Comments on: Ep. 123: Homogeneity http://www.astronomycast.com/astronomy/cosmology/ep-123-homogeneity/ Take a weekly facts-based journey through the cosmos with Astronomy Cast. Tue, 16 Mar 2010 14:18:43 +0000 http://wordpress.org/?v=2.9.1 hourly 1 By: craigr http://www.astronomycast.com/astronomy/cosmology/ep-123-homogeneity/comment-page-1/#comment-1614 craigr Mon, 16 Mar 2009 13:29:00 +0000 http://www.astronomycast.com/?p=525#comment-1614 Really enjoyed this one. Very technical, but understandable, and very challenging intellectually. Really enjoyed this one. Very technical, but understandable, and very challenging intellectually.

]]> By: Andy http://www.astronomycast.com/astronomy/cosmology/ep-123-homogeneity/comment-page-1/#comment-1538 Andy Fri, 13 Feb 2009 00:15:31 +0000 http://www.astronomycast.com/?p=525#comment-1538 Nice show, certainly. But! Regarding the claim that the speed of light has not changed over time: I'd love to hear how the velocity of light can ever be anything other than constant when your units of distance and time are both defined in terms of wavelengths and durations of oscillations of light whilst light's velocity is dependent on exactly the same properties (see http://www.simetric.co.uk/sibasis.htm for the SI definitions). This has bothered me since I first learnt the definitions and I've not yet found an answer that doesn't either produce a circular argument or club the question into submission with Einstein and Michelson/Morley. (Oh, and I know about mu-nought and e-nought) Looking forward to some good answers. Andy Nice show, certainly. But!

Regarding the claim that the speed of light has not changed over time:

I'd love to hear how the velocity of light can ever be anything other than constant when your units of distance and time are both defined in terms of wavelengths and durations of oscillations of light whilst light's velocity is dependent on exactly the same properties (see http://www.simetric.co.uk/sibasis.htm for the SI definitions).

This has bothered me since I first learnt the definitions and I've not yet found an answer that doesn't either produce a circular argument or club the question into submission with Einstein and Michelson/Morley.

(Oh, and I know about mu-nought and e-nought)

Looking forward to some good answers.
Andy

]]> By: Mike http://www.astronomycast.com/astronomy/cosmology/ep-123-homogeneity/comment-page-1/#comment-1493 Mike Mon, 26 Jan 2009 18:22:58 +0000 http://www.astronomycast.com/?p=525#comment-1493 I enjoyed this show alot as it cast Pamela into Fraser's role with Chris Lintott being the expert and Pamela translating his answers. It worked well and I found it very informative particularly as I thought the subject matter was a difficult one to get across but I felt by the end I had a good idea about the cosmological principle and even explained it to my teenage son later. Have you (Pamela) perhaps thought about inviting more guests onto your regular podcast shows? Not that I would want to hear less of Fraser! I enjoyed this show alot as it cast Pamela into Fraser's role with Chris Lintott being the expert and Pamela translating his answers. It worked well and I found it very informative particularly as I thought the subject matter was a difficult one to get across but I felt by the end I had a good idea about the cosmological principle and even explained it to my teenage son later.

Have you (Pamela) perhaps thought about inviting more guests onto your regular podcast shows? Not that I would want to hear less of Fraser!

]]> By: Eric Twinge http://www.astronomycast.com/astronomy/cosmology/ep-123-homogeneity/comment-page-1/#comment-1490 Eric Twinge Fri, 23 Jan 2009 02:30:05 +0000 http://www.astronomycast.com/?p=525#comment-1490 sweet, thanks. didn't mean to jump the gun or rush you guys. sweet, thanks. didn't mean to jump the gun or rush you guys.

]]> By: Eric Twinge http://www.astronomycast.com/astronomy/cosmology/ep-123-homogeneity/comment-page-1/#comment-1489 Eric Twinge Wed, 21 Jan 2009 21:12:10 +0000 http://www.astronomycast.com/?p=525#comment-1489 Hey, this was a fantastic show. Loved it. Are there any links you can provide that give a bit more info around that alternative theory on dark energy discussed towards the end of the show? It sounded really interesting. Hey, this was a fantastic show. Loved it. Are there any links you can provide that give a bit more info around that alternative theory on dark energy discussed towards the end of the show? It sounded really interesting.

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