Science & Technology
Dark matter is an invisible substance that is suspected to exist in large quantity around galaxies, lending mass but emitting no radiation. The only evidence for it comes from its gravitational effect on the material around it... up to now, dark matter itself has not been directly detected. Regardless, it has been estimated to make up 80% of all the mass in the Universe.
A team of astronomers at ESO's La Silla Observatory in Chile has mapped the region around over 400 stars near the Sun, some of which were over 13,000 light-years distant. What they found was a quantity of material that coincided with what was observable: stars, gas, and dust... but no dark matter.
"The amount of mass that we derive matches very well with what we see - stars, dust and gas - in the region around the Sun," said team leader Christian Moni Bidin of the Universidad de Concepción in Chile. "But this leaves no room for the extra material - dark matter - that we were expecting. Our calculations show that it should have shown up very clearly in our measurements. But it was just not there!"
Based on the team's results, the dark matter halos thought to envelop galaxies would have to have "unusual" shapes - making their actual existence highly improbable.
Still, something is causing matter and radiation in the Universe to behave in a way that belies its visible mass. If it's not dark matter, then what is it?
"Despite the new results, the Milky Way certainly rotates much faster than the visible matter alone can account for," Bidin said. "So, if dark matter is not present where we expected it, a new solution for the missing mass problem must be found.
"Our results contradict the currently accepted models. The mystery of dark matter has just became even more mysterious."
Read the release on the ESO site here.
Reader Comments
"something is causing matter and radiation in the Universe to behave in a way that belies its visible mass. If it's not dark matter, then what is it?"
UMMM how about the Aether?
I thought that both my subject line of "Epicycles, anyone?" and my overall tone advertised my sarcasm. Over the years, I'd seen many snarky posts without the "/sarc" tag, so I didn't consider it either necessary or mandatory.
You do know about epicycles, don't you? Even if you don't, the spell checker does -- no red line under the word.
And, just to please you...
/sarc
"Dark matter is an invisible substance that is suspected to exist in large quantity around galaxies, lending mass but emitting no radiation. The only evidence for it comes from its gravitational effect on the material around it... up to now, dark matter itself has not been directly detected. Regardless, it has been estimated to make up 80% of all the mass in the Universe."
Of course dark matter exists. Our computer programs, based on the gravitational model of the universe, prove that it exists. Just because we haven't been able to find any of it yet is no reason to doubt its existence.
So no more of this heretical "suspected to exist" nonsense!
And don't pay any attention to those charlatans who promulgate the electric universe model, OK?