Al Cern di Ginevra il confronto tra materia e antimateria si fa sempre più serrato: la collaborazione dell’esperimento Alpha, a cui partecipa anche l’Istituto Nazionale di Fisica Nucleare (Infn), ha infatti realizzato la misura più precisa mai ottenuta di una proprietà fondamentale dell’antidrogeno, la cosiddetta struttura iperfine, migliorandone l’accuratezza di circa cento volte.

Il risultato, che segna un nuovo importante passo verso la comprensione dell’antimateria, è pubblicato sulla rivista Nature.

Secondo le più accreditate teorie cosmologiche, materia e antimateria sono state prodotte in quantità uguali subito dopo il Big Bang. Tuttavia, l’universo che conosciamo oggi è costituito quasi esclusivamente di materia: una delle grandi questioni aperte della fisica fondamentale è quindi comprendere che cosa abbia portato a un simile squilibrio. In questo contesto, la misura dei livelli energetici dell’antidrogeno, e il loro confronto con quelli dell’idrogeno, è di importanza fondamentale. Consente infatti di verificare la validità di queste simmetrie tra materia e antimateria e di esplorare eventuali deviazioni che potrebbero aprire la strada a una nuova fisica. E uno degli osservabili più sensibili è, appunto, la struttura iperfine dello stato fondamentale, legata all’interazione tra gli spin delle particelle che compongono l’atomo.

Nel corso dell’esperimento sono stati analizzati circa 24.000 antiatomi, prodotti combinando antiprotoni e positroni e mantenuti in una trappola magnetica a temperature estremamente basse. La tecnica impiegata, basata su spettroscopia a microonde, ha consentito di determinare con precisione le transizioni tra i livelli energetici dell’antidrogeno, da cui si ricava direttamente l’intervallo iperfine.

“Questo risultato rappresenta un passo fondamentale nello studio dell’antimateria”, osserva Germano Bonomi, ricercatore della sezione Infn di Pavia e professore all’Università di Brescia. “Grazie al significativo miglioramento nella precisione della misura, possiamo confrontare con sempre maggiore sensibilità le proprietà di materia e antimateria, mettendo alla prova i principi più profondi della fisica”.

well she’s right, after each rotation around the Earth the sun can get closer in some periods. at the same time you can observe the four elephants that hold the Earth sprinkling water on the turtle they stand on to keep it cool and hydrated.

it’s really basic knowledge.

Australia has recorded its first diphtheria death in almost a decade as the country grapples with the worst outbreak of the vaccine-preventable disease in decades.

In March, the Northern Territory (NT) declared an outbreak of diphtheria with cases also in Western Australia, South Australia and Queensland. Cases started rising in late-2025 with a sharp increase in February.

This year, there have been 245 cases, marking the largest outbreak in Australia since 1991, mainly in remote Indigenous communities.

On Tuesday, NT’s health minister said autopsy results from an overseas lab found diphtheria was the cause of a man’s death in April at Royal Darwin Hospital, the first such case since 2018.

In recent weeks, the government has ramped up vaccination efforts in areas most at risk and the number of new cases was now falling, health officials said on Tuesday.

“Our government has taken this situation very seriously, and we are working hard to understand the causes and working to contain the situation,” NT Health Minister Steve Edgington said.

Since 30 March, there have been 10,407 vaccinations, he said.

Between January last year and May this year, the NT reported 163 diphtheria cases with 48 respiratory cases and 115 cutaneous cases, which is spread via skin contact.

In March, health officials in Western Australia (WA) confirmed two cases of respiratory diphtheria, the first time in more than 50 years that WA had recorded such cases.

Sixty per cent of the cases this year are in the Northern Territory, followed by Western Australia with about 36%, with a few cases in South Australia and even fewer in Queensland.

Authorities are urging affected communities to update their vaccinations, especially teenagers and adults who need to get booster shots.

Health officials in the NT have set up pop-up clinics in Darwin, Katherine and Alice Springs to raise awareness of the vaccination campaign, as vaccines are the “most important measure for preventing, protecting and reducing transmission,” NT Health said.

Both strains of diphtheria - respiratory and cutaneous - are preventable via a vaccine, which is usually given to children - five doses between two months and four years old - with a booster between 12 and 13 years.

Respiratory diphtheria often starts with fever or chills, a sore throat that can lead to breathing and swallowing difficulties, and be life-threatening.

Cutaneous diphtheria usually causes infected sores or ulcers on exposed parts of the body which are slow to heal but rarely lead to severe illness.

It is understood that the last reported diphtheria death was in 2018, according to the national broadcaster ABC.

Last week, Australia’s Chief Medical Officer Prof Michael Kidd declared diphtheria a communicable disease incident of national significance.

The government also announced a AU$7.2m package to boost vaccinations and resources in affected areas.