The Belgian-American astrophysicist Francis Halzen will be awarded the Nobel Prize in Physics this year. This was announced by the Royal Swedish Academy of Sciences in Stockholm.
Halzen realized that the ice at the South Pole could be used to track particles known as neutrinos. His vision and scientific leadership made the IceCube neutrino observatory at the South Pole possible, it said. This enabled the discovery of high-energy neutrinos from space.
Using IceCube – a cubic kilometer of ice equipped with light sensors – researchers can detect neutrinos from extremely energetic processes in the distant universe.
Neutrinos – also called ghost particles – are among the most mysterious elementary particles. They have no electrical charge and almost no mass and react only very weakly with normal matter. Therefore, detection is extremely difficult.
A neutrino is a ghostly messenger from space, said Nobel Physics Committee Chairman Mark Pearce. On average, ten billion neutrinos hit every square centimeter of the Earth's surface every second. At least some of them are intended to detect large detector systems such as IceCube in the Antarctic ice.
Ghost particles are in and around us
Neutrinos are everywhere, but they are not noticeable, said the Royal Swedish Academy of Sciences. They would permeate the earth and our bodies without humans realizing this.
In very rare cases, a single neutrino interacts with an atomic nucleus. This allows someone with noisy equipment to spot them.
Halzen first presented his vision of capturing neutrinos at the South Pole in 1988. When a neutrino collides with an atomic nucleus, it produces a flash of light that sensors in the clear glacial ice can detect.
The ice at the South Pole offers many good conditions because it is free from various disturbances and the area is considered geologically stable. In addition, no earthquakes occur there. Halzen and his idea soon found support from other researchers. Just a few years later, the first tests were carried out with sensors in the ice.
Since cosmic neutrinos with extremely high energies are very rare, an enormous volume of ice is required to observe a sufficient number of collisions. IceCube covers an entire cubic kilometer and was completed in 2011.
The researchers soon discovered the first high-energy ghost particles and a few years later were able to publicize their discovery of neutrinos, which must originate far outside our solar system. The search for the universe's neutrino sources could now begin in earnest.
Nobel Prize Committee recognizes Halzen's perseverance
»Francis Halzen led an international team of researchers and engineers that gave us a fantastic instrument. “His persistence and scientific vision paved the way for a new kind of astronomy,” said Pearce.
Last year the Nobel Prize in Physics went to the British John Clarke, the French Michel Devoret and the American John Martinis. They received the award “for the discovery of the macroscopic quantum mechanical tunneling effect and energy quantization in an electrical circuit.”
The winners of the Nobel Prize in Medicine were announced on Monday: they are the two German researchers Peter Hegemann and Georg Nagel and the American Karl Deisseroth. They developed optogenetics, a method that shows how nerve cells in the living brain shape memories, feelings and behavior, the Nobel committee said.
The Nobel Prizes go back to the dynamite inventor and prize donor Alfred Nobel (1833-1896). He stipulated in his will that the awards should be given to those who have rendered the greatest benefit to humanity in each award category over the past year.
Physics was the first category that Nobel mentioned in his will. The first Nobel Prize winner in physics was the German Wilhelm Conrad Röntgen in 1901. He was recognized for his discovery of the X-rays that bear his name.
