5 ms·

I have a question: Just over 20 years ago when the accepted view was that the expansion of the universe was slowing down, would you have backed that position wi

I have a question: Just over 20 years ago when the accepted view was that the expansion of the universe was slowing down, would you have backed that position with as much certainty as you are backing this one? That the universe is a mere 13.7 billion years old? We cannot prove the absence of light in a place that is already so far away that it's light will never reach us. Do you agree? We can prove what we can observe, and from that proof we can make inferences about what we cannot observe. The entire premise of dating our universe is based on its observed rate of expansion. This was accomplished by extrapolating data from observable light and tracing it back to the so called Big Bang. I see a lot of problems with this one dimensional assumption, which to me seem really obvious. First of all, let's assume that we actually got it right this time and accurately traced light back to the Big Bang - how can anyone be sure that it was the first and only Big Bang? Pangea, the super continent, for instance - many may think of as a single place and time in history, but in fact it's more likely that many Pangea's have come and gone in various states as the planet roils on. There will likely be another in the far future. Perhaps the Big Bang was merely a "localized" event and there are Big Bangs occuring in distant places whose light will never reach us. Perhaps we have gone through many Big Bang / Big Crunch cycles. We simply cannot prove it one way or the other, and so to take a strong position on this would be unscientific. More food for thought - imagine that the universe has already been through a near infinite number of Big Bang / Big Crunch cycles, it begs the question, do we reset the clock every time or do we let it run? In my opinion, currently accepted theory is akin to believing that the Earth is the center of the universe and the sun revolves around us. We were wrong about that too.

morganvachon 6y ago
> Perhaps the Big Bang was merely a "localized" event and there are Big Bangs occuring in distant places whose light will never reach us. Perhaps we have gone through many Big Bang / Big Crunch cycles. This was always my view of the state of the universe from childhood onward. The Void of space is infinite, and within that Void our universe could be one of an infinite number of other universes that we will never know about because they are so far outside our ability to observe them. Perhaps there is as as much relative distance between universes in the Void as there is between galaxies in our own universe. This concept is the only way I've ever been able to accept that our own universe has a measurable size.
- s1artibartfast 6y ago
  I don't think your childhood view holds up with contemporary views. My understanding is that 3 dimensional space, as well as time are properties of our local universe. There is no space outside the big bang and between universes if multiple exist
  - morganvachon 6y ago
    That's exactly what I have such a hard time wrapping my head around: The concept that there is not even a Void outside of the borders of our own universe, that existence itself doesn't, well, exist. The fact that "space" (as we define it) is finite just feels so wrong, so impossible.
    - s1artibartfast 6y ago
      To be frank, I totally agree. I don't think our brains can comprehend what existence would mean without 3 dimensions and time.
outworlder 6y ago
> Just over 20 years ago when the accepted view was that the expansion of the universe was slowing down Was it ever a mainstream view? I thought it was just a conjecture, leading to the 'big crush', and was disproven long ago, way more than 2 decades ago. > The entire premise of dating our universe is based on its observed rate of expansion Also there's the cosmic microwave background radiation. We have mapped it, and this has also allowed us to corroborate when the universe has formed, what temperature it had, and when large scale structures appeared. There's probably other sources that allows us to estimate the age of the universe. > how can anyone be sure that it was the first and only Big Bang? We can't. But it is an irrelevant conjecture outside of philosophy, we can't observe anything before the big bang. > but in fact it's more likely that many Pangea's have come and gone in various states as the planet roils on Sure, but that's a planet. We can't extrapolate much from that and apply to the universe at large. > Perhaps the Big Bang was merely a "localized" event and there are Big Bangs occuring in distant places whose light will never reach us Unobservable, therefore unfalsifiable, therefore unscientific. Philosophy again. > imagine that the universe has already been through a near infinite number of Big Bang / Big Crunch cycles Unless the rate of expansion starts to slow down or we have indication that it will ever reverse, there's no big crunch. The rate of expansion is increasing > currently accepted theory is akin to believing that the Earth is the center of the universe and the sun revolves around us Not really. You are dismissing generations of people dedicated to the study of these things. We have a pretty good idea of what's going on based on the scientific method, not conjectures from single individuals. There are things that we don't know yet. On a macroscopic scale, dark matter. Things don't really behave as they should based on observations, so this is why we have dark matter as a hypothesis. There could be another mechanism, research is ongoing. But as far as the macro universe goes, that's the major thing we don't understand yet. Most discoveries will likely come from a better understanding of the 'building blocks', of which quantum physics is at the forefront. There's probably much more we don't know yet. But the age of the universe, as we observe it, is not among them.
- HideousKojima 6y ago
  >Unless the rate of expansion starts to slow down or we have indication that it will ever reverse, there's no big crunch. The rate of expansion is increasing Unless space wraps around like a globe and we'll all meet at the "south pole" (with the big bang being the "north pole") or something to that effect. Which is itself wild, unfalsifiable conjecture, but there are other ways for a Big Crunch to happen other than the expansion of space slowing down or reversing
s1artibartfast 6y ago
I think you are generally critiquing assumptions that most astrophysicists are not making. Most Theorists would not claim with confidence that the big bang was the first or only one, or that future big bangs are not possible. I think your criticism is more valid for the way the history of the universe is portrayed in news articles and high school text books. The term "multiverse" is used to describe the collection of multiple universes.Some have speculated that time has no direction in the multiverse and that time in each universe may be different. If our universe is cyclic, it makes sense to reset the clock because it may have run in a different direction last time or next time.
memetomancer 6y ago
The problem here is that you are taking a simplified layman's description, making naive assumptions about it and then brazenly dismissing the whole of contemporary cosmology as if you have profound insights that went completely over the heads of some seriously smart physicists. You then make an analogy about "Pangaea" as if you alone are the brilliant shining light of reason, but if you took just a small amount of time to read even Wikipedia you would find, for example, that several super-continents have formed and broken apart over the history of the Earth. The very first section of the Wikipedia article on Supercontinents lists eleven of them! [https://en.wikipedia.org/wiki/Supercontinent#Supercontinents_throughout_geologic_history https://en.wikipedia.org/wiki/Supercontinent#Supercontinents...] I for one see a lot of problems with your one dimensional analysis and obvious lack of awareness on these topics. In my opinion, your currently insufficient knowledge is akin to believing that the Earth is flat because you can't personally see curvature on the horizon. Seriously though, I recommend you take the time to read about 'the entire premise of dating our universe', all the many decades of development, criticisms, refinements and confirmations of the current best theory. You'll find that it's an amazing subject, that all of your concerns have been poured over for the past century in great detail, that many brilliant people have worked out fantastically brilliant methods for figuring this out... and then finally, maybe, you'll be ready to read about the various cyclic cosmological models.
- banmeagaindan2 6y ago
  I get where you're coming from but there is a general frustration out there about physics that a lot of nerds share. We need kicks as well as truth or the heart won't be in it. People invest a lot of energy into something if they feel they are involved with the general effort because it gives meaning and we enjoy that. Our lay ideas will be incorrect - but the urge to ask questions being stifled by a existing body of understanding we don't understand makes us apathetic and prone to leveling. Somebody like Graham Hancock is actually delivering more people to the pipeline of scientific understanding than Richard Dawkins. We don't want to hear it but it's true. Similar things are true of WebMD and doctors, Elon Musk and space research. All the time the domain experts are shooting themselves in the head because the true opposition isn't a cruder wrong idea - it's apathy. Creationists at least give a shit about what version of events took place, the population that doesn't care is much larger. There is no critical mass of creationists that is going to undermine scientific research but the universities being defunded by an apathetic public turning hostile because they believe we're a waste of dollars - that is only a matter of time. Science and expertise are an ecology - the people on the edge only exist because of a bigger enterprise capable of providing support. So it's not great that the stories the general public and scientists tell themselves are starting to sound like a protagonist antagonist relationship.
luhn 6y ago
This is just pedantry. Don't get me wrong, these are interesting questions, questions that should be asked and should be thought about, even if the answers are likely unknowable. But taking issue with the age of the universe because we don't know what existed before isn't useful. Age is a relative thing. I say I'm xx years old based on the date of my birth. But I existed as a fetus before then. I existed as an ovum before that. I existed as stardust for billions of years before that. Perhaps I can mull over what it means to exist, and when "me" came to be, but when I have to enter my age while filling out some form I'm not going to write a philosophy essay. For practical purposes I am xx years old, and for practical purposes the universe is 13.7 billion years old.

morganvachon 6y ago

> Perhaps the Big Bang was merely a "localized" event and there are Big Bangs occuring in distant places whose light will never reach us. Perhaps we have gone through many Big Bang / Big Crunch cycles. This was always my view of the state of the universe from childhood onward. The Void of space is infinite, and within that Void our universe could be one of an infinite number of other universes that we will never know about because they are so far outside our ability to observe them. Perhaps there is as as much relative distance between universes in the Void as there is between galaxies in our own universe. This concept is the only way I've ever been able to accept that our own universe has a measurable size.

s1artibartfast 6y ago
I don't think your childhood view holds up with contemporary views. My understanding is that 3 dimensional space, as well as time are properties of our local universe. There is no space outside the big bang and between universes if multiple exist
- morganvachon 6y ago
  That's exactly what I have such a hard time wrapping my head around: The concept that there is not even a Void outside of the borders of our own universe, that existence itself doesn't, well, exist. The fact that "space" (as we define it) is finite just feels so wrong, so impossible.
  - s1artibartfast 6y ago
    To be frank, I totally agree. I don't think our brains can comprehend what existence would mean without 3 dimensions and time.

outworlder 6y ago

> Just over 20 years ago when the accepted view was that the expansion of the universe was slowing down Was it ever a mainstream view? I thought it was just a conjecture, leading to the 'big crush', and was disproven long ago, way more than 2 decades ago. > The entire premise of dating our universe is based on its observed rate of expansion Also there's the cosmic microwave background radiation. We have mapped it, and this has also allowed us to corroborate when the universe has formed, what temperature it had, and when large scale structures appeared. There's probably other sources that allows us to estimate the age of the universe. > how can anyone be sure that it was the first and only Big Bang? We can't. But it is an irrelevant conjecture outside of philosophy, we can't observe anything before the big bang. > but in fact it's more likely that many Pangea's have come and gone in various states as the planet roils on Sure, but that's a planet. We can't extrapolate much from that and apply to the universe at large. > Perhaps the Big Bang was merely a "localized" event and there are Big Bangs occuring in distant places whose light will never reach us Unobservable, therefore unfalsifiable, therefore unscientific. Philosophy again. > imagine that the universe has already been through a near infinite number of Big Bang / Big Crunch cycles Unless the rate of expansion starts to slow down or we have indication that it will ever reverse, there's no big crunch. The rate of expansion is increasing > currently accepted theory is akin to believing that the Earth is the center of the universe and the sun revolves around us Not really. You are dismissing generations of people dedicated to the study of these things. We have a pretty good idea of what's going on based on the scientific method, not conjectures from single individuals. There are things that we don't know yet. On a macroscopic scale, dark matter. Things don't really behave as they should based on observations, so this is why we have dark matter as a hypothesis. There could be another mechanism, research is ongoing. But as far as the macro universe goes, that's the major thing we don't understand yet. Most discoveries will likely come from a better understanding of the 'building blocks', of which quantum physics is at the forefront. There's probably much more we don't know yet. But the age of the universe, as we observe it, is not among them.

HideousKojima 6y ago
>Unless the rate of expansion starts to slow down or we have indication that it will ever reverse, there's no big crunch. The rate of expansion is increasing Unless space wraps around like a globe and we'll all meet at the "south pole" (with the big bang being the "north pole") or something to that effect. Which is itself wild, unfalsifiable conjecture, but there are other ways for a Big Crunch to happen other than the expansion of space slowing down or reversing

s1artibartfast 6y ago

I think you are generally critiquing assumptions that most astrophysicists are not making. Most Theorists would not claim with confidence that the big bang was the first or only one, or that future big bangs are not possible. I think your criticism is more valid for the way the history of the universe is portrayed in news articles and high school text books. The term "multiverse" is used to describe the collection of multiple universes.Some have speculated that time has no direction in the multiverse and that time in each universe may be different. If our universe is cyclic, it makes sense to reset the clock because it may have run in a different direction last time or next time.

memetomancer 6y ago

The problem here is that you are taking a simplified layman's description, making naive assumptions about it and then brazenly dismissing the whole of contemporary cosmology as if you have profound insights that went completely over the heads of some seriously smart physicists. You then make an analogy about "Pangaea" as if you alone are the brilliant shining light of reason, but if you took just a small amount of time to read even Wikipedia you would find, for example, that several super-continents have formed and broken apart over the history of the Earth. The very first section of the Wikipedia article on Supercontinents lists eleven of them! [https://en.wikipedia.org/wiki/Supercontinent#Supercontinents_throughout_geologic_history https://en.wikipedia.org/wiki/Supercontinent#Supercontinents...] I for one see a lot of problems with your one dimensional analysis and obvious lack of awareness on these topics. In my opinion, your currently insufficient knowledge is akin to believing that the Earth is flat because you can't personally see curvature on the horizon. Seriously though, I recommend you take the time to read about 'the entire premise of dating our universe', all the many decades of development, criticisms, refinements and confirmations of the current best theory. You'll find that it's an amazing subject, that all of your concerns have been poured over for the past century in great detail, that many brilliant people have worked out fantastically brilliant methods for figuring this out... and then finally, maybe, you'll be ready to read about the various cyclic cosmological models.

banmeagaindan2 6y ago
I get where you're coming from but there is a general frustration out there about physics that a lot of nerds share. We need kicks as well as truth or the heart won't be in it. People invest a lot of energy into something if they feel they are involved with the general effort because it gives meaning and we enjoy that. Our lay ideas will be incorrect - but the urge to ask questions being stifled by a existing body of understanding we don't understand makes us apathetic and prone to leveling. Somebody like Graham Hancock is actually delivering more people to the pipeline of scientific understanding than Richard Dawkins. We don't want to hear it but it's true. Similar things are true of WebMD and doctors, Elon Musk and space research. All the time the domain experts are shooting themselves in the head because the true opposition isn't a cruder wrong idea - it's apathy. Creationists at least give a shit about what version of events took place, the population that doesn't care is much larger. There is no critical mass of creationists that is going to undermine scientific research but the universities being defunded by an apathetic public turning hostile because they believe we're a waste of dollars - that is only a matter of time. Science and expertise are an ecology - the people on the edge only exist because of a bigger enterprise capable of providing support. So it's not great that the stories the general public and scientists tell themselves are starting to sound like a protagonist antagonist relationship.

luhn 6y ago

This is just pedantry. Don't get me wrong, these are interesting questions, questions that should be asked and should be thought about, even if the answers are likely unknowable. But taking issue with the age of the universe because we don't know what existed before isn't useful. Age is a relative thing. I say I'm xx years old based on the date of my birth. But I existed as a fetus before then. I existed as an ovum before that. I existed as stardust for billions of years before that. Perhaps I can mull over what it means to exist, and when "me" came to be, but when I have to enter my age while filling out some form I'm not going to write a philosophy essay. For practical purposes I am xx years old, and for practical purposes the universe is 13.7 billion years old.