Balancing the balance
My checking account currently holds $10.000. That is $90k short of the car I want. But the equation works if I just add enough dark currency
Data gathered by the International Space Station's (ISS') Alpha Magnetic Spectrometer (AMS) is being cautiously suggested as useful evidence for the existence of dark matter. The AMS is a particle detector on the ISS and keeps its eyes on cosmic rays, in order to observe the high-energy particles they carry. As explained in a …
It seems this is a case of the English language changing before our very eyes:
www.theguardian.com/news/datablog/2010/jul/16/data-plural-singular
blogs.wsj.com/economics/2012/07/05/is-data-is-or-is-data-aint-a-plural/
All right, engineering and cartographers.
But then what about a datum line, which has an infinite (aleph 1) number of points on it?
Perhaps what this really shows is that we should stop pretending that scientific and technical terms are actually Latin words and should follow Latin grammar.
It's quire obvious that the 'is' refers to the fact of a single suggestion rather than a single datum. I personally use 'is' when the data represents a single set, 'this set' is much smother English than 'these set'.
A mob is made up from numerous individuals but you refer to it as 'a mob', 'the mob is unruly', etc... 'These mob' just sounds like some foreign person with an English pronunciation problem.
But when you're referring to a mob you're referring to a singular subject- the mob. Same with Set- It's a collective noun that allows you to refer to its members as a singular rather than a plural.
So 'these mob' is nonseneical, but 'these mobs' would make sense if you had multiple mobs.
"So you're saying that Dr. Who isn't an entertainment program, but a documentary?"
The documentary version is available separately from BBC Worldwide.
It features 30 minutes of footage of a Doctor Who costumed Peter Capaldi pointing his Sonic Screwdriver at the camera and shouting in his best psychotic Glaswegian, 'Kiss my sweaty balls you fat fuck'...
... actually, I think it's my toaster. It's been humming and fizzing for a while now and I've had to turn it up to max to get decent toast. I concluded that it's been manufacturing a lot of anti-elecricity and some of it must have leaked upwards out of the two slots on top.
I'm not sure if you're being serious. Is there any suggestion that dark matter particles may be unstable and have a positron decay route, rather than needing a collision to make them annihilate?
AFAIK current ideas are that at one extreme dark matter may only feel gravity, making it behave like a perfect gas of near-point particles in total darkness. But at the other we have WIMPs, which experience the weak force. And this is necessary to provide a mechanism for dark particles to decay, otherwise they will be undetectable.
WIMPs are psychological particles, because (as Fermilab observes) the search for them involves a degree of wishful thinking. Scientists like things to be detectable. (So do I, or it's no fun any more.)
I have never heard of dark matter annihilation, but decay, yes:
Synopsis: Sterile Neutrino as Dark Matter Candidate
A hypothetical neutrino that does not interact through the weak force could be the source of a recently detected x-ray emission line coming from galaxy clusters. However, previous models using this so-called “sterile” neutrino as a form of dark matter were not able to satisfy constraints from cosmological observations. Now, writing in Physical Review Letters, Kevork Abazajian of the University of California, Irvine, shows that a sterile neutrino with a mass of 7 kilo-electron-volts (keV) could be a viable dark matter candidate that both explains the new x-ray data and solves some long-standing problems in galaxy structure formation.
Cosmologists have long considered neutrinos as possible dark matter particles. However, because of their small mass (less than about 1 eV), conventional neutrinos are too fast, or “hot,” to form the dense dark matter structures needed to hold galaxies and galaxy clusters together. By contrast, sterile neutrinos, which result from certain neutrino theories, can have larger masses and could have been naturally produced in the big bang by neutrino flavor mixing.
The problem has been that sterile neutrinos should decay, producing an x-ray signal that no one has observed—until maybe now. Earlier in 2014, an analysis of galaxy cluster data revealed an x-ray emission line, which is consistent with the decay of a 7-keV sterile neutrino. Normally, dark matter with this mass would be too “warm” to match galaxy data. However, Abazajian showed that the sterile neutrinos could have a “cooler” momentum distribution if they were produced through resonantly enhanced neutrino flavor mixing (the MSW effect). When Abazajian plugged this neutrino into a cosmological model, he found it could explain both the small number of Milky Way satellite galaxies and their central densities, which have eluded the currently favored cold dark matter model. – Michael Schirber
"I have never heard of dark matter annihilation"
Positrons being produced near the word "Neutrinos" on the left hand diagram.
The sterile neutron hypothesis results in x rays, not positrons.
Shirley, shouldn't it be dark matter particles colliding with anti-dark matter particles that result in annihilation?
But then if anti-matter (electron + positron) can be created by a pair of gamma photons, and photons are their own anti-particles, then shouldn't we be talking about dark-matter anti-anti-particles?
Posicles?
Erm, it's a bit more than that. positrons *are* antimatter. They are the antiparticle of the electron and will annihilate if they collide with one. Antimatter (more correctly Antiparticles) don't need any more evidence of existence, they're an actual thing.
Where the ambiguity comes in is that an assumption has been made (from the article which I'm sure you've read) "it is assumed they are created when dark matter particles collide and annihilate each other." and so this assumption is leaned upon as explanation for the larger than expected number of positrons. So, the confidence in these extra observed positrons signalling extra dark matter collisions hinges entirely on the confidence of the central assumption.
Not utter garbage at all, then, just not a high confidence conclusion. Which, to be fair, was what the author of the article said at the end.
Just £2.99 a month will let you adopt a positron.
You'll get a picture of your positron, a monthly newsletter telling you all about the work of the Positron Sanctuary* and, as a special offer this week only, a cuddly positron hand-crafted from dark matter plush.
*The positron sanctuary is a registered charity in England and Wales.
Currantly being used in Medical Imaging, called PET / CT... positrons were the first man made radioactive sources in the 1930's, cosmic Rays from Earth's Lightning strikes n hi energy galactic sourced particles both decay into positron emmission n other particles... we have been looking at these things since 1934.
IMHO= ISS positron detecter ?? sure... seeing some positrons and calling dark matter is similar to calling any newfound object a UFO, which by definition it is... just no LGM's looking out of viewing ports on the Real UFO's that aren't there.
Please Note= positrons are part of the VISIBLE, countable, Universe and Not by anyone's definition= "Dark Matter"... RS.