An artist's impression of a supermassive black hole. EPA
An artist's impression of a supermassive black hole. EPA
An artist's impression of a supermassive black hole. EPA
An artist's impression of a supermassive black hole. EPA

Science

How the collision of two black holes may solve one of the universe's biggest mysteries

Invisible particles that clump together to create 'boson stars' with massive gravitational force could be the key to unlocking the mysteries of dark matter

Robert Matthews

March 07, 2021

  • English
  • Arabic

A year after scientists witnessed the "mind-boggling" collision of two giant black holes, they now suspect the event actually involved two even more bizarre objects – and could answer one of the biggest mysteries about our universe.

What could be weirder than black holes?

Astronomers have long suspected that our universe contains vast quantities of a substance unlike anything observed on Earth.

Studies of galaxies hint at the presence of invisible “dark matter” lurking between the visible stars, revealing its presence through its gravitational pull.

Quite what this dark matter consists of is one of the biggest of all cosmic mysteries. Now an international team of scientists think they may have an answer.

After re-examining what was thought to be the collision of two huge black holes announced last September, the scientists think the event was actually the merger of two colossal clumps of invisible dark matter known as boson stars.

An illustration depicting two black holes of about 66 and 85 solar masses spiralling into each other to form the huge black hole. AP
An illustration depicting two black holes of about 66 and 85 solar masses spiralling into each other to form the huge black hole. AP

What on Earth are boson stars?

All the matter we are familiar with consists of electrons, protons and neutrons – particles collectively known as fermions. All other particles are bosons, and they are best-known for transmitting forces like gravity and electromagnetism.

But attempts to solve the dark matter mystery have led theorists to suggest another type of boson might exist. Known as an ultralight boson, it would have a mass far below even that of the electron. But if such particles gather together in sufficient numbers they would form vast, invisible star-sized clumps called “boson stars”.

Spread across the whole cosmos, these could invisibly exert enough gravitational pull to account for dark matter.

So why do scientists now think boson stars exist?

Last September’s announcement of a collision between two giant black holes made headlines because even astronomers were shocked by what they had witnessed. Ripples in the very fabric of space and time were picked up by observatories in the US and Europe, which appeared to come from the collision of two black holes halfway across the universe.

Dozens of such events have been detected before, but the sheer size of the black holes involved made this one different – and perplexing.

Black holes are typically formed when huge stars run out of nuclear fuel and collapse under their own gravity. But calculations suggest that stars over 65 times the mass of the sun explode before they can form black holes. Last September’s event involved black holes 66 and 85 times the mass of the sun – both breaking this limit.

Now a team led by Dr Juan Calderón Bustillo of the University of Santiago de Compostela, Spain, believe the mystery can be solved if the collision actually involved two boson stars.

In research published in the leading physics journal Physical Review Letters, the team compare the observations with predictions of what would happen if two such objects collided. They found boson stars gave a better fit than assuming black holes were involved.

What are the implications?

Literally cosmic. First, the boson star explanation means there is no need to worry about how two “impossibly” massive black holes came to exist.

Second, the team calculates that the collision of the two boson stars would still have created a huge black hole around 250 times the mass of the sun. This opens up the possibility that truly colossal black holes may be formed by colliding clumps of dark matter, rather than lots of smaller black holes.

But most important of all, the boson star explanation would mean scientists have had their first-ever glimpse of what dark matter really is. Calculations by the team suggest the two objects each contained around 100 billion billion billion tonnes of dark matter in the form of ultralight vector bosons, particles each around a billion billion times lighter than the electron.

What happens next?

When two huge boson stars collide, they affect the surrounding space differently from colliding black holes – giving clues to their true identity. Astronomers will now be looking out for these in future events. Laboratory experiments have been set up to detect dark matter particles on Earth – so far without success. Now scientists have a better idea of what they may be looking for, this will help tune their detectors and design new experiments.

The hope is that, almost a century after the mystery of dark matter reared its head, scientists may soon have a good answer when schoolchildren ask: “What is the universe made of?”

Robert Matthews is Visiting Professor of Science at Aston University, Birmingham, UK

13 of the most incredible pictures from space

Nasa's Hubble Space Telescope captured the tiny moon Phobos during its orbital trek around Mars. Because the moon is so small, it appears star-like in the Hubble pictures. The Hubble observations were intended to photograph Mars, and the moon's cameo appearance was a bonus. Phobos is one of the smallest moons in the solar system. It is so tiny that it would fit comfortably inside the Washington, DC. Courtesy: Nasa
Nasa's Hubble Space Telescope captured the tiny moon Phobos during its orbital trek around Mars. Because the moon is so small, it appears star-like in the Hubble pictures. The Hubble observations were intended to photograph Mars, and the moon's cameo appearance was a bonus. Phobos is one of the smallest moons in the solar system. It is so tiny that it would fit comfortably inside the Washington, DC. Courtesy: Nasa
This is the first image of Saturn's ultraviolet aurora taken by the Space Telescope Imaging Spectrograph (STIS) on board the Hubble Space Telescope (HST) in October 1998, when Saturn was a distance of 810 million miles (1.3 billion km) from Earth. Courtesy: Nasa
This is the first image of Saturn's ultraviolet aurora taken by the Space Telescope Imaging Spectrograph (STIS) on board the Hubble Space Telescope (HST) in October 1998, when Saturn was a distance of 810 million miles (1.3 billion km) from Earth. Courtesy: Nasa
Astronomers are using the Nasa / ESA Hubble Space Telescope to study auroras — stunning light shows in a planet’s atmosphere — on the poles of the largest planet in the solar system, Jupiter. Courtesy: Nasa
Astronomers are using the Nasa / ESA Hubble Space Telescope to study auroras — stunning light shows in a planet’s atmosphere — on the poles of the largest planet in the solar system, Jupiter. Courtesy: Nasa
This colourful bubble is a planetary nebula called NGC 6818, also known as the Little Gem Nebula. It is located in the constellation of Sagittarius (The Archer), roughly 6000 light-years away from us. Courtesy: Nasa
This colourful bubble is a planetary nebula called NGC 6818, also known as the Little Gem Nebula. It is located in the constellation of Sagittarius (The Archer), roughly 6000 light-years away from us. Courtesy: Nasa
This majestic false-colour image from Nasa's Spitzer Space Telescope shows 'mountains' where stars are born. These towering pillars of cool gas and dust are illuminated at their tips with light from warm embryonic stars. Courtesy: Nasa
This majestic false-colour image from Nasa's Spitzer Space Telescope shows 'mountains' where stars are born. These towering pillars of cool gas and dust are illuminated at their tips with light from warm embryonic stars. Courtesy: Nasa
This Nasa Hubble Space Telescope photograph captures the chaotic activity atop a three-light-year-tall pillar of gas and dust that is being eaten away by the brilliant light from nearby bright stars. The pillar is also being assaulted from within, as infant stars buried inside it fire off jets of gas that can be seen streaming from towering peaks. This turbulent cosmic pinnacle lies within a tempestuous stellar nursery called the Carina Nebula, located 7,500 light-years away in the southern constellation Carina. Courtesy: Nasa
This Nasa Hubble Space Telescope photograph captures the chaotic activity atop a three-light-year-tall pillar of gas and dust that is being eaten away by the brilliant light from nearby bright stars. The pillar is also being assaulted from within, as infant stars buried inside it fire off jets of gas that can be seen streaming from towering peaks. This turbulent cosmic pinnacle lies within a tempestuous stellar nursery called the Carina Nebula, located 7,500 light-years away in the southern constellation Carina. Courtesy: Nasa
These eerie, dark, pillar-like structures are actually columns of cool interstellar hydrogen gas and dust that are also incubators for new stars. The pillars protrude from the interior wall of a dark molecular cloud like stalagmites from the floor of a cavern. They are part of the Eagle Nebula (also called M16), a nearby star-forming region 7,000 light-years away, in the constellation Serpens. Courtesy: Nasa
These eerie, dark, pillar-like structures are actually columns of cool interstellar hydrogen gas and dust that are also incubators for new stars. The pillars protrude from the interior wall of a dark molecular cloud like stalagmites from the floor of a cavern. They are part of the Eagle Nebula (also called M16), a nearby star-forming region 7,000 light-years away, in the constellation Serpens. Courtesy: Nasa
In this image provided by the Hubble Space Telescope (HST), the Omega Nebula (M17) resembles the fury of a raging sea, showing a bubbly ocean of glowing hydrogen gas and small amounts of other elements such as oxygen and sulphur. The nebula, also known as the Swan Nebula, is a hotbed of newly born stars residing 5,500 light-years away in the constellation Sagittarius. Courtesy: Nasa
In this image provided by the Hubble Space Telescope (HST), the Omega Nebula (M17) resembles the fury of a raging sea, showing a bubbly ocean of glowing hydrogen gas and small amounts of other elements such as oxygen and sulphur. The nebula, also known as the Swan Nebula, is a hotbed of newly born stars residing 5,500 light-years away in the constellation Sagittarius. Courtesy: Nasa
Nasa / ESA Hubble Space Telescope image reveals the heart of the Lagoon Nebula. Courtesy: Nasa
Nasa / ESA Hubble Space Telescope image reveals the heart of the Lagoon Nebula. Courtesy: Nasa
The Cat's Eye Nebula, one of the first planetary nebulae discovered, also has one of the most complex forms known to this kind of nebula. Eleven rings, or shells, of gas make up the Cat's Eye. Courtesy: Nasa
The Cat's Eye Nebula, one of the first planetary nebulae discovered, also has one of the most complex forms known to this kind of nebula. Eleven rings, or shells, of gas make up the Cat's Eye. Courtesy: Nasa
The Cone Nebula resides 2,500 light-years away in the constellation Monoceros. Radiation from hot, young stars (located beyond the top of the image) has slowly eroded the nebula over millions of years. Courtesy: Nasa
The Cone Nebula resides 2,500 light-years away in the constellation Monoceros. Radiation from hot, young stars (located beyond the top of the image) has slowly eroded the nebula over millions of years. Courtesy: Nasa
This planetary nebula's simple, graceful appearance is thought to be due to perspective: our view from Earth looking straight into what is actually a barrel-shaped cloud of gas shrugged off by a dying central star. Hot blue gas near the energising central star gives way to progressively cooler green and yellow gas at greater distances with the coolest red gas along the outer boundary. Courtesy: Nasa
This planetary nebula's simple, graceful appearance is thought to be due to perspective: our view from Earth looking straight into what is actually a barrel-shaped cloud of gas shrugged off by a dying central star. Hot blue gas near the energising central star gives way to progressively cooler green and yellow gas at greater distances with the coolest red gas along the outer boundary. Courtesy: Nasa
This image shows the galaxy Messier 94, which lies in the small northern constellation of the Hunting Dogs, about 16 million light-years away. Within the bright ring around Messier 94 new stars are forming at a high rate and many young, bright stars are present within it – thanks to this, this feature is called a starburst ring. The cause of this peculiarly shaped star-forming region is likely a pressure wave going outwards from the galactic centre, compressing the gas and dust in the outer region. Courtesy: Nasa
This image shows the galaxy Messier 94, which lies in the small northern constellation of the Hunting Dogs, about 16 million light-years away. Within the bright ring around Messier 94 new stars are forming at a high rate and many young, bright stars are present within it – thanks to this, this feature is called a starburst ring. The cause of this peculiarly shaped star-forming region is likely a pressure wave going outwards from the galactic centre, compressing the gas and dust in the outer region. Courtesy: Nasa
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RESULTS

Bantamweight title:
Vinicius de Oliveira (BRA) bt Xavier Alaoui (MAR)
(KO round 2)
Catchweight 68kg:
Sean Soriano (USA) bt Noad Lahat (ISR)
(TKO round 1)
Middleweight:
Denis Tiuliulin (RUS) bt Juscelino Ferreira (BRA)
(TKO round 1)
Lightweight:
Anas Siraj Mounir (MAR) bt Joachim Tollefsen (DEN)
(Unanimous decision)
Catchweight 68kg:
Austin Arnett (USA) bt Daniel Vega (MEX)
(TKO round 3)
Lightweight:
Carrington Banks (USA) bt Marcio Andrade (BRA)
(Unanimous decision)
Catchweight 58kg:
Corinne Laframboise (CAN) bt Malin Hermansson (SWE)
(Submission round 2)
Bantamweight:
Jalal Al Daaja (CAN) bt Juares Dea (CMR)
(Split decision)
Middleweight:
Mohamad Osseili (LEB) bt Ivan Slynko (UKR)
(TKO round 1)
Featherweight:
Tarun Grigoryan (ARM) bt Islam Makhamadjanov (UZB)
(Unanimous decision)
Catchweight 54kg:
Mariagiovanna Vai (ITA) bt Daniella Shutov (ISR)
(Submission round 1)
Middleweight:
Joan Arastey (ESP) bt Omran Chaaban (LEB)
(Unanimous decision)
Welterweight:
Bruno Carvalho (POR) bt Souhil Tahiri (ALG)
(TKO)

Mohammed bin Zayed Majlis
World record transfers

1. Kylian Mbappe - to Real Madrid in 2017/18 - €180 million (Dh770.4m - if a deal goes through)
2. Paul Pogba - to Manchester United in 2016/17 - €105m
3. Gareth Bale - to Real Madrid in 2013/14 - €101m
4. Cristiano Ronaldo - to Real Madrid in 2009/10 - €94m
5. Gonzalo Higuain - to Juventus in 2016/17 - €90m
6. Neymar - to Barcelona in 2013/14 - €88.2m
7. Romelu Lukaku - to Manchester United in 2017/18 - €84.7m
8. Luis Suarez - to Barcelona in 2014/15 - €81.72m
9. Angel di Maria - to Manchester United in 2014/15 - €75m
10. James Rodriguez - to Real Madrid in 2014/15 - €75m

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%3Cp%3E%0DDeveloper%3A%20Ubisoft%20Bordeaux%0D%3Cbr%3EPublisher%3A%20Ubisoft%0D%3Cbr%3EConsoles%3A%20PlayStation%204%26amp%3B5%2C%20PC%20and%20Xbox%20Series%20S%26amp%3BX%0D%3Cbr%3ERating%3A%203.5%2F5%3C%2Fp%3E%0A
Cherry

Directed by: Joe and Anthony Russo

Starring: Tom Holland, Ciara Bravo

1/5

ENGLAND SQUAD

For first two Test in India Joe Root (captain), Jofra Archer, Moeen Ali, James Anderson , Dom Bess, Stuart Broad , Rory Burns, Jos Buttler, Zak Crawley, Ben Foakes, Dan Lawrence, Jack Leach, Dom Sibley, Ben Stokes, Olly Stone, Chris Woakes. Reserves James Bracey, Mason Crane, Saqib Mahmood, Matthew Parkinson, Ollie Robinson, Amar Virdi.

INDIA SQUAD

Rohit Sharma (captain), Shikhar Dhawan (vice-captain), KL Rahul, Suresh Raina, Manish Pandey, Dinesh Karthik (wicketkeeper), Deepak Hooda, Washington Sundar, Yuzvendra Chahal, Axar Patel, Vijay Shankar, Shardul Thakur, Jaydev Unadkat, Mohammad Siraj and Rishabh Pant (wicketkeeper)

Remaining fixtures
  • August 29 – UAE v Saudi Arabia, Hazza bin Zayed Stadium, Al Ain
  • September 5 – Iraq v UAE, Amman, Jordan (venue TBC)
The alternatives

• Founded in 2014, Telr is a payment aggregator and gateway with an office in Silicon Oasis. It’s e-commerce entry plan costs Dh349 monthly (plus VAT). QR codes direct customers to an online payment page and merchants can generate payments through messaging apps.

• Business Bay’s Pallapay claims 40,000-plus active merchants who can invoice customers and receive payment by card. Fees range from 1.99 per cent plus Dh1 per transaction depending on payment method and location, such as online or via UAE mobile.

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• PayPal is probably the best-known online goods payment method - usually used for eBay purchases -  but can be used to receive funds, providing everyone’s signed up. Costs from 2.9 per cent plus Dh1.2 per transaction.

On Women's Day
Specs

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Evacuations to France hit by controversy
  • Over 500 Gazans have been evacuated to France since November 2023
  • Evacuations were paused after a student already in France posted anti-Semitic content and was subsequently expelled to Qatar
  • The Foreign Ministry launched a review to determine how authorities failed to detect the posts before her entry
  • Artists and researchers fall under a programme called Pause that began in 2017
  • It has benefited more than 700 people from 44 countries, including Syria, Turkey, Iran, and Sudan
  • Since the start of the Gaza war, it has also included 45 Gazan beneficiaries
  • Unlike students, they are allowed to bring their families to France
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