4 ms·

The "big bang theory" just describes the evolution of the universe to what we see today from an earlier, hot and dense state. It doesn't say anything about wha

The "big bang theory" just describes the evolution of the universe to what we see today from an earlier, hot and dense state. It doesn't say anything about what went bang, how it went bang, why it went bang, what was before the bang, etc... it is a "bangless theory" according to cosmologists like Alan Guth, and the preceding is a loose quote from the first lecture in his intro to cosmology course at MIT. So yes, discovery of the CMB did prove the big bang theory. Only the universe being small, hot, and dense can explain the CMB but we still don't know what the big bang itself is or whether the universe always existed.

MangoToupe 1y ago
> whether the universe always existed. Seems a bit of a silly condition when time is part of the universe. It has tautologically always existed.
- edoceo 1y ago
  Maybe time has always existed; matter and energy are new? And the universe is just the product of time&energy (where matter and energy are interchangeable and fungible)
  - thro1 1y ago
    - but isn't the universe converting time into space ? (we don't see the speed of light as changing ?)
- hnlmorg 1y ago
  Time, as a dimension of this universe, has always existed in this universe. But that doesn’t mean that this universe has always existed (eg in the context of a multiverse).
  - MangoToupe 1y ago
    I don't understand the semantics of what you're saying. "Always" simply has no referent outside the dimension of time in this universe. Even in the context of a multiverse, if you accept such a concept as somehow "existing" outside of all possible empirical observation, time (or "always", or the past tense for that matter) has no obvious semantics. I will go so far as to say there's just as little that we can meaningfully state about the multiverse as we can about the flying spaghetti monster. But perhaps I'm just being dense.
    - hnlmorg 1y ago
      You’re getting hung up on the semantics of a word. The reality (no pun intended) is that language doesn’t really exist to define these concepts well because the concepts exist beyond our perception of reality. The argument being made about the universe is that: just because time has always been a property of this universe, it doesn’t mean that this universe has existed forever.
      - MangoToupe 1y ago
        If you chuck language out the window, you're also chucking meaning and concepts out with it. Just because you can string together the words "time has always" doesn't mean I can ever grasp what it refers to empirically, let alone objectively—what does it refer to for time to exist outside or inside of time? Language allows the construction of many contradictory statements, but this ability doesn't imply that those statements cohere with reality others can perceive or share. Perhaps if you tried using koans you'd be more effective at communicating the concepts you're reaching for. Anyway, if we're making up fun ways to think about the meaning of the universe, I strongly prefer Tegmark's mathematical universe—which conveniently doesn't rely on trying to extrapolate our perception outside the bounds of our perception. And it's far neater and more amusing than the ridiculousness of trying to find evidence of something for which by definition there can be no evidence. You might as well try and find the cause of causation! ...but, there could be time before a big bang. Maybe that's what you're trying to refer to? Maybe it's less of a big bang and more of a big yo-yo.
        1y ago
- hackingonempty 1y ago
  That's what a lot of cosmologists think but nobody really knows. It "seems a bit of a silly condition" but the Bible says the universe did not exist until God brought it into existence so a lot of people believe that must be the case.
  - nadermx 1y ago
    But then who brought god into existance?
    - amy_petrik 1y ago
      >But then who brought god into existance? Sam, Elon, Zuck, choose your favourite

MangoToupe 1y ago

> whether the universe always existed. Seems a bit of a silly condition when time is part of the universe. It has tautologically always existed.

edoceo 1y ago
Maybe time has always existed; matter and energy are new? And the universe is just the product of time&energy (where matter and energy are interchangeable and fungible)
- thro1 1y ago
  - but isn't the universe converting time into space ? (we don't see the speed of light as changing ?)
hnlmorg 1y ago
Time, as a dimension of this universe, has always existed in this universe. But that doesn’t mean that this universe has always existed (eg in the context of a multiverse).
- MangoToupe 1y ago
  I don't understand the semantics of what you're saying. "Always" simply has no referent outside the dimension of time in this universe. Even in the context of a multiverse, if you accept such a concept as somehow "existing" outside of all possible empirical observation, time (or "always", or the past tense for that matter) has no obvious semantics. I will go so far as to say there's just as little that we can meaningfully state about the multiverse as we can about the flying spaghetti monster. But perhaps I'm just being dense.
  - hnlmorg 1y ago
    You’re getting hung up on the semantics of a word. The reality (no pun intended) is that language doesn’t really exist to define these concepts well because the concepts exist beyond our perception of reality. The argument being made about the universe is that: just because time has always been a property of this universe, it doesn’t mean that this universe has existed forever.
    - MangoToupe 1y ago
      If you chuck language out the window, you're also chucking meaning and concepts out with it. Just because you can string together the words "time has always" doesn't mean I can ever grasp what it refers to empirically, let alone objectively—what does it refer to for time to exist outside or inside of time? Language allows the construction of many contradictory statements, but this ability doesn't imply that those statements cohere with reality others can perceive or share. Perhaps if you tried using koans you'd be more effective at communicating the concepts you're reaching for. Anyway, if we're making up fun ways to think about the meaning of the universe, I strongly prefer Tegmark's mathematical universe—which conveniently doesn't rely on trying to extrapolate our perception outside the bounds of our perception. And it's far neater and more amusing than the ridiculousness of trying to find evidence of something for which by definition there can be no evidence. You might as well try and find the cause of causation! ...but, there could be time before a big bang. Maybe that's what you're trying to refer to? Maybe it's less of a big bang and more of a big yo-yo.
      - 1y ago
hackingonempty 1y ago
That's what a lot of cosmologists think but nobody really knows. It "seems a bit of a silly condition" but the Bible says the universe did not exist until God brought it into existence so a lot of people believe that must be the case.
- nadermx 1y ago
  But then who brought god into existance?
  - amy_petrik 1y ago
    >But then who brought god into existance? Sam, Elon, Zuck, choose your favourite