Facebook steps up battle on 'fake likes'

Washington DC, Jun 8: Astronomers acting on a hunch have likely resolved a mystery about young, still-forming stars and regions rich in organic molecules closely surrounding some of them.

They used the National Science Foundation's Karl G Jansky Very Large Array (VLA) to reveal one such region that previously had eluded detection and that revelation answered a longstanding question.

The regions around the young protostars contain complex organic molecules which can further combine into prebiotic molecules that are the first steps on the road to life.

The regions, dubbed "hot corinos" by astronomers, are typically about the size of our solar system and are much warmer than their surroundings, though still quite cold by terrestrial standards.

The first hot corino was discovered in 2003 and only about a dozen have been found so far. Most of these are in binary systems, with two protostars forming simultaneously.

Astronomers have been puzzled by the fact that, in some of these binary systems, they found evidence for a hot corino around one of the protostars but not the other.

"Since the two stars are forming from the same molecular cloud and at the same time, it seemed strange that one would be surrounded by a dense region of complex organic molecules and the other wouldn't," said Cecilia Ceccarelli, of the Institute for Planetary Sciences and Astrophysics at the University of Grenoble (IPAG) in France.

The complex organic molecules were found by detecting specific radio frequencies, called spectral lines, emitted by the molecules. Those characteristic radio frequencies serve as "fingerprints" to identify the chemicals.

The astronomers noted that all the chemicals found in hot corinos had been found by detecting these "fingerprints" at radio frequencies corresponding to wavelengths of only a few millimetres.

"We know that dust blocks those wavelengths, so we decided to look for evidence of these chemicals at longer wavelengths that can easily pass through dust," said Claire Chandler of the National Radio Astronomy Observatory, and principal investigator on the project.

"It struck us that dust might be what was preventing us from detecting the molecules in one of the twin protostars," added Chandler.

The astronomers used the VLA to observe a pair of protostars called IRAS 4A, in a star-forming region about 1,000 light-years from Earth. They observed the pair at wavelengths of centimetres.

At those wavelengths, they sought radio emissions from methanol, CH3OH (wood alcohol, not for drinking). This was a pair in which one protostar clearly had a hot corino and the other did not, as seen using the much shorter wavelengths.

The result confirmed their hunch. "With the VLA, both protostars showed strong evidence of methanol surrounding them. This means that both protostars have hot corinos. The reason we did not see the one at shorter wavelengths was because of dust," said Marta de Simone, a graduate student at IPAG who led the data analysis for this object.

The astronomers cautioned that while both hot corinos now are known to contain methanol, there still may be some chemical differences between them. That, they said, can be settled by looking for other molecules at wavelengths not obscured by dust.

"This result tells us that using centimetre radio wavelengths is necessary to properly study hot corinos," Claudio Codella of Arcetri Astrophysical Observatory in Florence, Italy, said.

"In the future, planned new telescopes such as the next-generation VLA and SKA, will be very important to understanding these objects," added Codella.

US dictionary Merriam-Webster will update the meaning of the word "racism" after being contacted by a Missouri black woman, who claimed the current definition fell short of including the systematic oppression of people of colour, according to media reports.

"A revision to the entry for racism is now being drafted to be added to the dictionary soon, and we are also planning to revise the entries of other words that are related to racism or have racial connotations," according to a statement of the 189-year-old dictionary shared by Kennedy Mitchum, a recent graduate of Drake University in Iowa, on her Facebook.

Mitchum, 22, emailed the dictionary last month, following the death of African American George Floyd in the custody of four Minneapolis police officers, Xinhua news agency reported.

"I kept having to tell them that definition is not representative of what is actually happening in the world," Mitchum told CNN. "The way that racism occurs in real life is not just prejudice, it's the systemic racism that is happening for a lot of black Americans."

Merriam-Webster's first definition of racism is "a belief that race is the primary determinant of human traits and capacities and that racial differences produce an inherent superiority of a particular race."

"It's not just disliking someone because of their race," Mitchum wrote in a Facebook post on Friday. "This current fight we are in is evidence of that, lives are at stake because of the systems of oppression that go hand-in-hand with racism."

New Delhi, Jan 19: Messaging service WhatsApp which on Sunday faced issues in transmitting multimedia content including pictures and images, prompting social media users to share hilarious memes and messages, resumed regular services after over two hours.

#WhatsAppDown was the trending hashtag on Twitter for most part of Sunday afternoon in India along with several other countries such as Brazil, Europe and also parts of Middle-East including UAE, reported downdetector.in, a realtime problem and outage monitoring website.

Users of the popular messaging app were unable to send media files, stickers and GIFs.

Most users immediately went to Twitter to find out about the problem and check if others were facing the same issue.

Numerous tweets and memes took over the internet as soon as the news broke about the WhatsApp tech issue. After around two hours of technical glitch, the app resumed full service.

Even after full recovery of media transfer, people globally still continued checking the status of the messaging app.

WhatsApp has been one of the prime messaging apps since May 2009 and has recently collaborated with Facebook.