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B Flaws in general relativity

  1. Jun 10, 2017 #1
    Dark matter and dark energy are fudge factors to solve problems in general relativity such as unexplained mass and drag. Is this correct or am I missing something?
  2. jcsd
  3. Jun 10, 2017 #2


    Staff: Mentor

    The evolution of physics is that we develop theories that explain the things we can measure and then we continue to explore new areas and continue to apply the theory. When a given theory doesn't seem to work we check if our understanding is correct or that there is some hidden cause for the discrepancy before we decide to sack the theory and look for a new one.

    In the case,of General Relativity every measureable experiment has confirmed that is still a valid and useful theory to explore the cosmos. It is because of its predictive accuracy that we have discovered the effects that we now say are due to dark matter and dark energy. It's natural then that scientists seek something to explain the discrepancies in measurements rather than scrap General Relativity.

    If someone were to come along with a new theory that explained all of General Relativity's results, together with dark energy and dark matter anomalies then it could be a contender but we've not seen such a theory yet.
  4. Jun 10, 2017 #3
    Besides the cases I mentioned
  5. Jun 10, 2017 #4


    Staff: Mentor

    You're missing something. What you're missing is that there are no other models currently known that account for all the data and do not have dark matter and dark energy in them. There are speculative models that do not include dark matter and dark energy, but they only account for some of the data, not all of it.

    The cases you mention don't disconfirm GR, since we have a valid GR model that accounts for that data. So your claim here is false.
  6. Jun 10, 2017 #5


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    Staff: Mentor

    How would you characterize the discovery of the neutrino, or the planet Neptune? Both were predicted because it was more plausible that they existed and explained the discrepancy between theory and observation than that the theory was wrong.
  7. Jun 10, 2017 #6

    Vanadium 50

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    I'm sorry - where in the Einstein Field Equations does it say "all matter must be luminous"? I'm having a hard time finding it.
  8. Jun 11, 2017 #7
    Mass density of the universe is a parameter of our GR models. The "cosmological constant" is a parameter of the same models. Neither is known a priori, so both need to be established by experiment. That called is doing science, not fudging.
  9. Jun 11, 2017 #8


    Staff: Mentor

    Yes and because it kept getting fine tuned some felt the theory was getting fudged which isnt the case since every theory has some constants that need to be established in order for it to be testable and make predictions.

  10. Jun 17, 2017 #9
    Exactly what I told the judge after running over the dog:cry:
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