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| ©THE CAP TIMES |
*I joined CERN in 1968 and never met him
While writing a research proposal for a committee meeting with his peers, the newborn primus inter pares said, “I hope I don’t disturb the peace there too much.”
While writing a research proposal for a committee meeting with his peers, the newborn primus inter pares said, “I hope I don’t disturb the peace there too much.”
He told Madison’s THE CAP TIMES: “This project was challenging enough that it ending up with the Nobel Prize was so unlikely that until we started to finally achieve some results recently in the last 10 years, I certainly … never thought about this, and this certainly was not a motivation.”
“I was lucky enough that the right people showed up at the right time with the right talents to overcome the challenges the project faced. Some were overcome with pure luck, but that's science,” Halzen chuckled. “It's a combination of perseverance and talent and luck.”
Neutrino research was a field in high-energy physics where CERN led when Red Baron worked there.
And CERN continued its neutrino research beyond my retirement. In 2011, experimental results caused an outcry in physics when physicists measured neutrinos produced at CERN in the Laboratori Nazionali del Gran Sasso buried deep below the mountains that were “speedier” than the speed of light.
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| Laboratori Nazionali del Gran Sasso (©Alastair Philip Wiper) |
*Oscillation Project with Emulsion-tRacking Apparatus
Did we have to rewrite Einstein’s Theory of Relativity? I can reassure you, no.
In May 2012, OPERA repeated its measurement with a new, short-pulse neutrino beam. The final conclusion was that the CERN-to-Gran Sasso neutrino flight time matched the speed of light. The physicists concluded that a faulty fiber-optic timing element caused the original OPERA result.
The team compensated for the experimental blunder. In 2018, OPERA produced the long-desired result, observing 10 tau-neutrino candidates. The researchers confirmed that muon neutrinos produced at CERN can transform into tau neutrinos while traveling 730 km.
Back from “speedy” to ice-cold neutrinos.
To put it right away, the neutrinos aren't cold; Francis Halzen’s detector is. Instead of building an enormous artificial detector, he turned Antarctic ice into a gigantic neutrino telescope with thousands of photomultipliers watching for the tiny flashes of blue Cherenkov light produced when a neutrino interacts. Francis proposed the basic idea of an IceCube Neutrino Observatory in the late 1980s, and the detector now covers about one cubic kilometer of ice with more than 5,000 light sensors.
The important results are:
IceCube established that extremely high-energy astrophysical neutrino fluxes in the 100 TeV* to PeV range are coming from outside our Solar System.
*CERN’s LHC has a maximum collision energy of 13.6 TeV
Its findings opened a new form of neutrino astronomy. Light is absorbed or deflected, and magnetic fields bend charged cosmic rays. Neutrinos interact extremely weakly and travel directly from their birthplaces to Earth.
As a result, IceCube has identified individual cosmic sources. A particularly important source is NGC 1068 (Messier 77), an active galaxy about 47 million light-years away. Over the past decade, IceCube has detected about 80 (!) high-energy neutrino events.
With IceCube's results, scientists can now locate neutrino sources, i.e., cosmic-ray accelerators. Extremely high-energy neutrinos point back to these active galaxies containing supermassive black holes.
In short, Francis Halzen created a new astronomical instrument that began identifying the cosmic engines producing the most energetic particles known.
While neutrino oscillation experiments essentially asked: “What are neutrinos telling us about particle physics and stars?” Francis’s IceCube tells us something fundamentally new about the universe: “What can neutrinos tell us about the most violent objects in the universe?”
As Red Baron wrote before: Astrophysics is the new spearhead of physics.
Did we have to rewrite Einstein’s Theory of Relativity? I can reassure you, no.
In May 2012, OPERA repeated its measurement with a new, short-pulse neutrino beam. The final conclusion was that the CERN-to-Gran Sasso neutrino flight time matched the speed of light. The physicists concluded that a faulty fiber-optic timing element caused the original OPERA result.
The team compensated for the experimental blunder. In 2018, OPERA produced the long-desired result, observing 10 tau-neutrino candidates. The researchers confirmed that muon neutrinos produced at CERN can transform into tau neutrinos while traveling 730 km.
Back from “speedy” to ice-cold neutrinos.
To put it right away, the neutrinos aren't cold; Francis Halzen’s detector is. Instead of building an enormous artificial detector, he turned Antarctic ice into a gigantic neutrino telescope with thousands of photomultipliers watching for the tiny flashes of blue Cherenkov light produced when a neutrino interacts. Francis proposed the basic idea of an IceCube Neutrino Observatory in the late 1980s, and the detector now covers about one cubic kilometer of ice with more than 5,000 light sensors.
The important results are:
IceCube established that extremely high-energy astrophysical neutrino fluxes in the 100 TeV* to PeV range are coming from outside our Solar System.
*CERN’s LHC has a maximum collision energy of 13.6 TeV
Its findings opened a new form of neutrino astronomy. Light is absorbed or deflected, and magnetic fields bend charged cosmic rays. Neutrinos interact extremely weakly and travel directly from their birthplaces to Earth.
As a result, IceCube has identified individual cosmic sources. A particularly important source is NGC 1068 (Messier 77), an active galaxy about 47 million light-years away. Over the past decade, IceCube has detected about 80 (!) high-energy neutrino events.
With IceCube's results, scientists can now locate neutrino sources, i.e., cosmic-ray accelerators. Extremely high-energy neutrinos point back to these active galaxies containing supermassive black holes.
In short, Francis Halzen created a new astronomical instrument that began identifying the cosmic engines producing the most energetic particles known.
While neutrino oscillation experiments essentially asked: “What are neutrinos telling us about particle physics and stars?” Francis’s IceCube tells us something fundamentally new about the universe: “What can neutrinos tell us about the most violent objects in the universe?”
As Red Baron wrote before: Astrophysics is the new spearhead of physics.
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