’Best ever’ simulation solves 40-year black hole mystery

This handout photograph released by Northwestern University on June 5, 2019, shows a vertical slice of a black hole alignment as scientists on unveiled the most detailed simulation of a black hole yet seen, solving a mystery dating back more than four decades over how the star-devouring monsters consume matter. (AFP)
Updated 06 June 2019
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’Best ever’ simulation solves 40-year black hole mystery

  • It is precisely this electromagnetic effect that causes matter to fall to the center of the black hole

PARIS: Scientists on Thursday unveiled the most detailed simulation of a black hole yet, solving a mystery dating back more than four decades over how the star-devouring monsters consume matter.
Coming fresh on the heels of the first ever photo of one of the giant objects, which are scattered across the Universe, astrophysicists are now several steps closer to understanding how they form and develop.
A black hole is born when a large star collapses in on itself. Far from being a “hole,” they are instead incredibly dense objects with a gravitational pull so strong that nothing, not even light, may escape them.
As they suck in matter such as gas, dust and space debris, they form an accretion disk — a churning mass of super-accelerated particles that are among the brightest objects in the Universe — around them.
It is the accretion disk that can be seen as a blurry halo around the image of the black hole released in April from the Event Horizon Telescope.
But accretion disks are nearly always tilted at an angle to the orientation of the black hole, known as its equatorial plane.
In 1975, Nobel Prize-winning physicist John Bardeen and astrophysicist Jacobus Petterson theorized that a rotating black hole would cause the inner region of a tilted accretion disk to line up with the black hole’s equatorial plane.
But no model could ever work out how, precisely, that would happen. Until now.
A team of astrophysicists from Northwestern University, Oxford University, and the University of Amsterdam, used graphical processing units to crunch large sets of data and simulate how black holes interact with their accretion disks.
Crucially, their approach gave them the computing power to account for magnetic turbulence, which occurs when different particles churn at different speeds within the accretion disk.
It is precisely this electromagnetic effect that causes matter to fall to the center of the black hole.
Alexander Tchekhovskoy, assistant professor of physics and astronomy at Northwestern’s Weinberg College of Arts and Sciences, likened matter accumulating near a black hole to throwing a dart toward the board at random.
“If you don’t really aim it will never hit the bullseye,” he said. “In the same way, when (matter) falls into the black hole it has some rotation but this rotation will have nothing generally to do with how the black hole rotates. The two rotations will not know anything about each other.”

Previous simulations manually predicted the additional friction their creators believed was needed to make matter move toward the black hole.
“Whereas now in our model, we don’t have to postulate this friction,” Tchekhovskoy told AFP. “We put in magnetic fields and these actually cause an instability that then causes friction and the disk falls in as a result.”
This might seem like a small detail but it directly affects how fast black holes spin and, consequently, what effect they have on the galaxies that surround them.
The simulation, which produces a disk with two jets of gas and magnetic fields protruding from the center like fountains, shows the inner part of the accretion disk aligning perfectly with the black hole’s equator even as the outer part remains at an angle.
“Before now there was a worry that when you take into account all the complications that come with matter interacting with a black hole, such as magnetic fields, the turbulence in the disk, the swirling motions — those things might kill the alignment effect,” said Tchekhovskoy.
“We found that, no, it doesn’t kill it, actually the inner parts of the disk do align with the black hole and we can now more confidently make predictions about how black holes would look.”


It takes a hacker to catch a hacker, says prize-winning Saudi cyber whiz

Cybersecurity is growing in importance and cyberwars now represent a serious threat to national security. (FIle/Shutterstock)
Updated 15 June 2019
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It takes a hacker to catch a hacker, says prize-winning Saudi cyber whiz

  • Cybersecurity specialist and winner of innovator award takes aim against rising threat of cybercrime

JEDDAH: A Saudi ethical hacker named “inspiring innovator of the year” at a prestigious awards ceremony in London has revealed her secret for staying one step ahead of cyberattackers.
“I act as an attacker and adopt the hacker’s mindset,” 28-year-old cybersecurity specialist Noor Al-Rayes told Arab News.
“It takes a hacker to catch a hacker.”
Al-Rayes, founder and CEO of Alien Security and co-founder and chief operation officer of Securmind, received the “inspiring innovator of the year” award from London-based private bank Arbuthnot Latham on June 5.

Information security
After accepting the award, she urged governments and businesses to step up their campaign and be more aggressive in the fight against cybercrime.
“Many companies offer ethical hacking services, but they approach it from an information security perspective, not a hacker perspective.
“We believe this service must be provided in a more aggressive way, exactly like hackers do,” she said.
“The severity and complexity of recent cyberattacks require more than traditional approaches to fight cybercrime and maximize cyber defense.
“Ethical hacking should be part of any organization’s cybersecurity strategy. When I provide ethical hacking services, I act as an attacker and adopt the hacker’s mindset. That way, companies will stay one step ahead of attackers and avoid costly cyber breaches.
“There is no better way to test the security level of IT systems than borrowing the skills of an experienced ethical hacker, which is why I created Alien Security,” she said.
Al-Rayes described recent major advances in the digital world as “a double-edged sword,” and warned that future cybersecurity incidents could prove “catastrophic.”
“Advances in technology have brought so many positive aspects, but there is a downside ... everything is susceptible to hacking,” she said. “If a hacker has the right skills, experience, knowledge, tools and time, they will be able to hack into any system.”

Serious threat
Cybersecurity is growing in importance, Al-Rayes said, and cyberwars now represent a serious threat to national security.
“The outcomes of a major cybersecurity incident of that nature could be catastrophic, which is why ethical hackers are a powerful addition to any defense strategy where they work both on the defensive and offensive sides,” she said.
Al-Rayes came to the UK on the King Abdullah Scholarship Program and gained a master’s degree in cybersecurity at City University of London.

HIGHLIGHTS

• Cybercrime will cost the world $6 trillion annually by 2021, up from $3 trillion in 2015, according to a recent report from Cybersecurity Ventures.

• Cybercrime costs include damage and destruction of data, stolen money, lost productivity, theft of intellectual property, theft of personal and financial data, embezzlement, fraud, post-attack disruption to the normal course of business, forensic investigation, restoration and deletion of hacked data and systems and reputational harm, according to experts.

“I was endorsed by the UK government and was granted an exceptional talent visa and world leader in technology. I also received the young achievers award at a ceremony at the Houses of Parliament, and was recognized as a future leader for my efforts for the cybersecurity industry,” she said.
The Saudi entrepreneur founded the cybersecurity consultancy Alien Security in 2018.
“We provide cybersecurity penetration testing, management and support. We also provide cybersecurity forensics where we launch a full cybersecurity investigation to explain how the cyberattack happened, why, when, and how we can fix it and avoid it in the future.”
Al-Rayes said she was honored to receive Arbuthnot Latham’s inspiring innovator of the year award.
“Arbuthnot Latham offers great support for startups and entrepreneurs. I am very happy I got the chance to share my passion with them and introduce Alien Security to the amazing audience at the event. I also hope that I made my country proud as the government and everyone at the Saudi Embassy and Cultural Bureau in London were extremely supportive and encouraging.
“As for receiving it as a Saudi woman, it is our mission as scholarship holders to represent our country in the best way possible, and I hope I fulfilled my part and will continue to do so throughout my journey,” Al-Rayes said.
“We already have such strong and amazing Saudi women ... and I hope this inspires more women and encourages them to get involved in science and cybersecurity.”
Al-Rayes also said that receiving the exceptional talent visa was a “great honor and a major boost as a cybersecurity specialist, woman and a Saudi student.”
“It pushed me to work harder. I was endorsed by the UK government and recognized as a world leader in technology because of my entrepreneurial career and also for the projects I am working on now, including a project fighting cyber terrorism.
“There are a lot of pressing issues that requires immediate attention such as human error in information security, improving facial and object recognition systems to minimize cyber terrorism, analyzing dark web criminal activity and detecting cybercrime. These are some of the projects that I am gathering data for.”

Artificial intelligence
Al-Rayes’ master’s project explored the targeting of cybercrime within dark web forums using machine learning, artificial intelligence and data mining techniques.
“The dark web is an underground society for criminal activity, including cyberterrorism,” said Al-Rayes.

 

 “The main goal of this project is to aid police and governments in fighting cybercrime using an advanced and intelligent system that can target specific crimes, detect and analyze them.”
She highlighted that many extremist groups use social media and the dark web to recruit young people.
“Using artificial intelligence and advanced technology to help fight these problems is important since it would be used not only for detection purposes but also for analyzing criminal behavior and recognizing threats before it is too late.
“That is why I am working on redeveloping this project and enhancing the training to make the system more powerful.”

Decoder

• Exceptional talent visas are granted to international individuals who can prove they have had an exceptional impact on the industry in which they work. • It is also given to people working on projects that will significantly advance the industry and benefit the economy.