May 2011 Extra - show notes

In this show we talk to Dr Karen Masters about LOFAR and Galaxy Zoo, Dr Haley Gomez talks about dust in galaxies and Dr Stephen Serjeant tells us about star-forming galaxies and strong gravitational lensing. Dr Tim O'Brien answers your astronomical questions, and we report on some odds and ends from the world of astrophysics.

Interview with Dr Karen Masters

Dr Karen Masters (Institute of Cosmology and Gravitation, University of Portsmouth) works on LOFAR, a low frequency radio telescope array, largely located in the Netherlands but with stations located in other European countries, including a station in the UK at Chilbolton. Karen describes some of the computing challenges of the project, and the exciting science that will come out of this telescope. Karen is also involved with Galaxy Zoo and describes some new results on the nature of red spiral galaxies, and the latest Galaxy Zoo project using images from the Hubble Space Telescope.

Interview with Dr Haley Gomez

Dr Haley Gomez works at Cardiff University studying dust in galaxies. In this interview, Haley explains what cosmic dust is and where it is found. She also talks about the Herschel Space Observatory and how it is being used to understand more about dust in the Universe.

Interview with Dr Stephen Serjeant

Dr Stephen Serjeant (The Open University) works on extragalactic surveys of star-forming galaxies, as well as acting as a consultant for the popular TV show Bang Goes the Theory. In this interview, Stephen talks about his work on the Herschel ATLAS; including the star formation history of quasar host galaxies and the properties of strongly gravitationally lensed sub-millimetre galaxies.

Ask an Astronomer

Dr Tim O'Brien answers your astronomical questions:

The first question is from Greg. He wants to know about the relationship between mathematics and astronomy. In particular he wants to know whether, as either a professional or a hobbyist, if one lacks mathematics will a pursuit of astronomy end in a frustrated exercise?
Willie Wilson has several questions about the structure of our Galaxy. Is the plane of our solar system the same as the plane of the Milky Way? Why is there a central bulge in our Galaxy? Is there matter - gas, stars, etc. - lying above and below the galactic plane and, if so, how is this matter distributed?
Jim Omans from Virginia writes in to say: "While landing in a plane on a very windy day, I began to wonder if galaxies wobble. Many galaxies rotate - ours does. Do galaxies also pitch, yaw and roll as they move through space?"
The next question is from Ian Kennedy: "If the Universe is expanding and everything is moving apart, how come galaxies collide?"
David Entwistle wants to know how we decide on the arrangement of individual elements (e.g. aerials, dishes, etc.) in the new radio telescope systems such as LOFAR and the SKA.
Finally, Mark Randles asks "When can we expect to begin to get pictures of Pluto taken by the New Horizons space probe which are of better quality and resolution than the ground-based and Hubble pictures so far obtained?"

Odds and Ends

NASA satellite Gravity Probe B, which was launched in April 2004 after over 40 years of development, confirmed two crucial points in Albert Einstein's general theory of relativity. Using fast-spinning gyroscopes, the instrument measured how the tug of Earth's gravity and the planet's spin distort space and time in its cosmic neighbourhood.

A Polish farmhouse received a direct hit from outer space on the 30th of April, when a meteorite crashed through its roof and smashed into several pieces on the ground. The largest fragment weighed around 1kg, and was still warm when it was found. One end of the rock appeared to have been moulded into a rounded shape during its descent through the Earth's atmosphere, allowing it to avoid vaporisation. Although no-one was injured by this rare event, there is at least one documented case of a meteorite striking a human being (non-fatally).

INTECH, near Winchester in Hampshire, is doing a day of events for the deaf and hard of hearing on the 22nd of May, including signed and subtitled planetarium shows.

On the 15th of June a total lunar eclipse will be visible from the UK. The Museum of Science and Industry in Manchester is holding a series of talks, demonstrations and planetarium shows (with some of the Jodcasters and friends), before heading over to Cloud 23 in the Hilton Hotel to observe the moon rising in eclipse. It would be great to see some of you there.

Show Credits

Interview:	Dr Karen Masters and Megan Argo
Interview:	Dr Haley Gomez and Jen Gupta
Interview:	Dr Stephen Serjeant and Libby Jones
Ask An Astronomer:	Dr Tim O'Brien
Presenters:	Melanie Gendre, Libby Jones and Mark Purver
Editors:	Mark Purver, Melanie Gendre, Jen Gupta, Libby Jones and Tim O'Brien
Producer:	Libby Jones
Segment Voice:	Liz Guzman
Website:	Stuart Lowe and Libby Jones
Cover art:	A Hubble Space Telescope image of galaxies in the cluster Abell 2218. This cluster gravitationally lenses, magnifies, and brightens the light from very distant galaxies. CREDIT:: Andrew Fruchter (STScI) et al., WFPC2, HST, NASA

Comments

Comment by Libby on May 17 2011:
Comments, clarifications and corrections for the May Extra 2011 show go here.
Comment by suitti on May 19 2011:
In the May Extra, but also in other shows, and even outside of the Jodcast, there was a mention that Andromeda and the Milky Way will merge. One would expect that since radial velocity is relatively easy to measure, and since no proper motion has been detected for Andromeda (though it has been detected for M33), so the proper motion must be really small, and therefore the merger should happen on the first pass, and since the distance to Andromeda is understood to at least two significant digits, the error bar on when there will be a collision should be small, perhaps less than ten percent. But one hears numbers like "between 4 and 10 billion years", which isn't a small error bar. The Milky Way is perhaps 100,000 light years across, so perhaps a collision will take time. But that's only 1/25th the current distance to Andromeda. Is it some ambiguity for a term like "collision" or "merge"? Is it that there is more than one estimate? What gives?
Comment by RapidEye on May 19 2011:
Suitti wrote: "merger should happen on the first pass"
Not so - its not like two pieced of putty that will stick to each other when they pass. Instead think of throwing two handfuls of sand at each other - the vast majority will pass past each other without hitting anything. The mutual gravity will cause everything to slow down, then reverse back towards the center of gravity in a yo-yo type merger.
Now try and calculate the gravitational attraction between those two handfuls of sand as they pass each other, on an individual grain bases, to see how much they'll gravitationaly interact. Keep in mind many of the more massive stars have lifetimes of less that a billion years and those burning now will have gone supernova before the merger and those that will play a major role during the merger haven't even been born yet....
Much higher than a 10% error bar =-)
Comment by Jen Gupta on May 22 2011:
RapidEye is spot on, sand is a nice analogy! It's thought that the Milky Way and Andromeda will make a few passes through each other before they eventually merge into one galaxy. There are some nice videos on youtube, although it's hard to tell which (if any) are actually based on astrophysical simulations and which are more "artist's impressions".
A lovely example of galaxies mid-collision is "The Mice". Lots of brilliant images available online (e.g. from the Hubble Space Telescope - http://hubblesite.org/newscenter/archive/releases/2002/11/image/d/). Probably one of my favourite astronomical sights.
Comment by Jen Gupta on May 22 2011:
On a completely different note, I can't believe we haven't used this cover art image before! It's a classic :-D
Comment by SusanK on May 23 2011:
I really enjoyed the interview with Dr Stephen Serjeant. His excitement for his work is contagious.
Comment by EarthUnit on May 26 2011:
Another very informative show and great interviews, nice to hear Dr Tim's Q & A section, seems like ages since he's been on.
PS I don't suppose during the Stephen Serjeant interview he said anything about Dr Yan getting a bigger part on the TV show ? His experiments are the best bits :-)
Thanks again for getting another show out, keep up the good work Joder's.

Leave a comment on this episode in the forum

Download Options

The whole episode [Duration 78:20]:
standard [35.9 MB]
low quality [13.5 MB]
high quality [71.8 MB]
Interview with Dr Karen Masters [Duration 10:39]:
standard [4.9 MB]
low quality [1.9 MB]
high quality [9.8 MB]
Interview with Dr Haley Gomez [Duration 06:50]:
standard [3.2 MB]
low quality [1.2 MB]
high quality [6.3 MB]
Interview with Dr Stephen Serjeant [Duration 28:09]:
standard [12.9 MB]
low quality [4.9 MB]
high quality [25.8 MB]
Ask an astronomer - Mathematics, Pluto and Galactic Structure and dynamics [Duration 25:01]:
standard [11.5 MB]
low quality [4.4 MB]
high quality [23 MB]

May 2011 Extra: Einstein