7,000-year-old Native American burial site found off Florida The site was discovered by an amateur diver who was looking for shark teeth but stumbled on an ancient jawbone. Archeologist Ryan Duggins noticed a worn – down molar tooth attached to the jawbone in a picture…
Poor old Uranus just can’t seem to catch a break. Something already tipped the planet on its side, so its orbit is perpendicular to those of the other Solar System planets. It probably smells terrible. And now scientists have discovered that the atmosphere of Uranus is leaking…
Once again, a search for signs of dark matter outside its gravitational effect has turned up zilch – but this time it’s a little more controversial. Astronomers peering into empty space have not found an X-ray glow hypothesised to be the product of one particular dark matter candidate: the sterile neutrino.
It is, the researchers say, a result that throws a bit of a dampener on this candidate as a leading contender for dark matter – but doesn’t extinguish it entirely.
Dark matter is a huge old question mark. Although we can’t detect it directly, we know it’s out there because it’s having a really big gravitational effect on the stuff we can detect, also known as normal matter.
For instance, stuff on the outer edges of galaxies moves faster than it should if it were under the gravitational influence of normal matter alone. And gravitational lensing – the way gravity bends the path of light – is stronger than we would expect, too. From these effects, astronomers have calculated that as much as 85 percent of the matter in the Universe is dark matter.
Because we can’t detect it, though, we don’t know what it is. And there are a number of hypothetical candidates, with astronomers trying to come up with ways to detect these.
The sterile neutrino is a hypothetical particle. Normal neutrinos, the most abundant particles in the Universe, are very hard to detect at the best of times – they are similar to electrons, but with no charge and very little mass, so they barely interact with normal matter. A sterile neutrino, physicists have hypothesised, wouldn’t interact with normal matter at all, except maybe gravitationally.
But these hypothetical neutrinos are unstable, too. They should decay into normal neutrinos and electromagnetic radiation. And, if they are so decaying, then that radiation should be detectable. Very faint, but detectable.
That’s what a 2014 study claimed to have done – detected the faint X-rays from sterile neutrino decay from distant galaxies, an emission called the 3.5 KeV line. But then follow-up studies – one in 2016 on a dwarf galaxy 260,000 light-years away, and another in 2017 on a galaxy cluster 240 million light-years away – found no such thing.
So, a team of researchers decided to look a bit closer to home. We know the Milky Way has a substantial dark matter halo, so if sterile neutrinos are decaying in it, they should be detectable around the galaxy.
The team conducted a meta-analysis of 20 years of raw archival X-ray data of empty space around the Milky Way, where other glowing objects wouldn’t create interference, taken by the XMM-Newton space telescope, looking for signs of that 3.5 KeV emission. They didn’t find any.
“This 2014 paper and follow-up works confirmed the signal generated a significant amount of interest in the astrophysics and particle physics communities because of the possibility of knowing, for the first time, precisely what dark matter is at a microscopic level,” said physicist Ben Safdi of the University of Michigan.
“Our finding does not mean that the dark matter is not a sterile neutrino, but it means that – contrary to what was claimed in 2014 – there is no experimental evidence to-date that points towards its existence.”
The result suggests that something else was causing the 3.5 KeV glow seen in that 2014 study, the researchers said. But not everyone is convinced. Physicist Alexey Boyarsky of Leiden University in the Netherlands posted a similar survey to preprint server arXiv, looking at the blank sky of the Milky Way. His team believes they did find the 3.5 KeV line.
“I think this paper is wrong,” he said of the new research to Science Magazine. The different results could be the product of the two different analysis techniques; both teams believe their method is superior, although Boyarsky’s paper is yet to be peer-reviewed.
So it seems the question may still be somewhat open, and only more research can help to resolve it.
Meanwhile, there’s another direction that can be taken, too. Safdi says that his team’s conclusions open up a new avenue for further search on the matter.
“While this work does, unfortunately, throw cold water on what looked like what might have been the first evidence for the microscopic nature of dark matter, it does open up a whole new approach to looking for dark matter which could lead to a discovery in the near future,” he said.
Polls show that more Americans approve of President Trump’s handling of this health crisis than approved of the job Barack Obama did during the various health crises that hit during his two failed presidential terms. People also have more faith in the overall job the…
Rep. Joe Cunningham (D-SC) announced Friday that he has tested positive for the Chinese coronavirus and is in self-quarantine. Cunningham, a freshman congressman, began self-isolating March 19 after coming into contact with a lawmaker who was infected with the deadly illness. The South Carolina Democrat said…
Massachusetts Gov. Charlie Baker (R) is urging all travelers entering the state to self-quarantine for 14 days, he announced on Friday.
Baker said officials in the Bay State are “doing everything we can to keep people at home and prevent the spread.” As part of that effort, Baker is urging travelers entering the state, specifically those traveling via plane or train, to self-isolate for two weeks.
“Here in Massachusetts we’re doing everything we can to keep people at home and prevent the spread,” he stated at a Friday press conference. “Starting today, all travelers allowed into the commonwealth are instructed to self-quarantine for 14 days.”
Pamphlets will be distributed to travelers, and drivers “will see pamphlets at rest stops and see the message on digital highway signs,” according to Boston 10.
“I would call it at this point instruction and advisory,” Baker emphasized, noting that there is “no enforcement at this point.”
The governor also urged travelers to rethink their travel plans and steer clear of Massachusetts communities if they are experiencing symptoms of the virus.
“We are taking extraordinary steps here to keep our residents safe, including asking folks to stay home and closing nonessential businesses,” he said.
“Every which decision comes with a certain amount of pain, frustration and disruption for the people of the commonwealth,” he added.
Baker issued a stay-at-home order this week, resulting in the statewide shutdown of businesses deemed “nonessential.” The order is slated to stay in effect until April 7. Schools are closed until May 4.
As of Friday afternoon, the state had over 2,400 coronavirus cases and 25 related deaths.
Baker’s call for self-isolation follows Florida Gov. Ron DeSantis’s (R) executive order, requiring all travelers from the New York Tri-State area, a hotspot of the virus, to self-isolate. Violation of the order is “actually a criminal offense,” DeSantis noted upon his announcement.
Undisturbed 2,000-Year-Old Roman Shipwreck Discovered In Cyprus From the 8th century B.C. in the classical age. Roman ports dominated the Mediterranean Sea coasts until the sixth century A.D. Before its notorious collapse in the third century the Roman Empire – which was famous for trade…
Researchers and archeologists found something quite wonderful in Iceland a little while ago in an archeological dig. The team was digging under a parking lot by Lækjargata Street in downtown Reykjavik when they found one of the largest Viking longhouses ever discovered in Iceland. The…
Derek McLennan uncovered a stunning find of gold, silver, and religious objects in the Dumfries and Galloway field five years ago. The beautiful, allegedly abandoned’ Galloway Hoard’ from 850 to 950 AD was declared one of the’ most important Viking hoards ever discovered in Scotland.’
Among the most fascinating items, there were silver bracelets and brooches, a gold ring, an enamel Christian cross, and a bird-Shaped gold pin.
The funders in Scotland are paid for these discoveries, while awards are split with the landowner in England.
Derek McLennan, 47, holding ingots from the hoard of Viking treasure (Picture: PA) Initially, it was reported the church would share in the proceeds but now trustees are taking legal action at the Court of Session in Edinburgh.
A Church of Scotland spokesman said: ‘It can be confirmed the general trustees of the Church of Scotland have raised an action against Derek McLennan.
‘As that is now a matter before the court it would be inappropriate for us to provide any further commentary at this time.’
Mr McLennan, a retired businessman and amateur detectorist, had been searching the unidentified area for a year with the church’s permission before he came across the incredible haul.
At the time, he said: ‘I unearthed the first piece, initially I didn’t understand what I had found because I thought it was a silver spoon and then I turned it over and wiped my thumb across it and I saw the Saltire-type of design and knew instantly it was Viking.
‘Then my senses exploded, I went into shock, endorphins flooded my system and away I went stumbling towards my colleagues waving it in the air.’
The hoard included silver bracelets and brooches, a gold ring and an enamelled Christian cross (Picture: The National Museums Scotland) A pectoral cross from the Viking hoard (Picture: PA) The haul included a large Carolingian pot from what is now France which could have been 100 years old when it was deposited.
Inside they found silver Anglo-Saxon disc brooches, an Irish silver brooch, Byzantine silk from the area around Constantinople (now Istanbul), a gold ingot and gold and crystal objects wrapped in cloth.
It is not known why the treasures were deposited. Vikings from Scandinavia terrorised Britain and Ireland for more than 250 years from 793AD and frequently targeted monasteries where valuables were stored.
A bird pin from the Viking hoard (Picture: PA) The raiders failed to conquer mainland Scotland but settled in outlying islands such as Orkney and Shetland.
In Galloway and Dumfries, the word ‘Kirk’ which means church, features on many places and personal names are of Scandinavian origin.
The Galloway Hoard will be displayed at the National Museum of Scotland in Edinburgh from May to November next year, before visiting Kirkcudbright, Dundee and Aberdeen.
The stone points and other tools retrieved close a riverbank in Idaho show ancient human beings arrived more than 16,000 years ago in the western part of the United States. The site is known as Cooper’s Ferry, one of North America’s oldest human settlements, says…