Just a minute! Is space really expanding?

Now then. I’m sure this little video will get a few cosmologists’ hackles rising:

The video was produced by minutephysics, so presumably the expansion of time accounts for the fact that lasts more than two minutes. More importantly, though, is the content. Here’s an old  discussion of mine on this question. Let me know what you think via the comments box!

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24 Responses to “Just a minute! Is space really expanding?”

  1. John Peacock Says:

    What a shame that such a neat production is devoted to such misleading nonsense. Apparently this has been viewed by >100,000 people. I despair. Where did you find it?

    • “Where did you find it?”

      On the internet, where else? :-) And thereby hangs a tale.

      I wasn’t there, but I heard the story a few hours later from several people who were: When I was at Jodrell Bank, the late Bernard Lovell (Sir Bernard, of course) used to come in regularly, even though he was quite old by then. Of course, he was one of the founders of radio astronomy, but even when he was Director at Jodrell Bank he had already moved more into management, politics, organization, networking etc. I’m not sure if he personally ever worked with computers at all, even things like Atlas back in the 1960s in Manchester. One day at coffee, out of the blue, he asked one of the professors (as always, addressing him by last name with no title (of course, we addressed Sir Bernard by first name with title)) “Tell me, what is the internet”. After some discussion (where to start? how much background?), one of the lecturers gave him an executive summary. Sir Bernard thought for a minute then asked “What’s to prevent someone from populating it with rubbish?” :-)

    • telescoper Says:

      John,

      To answer your question, someone “recommended” it to me..

      Peter

    • Actually, I think John’s comment is wrong. Not that the video is correct. When the cat and its owner have no relative motion, then one can think of this as the cat’s peculiar motion balancing the motion from the Hubble flow at this point in time. What happens next depends on the cosmological parameters. The cat might approach you or might drift away from you. (This assumes that both cat and owner are part of the Hubble flow.)

      There is a paper on the “chained-galaxy problem” by Davis and Lineweaver which explains this in detail: http://arxiv.org/abs/astro-ph/0104349 (note that, among others, John, I and Ted Harrison are mentioned in the acknowledgements!)

      (What happens, of course, can be determined by the “shut up and calculate” method; it doesn’t depend on whether one thinks of space expanding or not; whether “space is expanding” is a red herring here.)

  2. Hello I’m sorry I cant follow the math component of your today post but I’m interested in the point generally. Isnt expanding space somewhat against GR and “equivalence”… and the different forces having their differing fields of action to operate within, depending on the question of scale

    BTW: I came across your paper fairly recently about Vesto Slipher who ‘ve I’ve always thought was unfairly neglected etc etc despite whatever personality quirks he had (we all do)

    I’m a schoolteacher in Edinburgh who for various reasons has always had some interest in astro questions- going back to Sputnik and dear old Patrick. Used to live in Africa so the night sky there was my first view (hence the pic)

    A friend of mine from Rhod/Zim days is @Tetenterre – The Binocular Sky (Steve Tonkin)

    I try to see the implications of the science/maths and sometimes think I have some ideas because of this. I recently got Jim Baggotts book on Fairytale Physics in Morningside- I was attracted by his intro where he complains about the dumbing down of eg. ‘Horizon’ and the geewhiz Brian Cox/ Michio pop viewpoint which is so common now rather opposed to more trad view exemplified by Jim AlKalili perhaps.

    I just about remember Feynman as someone who seldom patronised his audience and yet he was a genius with a common touch- who played bongos for Gods sake!

    Regards Nick Weech

    • I foolishly ascribed Mr Peacocks paper on Vesto Slipher to you. Sorry for that mistake -but the rest of my stuff is accurate. I dont find the Minute Physics completely bad either- trying to explain complex ideas simply and yet as accurately as possible and with some illustration, which helps & humour with a little backbeat. Tx for introducing me to it

  3. Ugh. But I notice a comment below the video from a certain John Peacock. I know it’s dangerous to venture into such territory, but it might not do any harm to “Vote Up” that comment…

    • Nicholas Cross Says:

      I tried reading John’s comment, but it has been marked as spam.

      • telescoper Says:

        Really? It seems fine to me..

      • I’ve attempted to email the uploader to correc this incorrect flagging, but to no avail.

      • I also saw it flagged as spam, but one can select a link to read it nonetheless.

        As to why it is flagged as spam, no idea!

      • Well, maybe one idea. Some sites have certain words, which might occur within other words, on a black list, in order to avoid obscene comments and so on. This has led to problems with words being OK in one language but not in another, place names, proper names etc. John Smith would have less of a problem.

      • telescoper Says:

        It’s probably his cock that did for him…

  4. Ian Douglas Says:

    Fear ye the YouTube comments. There be monsters. Duly voted up, though.

  5. Strangely, I just discovered Minutephysics today and it seemed quite good. Glad I didn’t find that episode first!

    There is a curious feature involved in the illustration of the person and cat held together by a strong leash. Watch the cartoon and you will see the space sliding past under their feet. For me, this is the bit that in the “expanding space” story that makes you realise it can’t be right. In this picture, the galaxies ride along with the space; but here in the solar system, space must be rushing past us, sliding out from under our feet as if we were on ice.

    So that cartoon could be used as a beautiful illustration of whats wrong with the idea.

  6. Thought we finally dispatched that odd notion that the universe only had three spatial dimensions plus time?
    When I used to work with speed detection radar I realised I could make artificial red shifts and blue shifts just by continuous alteration of frequency. I could make a stationary object appear to speed away or come closer..
    Similarly if light accelerated or slowed down over great distance in space due to gravitons darkmatter or what not, then the illusion of red shift would be observed, but not necessarily locally. Neither would light speed being other than constant be observed locally.
    Just a thought from the uneducated.

  7. I wonder if large areas of matter like the galaxy, or solar system itself clears It’s own surroundings of light slowing gravitons or dark matter o light can resume It’s normal speed, thus we observe an artificial red shift, through a lens if you like. Into deep space. Or light from deep space?

  8. My foray into this subject is here http://arxiv.org/abs/0808.1081 . We argue that you certainly don’t have to see space as expanding if you don’t want to!

    • If we’re positing our fav expanding space papers, I’d be happy to recommend my own :)

      Expanding Space: the Root of all Evil?

      Matthew J. Francis, Luke A. Barnes, J. Berian James, Geraint F. Lewis
      (Submitted on 3 Jul 2007)
      While it remains the staple of virtually all cosmological teaching, the concept of expanding space in explaining the increasing separation of galaxies has recently come under fire as a dangerous idea whose application leads to the development of confusion and the establishment of misconceptions. In this paper, we develop a notion of expanding space that is completely valid as a framework for the description of the evolution of the universe and whose application allows an intuitive understanding of the influence of universal expansion. We also demonstrate how arguments against the concept in general have failed thus far, as they imbue expanding space with physical properties not consistent with the expectations of general relativity.

      http://arxiv.org/abs/0707.0380

  9. At the risk of the world and his wife and Mrs Trellis pointing out all our egregious mistakes and glossed-over subtleties (you sell your soul when you do media stuff), you may enjoy the Sixty Second Adventures in Astronomy that STFC funded the Open University to make. Avid readers of this blog might also spot something we gleaned originally from these very pages. http://www.youtube.com/playlist?list=PLhQpDGfX5e7CSp3rm5SDv7D_idfkRzje-

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