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Dark Energy & The Big Bang

  1. Nov 5, 2014 #1
    Two Issues:

    1 Accellerating Universe Expansion (Inflation)

    As I understand this this arises out of the observation that the further away object are, the faster they are moving, (relative to us). This I assume is the origin of the search for “Dark Matter” & “Dark Energy”

    Surely if a star 1,000 light years away is travelling faster than a star 100 LY away this means that 1000 years ago it was travelling faster than it was 100 years ago – ergo it is SLOWING DOWN. Does this not remove some of the problems we are trying to solve?

    1 Big Bang Issues.

    Many of the currently available books written as explanations of the BB and posing the questions of the issues of inflation mention what happens in the “first Micro second” or the “first 4 minutes”. If we assume that just before the BB there was no mass and nearly infinite energy then from

    E= 1/2MV² then V must beclose to the limiting velocity C. Now Uncle Albert told us that time slows down as relative velocity increases so on this model one second could be the sam as 100 present day years. As all of our calculations are based on our experience of present “earth” seconds does this not go a long way to explaining the mysteries of the first few seconds?
  2. jcsd
  3. Nov 5, 2014 #2


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    Gold Member

    All of your statements represent common misconceptions about these topics that have been explored many times here on this forum. I suggest a forum search and/or further reading on cosmology.

    Also, the expanding universe is related to dark energy. Dark matter is a contributing factor to slowing down the expansion, not speeding it up as you seem to think, but the effects of dark energy became dominant about 6 or 7 billion years ago. Dark matter was discovered because of its gravitational effect on large structures (galaxies) and not because of anything relating to the expansion of the universe or the acceleration of that expansion.

    You might take a look at the link in my signature.

    EDIT: One other thing. About your statement "If we assume that just before the BB there was no mass and nearly infinite energy then from ...", the Big Bang Theory does not say ANYTHING about "before the BB", it is a theory about the evolution of the universe starting at about one Plank Time after the singularity but says nothing about the singularity, so we don't make any assumptions about "before the BB" or before one Plank Time.
  4. Nov 5, 2014 #3
    ... and finally E= 1/2MV² is newtonian formula, not valid when v-->c
  5. Nov 5, 2014 #4


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    The observation you described is the idea behind the concept of an expanding universe, leading to the idea of a big bang.

    Dark matter is a separate issue, based on observations of stellar motion in galaxies and relative motion of galaxies within clusters.

    Dark energy is proposed as an explanation for the observation that the expansion is speeding up, rather than slowing down. If there was no dark energy there still would be expansion.
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