Connect with us

Science

Experts recreate a mechanical Cosmos for the world's first computer – Science Daily

Published

 on


Researchers at UCL have solved a major piece of the puzzle that makes up the ancient Greek astronomical calculator known as the Antikythera Mechanism, a hand-powered mechanical device that was used to predict astronomical events.

Known to many as the world’s first analogue computer, the Antikythera Mechanism is the most complex piece of engineering to have survived from the ancient world. The 2,000-year-old device was used to predict the positions of the Sun, Moon and the planets as well as lunar and solar eclipses.

Published in Scientific Reports, the paper from the multidisciplinary UCL Antikythera Research Team reveals a new display of the ancient Greek order of the Universe (Cosmos), within a complex gearing system at the front of the Mechanism.

Lead author Professor Tony Freeth (UCL Mechanical Engineering) explained: “Ours is the first model that conforms to all the physical evidence and matches the descriptions in the scientific inscriptions engraved on the Mechanism itself.

“The Sun, Moon and planets are displayed in an impressive tour de force of ancient Greek brilliance.”

The Antikythera Mechanism has generated both fascination and intense controversy since its discovery in a Roman-era shipwreck in 1901 by Greek sponge divers near the small Mediterranean island of Antikythera.

The astronomical calculator is a bronze device that consists of a complex combination of 30 surviving bronze gears used to predict astronomical events, including eclipses, phases of the moon, positions of the planets and even dates of the Olympics.

Whilst great progress has been made over the last century to understand how it worked, studies in 2005 using 3D X-rays and surface imaging enabled researchers to show how the Mechanism predicted eclipses and calculated the variable motion of the Moon.

However, until now, a full understanding of the gearing system at the front of the device has eluded the best efforts of researchers. Only about a third of the Mechanism has survived, and is split into 82 fragments — creating a daunting challenge for the UCL team.

The biggest surviving fragment, known as Fragment A, displays features of bearings, pillars and a block. Another, known as Fragment D, features an unexplained disk, 63-tooth gear and plate.

Previous research had used X-ray data from 2005 to reveal thousands of text characters hidden inside the fragments, unread for nearly 2,000 years. Inscriptions on the back cover include a description of the cosmos display, with the planets moving on rings and indicated by marker beads. It was this display that the team worked to reconstruct.

Two critical numbers in the X-rays of the front cover, of 462 years and 442 years, accurately represent cycles of Venus and Saturn respectively. When observed from Earth, the planets’ cycles sometimes reverse their motions against the stars. Experts must track these variable cycles over long time-periods in order to predict their positions.

“The classic astronomy of the first millennium BC originated in Babylon, but nothing in this astronomy suggested how the ancient Greeks found the highly accurate 462-year cycle for Venus and 442-year cycle for Saturn,” explained PhD candidate and UCL Antikythera Research Team member Aris Dacanalis.

Using an ancient Greek mathematical method described by the philosopher Parmenides, the UCL team not only explained how the cycles for Venus and Saturn were derived but also managed to recover the cycles of all the other planets, where the evidence was missing.

PhD candidate and team member David Higgon explained: “After considerable struggle, we managed to match the evidence in Fragments A and D to a mechanism for Venus, which exactly models its 462-year planetary period relation, with the 63-tooth gear playing a crucial role.”

Professor Freeth added: “The team then created innovative mechanisms for all of the planets that would calculate the new advanced astronomical cycles and minimize the number of gears in the whole system, so that they would fit into the tight spaces available.”

“This is a key theoretical advance on how the Cosmos was constructed in the Mechanism,” added co-author, Dr Adam Wojcik (UCL Mechanical Engineering). “Now we must prove its feasibility by making it with ancient techniques. A particular challenge will be the system of nested tubes that carried the astronomical outputs.”

Let’s block ads! (Why?)



Source link

Continue Reading

Science

Top oil exporter Saudi Arabia targets net zero emissions by 2060

Published

 on

Saudi Arabia’s crown prince said on Saturday that the world’s top oil exporter aims to reach ‘net zero’ emissions of greenhouse gases – mostly produced by burning fossil fuels – by 2060 – 10 years later than the United States.

He also said it would double the emissions cuts it plans to achieve by 2030.

Crown Prince Mohammed bin Salman and his energy minister said Saudi Arabia would tackle climate change, but also stressed the continued importance of hydrocarbons and said it would continue to ensure oil market stability.

They were speaking at the Saudi Green Initiative (SGI) ahead of COP26, the U.N. climate conference in Glasgow at the end of the month, which hopes to agree deeper global emissions cuts to tackle global warming.

The United States, the world’s second biggest emitter, is committed to achieving ‘net zero’, meaning that it emits no more greenhouse gases than it can capture or absorb, by 2050. But China and India, the world’s biggest and third-biggest emitters, have not committed to this timeline.

Amin Nasser, chief executive of the state oil giant Saudi Aramco, said it was counterproductive to “demonise” hydrocarbons. He said Aramco aimed to expand its oil and gas production capacity while also achieving net zero emissions from its own operations by 2050.

He called for more global investment to ensure adequate crude oil supplies.

Prince Mohammed said in recorded remarks that the kingdom aimed to reach net zero by 2060 under its circular carbon economy programme, “while maintaining its leading role in strengthening security and stability of global oil markets”.

He said Saudi Arabia would join a global initiative on slashing emissions of methane by 30% from 2020 levels by 2030, which both the United States and the EU have been pressing.

‘HYDROCARBONS STILL NEEDED’

U.S. climate envoy John Kerry is due to attend a wider Middle East green summit in Riyadh on Monday.

The SGI aims to eliminate 278 million tonnes of carbon dioxide emissions per year by 2030, up from a previous target of 130 million tonnes. The crown prince said the SGI initiative would involve investments of over 700 billion riyals ($190 billion) in that time period.

Saudi Arabia’s economy remains heavily reliant on oil, although the crown prince is trying to promote diversification.

Energy minister Prince Abdulaziz bin Salman said the world needed fossil fuels as well as renewables.

“It has to be a comprehensive solution,” he said. “We need to be inclusive, and inclusivity requires being open to accept others’ efforts as long as they are going to reduce emissions.”

He said the kingdom’s younger generation “will not wait for us to change their future”.

He said net zero might be achieved before 2060 but the kingdom needed time to do things “properly”.

Another Gulf oil producer, the United Arab Emirates, this month announced a plan for net zero emissions by 2050.

The non-profit Climate Action Tracker consortium gives Saudi Arabia its lowest possible ranking, “Critically insufficient”.

Saudi Arabia’s first renewable energy plant opened in April and its first wind farm began generating in August.

It does, however, have plans to build a $5 billion plant to produce hydrogen, a clean fuel, and state-linked entities are pivoting to green fundraising. ($1 = 3.7507 riyals)

(Reporting by Yousef Saba and Saeed Azhar in Riyadh, Marwa Rashad in London and Maher Chmaytelli in Dubai; additional reporting by Raya Jalbi in Dubai; writing by Ghaida Ghantous; editing by Jason Neely and Kevin Liffey)

Continue Reading

Science

Former NASA Administrator Says Flooding Of Orbit With Satellites Could Block Humanity From Space – Space Bollyinside – BollyInside

Published

 on


‘The U.S. government and governments around the world are failing to properly manage collision risk.’ ‘If not remedied, the consequence will be losing access to space entirely, devastating not only satellite communications, but also human spaceflight, national security, weather prediction, disaster relief, climate science, and so much more.’

Former NASA administrator Jim Bridenstine calls on the US government to mandate better regulations for launching satellites into orbit Amazon’s Kuiper Systems is looking to send 3,326 communication satellites and OneWeb is proposing to build a constellation of 648 devices.

The company has sent more than 1,700 Starlink satellites in orbit, but it hopes to have as many as 42,000 devices circling Earth.  More than 3,000 communication satellites are orbiting Earth, but dozens of companies are seeking approval from the Federal Communications Commissions (FCC) to launch thousands more. SpaceX, founded by Elon Musk, is building a megaconstellation to provide internet service to even the most remote parts of the world

SpaceX, founded by Elon Musk, is building a megaconstellation to provide its Starlink internet service to the most remote parts of the world.  The development and use of satellite communications are advancing rapidly and transforming humanity.

However, these are just a few of the dozens of companies looking to achieve similar feats.   Bridenstine said: ‘The US government and governments around the world are failing to properly manage collision risk.’  SpaceX has sent more than 1,700 Starlink satellites in orbit, but it hopes to have as many as 42,000 devices circling Earth

Bridenstine proposed solutions during the briefing, putting much of the responsibility on Congress and the FCC. ‘Dramatic increases in space collisions, and new space debris, are expected within just a few years,’ Bridenstine said during the briefing. ‘In the longer-term satellites are destroyed faster than they are launched.’

News Highlights Space

  • Headline: Former NASA Administrator Says Flooding Of Orbit With Satellites Could Block Humanity From Space
  • Check all news and articles from the Space news information updates.
Disclaimer: If you need to update/edit this article then please visit our help center. For Latest Updates Follow us on Google News

Adblock test (Why?)



Source link

Continue Reading

Science

Musk says Starship may be ready for orbital launch next month, but FAA review continues – Spaceflight Now – Spaceflight Now

Published

 on


Elon Musk, the billionaire founder of SpaceX, said Friday the company’s huge new Starship rocket could be ready for its first orbital test launch from South Texas as soon as November, but the schedule comes with two big uncertainties that may push the launch to next year.

“If all goes well, Starship will be ready for its first orbital launch attempt next month, pending regulatory approval,” Musk tweeted.

The new schedule update from Musk came the day after SpaceX test-fired the newest Starship vehicle, known as Ship 20 or SN20, at the company’s development facility near Boca Chica Beach east of Brownsville, Texas. A vacuum-rated Raptor engine, similar to the engines Starship will use in space, ignited for several seconds on a launching stand at SpaceX’s Starbase complex Thursday night.

SpaceX briefly fired the privately-developed rocket again later the same night.

It was the first test-firing of a Raptor vacuum engine mounted to a Starship rocket. The vacuum variant of the methane-fueled Raptor engine has a larger nozzle to improved performance in the airless environment of space.

Three vacuum-rated Raptor engines will fly on orbital-class Starship missions. Three sea level Raptor variants, with smaller nozzles, will be used for vertical Starship landings after returning from space.

Unlike the Starship prototypes flown on the recent atmospheric hops, Ship 20 is covered in thousands of heat-resistant tiles to protect the craft’s stainless steel structure from the scorching heat it will encounter during re-entry into Earth’s atmosphere.

The Starship will launch on top of a huge reusable first stage booster called the Super Heavy. Made of stainless steel, the entire stack stands 394 feet (120 meters) tall, higher than any rocket ever built.

Fitted with up to 33 Raptor engines, the Super Heavy will propel the Starship into space with twice the thrust of NASA’s Apollo-era Saturn 5 moon rocket, and nearly double the power of NASA’s Space Launch System heavy-lift rocket.

In August, SpaceX teams in South Texas briefly stacked the entire Starship rocket on a launch mount for a fit check and photo opportunity. At the time, SpaceX connected 29 Raptor engines — four fewer than the booster will use on an operational flight — to the Super Heavy and rolled the booster to the ever-expanding launch complex, just east of the company’s build site.

After the fit check, SpaceX removed the Raptor engines from the Super Heavy, designated Booster 4, as attention turned to preparing Ship 20 for cryogenic proof testing in September.

SpaceX then readied Starship for its first static fire tests this week. More test-firings may occur before Ship 20 is mounted on top of the Super Heavy booster again.

Meanwhile, SpaceX plans to perform cryogenic proof testing of Booster 4 some time in the coming weeks, likely followed by a series of test-firings, culminating in a static fire with its full complement of Raptor engines.

Outfitting of the launch pad tower at Boca Chica has also continued since its initial construction over the summer. Earlier this week, crews lifted massive arms, nicknamed “chopsticks,” onto the launch tower that SpaceX aims to use for catching descending Super Heavy boosters.

Although SpaceX has moved forward with great speed at Boca Chica, the chances of the Super Heavy and Starship vehicles being ready for flight next month are uncertain. Musk often sets aspirational schedule goals, and in September 2019 said he wanted to attempt the first orbital launch attempt with Starship within six months.

Another schedule hurdle might be the Federal Aviation Administration, which is reviewing the environmental impacts of SpaceX’s operations in South Texas. The FAA issued a draft environmental report last month after consultation with several federal and state agencies.

The draft report marks a re-evaluation of the FAA’s original environmental impact statement before SpaceX started construction of the Boca Chica site in 2014. At that time, SpaceX planned to launch Falcon 9 and Falcon Heavy rockets from South Texas, but the scope of the project has since changed to focus on development of Starship and Super Heavy.

The FAA held public hearings Monday and Wednesday, and some 120 people voiced their opinions on the project’s environmental impacts. The public comments were more than two-to-one in favor of the FAA finalizing the draft programmatic environment assessment, and issuing SpaceX a launch license for the Starship orbital test flight.

Many of the comments in favor of SpaceX came from members of the public outside Texas. The share of people who identified themselves as local residents and voiced opposition was higher.

Joyce Hamilton, who said she was a member of the local community, worried that SpaceX would damage the “fragile and unique coastline” at Boca Chica Beach.

“In fact, we’ve already seen the damaging impact of a recent launch failure with a wide and destructive debris field along the beach and surrounding wetlands,” Hamilton said. “I’d like to just end by urging the FAA to conduct a serious comprehensive environmental impact study.”

Rebecca Hinojosa, a Brownsville resident, said SpaceX has been a destructive influence on the community through gentrification, and displaced residents who once lived near the Boca Chica site. SpaceX bought out homes in the area as it constructed the facility.

Others were supportive of the FAA allowing SpaceX to go ahead with no delay, citing the positive economic effects of SpaceX’s presence in the Rio Grande Valley.

“Elon Musk chose our community to be the next home of his SpaceX operation, and very, very quickly after setting up, this area went from being one of the poorest areas, one of the most looked-down, in the entire nation … We’re no longer in that position. We’re now one of the most sought after zip codes to live and raise your children,” said Jessica Tetreau, a Brownsville city commissioner.

“I don’t just ask you,” she concluded. “I beg you to give them that permit.”

“As far as the environment goes, it seems to me that SpaceX has a good plan in place to mitigate the vast majority of environmental effects from the build and test sites,” said Michael O’Halloran, who did not identify himself as a local resident. “Starship and Super Heavy are clearly worth the gamble.”

Crews at SpaceX’s Starbase test site in South Texas stack the company’s first full-scale Starship launch vehicle for a fit check in August. Credit: SpaceX

The FAA is accepting written comments until Nov. 1, then will determine whether to finalize the draft environmental assessment or begin a new environmental impact statement if the environmental effects would be significant and could not be properly mitigated.

A new environmental impact statement would take months, or even years, to complete.

A decision by the FAA on which route to take is not expected immediately. The FAA said it is reviewing the environmental impacts from SpaceX’s Starship launch and re-entry operations, debris recovery, the launch pad integration tower and other launch-related construction, and local road closures at Boca Chica.

SpaceX can’t launch the Starship and Super Heavy vehicle until the FAA issues a license, which will only come after the completion of the environmental process.

NASA awarded SpaceX a contract to develop a version of the Starship rocket as a human-rated lander for the agency’s Artemis moon missions.

That contract award is currently on hold after Blue Origin, the space company founded by billionaire Jeff Bezos, filed suit in the U.S. Court of Federal Claims. A ruling on the lawsuit could come next month.

SpaceX is developing the privately-owned Starship vehicle as a fully reusable launch and space transportation system capable of ferrying more than 100 metric tons of cargo into low Earth orbit, more than any other rocket in the world. SpaceX eventually aims to develop an in-space refueling capability to extend Starship’s heavy-duty cargo carrying range into the solar system.

During an orbital launch attempt, a reusable Super Heavy first stage booster will detach from the Starship and come back to Earth for a vertical landing. For the first orbital mission, SpaceX plans to guide the the booster to a water landing in the Gulf of Mexico.

SpaceX is also modifying offshore oil drilling rigs to serve as floating Starship launch and landing platforms.

The Starship will continue into orbit and deploy its payloads or travel to its deep space destination, and finally return to Earth to be flown again. The Starship vehicle doubles as an upper stage and a refillable transporter to ferry people and cargo through space to destinations in Earth orbit, the moon, Mars, and other distant locations.

The reusable architecture, which builds upon SpaceX’s partially reusable Falcon 9 rocket, is designed to reduce the cost of each flight.

The Starship’s first orbital test flight, though audacious in scale, will aim to prove out the rocket’s basic launch and re-entry capabilities without fully testing out the complicated landing and recovery systems, according to a SpaceX’s filing with the Federal Communications Commission earlier this year.

On the first orbital mission, SpaceX plans for the Starship to re-enter the atmosphere after one trip around Earth, heading for a controlled landing at sea in the Pacific Ocean near Hawaii.

Email the author.

Follow Stephen Clark on Twitter: @StephenClark1.

Adblock test (Why?)



Source link

Continue Reading

Trending