In the show this time, Dr Tom Broadhurst talks to us about cold dark matter in galaxy clusters, Dr Simon Rookyard explains describes porridge, pulsars and polarisation, and your astronomical questions are answered by Dr Anna Scaife in Ask an Astronomer.
JodBite with Dr Simon Rookyard
Brand new Dr Simon Rookyard won the acclaimed world championship for porridge making just a few days after he submitted his PhD thesis. He talks to Charlie about his research into polarisation and what it can tell us about pulsar geometry and describes his 7 year porridge making career, what makes the perfect bowl how he won the celebrated Golden Spurtle for 2015.
Interview with Dr Tom Broadhurst
Heavy particles are not the only interpretation for the observed coldness of dark matter. Dr Tom Broadhurst tells us about cosmological simulations of a cold Bose-Einstein state that reveals an unknown world of galaxy structure. He explains how he tests his simulations on local dwarf galaxies and Hubble 'Frontier Field' data and how light bosons may prevail as the best explanation for dark matter.
Ask an Astronomer
New Jodcaster Dr Anna Scaife answers your astronomical questions:
- Stanely Furtig asks us about the relativity corrections applied to the clock on GPS satellites.
- Matthew Wilday wants to know about the number of stars that intercept our radio transmissions
- Russ Jenkins asks us about the interior of Mars
Odds and Ends
Researchers from Swiss Federal Institute of Technology (ETH) in Zurich have used time delays in a strong gravitational lensing system to measure the Hubble constant within 5%. This technique can be used in systems where the source (the background object) varies its emission with time. When a source object is lensed it may produce multiple images. Light travels along different paths to produce each image, and these paths may not be of the same length. That means that light will take a different amount of time to travel along different paths, leading to time delays between the images. This technique - using time delays in lensing to constrain the Hubble constant - is just starting to be used widely. This paper isn't the first to do it, but it's interesting because they claim to have constrained the Hubble parameter very tightly.
Cracks appearing on the surface of Mars' larger moon Phobos are now thought to be caused by the impending break up of the satellite. Phobos, which orbits Mars faster that Mars rotates on its axis, orbits so close to the planet that it is inside it's Roche limit. This means that the gravitational pull due to Mars on the near side of the moon is greater that the self gravity that holds phobos together. The result, in 30 - 50 million years, will be the disintegration of Phobos, possibly forming a ring of material around the red planet.
We had a really great question for our coffee room whiteboard. Steven asked us, "Hi everyone I have a silly question. I play Elite Dangerous, a game that procedurally models the entire milky way and incorporates databases of stars to fine tune the the simulation. I get to rocket around this simulation in a faster than light ship and can go pretty much anywhere. Where should I go for a lovely view?" Well Steven, here's what the JBCA astronomers had to say! We hope you enjoy superluminally rocketing around Batley.
|JodBite:||Dr Simon Rookyard and Charlie Walker|
|Interview:||Dr Tom Broadhurst and Indy Leclercq|
|Ask An Astronomer:||Dr Anna Scaife and James Bamber|
|Presenters:||Monique Henson, Benjamin Shaw and Hannah Stacey|
|Editors:||Charlie Walker, Cristina Ilie, Nialh McCallum and Damien Trinh|
|Segment Voice:||Kerry Hebden|
|Website:||Benjamin Shaw and Stuart Lowe|
|Cover art:||Porridge! CREDIT: Dr Simon Rookyard|