Physicists have discovered a strange twist of space-time that can mimic black holes — until you get too close. Known as “topological solitons,” these theoretical kinks in the fabric of space-time could lurk all around the universe – and finding them could push forward our understanding of quantum physics, according to a new study published April 25 in the journal Physical Review D (opens in new tab) .
Black holes are perhaps the most frustrating object ever discovered in science. Einstein’s general theory of relativity predicts their existence, and astronomers know how they form: All it takes is for a massive star to collapse under its own weight. With no other force available to resist it, gravity just keeps pulling in until all the star’s material is compressed into an infinitely tiny point, known as a singularity. Surrounding that singularity is an event horizon, an invisible boundary that marks the edge of the black hole. Whatever crosses the event horizon can never get out.
But the main problem with this is that points of infinite density can’t really exist. So while general relativity predicts the existence of black holes, and we have found many astronomical objects that behave exactly as Einstein’s theory predicts, we know that we still don’t have the full picture. We know that the singularity must be replaced by something more reasonable, but we don’t know what that something is.
Related: Are black holes wormholes?
Figuring that out requires an understanding of extremely strong gravity at extremely small scales — something called quantum gravity. To date, we have no viable quantum theory of gravity, but we do have several candidates. One of those candidates is string theory, a model that suggests all the particles that make up our universe are really made of tiny, vibrating strings.
To explain the wide variety of particles inhabiting our universe, those strings can’t just vibrate in the usual three spatial dimensions. String theory predicts the existence of extra dimensions, all curled up on themselves at some unfathomably small scale — so small that we can’t tell those dimensions are there.
And that act of curling up extra spatial dimensions at incredibly tiny scales can lead to very interesting objects.
In the new study, researchers proposed that these compact extra dimensions can give rise to defects. Like a wrinkle that you just can’t get out of your shirt no matter how much you iron it, these defects would be stable, permanent imperfections in the structure of space-time — a topological soliton. The physicists suggested that these solitons would largely look, act and probably smell like black holes.related stories—1st image of our galaxy’s ‘black hole heart’ unveiled
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The researchers studied how rays of light would behave when passing near one of these solitons. They found that the solitons would affect the light in almost the same way as a black hole would. Light would bend around the solitons and form stable orbital rings, and the solitons would cast shadows. In other words, the famous images from the Event Horizon Telescope, which zoomed in on the black hole M87* in 2019, would look almost exactly the same if it were solitons in the center of the image, rather than a black hole.
But up close the mimicry would end. Topological solitons are not singularities, so they do not have event horizons. You could get as close as you wanted to a soliton, and you could always leave if you wanted to (assuming you packed enough fuel).
Unfortunately we have no black holes close enough to dig around in, and so we can only rely on observations of distant objects. If any topological solitons are ever discovered, the revelation wouldn’t just be a major insight into the nature of gravity, but it would enable us to directly study the nature of quantum gravity and string theory as well.
Former Bank of England governor Mark Carney has been named Canadian prime minister after winning the Liberal Party leadership in a landslide victory.
Mr Carney, who also used to head up Canada’s central bank, had emerged as the frontrunner as his country was hit with tariffs imposed by President Trump.
He ended up winning 85.9% of the vote.
During his victory speech, he told the crowd: “Donald Trump, as we know, has put unjustified tariffs on what we build, on what we sell and how we make a living.
“He’s attacking Canadian families, workers and businesses and we cannot let him succeed and we won’t.”
Mr Carney said Canada would keep retaliatory tariffs until “the Americans show us respect”.
Mr Trump’s tariffs against Canada and his talk of making the country America’s 51st state have infuriated Canadians.
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The American national anthem has been repeatedly booed at NHL and NBA games.
“Think about it. If they succeeded, they would destroy our way of life… America is a melting pot. Canada is a mosaic,” Mr Carney added.
“America is not Canada. Canada will never ever be part of America in any way, shape or form.”
An easy pick for his party – but now he must win over Canada
Mark Carney had no problem convincing the Liberal Party he was the best man for the job. 85.9% of the vote speaks for itself. Now he must convince the country.
After unparalleled experience as central bank governor, both of Canada and of the UK, albeit at different times, he has the economic wherewithal to fortify the economy against the battering Donald Trump seems intent on dealing it.
He has made it very clear he is ready for the fight to come. “In trade, as in hockey, we will win!” he told his fellow liberals to wild applause. “We’re strongest when we are united,” he told the country on X.
His conservative rivals had what seemed like an unbeatable lead in the polls until just a few short weeks ago, but Trump’s trade tariffs have rallied Canadians behind the flag and their government.
That gives Mr Carney momentum ahead of a general election that will likely come sooner rather than later. Now he must exercise the political genius to capitalise on that.
The 59-year-old will replace Justin Trudeau, who has served as prime minister since 2015.
In just 50 days, Donald Trump has upended our world. He has ripped up rules, attacked allies and sided with enemies.
A country we thought for decades had our backs is no longer a reliable partner.
We travelled thousands of miles to ask what that means for our lives and millions of others – from the sweltering backstreets of Africa to the frozen wastes of Greenland and Finland’s tense border with Russia.
Donald Trump‘s supporters at home and abroad see him as the disruptor-in-chief who will bring peace and prosperity, putting America first.
But to many others we found he threatens chaos and a far darker future.
While Mr Trump may be challenging convention and bringing fresh thinking, his critics say he is moving too fast and erratically. His first 50 days in office, they claim, have weakened America’s place in the world and that will be exploited by rivals.
Risk of resurgent epidemics in Kenya
We went first to Kenya. The focus in the West may have been on Mr Trump and Russia but in the developing world, it’s the end of US aid that is grabbing the headlines.
On the frontlines of Africa’s war on HIV we heard Mr Trump’s actions being compared to an act of “biological warfare”.
Even among allies and admirers of the American president, there is deep unease and fear about what could come next, most of all the risk of resurgent epidemics of diseases like HIV, TB, malaria, ebola, and polio.
Image: A street in one of Kenya’s poorest neighbourhoods in Nairobi
In one of Kenya’s poorest neighbourhoods in Nairobi, we joined health workers on their rounds, down sewage-filled alleyways into cramped, overcrowded buildings.
In a one-room home, we met a young mother who is dependent on American aid. Anne is HIV positive and needs daily medication and nutritional support for both herself and her one-year-old son. She is terrified for their future because of the cut in US aid.
Image: Anne, who is HIV positive, with her young child
Image: An alleyway of one-room homes in Nairobi
“I’m so worried,” she told us, “because if it carries on like this the medication could run out. When the medicine is not there, the protector of my body is not there, so anything can just pass through me.”
‘We had no warning’
Kenya received $850m (£658m) in aid a year and that has now been abruptly severed. A US Supreme Court decision against the Trump administration may restore some of that but there is complete uncertainty about what happens next.
Martha, a healthcare manager in Nairobi, spelled out what is at stake: “We had no warning. We could not prepare the households. It was so sudden.
Image: Martha, a healthcare manager in Nairobi
“We expect more death. We expect more children to die before the age of five. We expect more death for children living with HIV and it is going to be bad,” Martha said, adding that more than 20,000 children who use her organisation’s services will be affected.
90% of all US aid contracts cut
The Trump administration says the aid has been only been suspended for 90 days pending a review. But in reality, many key programmes appear to have been shut down completely.
After a 45-minute flight west of Nairobi to Kisumu, we saw what is happening away from big cities. The impact seemed just as severe.
At one provincial hospital US Agency for International Development (USAID) signs were everywhere but on doors that are now shut. It had been a hub for patients to receive their treatment but that’s now in doubt.
Image: A health worker delivering medication in Kisumu
Image: Kisumu, Kenya
Staff told us there were just two months of supplies left for some medication, and less than a month for others, because there have been no more deliveries.
Patients were stockpiling drugs, said doctors, panicking for the future.
‘Biological warfare’
The US-supplied ammunition for Africa’s war against HIV, malaria, TB and other diseases is running out. It has taken decades and billions to bring them under control. The fear is of a return to epidemics not seen for years.
Image: A sign thanking the American people in the hospital in Kisumu
Image: Deliveries of medication supplied by USAID in the Kisumu hospital
Eric Okioma is HIV positive and runs a charity helping others with the disease in Kisumu.
“When you look at it from a public health aspect, that’s biological warfare that’s the way I’m seeing it because from a human rights perspective, he did the wrong thing – he should not have taken it abruptly.”
Image: Eric Okioma, who runs a charity helping others HIV in Kisumu
Mr Trump is popular among many in Kenya. His conservative stance on issues like gender and sexuality resonates in this predominantly Christian country.
But even among admirers and supporters there is deep unease about his aid cut.
Peter Gunday, a father and churchgoer, told us he agreed Kenya should be less dependent on US aid and encouraged to provide for itself – but Mr Trump’s action had been too sudden.
“He wants to make America great again… [but give an] olive branch to us even if it is only for some time.”
Image: Peter Gunday, a churchgoer in Kisumu
The aid cut threatens lives and America’s standing in the world. The US has used aid to wield soft power and influence.
Its superpower rival China prefers building. They have lent billions for massive infrastructure projects like the new railway from Nairobi to the coast through the heart of the city’s safari park.
For Beijing it’s all leverage, applied ruthlessly to increase access to Africa’s abundant natural resources.
Image: One of the new Chinese-built roads in Kenya
Under Trump, America is unilaterally deserting that battle for power and influence. Its values and interests will inevitably suffer. Not so much America first but America in retreat.
Finland prepares for Russian aggression
Closer to home, it is America’s shift on security causing the greatest concern. We flew thousands of miles north to one of NATO‘s newest member countries that sits on a border with Russia.
What did people in Finland make of what Mr Trump is doing to the Western alliance they have only just joined?
We filmed with Finland‘s military on the border with Russia that was closed because of the war in Ukraine.
Image: On Finland’s border with Russia
In sparsely populated woods, locals report sightings of Russian drones, we were told. And there has been a surge in recruits to the border guard because of the international situation.
One of them, Aku Jaeske, told us he had joined up “for the defence of our own country”.
Image: Aku Jaeske
He said: “I think most of us, I think, are here because of that. It’s really hard if we have a 1,300 and something kilometre border with Russia – it’s pretty long – we have to have good men there.”
‘Bring it on’, says one Finn
What did he make of Mr Trump and what he saw on the news?
“I think it’s crazy when you turn your TV on today, you can’t know what is really happening.”
The war with Ukraine and Russia’s belligerence has sparked a boom in shooting, with hundreds of new ranges opening up in Finland to meet demand.
In a range outside Helsinki, one shooting enthusiast Jerkri told us what he thought was behind its growing popularity.
Image: Jerkri says shooting has become popular in Finland because ‘people are noticing maybe [they are] to take care of themselves’
Image: Inside one of Finland’s growing number of shooting ranges
“The situation in Ukraine and people are noticing that maybe [they are] having to take care of themselves… think about it.”
Amateur shooters go through their paces, crisscrossing an open range at speed firing at targets dotted around the room. Patrick said he was worried by the direction of events.
“But if it did come to it… bring it on,” he said.
Image: Patrick says ‘bring it on’ in response to a question on having to use his shooting skills in the future
In a service station, Finland’s most popular tabloid had the headline, “Trump’s 10 gifts to Putin.”
Finns were once a byword for peace-loving neutrality. They are arming up now, and watching Mr Trump’s overtures to the Kremlin warily.
Finland after all is where Mr Trump stood next to Russian President Vladimir Putin during his first term in office and infamously said he would believe him over the word of US spy agencies.
US may be deserting the West
The Finns know from their history a belligerent Russia cannot be trusted.
In Europe, the US is not just withdrawing under Donald Trump, who says the US cannot prioritise the continent’s security any longer. It looks like it may be changing sides deserting the West entirely: Cutting off aid and intelligence to Ukraine while it is pummelled by Russian rockets and drones; branding Ukraine’s leader – and not the tyrant of Moscow – a dictator; attacking close allies with tariffs; resetting relations with Russia while it continues to invade a part of Europe.
‘Trump is ridiculous’, Greenlanders say
And threatening to take over its neighbours. Our journey ended in Greenland, top of the list of Mr Trump’s planned acquisitions.
Most people we spoke to were genuinely worried by him.
Image: Nuuk, the capital of Greenland
Students Aviana and Julie told us Mr Trump’s antics were alarming.
“That’s very scary actually – it seems he’s more with Russia than Ukraine. I’m really scared.”
Image: Students Aviana and Julie said they were scared by Trump’s actions
Another passerby said Mr Trump had no right to make a play for their homeland. They said: “I think it’s ridiculous that he thinks he can just take our land. We don’t have the resources to fight against the USA.”
Jurgen Boassen has become a well-known figure for having opposing views – he is outspokenly pro-Trump.
Image: Jurgen Boassen, who is pro-Trump and is paid by MAGA groups to promote ‘cultural ties’ between Greenland and the US
“I think he is a great man who wants to have peace in the world,” he told us.
‘Europe is failing’
He admits he is paid by MAGA groups in America to promote “cultural ties” and believes Greenland will gradually come around to the idea of becoming closer to America.
Image: Ice caps in Greenland
“I don’t care because they will realise I’m doing the good thing for Greenland. Europe is failing, Britain, Sweden, Belgium, Holland even Germany,” he said.
Wherever we travelled people seemed in shock. America used to believe helping others was good for America – keeping the peace in Europe, saving lives, or protecting the sovereignty of neighbours.
The fear is under President Trump it is just out for itself. The idea Mr Trump could carve up the world into spheres of influence with other authoritarian leaders seems plausible. If that is the case, lesser nations like Greenland may have plenty to fear.
From what we were told on our journey, Donald Trump’s America First foreign policy risks the lives of millions, the security and sovereignty of allies, and America’s own place in the world while potentially strengthening its enemies.