![]() ![]() So, the idea with laser cooling in this particular experiment is if I have atoms that are moving quickly towards my laser, they absorb photons and get slowed down, so I can slow down the fast ones and not mess with the ones that are already slow enough. Absorption of the light is dependent on how fast the atom is moving. Now, light carries momentum, and when an atom absorbs one of its preferred photons, it gets a kick from the momentum of the photon, sort of like catching a heavy medicine ball if you’re standing on ice. When I spoke to Jeffrey, I asked: Can you explain how the technique that you use, which is called laser cooling, works?Īntihydrogen, like other atoms as far as we know, can absorb light, and atoms like to absorb particular colours of light. Slowing down antihydrogen could unlock experiments that will be able to compare anti-hydrogen and regular hydrogen with unprecedented precision. Antihydrogen consists of just one antiproton and one antielectron. In an experiment described in this week’s Nature, Jeffrey and the team were investigating how to slow down the movements of the simplest possible anti-atom – antihydrogen. It’s certainly lucky for us that it did, since if there’d been equal amounts of both it all would have annihilated and there would be no stars, planets, humans or podcasts. If physicists found some deviation in antimatter’s properties from the mirror image of matter that we’d expect, that could explain this fundamental question – why our Universe was created with a surplus of matter over antimatter. Why did the Universe evolve to matter instead of antimatter? If the Universe started as energy and it went on to evolve some mass, what happened to the anti-mass that should have been created at the same time? And the answer is we simply don’t know. ![]() The answer is how could you not if you can? So, there’s some mysteries associated with these antimatter particles, and this dates back to the beginning of the Universe. So, given that these experiments are so challenging, why are Jeffrey and collaborators painstakingly studying antimatter? It means that any experiments with antimatter are incredibly tricky, as one wrong move and your antimatter bumps into some matter and is annihilated. The interesting thing about these particles is they don’t exist normally because if they come into contact with normal matter they will annihilate and release a bunch of energy. Now, we know in modern physics that for every particle that we’ve been able to observe, you can have an equal but opposite antiparticle. ![]() This is physicist Jeffrey Hangst of Aarhus University in Denmark, and spokesperson of the ALPHA antimatter experiment at CERN in Switzerland. You see, in physics, there’s also something called antimatter.įor the lay person, we like to think of antimatter as kind of an evil twin of the matter that makes up everything that you and I know. Our Universe is made up of matter, but matter is only half the story. I’m Nick Petrić Howe.įirst up on the show, reporter Adam Levy is here to talk about an important matter. This week, antimatter gets cool…Īnd the global cost of biological invasions. Head here for the Nature Podcast RSS feed. Never miss an episode: Subscribe to the Nature Podcast on Apple Podcasts, Google Podcasts, Spotify or your favourite podcast app. Subscribe to Nature Briefing, an unmissable daily round-up of science news, opinion and analysis free in your inbox every weekday. Science: Octopuses, like humans, sleep in two stages The Financial Times: The bank effect and the big boat blocking the Suez This time, the physics that might explain how a ship blocked the Suez Canal, and a new insight into octopuses’ sleep patterns. We discuss some highlights from the Nature Briefing. This week, researchers estimate that the economic impact of invasive species to be over US $1 trillion. These species can cause loss of biodiversity and a host of damage to their new environments. Invasive alien species are organisms that end up in places where they don’t really belong, usually as a result of human activity. Research Highlight: Rabbits that do ‘handstands’ help to find a gene for hopping 11:53 Cost of invasion Research Highlight: Rising temperatures spark boom in Arctic lightning News and Views: Antimatter cooled by laser light 09:27 Research HighlightsĪ dramatic increase in Arctic lightning strikes, and an acrobatic bunny helps researchers understand hopping. Now though, a team at CERN have developed a way to trap and cool antihydrogen atoms using lasers, allowing them to better study its properties. In this episode: 00:44 Cooling antimatter with a laser focusĪntimatter is annihilated whenever it interacts with regular matter, which makes it tough for physicists to investigate. ![]()
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