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> The totality of all the observations we have cannot be explained in any other way than an expanding universe. Surely there are infinite other possible explan

> The totality of all the observations we have cannot be explained in any other way than an expanding universe. Surely there are infinite other possible explanations that fit the finite number of data points available to us. Probably what you meant is that the expanding universe theory is the simplest of them all and creates less problems then others.

pdonis 2y ago
> Surely there are infinite other possible explanations If you think there are others, please exhibit one. > Probably what you meant is that the expanding universe theory is the simplest of them all and creates less problems then others. There are no other theories that I'm aware of that account for all the data we have, even approximately.
- oraphalous 2y ago
  > If you think there are others, please exhibit one. If everyone like you attempts to rail road the imaginative process at the beginning of hypothesis formation, then we'll never get to the point of being able to exhibit one, should one be possible. The demand for rigour at this point in a discourse - which was pretty clearly signalled by the commenter to be offered at a stage prior to substantive hypotheis formation - just shuts down the imaginative process. It's not constructive.
  - dtgriscom 2y ago
    When a random techie comes up with a completely novel hypothesis that contradicts a broad range of theories accepted by the vast majority of practicing physicists, the proper response is not to stop and say "Hmmm. I wonder if he's right. Let's talk about it."
    - JasonSage 2y ago
      Why not? Seems perfectly normal to just talk about it. I learn things all the time by wondering if somebody else is right. Much better than just thinking everything is simply the way I think it is now. Even if you know somebody is wrong, talking about it is absolutely harmless.
      - layer8 2y ago
        The issue is that these physics threads always end up the same, with commenters having only popular-level background offering suggestions they came up in five minutes, mirroring obvious thoughts that actual physicists have of course already thought of decades ago, and in much more detail. It is really hard and quite unlikely to come up with novel ideas that haven't already been discussed and played out ad nauseum in that field.
        JasonSage 2y ago
        I’m not suggesting the techie is correct, I just don’t think the right answer is complete dismissal instead of communication. Ok, so you know it’s obviously wrong, but there’s no obligation to then go and stifle their curiosity or imagination. Just don’t say anything or let them talk to somebody who has the time and care to indulge. The original commenter I’m replying to, taken at their word, is ready to dismiss anything somebody says, regardless of merit with no further discussion, just because they think there’s “no way” that person could be right. Which is hilariously close-minded way to conduct oneself.
        layer8 2y ago
        This is fine the first few times, but after a few dozens it gets exhausting. This is also not about stifling their curiosity or imagination. It's about understanding that in a field as advanced as physics and cosmology, how incredibly unlikely it is for some layman to come up with a worthwhile idea that hasn't already be tackled. To even be able to explain why an idea is impractical or beside the point, a solid knowledge and understanding of the field is often aready necessary. Articles like from Quanta Magazine dress the topics up in language that make them seem substantially simpler, and closer to human intuition, than they actually are.
    - koolala 2y ago
      What are you busy with? Are there any particular other subjects you would want to talk about instead?
    - tqi 2y ago
      On the one hand, I agree that those people are usually wrong and generally pretty annoying. On the other hand, who cares? This is a random internet forum, not the Proceedings of the National Academy of Sciences, so maybe there is no such thing as a proper response?
    - alexey-salmin 2y ago
      Thanks, but I don't think it's a fair description of what happened here. I'm a mathematician who noticed that the statement "The totality of all the observations we have cannot be explained in any other way" is obviously false. Explaining is neither hard nor useful and it's not what science is normally concerned with. The goal is to predict new observations not to explain known ones.
  - thrance 2y ago
    No one prevents new ideas from being presented, but simply suggesting the universe does not expand without giving any arguments for this position nor trying to explain the observed red shifts, contributes exactly nothing to the discourse. This, is not constructive.
  - rachofsunshine 2y ago
    There's a difference between being closed-minded and saying "yes, we've obviously thought about this thing that you, someone with no apparent background in our field, thought of in ten seconds". And if you're an expert in any field that gets a lot of people who are interested, but not a lot of people who are experts, you hear these kinds of half-baked theories all the time, often with this exact "oh you orthodox experts just can't handle my field-disrupting free-thinking!" kind of framing. I'm a mathematician by education, and I cannot tell you how many people insist on things like 0.999... < 1 without an understanding of (a) what the left side of that expression even means, (b) what a real number is, or (c) what basic properties the real numbers have. Going "no, you're wrong, and it would take me a couple of full lectures to explain why but trust me we're pretty sure about this" is a reasonable answer to that, provided that you have indeed established that to your own satisfaction, at least.
    - eszed 2y ago
      Whoa! What? Not a mathematician in any way (in case that isn't obvious), but I'd have totally thought 0.999... asymptomatically _approaches_ 1, but never reaches it, and so is <1. Is there a short-form explanation (that I might have a chance of understanding, lol) of why that's incorrect? I'd love to have my mind blown.
      - techno_tsar 2y ago
        There's a rigorous proof on Wikipedia, but there's simpler ways to show it. For example, we know that 1/3 = 0.333... 3 * 1/3 = 3 * 0.333... 1 = 0.999... You can also do it with subtraction. For example, 1 - 0.999... = x. Assuming x is greater than 0, then it should evaluate to 0.000...1. But we can't have the digit 1 after an infinite number of zeros. If there truly were a "1" after infinite zeros, it implies reaching the end of infinity, which is a logical contradiction. So x can't be greater than 0.
      - justsomeshmuck 2y ago
        1/3 + 1/3 + 1/3 = 3/3 = 1 .3… + .3… + .3… = .9… = 1 https://en.m.wikipedia.org/wiki/0.999 https://en.m.wikipedia.org/wiki/0.999...
  - ants_everywhere 2y ago
    > at the beginning of hypothesis formation But the expansion of the universe has been thoroughly studied for over a century. We're past the brainstorming phase. I generally think people should brainstorm to generate ideas and then filter them down. And it's true that filtering too early can significantly decrease the quality of ideas. And it's also true that in a place like Hacker News there will be smart people from all sorts of backgrounds getting to experience the joy of exploring a new topic that they're not fully up to speed on yet. The risk though is that somebody who thoroughly understands the field is reading your comment. So for that reason I think it's a good practice to always be aware that technical fields we're not expert in are usually more subtle than we initially think.
  - xwolfi 2y ago
    BS, nobody has to listen to your imaginative process. Imagine away, build something that conforms with the data, then show it ! For now, we dont know any other way to explain than to say it expands, except maybe imaginative fantasies from amateurs on Hackernews, but does it count ?
    - koolala 2y ago
      What if it expanded from anti-mass? Couldn't we form testable hypotheses from that? I looked it up on the Wikipedia page for Exotic Matter and there isn't much exploration or tested theories on it.
      - BlarfMcFlarf 2y ago
        You certainly could try. But don’t expect experts in the field to bother to do any of the legwork for you, and that includes learning about all the evidence that your model has to account for to be remotely as good as our existing ones.
        koolala 2y ago
        It's exciting to me just even being able to ask experts if anyone has tried before! progress = legwork + new direction!
  - snowwrestler 2y ago
    It seems pretty silly to think that we are collectively “at the beginning of hypothesis formation” about the structure of the universe today, in 2024.
- quotemstr 2y ago
  > If you think there are others, please exhibit one. Benevolent giant omnitech space squid manipulate EM radiation incident on the solar system to fool our primitive meat brains and sand computers into thinking we're alone in the universe so we don't go venture our and embarrass our local cluster. See? There exist infinite theories explaining any set of data points. Parsimony, choosing the simplest theory that explains the facts, is what lets us make progress understanding and predicting the world around us. It's hard to predict space squid.
  - MaxikCZ 2y ago
    Thats like saying cars run because they want to, and only make us perfect the engine, and processes that happen inside it, to fool us into thinking we have a say in whether a car will run. Sure, it is a hypothesis, but thanks to the Scientific Method the majority of people with knowledge in the field knows its most likely BS. Going the same "it can be for ANY reason, guys!" in any field, will not get you much far, regardless if you feel justified in your ignorance or not.
    - shiroiushi 2y ago
      The funny thing is, though, you can easily dismiss a crazy idea like "omnitech space squid", but a majority of humans on Earth today have entire worldviews based on equally silly ideas, and it's considered wrong somehow to mock these belief systems. In fact, many scientists subscribe to these silly belief systems, but then get offended if you make up an equally silly idea about space squid or flying spaghetti monsters.
    - quotemstr 2y ago
      > it can be for ANY reason, guys!" in any field, will not get you much far, regardless if you feel justified in your ignorance or not. Of course not. The point is logical correctness: as a matter of logic, infinite theories explain any set of facts. Are almost all of these theories useless? Of course. We should restrict our attention to plausible theories. But how do we decide which theories are plausible? We look for the ones that require the fewest assumptions.
    - 2y ago
- deleted 2y ago
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- alexey-salmin 2y ago
  > If you think there are others, please exhibit one. I could easily do that (god tinkering with our measurements? we live in a simulation?) but explanations by themselves are worthless. Any set of facts can be "explained" but it doesn't really help. The science is concerned with theories that don't just explain known facts and measurements but also predict new ones. These are also known as falsifiable theories because a theory is falsifiable IFF it predicts at least one new observation that can be actually made and tested. Now even these can obviously be constructed ad infinitum. For your question of alternatives to expansion, take a theory from the same field (e.g. tired light), then take facts it doesn't fit and make specific ad-hoc carve-outs for these facts in the theory. Sure it makes it ugly and complex but it remains a scientific falsifiable theory. Furthermore this exact things happens very often in the scientific community because theories don't fall immediately when the first contradiction is found. They only fall when a better theory appears to supersede them and until then they just develop a "protective belt of ad-hoc assumptions" as Lakatos called it. No need to mention that the same thing will happen to the "better theory" in due time. I write all of this not because I have a good cosmological theory sitting in my closet but rather because your statement "The totality of all the observations we have cannot be explained in any other way than an expanding universe" is outright false. As I show above it not only can be explained in an infinite number of ways, but you can also construct and infinite number of scientific theories that fit the totality of observations. Because this "totality" is alas finite. This reminds me of my school math teacher who once told me that "the sequence 1, 2, 6, 24, 120, 720 cannot be explained other way than by n!". A pity I didn't know about Lagrange Polynomials at that age and had to spend the whole evening to construct a fitting polynomial by hand.
  - fpoling 2y ago
    A big problem of the modern cosmology is not only that we have observations that do not fit models but that we do not know if the observed discrepancies are the real problems with the models or are artifacts of calculations. For example, to simulate a galaxy one should use a model based on General Relativity. But mathematics behind GR is too complex to allow simulations on the scale of the galaxy even with all that modern computation power. So instead of GR the calculations use Newtonian mechanics with minimal corrections for the light speed limit. Plus there are a lot of other simplifications like replacing star systems with hard balls that reflects when hit each other with no notion of matter transfer or ejection in the process. Then we see that the simulation does not fit data. A typical explanation that is used is that of dark matter hypothesis. But this is unjustified. We have no proof that numerical simplifications are mathematically valid and do not lead to a big error on a galactic scale. Moreover, there were recent papers that tried to account at least for some effect of General Relativity. Apparently it was enough to explain at least some effects previously attributed to the dark matter. So it can be that the dark matter is just an artifact of inaccurate simulations.
- raattgift 2y ago
  There are a fair number of extensions to GR that can reproduce the standard cosmology, typically avoiding or recasting DM, DE, or both. Examples include generalized teleparallel gravity and Cotton gravity. In such theories, any solution of the EFEs are solutions of the (sometimes very different) field equations of these families of theories, although the field content may have a somewhat different physical interpretation from GR. However, generically, these extensions tend to have an under-determination problem frustrating attempts to arrive at a unique spacetime for a given distribution of matter or a unique distribution of matter which can exist in a given spacetime (or both problems). That makes them less attractive than GR, or even possibly outright unsuitable bases for initial-values formulations (and thus are unlikely to overthrow numerical relativity soon).
- khafra 2y ago
  > > Surely there are infinite other possible explanations that fit the finite number of data points available > If you think there are others, please exhibit one. One easy process for generating infinite explanations that fit a finite number of data points is taking the simplest theory you have, and adding extra rules that don't affect any of the existing data points. e.g., if the standard explanation for observations like red shift, CMB, the abundance of light elements, etc. is H² = (ȧ/a)² = (8πG/3)ρ - kc²/a² + Λc²/3, One alternate explanation that fits all the data is H² = (ȧ/a)² = (8πG/3)ρ - kc²/a² + Λc²/3 + T, where T is the number of teacups in the asteroid belt. No observation has yet been made which would falsify this theory, and it fits the data just as well as the standard explanation. We reject it on the grounds of parsimony, not falsification.
- krisoft 2y ago
  > If you think there are others, please exhibit one. One can construct such alternative theories quite easily: Everything is exactly as the "expanding universe theory" predicts except in a phone booth sized volume in a specific part of space 10 lightyears away from Earth where the universe is contracting. Does not explain anything, and it is not testable in any practical sense. So it is not a good theory in any way, but it is a different one and it matches all the current observations.

pdonis 2y ago

> Surely there are infinite other possible explanations If you think there are others, please exhibit one. > Probably what you meant is that the expanding universe theory is the simplest of them all and creates less problems then others. There are no other theories that I'm aware of that account for all the data we have, even approximately.

oraphalous 2y ago
> If you think there are others, please exhibit one. If everyone like you attempts to rail road the imaginative process at the beginning of hypothesis formation, then we'll never get to the point of being able to exhibit one, should one be possible. The demand for rigour at this point in a discourse - which was pretty clearly signalled by the commenter to be offered at a stage prior to substantive hypotheis formation - just shuts down the imaginative process. It's not constructive.
- dtgriscom 2y ago
  When a random techie comes up with a completely novel hypothesis that contradicts a broad range of theories accepted by the vast majority of practicing physicists, the proper response is not to stop and say "Hmmm. I wonder if he's right. Let's talk about it."
  - JasonSage 2y ago
    Why not? Seems perfectly normal to just talk about it. I learn things all the time by wondering if somebody else is right. Much better than just thinking everything is simply the way I think it is now. Even if you know somebody is wrong, talking about it is absolutely harmless.
    - layer8 2y ago
      The issue is that these physics threads always end up the same, with commenters having only popular-level background offering suggestions they came up in five minutes, mirroring obvious thoughts that actual physicists have of course already thought of decades ago, and in much more detail. It is really hard and quite unlikely to come up with novel ideas that haven't already been discussed and played out ad nauseum in that field.
      - JasonSage 2y ago
        I’m not suggesting the techie is correct, I just don’t think the right answer is complete dismissal instead of communication. Ok, so you know it’s obviously wrong, but there’s no obligation to then go and stifle their curiosity or imagination. Just don’t say anything or let them talk to somebody who has the time and care to indulge. The original commenter I’m replying to, taken at their word, is ready to dismiss anything somebody says, regardless of merit with no further discussion, just because they think there’s “no way” that person could be right. Which is hilariously close-minded way to conduct oneself.
        layer8 2y ago
        This is fine the first few times, but after a few dozens it gets exhausting. This is also not about stifling their curiosity or imagination. It's about understanding that in a field as advanced as physics and cosmology, how incredibly unlikely it is for some layman to come up with a worthwhile idea that hasn't already be tackled. To even be able to explain why an idea is impractical or beside the point, a solid knowledge and understanding of the field is often aready necessary. Articles like from Quanta Magazine dress the topics up in language that make them seem substantially simpler, and closer to human intuition, than they actually are.
  - koolala 2y ago
    What are you busy with? Are there any particular other subjects you would want to talk about instead?
  - tqi 2y ago
    On the one hand, I agree that those people are usually wrong and generally pretty annoying. On the other hand, who cares? This is a random internet forum, not the Proceedings of the National Academy of Sciences, so maybe there is no such thing as a proper response?
  - alexey-salmin 2y ago
    Thanks, but I don't think it's a fair description of what happened here. I'm a mathematician who noticed that the statement "The totality of all the observations we have cannot be explained in any other way" is obviously false. Explaining is neither hard nor useful and it's not what science is normally concerned with. The goal is to predict new observations not to explain known ones.
- thrance 2y ago
  No one prevents new ideas from being presented, but simply suggesting the universe does not expand without giving any arguments for this position nor trying to explain the observed red shifts, contributes exactly nothing to the discourse. This, is not constructive.
- rachofsunshine 2y ago
  There's a difference between being closed-minded and saying "yes, we've obviously thought about this thing that you, someone with no apparent background in our field, thought of in ten seconds". And if you're an expert in any field that gets a lot of people who are interested, but not a lot of people who are experts, you hear these kinds of half-baked theories all the time, often with this exact "oh you orthodox experts just can't handle my field-disrupting free-thinking!" kind of framing. I'm a mathematician by education, and I cannot tell you how many people insist on things like 0.999... < 1 without an understanding of (a) what the left side of that expression even means, (b) what a real number is, or (c) what basic properties the real numbers have. Going "no, you're wrong, and it would take me a couple of full lectures to explain why but trust me we're pretty sure about this" is a reasonable answer to that, provided that you have indeed established that to your own satisfaction, at least.
  - eszed 2y ago
    Whoa! What? Not a mathematician in any way (in case that isn't obvious), but I'd have totally thought 0.999... asymptomatically _approaches_ 1, but never reaches it, and so is <1. Is there a short-form explanation (that I might have a chance of understanding, lol) of why that's incorrect? I'd love to have my mind blown.
    - techno_tsar 2y ago
      There's a rigorous proof on Wikipedia, but there's simpler ways to show it. For example, we know that 1/3 = 0.333... 3 * 1/3 = 3 * 0.333... 1 = 0.999... You can also do it with subtraction. For example, 1 - 0.999... = x. Assuming x is greater than 0, then it should evaluate to 0.000...1. But we can't have the digit 1 after an infinite number of zeros. If there truly were a "1" after infinite zeros, it implies reaching the end of infinity, which is a logical contradiction. So x can't be greater than 0.
    - justsomeshmuck 2y ago
      1/3 + 1/3 + 1/3 = 3/3 = 1 .3… + .3… + .3… = .9… = 1 https://en.m.wikipedia.org/wiki/0.999 https://en.m.wikipedia.org/wiki/0.999...
- ants_everywhere 2y ago
  > at the beginning of hypothesis formation But the expansion of the universe has been thoroughly studied for over a century. We're past the brainstorming phase. I generally think people should brainstorm to generate ideas and then filter them down. And it's true that filtering too early can significantly decrease the quality of ideas. And it's also true that in a place like Hacker News there will be smart people from all sorts of backgrounds getting to experience the joy of exploring a new topic that they're not fully up to speed on yet. The risk though is that somebody who thoroughly understands the field is reading your comment. So for that reason I think it's a good practice to always be aware that technical fields we're not expert in are usually more subtle than we initially think.
- xwolfi 2y ago
  BS, nobody has to listen to your imaginative process. Imagine away, build something that conforms with the data, then show it ! For now, we dont know any other way to explain than to say it expands, except maybe imaginative fantasies from amateurs on Hackernews, but does it count ?
  - koolala 2y ago
    What if it expanded from anti-mass? Couldn't we form testable hypotheses from that? I looked it up on the Wikipedia page for Exotic Matter and there isn't much exploration or tested theories on it.
    - BlarfMcFlarf 2y ago
      You certainly could try. But don’t expect experts in the field to bother to do any of the legwork for you, and that includes learning about all the evidence that your model has to account for to be remotely as good as our existing ones.
      - koolala 2y ago
        It's exciting to me just even being able to ask experts if anyone has tried before! progress = legwork + new direction!
- snowwrestler 2y ago
  It seems pretty silly to think that we are collectively “at the beginning of hypothesis formation” about the structure of the universe today, in 2024.
quotemstr 2y ago
> If you think there are others, please exhibit one. Benevolent giant omnitech space squid manipulate EM radiation incident on the solar system to fool our primitive meat brains and sand computers into thinking we're alone in the universe so we don't go venture our and embarrass our local cluster. See? There exist infinite theories explaining any set of data points. Parsimony, choosing the simplest theory that explains the facts, is what lets us make progress understanding and predicting the world around us. It's hard to predict space squid.
- MaxikCZ 2y ago
  Thats like saying cars run because they want to, and only make us perfect the engine, and processes that happen inside it, to fool us into thinking we have a say in whether a car will run. Sure, it is a hypothesis, but thanks to the Scientific Method the majority of people with knowledge in the field knows its most likely BS. Going the same "it can be for ANY reason, guys!" in any field, will not get you much far, regardless if you feel justified in your ignorance or not.
  - shiroiushi 2y ago
    The funny thing is, though, you can easily dismiss a crazy idea like "omnitech space squid", but a majority of humans on Earth today have entire worldviews based on equally silly ideas, and it's considered wrong somehow to mock these belief systems. In fact, many scientists subscribe to these silly belief systems, but then get offended if you make up an equally silly idea about space squid or flying spaghetti monsters.
  - quotemstr 2y ago
    > it can be for ANY reason, guys!" in any field, will not get you much far, regardless if you feel justified in your ignorance or not. Of course not. The point is logical correctness: as a matter of logic, infinite theories explain any set of facts. Are almost all of these theories useless? Of course. We should restrict our attention to plausible theories. But how do we decide which theories are plausible? We look for the ones that require the fewest assumptions.
  - 2y ago
deleted 2y ago
[deleted]
alexey-salmin 2y ago
> If you think there are others, please exhibit one. I could easily do that (god tinkering with our measurements? we live in a simulation?) but explanations by themselves are worthless. Any set of facts can be "explained" but it doesn't really help. The science is concerned with theories that don't just explain known facts and measurements but also predict new ones. These are also known as falsifiable theories because a theory is falsifiable IFF it predicts at least one new observation that can be actually made and tested. Now even these can obviously be constructed ad infinitum. For your question of alternatives to expansion, take a theory from the same field (e.g. tired light), then take facts it doesn't fit and make specific ad-hoc carve-outs for these facts in the theory. Sure it makes it ugly and complex but it remains a scientific falsifiable theory. Furthermore this exact things happens very often in the scientific community because theories don't fall immediately when the first contradiction is found. They only fall when a better theory appears to supersede them and until then they just develop a "protective belt of ad-hoc assumptions" as Lakatos called it. No need to mention that the same thing will happen to the "better theory" in due time. I write all of this not because I have a good cosmological theory sitting in my closet but rather because your statement "The totality of all the observations we have cannot be explained in any other way than an expanding universe" is outright false. As I show above it not only can be explained in an infinite number of ways, but you can also construct and infinite number of scientific theories that fit the totality of observations. Because this "totality" is alas finite. This reminds me of my school math teacher who once told me that "the sequence 1, 2, 6, 24, 120, 720 cannot be explained other way than by n!". A pity I didn't know about Lagrange Polynomials at that age and had to spend the whole evening to construct a fitting polynomial by hand.
- fpoling 2y ago
  A big problem of the modern cosmology is not only that we have observations that do not fit models but that we do not know if the observed discrepancies are the real problems with the models or are artifacts of calculations. For example, to simulate a galaxy one should use a model based on General Relativity. But mathematics behind GR is too complex to allow simulations on the scale of the galaxy even with all that modern computation power. So instead of GR the calculations use Newtonian mechanics with minimal corrections for the light speed limit. Plus there are a lot of other simplifications like replacing star systems with hard balls that reflects when hit each other with no notion of matter transfer or ejection in the process. Then we see that the simulation does not fit data. A typical explanation that is used is that of dark matter hypothesis. But this is unjustified. We have no proof that numerical simplifications are mathematically valid and do not lead to a big error on a galactic scale. Moreover, there were recent papers that tried to account at least for some effect of General Relativity. Apparently it was enough to explain at least some effects previously attributed to the dark matter. So it can be that the dark matter is just an artifact of inaccurate simulations.
raattgift 2y ago
There are a fair number of extensions to GR that can reproduce the standard cosmology, typically avoiding or recasting DM, DE, or both. Examples include generalized teleparallel gravity and Cotton gravity. In such theories, any solution of the EFEs are solutions of the (sometimes very different) field equations of these families of theories, although the field content may have a somewhat different physical interpretation from GR. However, generically, these extensions tend to have an under-determination problem frustrating attempts to arrive at a unique spacetime for a given distribution of matter or a unique distribution of matter which can exist in a given spacetime (or both problems). That makes them less attractive than GR, or even possibly outright unsuitable bases for initial-values formulations (and thus are unlikely to overthrow numerical relativity soon).
khafra 2y ago
> > Surely there are infinite other possible explanations that fit the finite number of data points available > If you think there are others, please exhibit one. One easy process for generating infinite explanations that fit a finite number of data points is taking the simplest theory you have, and adding extra rules that don't affect any of the existing data points. e.g., if the standard explanation for observations like red shift, CMB, the abundance of light elements, etc. is H² = (ȧ/a)² = (8πG/3)ρ - kc²/a² + Λc²/3, One alternate explanation that fits all the data is H² = (ȧ/a)² = (8πG/3)ρ - kc²/a² + Λc²/3 + T, where T is the number of teacups in the asteroid belt. No observation has yet been made which would falsify this theory, and it fits the data just as well as the standard explanation. We reject it on the grounds of parsimony, not falsification.
krisoft 2y ago
> If you think there are others, please exhibit one. One can construct such alternative theories quite easily: Everything is exactly as the "expanding universe theory" predicts except in a phone booth sized volume in a specific part of space 10 lightyears away from Earth where the universe is contracting. Does not explain anything, and it is not testable in any practical sense. So it is not a good theory in any way, but it is a different one and it matches all the current observations.