In science fiction stories, antimatter pops up everywhere as a power source for spaceships or the active ingredient in diabolical bombs. In real life, though, this mysterious substance is elusive.
However, that is to change: At the CERN particle collider in Geneva, physicists have created and trapped atoms of antihydrogen for up 10 1,000 seconds, it was announced on Sunday night. It might not sound like long, but it is enough time for experiments that could help answer some of the most fundamental questions in physics.
The same scientists were the first to trap antihydrogen last year when they created and held on to 38 atoms of the stuff for 172 milliseconds in a strong magnetic field.
In their latest work, published in this month’s edition of Nature Physics, they trapped 309 antihydrogen atoms for varying amounts of time up to 1,000 seconds (just over 16 minutes).
Jeffrey Hangst of the University of Aarhus in Denmark, who led the experiments, said that the purpose of the study was to compare antimatter with atoms of normal matter.
“We’ve studied what’s going on with these atoms while they’re in the trap, how they’re moving, what energy or velocity they have. With 38, that was difficult, but with 300 it starts to look like something you can make averages out of. We’re getting information about how they’re behaving in the trap,” Hangst said.
Antimatter was first postulated by the British physicist Paul Dirac in 1930 while working on a way to reconcile the ideas of quantum mechanics with Albert Einstein’s theory of relativity.
The question scientists want to answer is why antimatter seems to be missing from the universe. The laws of physics do not differentiate between matter and antimatter, so, at the creation of the universe during the big bang, equal amounts of both should have been made. For every particle of matter in the universe, there should be a particle of antimatter. In practice, though, we do not see them.
At the start of the universe, cosmologists think, there was probably an infinitesimally small excess of matter particles over antimatter particles.
When the particles came into contact and the inevitable annihilations occurred in the earliest seconds of time, the universe was left only with matter particles swimming with copious amounts of energy.
Why this asymmetry occurred at the start of the universe is unknown. There could be some as-yet-unknown differences between matter and antimatter particles — theoretically, there should be no differences, but the ideas have not been tested so far.
By shining microwave and laser light onto the atoms and looking at the differences between antihydrogen and normal hydrogen, scientists will be able to interrogate whether the two atoms are as identical as physics theories imply, or whether the theories themselves need to be tweaked.
Nearly half of China’s major cities are suffering “moderate to severe” levels of subsidence, putting millions of people at risk of flooding, especially as sea levels rise, according to a study of nationwide satellite data released yesterday. The authors of the paper, published by the journal Science, found that 45 percent of China’s urban land was sinking faster than 3mm per year, with 16 percent at more than 10mm per year, driven not only by declining water tables, but also the sheer weight of the built environment. With China’s urban population already in excess of 900 million people, “even a small portion
UNSETTLING IMAGES: The scene took place in front of TV crews covering the Trump trial, with a CNN anchor calling it an ‘emotional and unbelievably disturbing moment’ A man who doused himself in an accelerant and set himself on fire outside the courthouse where former US president Donald Trump is on trial has died, police said yesterday. The New York City Police Department (NYPD) said the man was declared dead by staff at an area hospital. The man was in Collect Pond Park at about 1:30pm on Friday when he took out pamphlets espousing conspiracy theories, tossed them around, then doused himself in an accelerant and set himself on fire, officials and witnesses said. A large number of police officers were nearby when it happened. Some officers and bystanders rushed
HYPOCRISY? The Chinese Ministry of Foreign Affairs yesterday asked whether Biden was talking about China or the US when he used the word ‘xenophobic’ US President Joe Biden on Wednesday called for a hike in steel tariffs on China, accusing Beijing of cheating as he spoke at a campaign event in Pennsylvania. Biden accused China of xenophobia, too, in a speech to union members in Pittsburgh. “They’re not competing, they’re cheating. They’re cheating and we’ve seen the damage here in America,” Biden said. Chinese steel companies “don’t need to worry about making a profit because the Chinese government is subsidizing them so heavily,” he said. Biden said he had called for the US Trade Representative to triple the tariff rates for Chinese steel and aluminum if Beijing was
Beijing is continuing to commit genocide and crimes against humanity against Uyghurs and other Muslim minorities in its western Xinjiang province, U.S. Secretary of State Antony Blinken said in a report published on Monday, ahead of his planned visit to China this week. The State Department’s annual human rights report, which documents abuses recorded all over the world during the previous calendar year, repeated language from previous years on the treatment of Muslims in Xinjiang, but the publication raises the issue ahead of delicate talks, including on the war in Ukraine and global trade, between the top U.S. diplomat and Chinese