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How is my short essay so far? Accurate?

  1. Nov 27, 2011 #1
    I'm writing an essay for a contest and I'm about half way done. I want to know how accurate my information is. It should be self explanatory as we are supposed to write it for the general non-physics person who might have no clue about the subject. The asterisks are places where I'll have to insert a footnote to briefly explain the concept, similarly to the way I explained the Doppler effect.

    After this I will start talking about dark matter/energy.

    Thanks for reading.
  2. jcsd
  3. Nov 28, 2011 #2
    Come on guys, 167 views on not one comment? I guess I'll ask my professor instead.
  4. Nov 28, 2011 #3


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    It looks pretty good for a non-physics audience.

    I would change "In other words, the clusters of galaxies he observed were not simply hovering at some fixed point in space, but rather flying towards the opposite direction" To something like 'flying in all different directions'.

    Also, I think the universe is still possibly closed, possibly flat, possibly open. (In other words they have not yet ruled out a big crunch or a big freeze). I think I heard this in lecture, but things may have changed since then.
  5. Nov 28, 2011 #4
    "flying in all different directions" doesn't really convey the idea that they are moving in the exact opposite direction relative to the earth.

    as for the big crunch vs big freeze, I've been careful to use phrases like "seem to contradict" rather than "contradicts", etc.

    thanks for reading.
  6. Nov 30, 2011 #5
    I really like it and it would be great to interest non-academics for the objective of promoting cosmology within popular science but if you are proposing this essay for an academic institute I would, depending on your elected subject, include more science. Great for someone new to the subject but scientists cannot benefit from this. You need more formulas, numbers and much more physics.

    The fact is scientists love tried and tested formulas and experiments that are observational as supposed to something that attempts to explain what most people in the industry already know, albeit well written.

    You should talk about string theory, plank lengths and dimensions as supposed to a generic statement about the expansion.

    You mention Hubble but not the Hubble's phenomenological law (posterior of exp.datas), the speed of something x away from you is v=Hx...Where H is the Hubble constant which is 71 kps/Mpc (megaparsec). Also the Hubble sphere's derived velocity is c(1+q), also worth mentioning.

    Also, may be worth mentioning Friedmann and his equations for an isotropic universe. The main law being asq+kcsq/asq =8(pi)gp+^csq/3.

    More numbers and less romance. But good effort.
  7. Nov 30, 2011 #6
    Hey, sorry about the above i have just read that you aim to deliver it to a non-physics audience!!!! In that case, please ignore the above and well written!
  8. Nov 30, 2011 #7
    Yes, it's not supposed to be too technical. I did mention Hubble's law. :)

    I already finished the essay.
  9. Nov 30, 2011 #8
    'tis sweet. Sorry for the 'rant' didn't read that is was for the non-acs. And well done!
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