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Resurfacing. In the show this time, Professor Frank Close describes the life of Bruno Pontecorvo, Professor Ralph Spencer talks to us about cosmic rays, perytons and inteferometery in this month's Jodbite, and your astronomical questions are answered by Dr Ian McDonald in Ask an Astronomer.
JodBite with Professor Ralph Spencer
We left the comfort of our recording studio, packed up all our recording equipment and jumped on a bus to Jodrell Bank Observatory to talk to one Professor Ralph Spencer. Ralph has had a long and varied career at Jodrell Bank. First arriving as an MSc student in 1967, he's still here. His expertise in radio astronomy are many and varied and we talked about a small fraction of what he does here. Ralph tells us all about his early research in cosmic rays and his more recent efforts to use the moon as a giant detector. We talk about how microwave ovens try to mimic Fast Radio Bursts and his experiments to reproduce Perytons in a field here at Jodrell. We also discuss his interest in instrumentation - in particular his involvement in the developments of eMerlin and eVLBI. We could have gone on for a lot longer as we only scratched the surface of Ralph's career. We'll certainly be inviting him back to talk to us some more!
Interview with Professor Frank Close
Also known as 'Mr. Neutrino' and the father of neutrino astronomy, Bruno Pontecorvo (22/08/1912 - 24/09/1993) was an Italian nuclear physicst engaged in active research during both the Second World War and the Cold War.
His career began in Rome, and as a member of Enrico Fermi's Via Panisperna boys he contributed to experiments involving slow neutrons, an intrinsic part of modern day nuclear power, before moving to Paris to work with Nobel Laureates Irene and Frederic Joliot-Curie. He later fled to North America during the Fall of France in 1940 where he became an oil prospector, developing the first pratical application for the Via Panisperna boys' research, a well-logging technique which used a neutrino-emitting source to search for oil- and uranium.
Throughout a driven and bountiful career Pontecorvo's research moved toward the concept of neutrinos, the elusive subatomic particles produced by radioactive decay. His influence pervades the field, inspiring or otherwise predating that of many Nobel Laureates.
Pontecorvo first proposed that neutrinos came in different species, electron and muon, and devised an experiment to test this theory in 1960. Some two years later an independent experiment was performed by Lederman, Schwartz and Steinberger, who were awarded a Nobel Prize for their efforts in 1988. He is widely credited with insight into the workings of supernova collapse, and the prediction that a supernova will shine 100 times more brightly in neutrinos than it does in visible light. A speech by Raymond Davis Jr cited a 1946 paper by Pontecorvo as the inspiration for his 2002 Nobel Prize-winning research. A paper by Pontecorvo and Vladimir Gribov published in 1969 discussed the idea that neutrinos might flip back and forth between their species, a concept known as neutrino oscillation, the demonstration of which by Kajita and McDonald won the 2015 Nobel Prize in Physics.
Despite his many innovations in these fields, the enigmtic Pontecorvo was never awarded a Nobel Prize on his own. The reason for this is the subject of much controversy, but is in no small part due to the fact that, in 1950 during the height of the Cold War, Bruno Pontecorvo and his family disappeared from a summer holiday through the Iron Curtain with just 60kg of luggage between them. He did not resurface until 5 years later, at a conference in the Soviet Union.
Frank Close is an Emeritus Professor from Oxford University. Previously the head of the Rutherford Appleton Laboratory in Oxfordshire and of communication and public education at CERN, he is a prominent particle theorist and scientific communicator to the public. He talks to us about the topic of his latest book, Half Life, which began as a scientific biography of the work of Bruno Pontecorvo, but became an in-depth account of his life, career, and the mystery of his defection, which led Frank to contact colleagues, relatives, and even MI5 along the way.
Ask an Astronomer
Dr Iain McDonald answers your astronomical questions:
- Armando asks us about near Kuiper Belt misses by our long distance spacecraft
- Ian wonders about the curvature of the Earth
- Sean wants to know what the most distant object his eyes will allow him to see is
Odds and Ends
Alexander Tcheckhovskoy and Omer Bromberg have carried out 3D magnetohydrodynamical simulations of radio galaxies that include relativistic effects. Radio galaxies can be separated into low power (FR1) and high power (FR2) radio galaxies with the two showing very different morphologies. Using these simulations, Tcheckhovskoy and Bromberg are able to reproduce the morphologies of FR1 and FR2. These simulations are a useful step in understanding the important process of AGN feedback. Videos of the simulations can be found here
Whilst undertaking observation of alpha-Centauri, astronomer found what is thought to be the most distant object in the solar system. Designated V774104, the trans-neptunian object is estimated to be no larger than 1000 km across, and lying at over 3 times Pluto's distance from the Sun. Its orbit is not yet known as there have been too few observations to calculate its trajectory but its possible that this may be an Oort cloud object that is towards the inner part of its orbit. It's not clear how object like this form out there or how their orbits become so eccentric.
The Dawn Spacecraft revealed several bright spots on the surface of the dwarf planet Ceres. Their nature has been something of a mystery since, with people (with varying levels of authority) claiming they are water ice, signatures of photosynthesis or even aliens - among other weird and wonderful speculations. There are new clues however as to what they might me. Scientists have found that they may be caused by salts - specifically hydrated magnesium sulphate with some more recent observations of the planet showing that what they see is consistent with this explanation. Read more here
|JodBite:||Professor Ralph Spencer and Benjamin Shaw|
|Interview:||Professor Frank Close with Charlie Walker and Nialh McCallum|
|Ask An Astronomer:||Dr Iain McDonald and James Bamber|
|Akbar:||Chia Min Tam|
|Jar Jar:||Jack Radcliffe|
|Written by:||David Ault|
|Presenters:||Therese Cantwell, Mateusz Malenta and Benjamin Shaw|
|Editors:||Alex Clarke, Nialh McCallum, Benjamin Shaw and Charlie Walker|
|Segment Voice:||Kerry Hebden|
|Website:||Benjamin Shaw and Stuart Lowe|
|Cover art:||CREDIT: Professor Frank Close|