July 2010 Extra: School's out for summer

Comments

• Comment by Jen Gupta on Jul 20 2010:

  Surprise! Jodcasting is just too addictive to not have Extra shows! Once again, a MASSIVE thank you to all the work experience students who contributed to this episode. Comments and corrections go in here as normal.

• Comment by EarthUnit on Jul 20 2010:

  After waking up with a serious hangover, and the only high light of the day was looking forward to mowing the lawn ( I use the term lawn loosely, LOL) I decided to have a quick scan of the web in the hope of rain, clicking on the forum page through habit, it was great to find the extra show.
  Even better a great interview about Planck to start, excellent questions Mark, and the rest of the show just as brilliant. I enjoyed the interviews with the jodcaster's , again some great questions & answers.
  Armed with my mp3 player a most enjoyable bit of grass cutting, (I'm still working on the hangover).

  A big thanks Joder's for getting the show out, & welcome to the world of Jod Libby.

• Comment by Jen Gupta on Jul 20 2010:

  If only the Jodcast could cure hangovers! Then we'd be ready to take over the world... :-D

• Comment by RapidEye on Jul 20 2010:

  Heh - plotting to bring The British Empire back, one bitter beer at a time! =-)

  Good show - like it was pointed out at the end of the show, a bit remedial.
  <shrug> I don't mind occasional shows like that if it gets some new folks a chance to learn the ropes, but I'd not like a constant diet of shows like that.

• Comment by Mark Purver on Jul 26 2010:

  A slight technicality in the pulsar interview. I said that no pulsars had been detected outside our galaxy - but there are known pulsars in both the Small and Large Magellanic Clouds, which are dwarf galaxies believed to be satellites of the Milky Way.

  The Magellanic Clouds could be considered distant parts of our own galaxy, if you define the Milky Way as being everything within its inferred dark matter halo. But the Clouds are well away from the visible Milky Way and have their own structure, so calling them parts of our galaxy would be a bit like saying that the Moon is part of the Earth! Also, Spitzer data has suggested that the Magellanic Clouds may not be gravitationally bound to the Milky Way after all: http://www.physorg.com/news87572515.html

  So the Magellanic Clouds are generally considered to be galaxies within the Local Group and not parts of the Milky Way. That would make them the locations of the only known extragalactic pulsars.

• Comment by Jodatheoak on Aug 10 2010:

  Ahaaa on!y just finished listening to this and now another one comes along.
  Great stuff Jodders, love all the new voices and hope to hear more of them in the future.

• Comment by Mark Purver on Oct 10 2010:

  I just had another look at what colour a pulsar would be to our eyes, if we were close enough to see its thermal emission. Well, I was wrong to say that the power emitted would be constant across all visible colours. According to the blackbody radiation formula, an object at 1 million Kelvin would give a linear slope of power against frequency, and the blue emission would be about twice as bright as the red emission.

  This article on Wikipedia is about the 'Planckian locus', which gives the colour of hot things as a function of temperature: http://en.wikipedia.org/wiki/Planckian_locus. A typical pulsar would be near the infinity end of the temperature line.

  So the colour of most pulsars would be pale blue with possibly a hint of lilac. Like the early evening sky.

  Pulsars gradually cool, so very old neutron stars (no longer emitting as pulsars) would eventually move along the temperature line through white, lilac, yellow, orange and red.

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