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The ultimate demise of the universe

  1. Mar 30, 2012 #1
    As the universe started its creation with a big bang nearly about 13.7 billion years ago. The universe consists of trillions of galaxies receding from each other with the expansion of the universe. From the study of general relativity, the universe must have an end. The two possiblities of end depend upon the density of the universe. If the density of the energy and matter is less than a certain value called critical density the universe after expanding for some time will come to contract its initial state. The end is called big crunch and the universe is closed. But if the density of the universe will be greater than the critical density, the universe will be expanding forever untill its temperature comes to freeze. This end is known as big chill and the universe is open. General relativity fails to explain the ultimate end of the universe.

    Today's mordern theory is the M-theory and i think the only reason to know the end of this universe is known first how universe was created. According to concept of M-theory. The universe came to existance with the collusion of two multidimensional branes (branes are the multidimensional planes). There energy of collusion created the matter and energy of this universe. Understanding this very sensitivily, when the two branes collide with each other it is obvious that after the collusion the branes move apart from each other and allowed this universe to expand freely without any disturbance of their density. Presently, the universe is expanding due to the spreading of the two branes from each other and minimizing the effect of their density on this universe. The decreasing effect of the density of two branes increases the expansion energy of this universe. Physicist called this dark energy. The reason of increasing dark energy is due to spreading of branes from eachother.

    Now when the two branes can come back again for collusion as it was at the time of big bang when they will come towards each other the effect of their density on this universe as a bubble will slow down its expansion and will make it to contract. The space of this universe will contract with all matter and energy and thus finally when the branes will again collide the universe contracts to zero volume and thats singularity. Thus this makes the universe cyclic.

    I hope this makes us to understand the ultimate demise of this universe through the study of this new modal from M-theory. Thankyou!

    Sharik khursheed,
    Researcher, American physical society.
  2. jcsd
  3. Mar 30, 2012 #2


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    And there's the case where the universe is at critical density and is globally flat; this geometry too leads to heat death. But general relativity doesn't fail to explain the ultimate fate of the universe, any more than modern meteorology fails to explain the weather a month from now. If we knew precisely the current state of the universe (its density), we would be able to use general relativity to extrapolate its fate. It's not a failing of the theory, but a matter of our incomplete knowledge of the global curvature of the universe.

    That's not so much a prediction of M-theory as it is of braneworld models that are based on M-theory, like ekpyrosis. But, if I wish, I can base a braneworld model on M-theory that has no such collision.
    The mere separation of branes along an extra dimension does not by itself impart an accelerated expansion on either of the branes. You still need to introduce some sort of nonzero vacuum energy that exists along the extra dimension (for example, a scalar field with nonzero vacuum could be chosen to parameterize this distance, like the so-called radion field in ekpyrosis). Then this vacuum energy leads to a nonzero effective vacuum energy on the branes, driving the accelerated expansion. But you still need this added ingredient of positive vacuum energy, just like in good old GR.

    Yeah, but at the expense of introducing an incredibly ad hoc, fine-tuned, and grotesque scalar potential to control this behavior of the branes. It is by no means natural, and is perhaps one of the main criticisms against the cyclic models.
    Yes, it is one possibility. But M-theory is still speculation, as are the cosmologies built on it. Especially those that introduce fine-tuned degrees of freedom that are not themselves constrained or well-understood within M-theory.
  4. Mar 30, 2012 #3
    Im a bit confused as to what point you are trying to make. It seems you are simply recapping a model that was proposed more than 10 years ago. My guess is that most people here are well aware of this model. Its got a lot of press. It is simply one idea out of many. Do you have some new reference to make this model more attractive? if so please provide.
  5. Apr 9, 2012 #4
    you may remember that the modal of M-theory was put forth 10 years ago. which showed that how big bang created the universe by space and energy. But my modal describes that how the universe will come to an end in spite of M-theory modal. This was only a theoretical discussion but soon i will be giving also the mathematical to see the results more clearly.
  6. Apr 9, 2012 #5
    Can you provide proof that this is your model?
    With the small amount of information you provided nothing you said (except for stuff that was incorrect) hasn't already been modeled. There are lots of similar models for example The Steinhardt–Turok model. You need to provide far more information to distinguish this uniquely. This wasn't a discussion, it was a summary statement on your part. So when you say you'll be providing us with the mathematics 'of your model' you must be claiming to have made advancements in the mathematical framework of m-theory? Again provide proof of this please. Are you saying you have any type of meaningful understanding of colliding branes?

    Excuse me for my skepticism.

    Also, if you are indeed talking about something you are personally responsible for the development of and not just talking about well/long/widely established hypothesis this section of the forum to my knowledge doesn't allow for individual user's own theories/models/hypothesis. There used to be a sub-forum for that, although I don't think it is around anymore so not too sure on the current rule regarding that.
  7. Feb 4, 2013 #6


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    Closed, pending moderation.

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