDs when what we really need is a single scientist reasoning from first principles.
b@man
You can't see it because you have your nose up against the billboard trying to read it. The gravity wave is in the neighborhood of 50 trillion light years in length. It has properties of wave and particle, just as light does. It's a particle at it's wave length. The wave action accounts for the dark energy. It's simple, quit making it complicated. Infinite Wave Theory
Bob Flint
Or simply put "dark matter is were no form of light has acted upon it. We stare out into space and one sees the stars, all emitting energy, some are not actually there anymore, just faint rays of light energy having left thousands of light years ago.
The dark area "Dark Matter" surrounding the stars energy we cannot really see because of the light energy is influencing the overall visual focus.
Try to imagine looking through a very small diameter tube, and focus it away from any star light sort of peering into absolute darkness.
Who is to say that dark matter does not exist in the pitch blackness of a deep cave or in the basement during a power failure with no other forms of light or energy penetrating our eyes or instruments?
Lbrewer42
Thank you for reporting rather than distorting - which is so very prevalent nowadays. Your statement, "In spite of substantial scientific investigation and convincing indirect evidence, dark matter still eludes direct detection and its existence essentially remains a tantalizing, but unproven, hypothesis." at the start of the article is what is needed in the ACTUAL scientific community more often and at the head of all articles relating to true science. B/c of media and misonformation, we have people still beleiveing the THEORY of evolution is as sound as bedrock - where reality shows it is still simply theory with an ever changing base. We have people believing the THEORY of global warming is reality when even the IPCC's data, when compiled within the last few years, itself proved there has been none to the point of higher ups in the AGW community claiming there has been a 15-18 year hiatus (depending on which pro- AGW sources are referenced.
I see the lack of writer's desiring to call theory for what it is a huge detriment to actual science. People start trying to PROVE something, keep falling short, but become closed minded to data contrary to their own goals b/c they are not practicing true science. True science has to do with collection of data and observation without preconceived goals to be interpreted from the data. In the dark ages, they fit the "facts" to their own desired outcome. We are trending this direction in the modern world - especially where politicians stand to make money or further their own political goals.
This same process of desiring to prove a point, rather than finding what the data actually indicates, also is likely holding us back from advancement by closing the door to the actual working process behind some issues.
Again - thank you for swimming against the current - kudos!
Al Dutcher
I m still bothered by there being not a gravitational trace of it in our solar system. Also, wouldnt this stuff clump as normal matter does?
I still like the theory of there being 100k free floating planets, in interstellar space, for every star. This would account for dark matter.
Don Duncan
Instead of coming up with a new theory, theoretical physicists continue to stubbornly look for evidence which proves they calculated the total mass correctly. When the theory is not substantiated by experimentation, revisiting the premises takes imagination and original thought, but is the scientific method. Or the unproven theory can be amended by endless sub-theories, in a desperate attempt to make the evidence fit a flawed theory. This is not science, it is dogma. I thought we had outgrown that.
Perhaps not, as the faith in force (government) is the most destructive and popular superstition in every corner of the world.
amazed W1
Dark matter again! Surely there is/was a professor at a US university who postulated that all the unexplained forces of attraction and repulsion in the universe needed neither dark mass nor black holes? All could be explained by electromagnetic and electrostatic forces between moving plasma.
He further stated that huge plasma fields were observable by telescope in certain circumstances. He was able to miniaturise the effects in laboratory experiments that supported his theory (he never claimed they proved it however) and referenced others who had carried out related studies.
His telling statement is that all papers on astrophysical matters are examined by so called peer review, but that the "peers" are all anxious not to make suggestions that contradicted the Alpha Guys' view, on pain of losing their employment or being relegated to the coal face as ignoramuses. Same things happen with global warming? No serious examination of the relative effects of small changes in the sun's energy output when compared to the effect of a small increase in energy absorbtion due to the small increase in CO2 concentration? And water vapour, only just being considered seriously in the cause and effect argument?
Bob
The astrophysics boys keep inventing reasons why their theories don't work. What if the universe is really 50 billion years old and all this mysterious dark matter is just the ordinary cinders of past generations of burnt out or failed stars. But then that would negate their imaginary faster than light inflation and all their imaginary dark matter that is required to prop up their defective theories. How could space have inflated but left light behind? Wouldn't gravitational lensing have totally distorted any early light from the early universe? Why are we looking out there for dark matter when it should be right here around us and distorting our perception of gravity? It's OK to have theories, just present them as such. I'm tired of all this nonsense being presented as FACT when they are just guessing.