Is dark matter sterile? That’s one idea recently presented at the National Astronomy Meeting of the Royal Astronomical Society this week.
New observations of colliding galaxies shows that dark matter interacts with itself, and may do it through a “dark force.”
A study of 72 colliding galaxy clusters has found that dark matter is not only real, it interacts with itself even less than we thought.
New research finds evidence of a dark matter dwarf galaxy orbiting the Milky Way.
The effect of dark matter has been observed in the center of our galaxy, further confirming its existence.
Another day, another new idea for what dark matter might be. This time, it is a paper that proposes dark matter is made of regular matter. For those who are familiar with dark matter, this might raise an eyebrow because dark matter can’t be regular matter. In fact, what this paper shows is that while observational data excludes the usual suspects for dark matter such as cold gas and dust, small black holes and the like, there might be a way to shoehorn regular matter into the picture. The solution they propose is, quite literally, a bit strange.
The global positioning system (GPS) is an array of satellites orbiting the Earth, which can be used to pinpoint your location. Each of the satellites transmits a signal with its current position and time. A GPS receiver can then use signals from multiple satellites to determine where it is on the planet. GPS is perhaps most widely used in mobile phones. If you’ve ever had your phone give you directions, you’ve used GPS. In order to work properly, the clocks on a GPS satellite need to be extraordinarily precise. So precise that the effects of special and general relativity must be taken into account.
Dark matter remains an enigma of modern cosmology. We have indirect evidence of its existence, and even some evidence of its characteristics, but we have yet to detect dark matter directly. This puts us in a kind of middle ground where there’s enough evidence to support dark matter, but not enough to define it, which is the perfect playground for theorists to try new ideas. This week in Physical Review Letters, just such a new idea has been presented.
There’s been a few articles in the popular press recently announcing the discovery of dark matter particles coming from the Sun. This is not the case. No science team is claiming they’ve discovered dark matter. The story traces it origin to a paper being published in MNRAS, which could be an indirect detection of dark matter, but could also be a few other things. It is an interesting paper, nonetheless.