When did time begin?

  1. Does this question have an answer? Does the beginning of time coincide with the Big Bang? Is it appropriate to ask what happened before the Big Bang?

    I have read that the events prior to BB do not influence those after it. Does it mean that nothing happened before the BB? Or does it mean that events did occur but that they are useless for the discussions about our universe? If yes, what happened before the BB? Or does it mean that human mind cannot comprehend what happened before BB?

    I am new to this forum. Sorry if I am being too naive or if I have not worded my questions properly but I am curious to understand this. Could you provide links where this topic is discussed? Thanks in advance.
  2. jcsd
  3. Oh Yes! Time began at 2:30 p.m exactly 222222543344 years back ...

    Just Joking.


    See time is a man-made concept as far as my view is concerned.After analysing science since 10 years , I have come to this conclusion.Time is something that we seek for when we want to remember the past ,present and the future.

    I will post more in this same post.
  4. mathman

    mathman 6,748
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    To answer HMS: Current theory is able to describe what happened after the big bang. So far how the big bang came about and whether there is any meaning to "before" the big bang is unknown and perhaps unknowable. There is lots of speculation, but it is just that.
  5. saltydog

    saltydog 1,581
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    When I look outside of my window I see very much a non-linear world complete with all the trappings we normally associate with non-linearity: sensitive dependence, bifurcation, chaos, and catastrophe. The last one is particularly interesting. Many phenomena in nature are not continuous but rather exhibit abruptness, discontinuity, and qualitative change. This is most easily explained in terms of "the straw that breaks the camel's back: The system flows smoothly as a parameter is changed, but then at some point, it abruptly changes. An avalanche, an extinction, a stock market crash, many more examples. We say the system exhibits a "bifurcation".

    Imagine pushing a vase along the top of a desk. You push it, it moves a little. Push some more, it move some more. Eventually at the edge of the desk, you need push it ever so little and it's state changes from a nice vase to a shattered one on the floor: Two qualitatively different states separated by a "bifurcation point", the edge of the desk and traversed by a trajectory from desk to floor. That process, passing through the bifurcation point to another state is called "catastrophe".

    Not just the vase, but so much of the world is like this. It leads me to suspect that the Universe originated likewise as a catastrophe: A pre-existence, somehow pushed past it bifurcation point. The trajectory we follow, from pre-existence to final state, like the vase, is exhibited in that which we call time.
  6. Phobos

    Phobos 1,982
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    Welcome to Physics Forums, HMS!
    Obviously you asked a simple, yet confusing question. :smile:

    The mainstream theory is that Time, as we know it, started with the Big Bang. So, in that sense, "before" the Big Bang has no meaning. (Stephen Hawking posed a similar question...'what is north of the north pole?')

    But, perhaps the universe is even more complex then that. There are many scientific speculations/hypotheses about what caused the Big Bang (suggesting a timeline "before" the Big Bang in some form). Unfortunately, that information may not accessible to us, so we're left to speculate.

    String Theory (M-Theory) provides one example of a popular scientific attempt to explain the cause of the Big Bang. There are others.

    Right now it seems that there is no known influence. If that is true, and there was something "before", then we may never learn about it. The universe was essentially rebooted. Perhaps there was no 'before' at all. But there is some research going on to try & detect any such influence (e.g., distribution of matter & energy in the early universe).

    No worries. People of all levels who are interested in science-based discussions are welcome here.
  7. Phobos

    Phobos 1,982
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    Seems to be a self-contradictory statement (if time does not exist, then there is no past/present/future). Also seems to contradict the evidence that time can change based on its interaction with space (Time Dilation).

    But I'd prefer to keep a "Does Time Exist" debate in a separate topic so as not to get off-track on HMS's questions.
  8. Why would you presume time had a beginning?
    Really - I'm interested to know your reasoning, I'm not being facetious.
  9. How was the Universe created? When did it begin?

    Conventional wisdom has concluded the Universe must have come from somewhere, and the idea that it was ushered into being by some primordial nascent event appeals seductively to human intuition. The very process of thought is governed by the rules cause and effect, so scholars instinctively presume that an instance of "creation" must explain the physical presence of the cosmos.

    The existence of ‘Nothing’ ostensibly requires no justification, so most popular theories of Universal origin begin with a primal void. At the beginning of time a transformation must have taken place and the material manifestation of the cosmos resulted. But is the phenomenon of "being" the result of a process. Is it the product of cause and effect?

    How do you explain the existence of the Universe?

    Contemporary cosmologists espouse a Theory of Singularity - or Big Bang - which envisions a Universe cast from the bowels of a spontaneous cosmic eruption. Most organized religions believe an omnipotent deity gave birth to the infinite cosmos. But any premise of "creation" would require the pre-existence of a spawning force - the very presence of which would violate the original contention that nothing existed. And if all which exists was created, then whatever sired the Universe must, too, have been created by some predecessor which, in turn, must have been predated by a limitless procession of ancestry. The endless cycle of chicken-and-the-egg redundancy which results from any cause and effect approach to the enigma of existence implies no logical beginning.

    Supernatural versions of creation sidestep the issue of redundancy with the assertion that whatever created the Universe was not subject to the laws of nature and could freely breach the rules of reality. Of course, when the laws of nature are discarded anything is possible, even the absurd. To claim exemption from the laws of nature is to refute the validity of every canon of rational argument.

    The process of change is always explained in terms of cause and effect - action and reaction. Conditions or states of being change during the process of cause and effect. But existence is not a state of being, it is the phenomenon of being, itself. Before something can change, before something can act or be acted upon it must first exist. And if being is required in order for change to occur then cause and effect is a function of existence. This is, of course, the antithesis of the premise that existence is a function of cause and effect - the product of "creation".

    Theory of Reciprocity
  10. It began at all points in space.
  11. God might be recognized as the logic that maintains the logical consistency of all facts. This idea is conveyed by scientist whey they say things like, "God does not play dice with the universe". As such you are asking how God created the universe, and you suggest that cause and effect preclude a beginning of time. However, logic does allow for an effect without a cause. For a conclusion can be true when the premise is false. Thus the universe could have come from nothing. And the fact that it consistently continues to exist proves that there is a Logical Consistency that is responsible for its existence and maintains its structure.

    Inflation assumes that the universe expanded very rapidly from a singularity. Now if it is primarily the first nature of spacetime to expand, then the more spacetime expands, the faster the whole thing grows. So the universe as a whole grows at an exponential rate. This also implies that it started from a singularity in the infinite past since zero (or the singularity) is equal to the number to the power of negative infinity. This original near singularity that consisted of only one very slowly growing manifold of reality is the only unique thing existing from eternity past. As the only existing thing, it represent truth distinquish from false which is non-existence. This could also fulfill the expectation of a creative force/being/premise responsible for the creation of the universe, existing from everlasting to everlasting, who maintains and uphold the integrity of the truth.
  12. turbo

    turbo 7,063
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    It is permissable and proper to ask "when did time begin" and "how did time begin" and even "why did time begin". If all the answers involve the argument "because God did it" we have left the realm of science and need go no further. We are firmly in the realm of faith and religion and have no means by which to falsify those assertions (non-falsifiable assertions are not scientifically viable concepts).
  13. Chronos

    Chronos 10,348
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  14. Thank you all for those wonderful responses and references. It will take some time for me to go through and understand these, but this discussion has put things in perspective for further reading.

    Not having read much on physics and astronomy, I could not think that time could have existed without a beginning. But now, I need to stretch my imagination to understand that time might have existed forever.

    Since I am more at ease with computers than with abstract physics concepts, this statement makes a lot of sense to me in realising the futility of trying to understand events "before" BB.
  15. saltydog

    saltydog 1,581
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    Thanks Chronos. I found these two statements interesting:

    What is it that breathes fire into the equations, and makes a universe for them to govern?

    Why does the universe bother to exist?

    I know, that's for the Philosophy forum. They've probably already addressed them both.
  16. Supernatural versions of creation sidestep the issue of redundancy with the assertion that whatever created the Universe was not subject to the laws of nature and could freely breach the rules of reality. Of course, when the laws of nature are discarded anything is possible, even the absurd. To claim exemption from the laws of nature is to refute the validity of every canon of rational argument.
  17. Phobos

    Phobos 1,982
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    That is from the mainstream scientific theory.

    If you want to discuss a personal theory, please start a new topic (you can link to it from this one if you want) and we can discuss it in the Theory Development forum.

  18. lby

    lby 3

    I think--
    our time starts long after the time the universe outside our universe starts.
    we don't know the answer ,but "man" in the outside universe may know.
  19. Phobos

    Phobos 1,982
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    what outside universe?
  20. Things would be much easier if time didn't even begin at all.
  21. Isn't there a theory that claims the universe has been crunching and banging for all eternity, with time being a circular? There isn't a beginning point to a loop, and perhap time is like this as well.

    I for one am particularly fond of time. Without it I just don't know where I'd be! :smile: :smile:
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