Asia’s largest imaging Cherenkov telescope, located at an altitude of almost 4,300 metres, was inaugurated on Wednesday at Ladakh’s Hanle.

The Major Atmospheric Cherenkov Experiment (MACE) observatory, the highest of its kind of telescope in the world, has been indigenously built by the Mumbai-based Bhabha Atomic Research Centre (BARC) with support from the Electronics Corporation of India Ltd (ECIL) and other Indian industry partners.

The MACE observatory is touted to place India at the forefront of cosmic ray research globally by allowing scientists to study high-energy gamma rays. This will pave the way for deeper understanding of the universe’s most energetic events, such as supernovae, black holes, and gamma-ray bursts.

Even before its formal inauguration, the telescope produced high-quality work detecting gamma ray flares as far away as 200 million light years away.

About MACE observatory

MACE is 21 metres in diameter, 175 tonnes heavy, has reflector area of 356 sqm and 1,424 diamond-turned metallic mirror facets, 712 actuators, 1,088 photo-multiplier tubes, and 68 camera modules.

It is a lightweight construction and features high strength and temperature endurance. Reflector surface measuring over 350 square metres (sqm) comprises highly reflective diamond-turned custom-built metallic mirror facets that are required to be aligned with an accuracy of 2 mm over parabolic surface. The camera at the focal point contains a number of photomultiplier tubes mounted with specialised assembly to enhance light collection efficiency.

Ultrafast backend electronics with nanosecond digitization electronics is optimised for low-power and -temperature operations. Extreme weather conditions restrict transport to six-eight months a year and affect the availability of trained personnel on site.

How will the telescope work?

Gamma rays do not reach the Earth’s surface as they are stopped by the atmosphere. However, interaction with the atmosphere creates high-energy particles that travel faster than the speed of flight and emit Cherenkov radiation which is akin to a sonic boom. The mirrors and cameras capture these flashes and trace them back to its cosmic source.

Why Hanle?

The site has been carefully chosen for its unique scientific advantages as Hanle offers extremely low light pollution required for gamma ray observations. The longitudinal advantage of its location enables MACE to observe sources invisible to other parts of the world.

“Hanle is like heaven for gamma ray astronomers with its dark skies, low humidity and almost no air pollution,” said Dr AK Mohanty, chairman, Atomic Energy Commission and India’s nuclear chief. He said another few more gamma ray telescopes could be built here, making Hanle the go-to place for global astronomers, some with international collaboration.

A city usually starts as a small town and grows in area after new buildings are made and boundaries are extended. However, in recent times, taller buildings are seen as one of the elements of any modern city. Now, a new study has revealed that cities are soaring upward at a greater rate than they are spreading out. This new finding can reshape how we use our resources and the environment.

The satellite study, published in the journal Nature Cities, was conducted by a team of Earth scientists, environmental engineers and geomaticists. The team studied two types of satellite data by measuring the footprint and height of buildings or more than 1,500 cities globally from the 1990s to the 2010s. One kind displayed a city’s footprint, making it possible to calculate its size in two dimensions. The second kind, which used microwaves, made it possible to estimate city expansion in three dimensions and took skyscraper construction into account for upward growth.

According to the study, cities are increasingly growing upward instead of outward, with Asian cities leading the way. Previously, cities expanded by occupying more territory.

David Wilson, a professor of geography at the University of Illinois Urbana-Champaign, said that the study is “extremely interesting” and the change from horizontal to vertical growth in urban areas has both pros and cons.

“This trend is very positive for promoting sustainability and resource management. Less blocks, neighbourhoods, and communities will require the hand of government to reach out and expend scarce resources for policing, fire protection, and provision of housing services,” he told Newsweek.

He added, “At the same time, the prognosis for fostering equity in the city is grim. Dramatic increases in vertical development, especially in mega-cities, often signal the realities of downtown gentrification kicking into hyperdrive, a notorious process for displacing and further isolating the poor and the stigmatized.”

According to the study, larger cities with a population of more than 10 million people are at the forefront of the vertical transition.

In recent decades, China’s urban growth has experienced a remarkable transformation. Wide outward growth was the initial hallmark, but more recently, taller structures are displacing shorter ones as vertical development has taken hold. Nonetheless, Europe’s urban growth patterns have not changed much, with outward growth continuing to predominate and vertical development growing at a very slow rate.

Fast upward growth was rare in the 1990s but considerably more typical by the 2010s. Rapid outward development, on the other hand, declined throughout this time.

Manila:

The Philippine government on Monday accused Chinese ships of ramming and damaging its boats in the South China Sea during a confrontation in waters off the Second Thomas Shoal, home to a garrison of Filipino troops.

“The People’s Liberation Army-Navy, China Coast Guard and Chinese Maritime Militia vessels engaged in dangerous maneuvers, including ramming and towing,” Manila’s national task force on the West Philippine Sea said in a statement.

“Their actions put at risk the lives of our personnel and damaged our boats.”

The Second Thomas Shoal has seen an escalating number of confrontations between Chinese and Philippine ships in recent months.

These have often taken place during Philippine resupply missions to a garrison of Filipino troops on a grounded navy vessel, the Sierra Madre, aimed at asserting Manila’s claims to the reef.

The shoal lies about 200 kilometres (120 miles) from the western Philippine island of Palawan and more than 1,000 kilometres from China’s nearest major landmass, Hainan island.

The Chinese coast guard said early Monday a Philippine resupply ship in the area had “ignored many solemn warnings from the Chinese side” and that they “took control measures” against it “in accordance with the law.”

It “approached the… Chinese vessel in an unprofessional way, resulting in a collision”, Beijing said.

Philippine Defence Secretary Gilberto C. Teodoro, vowed to defend his country’s sovereignty, saying China’s “dangerous and reckless behaviour in the West Philippine Sea shall be resisted”.

“It should now be clear to the international community that China’s actions are the true obstacles to peace and stability in the South China Sea,” he added.

The Philippine government statement did not specify which boats were rammed and the extent of the damage.

Manila’s allies voiced concern over China’s actions.

The United States ambassador to Philippines, MaryKay Carlson said in a post on social media X that Washington “condemns” China’s “aggressive dangerous maneuvers which caused bodily injury, damaged Philippine vessels, and hindered lawful maritime operations.”

Japan’s ambassador Endo Kazuya expressed his country’s “grave concern over the repeated dangerous and aggressive actions” by the China Coast Guard.

“We oppose any threat or use of force contrary to international law,” reacted the French ambassador Marie Fontanel in a social media pos

(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)

Bangkok:

Thailand’s government said on Tuesday it had approved longer visa stay periods for tourists, postgraduate students and remote workers, and better visa conditions for retirees, in a move to boost its crucial tourism sector as its economy stutters.

Starting in June, Thailand will allow travelers from 93 countries to stay for periods of 60 days, up from the current 57 nations, while more will also be eligible for visas on arrival, government spokesperson Chai Wacharonke told reporters.

Foreign students will be permitted to stay for an additional year upon graduation, while insurance requirements for foreigners seeking to retire in Thailand will be relaxed, he added.

Tourism is a key driver of Southeast Asia’s second-largest economy and a big source of employment.

The new measures come as part of an effort to boost visitors, especially from its main and fastest-growing markets, by extending stay limits to 60 days from 30 days for on-arrival visas.

The validity of so-called “digital nomad” visas for self-employed, remote workers will be extended to five years, from 60 days presently, with each stay limited to 180 days.

Thailand recorded 14.3 million tourists in from January to May 26 this year and is targeting a record 40 million foreign arrivals for the full year, with revenue of 3.5 trillion baht ($95.73 billion).

In pre-pandemic 2019, Thailand welcomed a record 39.9 million arrivals, generating 1.91 trillion baht.

(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)