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andrew s

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About andrew s

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  1. andrew s

    Astronomy Now wrong again

    Looks like no one else pick up this approch rather than the standard cosmological model. Regards Andrew
  2. andrew s

    Astronomy Now wrong again

    Thanks for the link, I will give it a read. I will also try to see how often it has been referenced as this is normally a good test of how mainstream the position taken is. Regards Andrew
  3. andrew s

    Astronomy Now wrong again

    Just what I asked for. English was never my strong point having failed O level English. However, I did manage a PhD in physics. Regards Andrew
  4. andrew s

    A light read!

    David , it is a post graduate level text. With full on tensor maths e tc. Regards Andrew
  5. andrew s

    A light read!

    I had been reading a number of blogs on general relativity and kept coming across references to a book called Gravitation by Misner, Thorne and Wheeler. As it was relatively cheap (pun intended) on Amazon so I ordered a copy. The delivery man looked flushed after walking up the hill to our house and accepting it almost fractured my wrist. It weighs about 3kg and has more than 1200 pages. Scanning it I reckon at least 2 days or more a page to understand it so I might just get through it before I pop my clogs! Who says education is just for the young! Ok no one. Regards Andrew
  6. andrew s

    Astronomy Now wrong again

    Not if they are coming from within our galaxy or even our local cluster of galaxies where the force of gravity binding them together is some 10^7 time stronger than the tension caused by the expansion of the Universe. Regards Andrew
  7. In 1970 the McDonald 107 inch suffered a gun and hammer attack with small chunks removed. Opticians smoothed out the edges and carried on using the mirror. As above you may get some small effects but I doubt you will notice them. Regards Andrew
  8. andrew s

    Astronomy Now wrong again

    For what it is worth I thought I would have a go at the answer. Yes light does lose energy as the Universe expands as it's wavelength increases along with the expansion. However, the issue of the "conservation of energy" in General Relativity has a long history. Einstein and others were aware of this before it's publication in 1915. Emmy Noether , a brilliant lady mathematician, was asked to look at the problem. This lead her to what is now known as Noether's Theorem which linked continuous symmetries to conservation laws. For example, translational and rotational symmetry leads to the conservation of momentum and angular momentum respectively. Her theorem is a cornerstone of modern physics as it is applicable not only in relativity but in quantum theory where it leads, for example, to the conservation of electric charge in QED and colour in QCD, as well as being invoked by Higgs in the prediction of the Higgs boson. But back to the conservation of energy. This comes from time translational symmetry but in GR space-time is dynamical and this breaks the symmetry leading to the failure of the conservation of energy. Emmy Noether did prove that the that "Stress-Energy" is conserved at a point but there was no global conservation of stress-energy. Einstein and others were unhappy with this and came up with a pseudo-tensor for stress energy to fix the problem but this is not invariant under a change of co-ordinates and can give unphysical results. While some cosmologists still take the view that energy is conserved the main stream view is that it is not. See Sean Carroll http://www.preposterousuniverse.com/blog/2010/02/22/energy-is-not-conserved/ for more details. Have fun finding my errors and typos. Regards Andrew
  9. andrew s

    Astronomy Now wrong again

    Sorry if I gave that impression i was trying to describe what the question. was about The loss in energy of "photons" is due to the metrical expansion of space. Regards Andrew
  10. andrew s

    Astronomy Now wrong again

    I have put this in the Lounge as it is certainly not good science. The answer on page 95 of the November on the red shift of light due to the metrical expansion of the Universe. Almost all, no, all of it is utter rubbish. Would someone (thinking of you Olly) please point out to them that whoever is supplying these answered is not up to the job. They never reply to me not even an acknowledgement. Regards Andrew
  11. Nor is there any evidence for any GUT. It was expected that the LHC would find some of the supersymmetric particles predicted by the supersymmetric theory but none have been found. Regards Andrew
  12. The current values in the LCDM model indicate there will not be a big rip (i.e. the scale factor will not go to infinity in a finite time). No stars convert all their hydrogen to heavier elements so some hydrogen will always exist. Regards Andrew
  13. andrew s

    Science in Astronomy Now

    No but you could refer to this discussion and how you would have managed my letter had it been to your magazine! (I do realise this is unlikely to happen.) Regards Andrew
  14. andrew s

    Science in Astronomy Now

    It is now almost a week since I wrote to the editor of AN and not even an acknowledgement. Maybe Neil or Olly could try to see if their more nuanced approach gets results? Regards Andrew
  15. andrew s

    Science in Astronomy Now

    It seemed to me to do a good job but I suspect the Penrose diagram is a bit advanced for many. The words however were as I understood the situation to be. Regards Andrew

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