Germany's Lilium says successfully tests 'flying taxi' prototype

Leiden, Jul 2: Astronomers have discovered a luminous galaxy caught in the act of reionizing its surrounding gas only 800 million years after the Big Bang.

The research, led by Romain Meyer, PhD student at UCL in London, UK, has been presented at the virtual annual meeting of the European Astronomical Society (EAS).

Studying the first galaxies that formed 13 billion years ago is essential to understanding our cosmic origins. One of the current hot topics in extragalactic astronomy is 'cosmic reionization,' the process in which the intergalactic gas was ionized (atoms stripped of their electrons).

Cosmic reionization is similar to an unsolved murder: We have clear evidence for it, but who did it, how and when? We now have strong evidence that hydrogen reionization was completed about 13 billion years ago, in the first billion years of the universe, with bubbles of ionized gas slowly growing and overlapping.

The objects capable of creating such ionized hydrogen bubbles have however remained mysterious until now: the discovery of a luminous galaxy in which 60-100 percent of ionizing photons escape, is likely responsible for ionizing its local bubble. This suggests the case is closer to being solved.

The two main suspects for cosmic reionization are usually 1) a population of numerous faint galaxies leaking ~10 percent of their energetic photons, and 2) an 'oligarchy' of luminous galaxies with a much larger percentage (>50 percent) of photons escaping each galaxy.

In either case, these first galaxies were very different from those today: galaxies in the local universe are very inefficient leakers, with only <2-3 percent of ionizing photons escaping their host. To understand which galaxies governed cosmic reionization, astronomers must measure the so-called escape fractions of galaxies in the reionization era.

The detection of light from excited hydrogen atoms (the so-called Lyman-alpha line) can be used to infer the fraction of escaping photons. On the one hand, such detections are rare because reionization-era galaxies are surrounded by neutral gas which absorbs that signature hydrogen emission.

On the other hand, if this hydrogen signal is detected it represents a 'smoking gun' for a large ionized bubble, meaning we have caught a galaxy reionizing its surroundings. The size of the bubble and the galaxy's luminosity determines whether it is solely responsible for creating this ionized bubble or if unseen accomplices are necessary.

The discovery of a luminous galaxy 800 million years after the Big Bang supports the scenario where an 'oligarchy' of bright leakers emits most of the ionizing photons.

"It is the first time we can point to an object responsible for creating an ionized bubble, without the need for a contribution from unseen galaxies.

Additional observations with the upcoming James Webb Space Telescope will enable us to study further what is likely one of the best suspects for the unsolved case of cosmic reionization," said Meyer.

New Delhi, Feb 26: With the government pushing for the disinvestment of Air India, industrial conglomerate Adani Group may emerge as one of the bidders for the debt-laden national carrier, sources said.

According to highly placed sources, the Group has held internal rounds of deliberations on whether or not to submit an Expression of Interest (EoI) and the discussions are still in the preliminary stage.

If the company actually submits an EoI, it would be a major move towards further diversification of the company which has business interests across sectors right from edible oil, food to mining and minerals. 

It also entered into airport operations and maintenance business and won bids for privatisation of six airports, Ahmedabad, Lucknow, Jaipur, Guwahati, Thiruvananthapuram and Mangaluru in 2019. 

On being contacted by IANS, the company did not comment on the matter.

Air India is one of the most important divestment proposals for the current fiscal to reach the huge Rs 2.1 lakh crore target.

The government in January restarted the divestment process of the airline and invited bids for selling 100 per cent of its equity in the state-owned airline, including Air India's 100 per cent shareholding in AI Express Ltd. and 50 per cent in Air India SATS Airport Services Private Ltd.

After its unsuccessful bid to sell Air India in 2018, the government this time has decided to offload its entire stake. In 2018, it had offered to sell its 76 per cent stake in the airline.

Of the total debt of Rs 60,074 crore as of March 31, 2019, the buyer would be required to absorb Rs 23,286 crore.

Air India, along with its subsidiary Air India Express, has a total operational fleet of 146 aeroplanes.

Further, the disinvestment department has extended the last date for submission of written queries on the Performance Information Memorandum and Share Purchase Agreement to March 6.

The last date for submission of written queries on PIM and SPA was originally set for February 11, following which the Department of Investment and Public Asset Management (DIPAM) on February 21 issued 20 clarifications on the queries raised and expected.

Any delay in the tentatively rolled out timeline would also delay DIPAM's plan to identify the pre-qualified bidders by March 31 and the financial bids invitation as well. It is expected to take more than two months after the selection of the pre-qualified bidders to complete Air India's sale.

Washington, Jan 7: Facebook will ban deepfake videos ahead of the US elections but the new policy will still allow heavily edited clips so long as they are parody or satire, the social media giant said Tuesday.

Deepfake videos are hyper-realistic doctored clips made using artificial intelligence or programs that have been designed to accurately fake real human movements.

In a blog published following a Washington Post report, Facebook said it would begin removing clips that were edited--beyond for clarity and quality--in ways that "aren't apparent to an average person" and could mislead people.

Clips would be removed if they were "the product of artificial intelligence or machine learning that merges, replaces or superimposes content onto a video, making it appear to be authentic," the statement from Facebook vice-president Monika Bickert said.

However, the statement added: "This policy does not extend to content that is parody or satire, or video that has been edited solely to omit or change the order of words."

US media noted the new guidelines would not cover videos such as the 2019 viral clip -- which was not a deepfake -- of House Speaker Nancy Pelosi that appeared to show her slurring her words.

Facebook also gave no indication on the number of people assigned to identify and take down the offending videos, but said videos failing to meet its usual guidelines would be removed, and those flagged clips would be reviewed by teams of third-party fact-checkers -- among them AFP.

The news agency has been paid by the social media giant to fact-check posts across 30 countries and 10 languages as part of a program starting in December 2016, and including more than 60 organisations.

Content labeled "false" is not always removed from newsfeeds but is downgraded so fewer people see it -- alongside a warning explaining why the post is misleading.