6 ms·

"The universe is under no obligation to make sense to you" — Neil DeGrasse Tyson IMO the most embarrassing problem in physics is people pushing non-falsifiable

by ridaj 6y ago

"The universe is under no obligation to make sense to you" — Neil DeGrasse Tyson IMO the most embarrassing problem in physics is people pushing non-falsifiable, unscientific theories (multiverse). The fact that some futzing constant needs or doesn't need to be added in order to bring a model in line with empirical observation, in comparison, is quite benign.

JimBlackwood 6y ago
What you said is very true, it doesn’t apply to the cosmological constant though. It is not so much that we need it for a model to be in line with empirical observation, it’s that empirical observation gives one value and our models predict another value. The discrepancy is big and if we can’t make our models work empirical observations, that is really embarrassing. Regarding non-falsifiable theories; there’s not a physicist that thinks theories should not be tested. A lot of work is done to make these theories testable. Unfortunately, they are often only testsble on open problems since the limit of these theories just reduces to GR for instance.
jMyles 6y ago
> IMO the most embarrassing problem in physics is people pushing non-falsifiable, unscientific theories (multiverse). Is this a not-so-subtle dig at Beacham and other experimentalists who make room for multiverse? Or do I jump to the wrong conclusion? Two questions for you: 1) Does 'falsifiable' in this context per se mean that there needs to be some particle physics experiment that can be designed to test the theory? Is there no room for theoretical physics? Is Rovelli, for example, per se barking up the wrong tree by this measure? 2) Aren't these theories reasonably falsifiable insofar as they'll eventually result in experiments designed to map out the possible domains of the space? eg, what if we build a much higher energy collider and finally find real evidence of the super-symmetry particles?
- lmm 6y ago
  > 2) Aren't these theories reasonably falsifiable insofar as they'll eventually result in experiments designed to map out the possible domains of the space? eg, what if we build a much higher energy collider and finally find real evidence of the super-symmetry particles? Would you treat not finding super-symmetry particles as falsifying those theories? AIUI those theories admit the possibility of such particles but also the possibility of such particles not existing, so they're not actually falsifiable that way.
  - l33tman 6y ago
    Most theories' predictions are not open ended. It's possible to exhaustively search the prediction space to falsify them (up to an experimental standard that you need to agree on). I'm by far not an expert on super-symmetry but from what I've seen the prediction space of the most common SUSY models is getting continuously boxed in.
  - andi999 6y ago
    I think super symmetry is almost falsified. People just cling to it because there is (almost) nothing else. If any new theory comes around without supersymmetry (but other predictions) people will jump ship.
- throwaway3699 6y ago
  Science is defined by testability. A theory that can't be tested is just pseudoscience, unlike a theory that just can't be tested right now due to technological limitations.
  - JimBlackwood 6y ago
    It would be pseudoscience if it were to be seen as or communicated as fact. It’s not. Any newly observed fact can falsify these theories. It just takes a long time. There’s still tons of open issues on General Relativity too. So far though, it seems to have passed every test. Would you call GR pseudoscience too then? Since it’ll likely never be fully verified.
    - boomboomsubban 6y ago
      > would be pseudoscience if it were to be seen as or communicated as fact. It’s not. Pseudoscience is something labelling itself as science while not adhering to scientific standards. Claiming it's a fact would be a dead giveaway though. Relativity has been experimentally tested and made accurate predictions, it is impossible for it to be "fully verified."
piokoch 6y ago
So very true. The ideas mentioned in the article does not sound appealing to me: "In this picture, the curvature of space would constantly fluctuate on extremely small scales, well beyond anything we could hope to measure" "Her model is based on the idea that extra dimensions, beyond the three of space and one of time that we witness, might be hidden out of sight." Instead of cosmological constant "novel" approaches relay on something that could not be observed, even in principle. That does not sound like a good approach. My guess is that they try to make some assumptions, figure out math around it, hope that it will somehow stick nicely, which would give hope that there is something in it. Indeed, it seems that math "likes" to describe our universe, some mathematical theories (Riemannian geometry, group theory) fit physics wonderfully. The problem is that for physics math is just a language, it is unlikely that language alone will give us answers without understanding physical phenomena itself.
lmm 6y ago
How surprised would you be if it turned out we really did live in a multiverse? Would you expect things to look different if we did? Do you think it's extremely implausible a priori? I find multiverses far more plausible than futzing constants, because the universe in general seems to be absurdly big but simple and consistent physics-wise. Smaller but more fiddly/complicated models seem much less plausible, just judging by history.
- boomboomsubban 6y ago
  How would one develop an experiment that would result in evidence we live in a multiverse? Demonstrating observable phenomena is a result of something outside this universe seems like a logical impossibility currently. Philosophically I find the idea of the multiverse probable, but making it science is a separate thing. edit poor word usage.
  - akvadrako 6y ago
    Science doesn't prove anything so it's not really relevant to the question of the demarcation line. A theory involving a multiverse can make observable predictions even if the other regions are not accessible.
    - boomboomsubban 6y ago
      >Science doesn't prove anything I should have said evidence rather than proof, my mistake. >theory involving a multiverse can make observable predictions even if the other regions are not accessible All those predictions would serve as evidence for the same theory without involving a multiverse.
      - akvadrako 6y ago
        The multiverse is not some addon that can be removed easily; it's just another prediction of the theory.
        6y ago
atoav 6y ago
I see these multiverse theories more as a philosophical idea than anything empirical. To explore the different variations of our own world can also be intersting to understand what's going on (e.g. what if $variable in the beginning of the universe would have been slightly altered). But yeah more in the world of thoughts than anything else.
DavidSJ 6y ago
If you're referring to the Everett multiverse (although the OP was not, so maybe you're not), then its status is not so different from that of the unobservable portion of our own universe. That is, if we take the simplest known cosmological model consistent with our evidence, its equations predict space and matter outside our observable universe. That cosmological model is falsifiable in that it makes other predictions besides this one, many of which can be (and have been) tested, but this specific prediction cannot be directly tested. Similarly, the equations of quantum mechanics predict multiple "worlds" (although I find this term unfortunate: the state of the "multiverse" is always just a single point in Hilbert space, and it only seems like there are multiple "worlds" when we imperfectly try to map that physical state onto the intuitive level of everyday experience). That specific prediction cannot be directly tested, but other predictions of the equations can be, and have been. There is essentially no dispute about the math. The dispute is whether to deny the reality of something which is right there in that math, akin to denying the reality of a universe beyond that which is observable.
- simiones 6y ago
  The multiverse usually refers to multiple universes each with their own big bang, existing in regular space, but outside our light cone. It is a completely unscientific theory, in the sense that there is no chance of ever proving or denying it, by its very construction. The many worlds interpretation is completely unrelated, and it doesn't suffer from this problem of being unfalsifiable even in principle. However, I would also not say that the MWI is a straightforward deduction from the laws of QM. It rejects the most visible effect of those laws (the Born rule, i.e. that they predict probabilities of classical events and not certainties) and replaces it with an infinity of "worlds". Even worse, it still doesn't explain WHY we can only "see" one such "world", while elementary particles can "see" all of them (i.e. it doesn't solve the measurement problem any more than Copenhagen interpretation). And there is also debate on how plausible it is to even define the "probability of a world", so whether MWI is actually consistent with the Born rule is somewhat in doubt.
  - DavidSJ 6y ago
    it still doesn't explain WHY we can only "see" one such "world" It's just that there's one of us in each world. The one in this world sees this one. The one in that world sees that one.
jw1224 6y ago
> IMO the most embarrassing problem in physics is people pushing non-falsifiable, unscientific theories (multiverse) The Big Bang itself is a non-falsifiable, unscientific theory. We cannot prove it happened in the way we think it might have. The Big Bang created a universe of cause and effect, yet has no cause itself. All known laws of physics fail to work in the early moments of our existence. “Give me one free miracle, and science will explain the rest” (— maybe Terrence McKenna? I can’t remember)
- simonh 6y ago
  We can literally see the big bang happening, in the form of the CMB. That's the actual light from the big bang. Just because we don't understand it's cause yet doesn't mean we won't, and doesn't mean it didn't have a cause.
  - Daho0n 6y ago
    This is a tad disingenuous IMO. We can't "literally see the big bang happening". That's is like saying we can see the explosion of a stick of dynamite that exploded inside a mine because we see a dust-cloud and hear a boom a split second later at the mine entrance. We are standing outside the mine, talking about the effect of the dynamite. We see the effect (electromagnetic radiation or "the dust-wave"), not the cause or the event itself.
    - simonh 6y ago
      I don't see how it's disingenuous, that's literally what it is. It was even predicted well in advance of measurement. If you see the flash and hear the boom, how can you credibly say that was not witnessing the event?
      - Tenoke 6y ago
        The CMB is an observation well matching what you'd expect with a Big Bang but it is not the Big Bang itself and one can make other theories to try and explain it.
simonh 6y ago
Sexy exciting SF theories like the Everett Multiverse get a lot of press, but they are sideshows when it comes to bread and butter physics. No actual enquiries into physics or our understanding of the universe are being obstructed by it, so I don't really see how it's a problem.
- GoblinSlayer 6y ago
  Well, your life is not affected whether Earth is flat or not either.
Tenoke 6y ago
If you had added the right constant or few you could've proven geocentrism in the 1600s and said that "The fact that some futzing constant needs or doesn't need to be added" doesn't prove the model is wrong.
JesseMReeves 6y ago
„During March and April 1959, at Wheeler's request, Everett visited Copenhagen, on vacation with his wife and baby daughter, in order to meet with Niels Bohr, the "father of the Copenhagen interpretation of quantum mechanics". The visit was a complete disaster; Everett was unable to communicate the main idea that the universe is describable, in theory, by an objectively existing universal wave function (which does not "collapse"); this was simply heresy to Bohr and the others at Copenhagen. The conceptual gulf between their positions was too wide to allow any meeting of minds; Léon Rosenfeld, one of Bohr's devotees, talking about Everett's visit, described Everett as being "undescribably [sic] stupid and could not understand the simplest things in quantum mechanics". “ Source and original source here: https://en.wikipedia.org/wiki/Many-worlds_interpretation https://en.wikipedia.org/wiki/Many-worlds_interpretation Everett spent 4 years doing graduate studies, taking his first physics courses then and coming up with his many-worlds dissertation within a single year (137 pages ’typed’ (according to current historical records) by his later wife Nancy Gordon). He pretty much left physics afterwards, for doing weapons research(!) for the Pentagon. Many-worlds sounds like what an overconfident ‚pragmatic’ college graduate would come up with even to those who don’t do physics. Is it just my impression or is it mostly US-Americans who are pushing many worlds into physics?
- simonh 6y ago
  Not at all, Stephen Hawking was a proponent of the idea, as is David Deutch, another British physicist. It has plenty of proponents, or at least those unwilling to discount it, on both sides of the Atlantic.
garaetjjte 6y ago
I'm not a physicist and I don't really have an opinion there, but that's funny. One side argues that pushing multiverse is unscientific, while other side argues exactly the opposite, that pushing Copenhagen is unscientific. https://www.lesswrong.com/s/Kqs6GR7F5xziuSyGZ/p/xsZnufn3cQw7tJeQ3 https://www.lesswrong.com/s/Kqs6GR7F5xziuSyGZ/p/xsZnufn3cQw7...
- 8bitsrule 6y ago
  Different physicists will have different preferred ways of explaining (interpreting) observations. Given the same observations, competing theories/interpretations/models will arise. How to choose between those that don't conflict with any of the evidence? A famous scientist, Arthur Eddington, did a lot of work on what he called 'Fundamental Theory', an attempt at unifying everything. It went over 'like a submarine with screendoors'. After I'd looked through the book for a couple of hours, I asked a seasoned quantum theoretician if there was anything particularly wrong about it. 'No'. Then why hadn't I heard of it, why didn't anyone take it seriously? 'Because they didn't like it.'

by ridaj 6y ago

JimBlackwood 6y ago

What you said is very true, it doesn’t apply to the cosmological constant though. It is not so much that we need it for a model to be in line with empirical observation, it’s that empirical observation gives one value and our models predict another value. The discrepancy is big and if we can’t make our models work empirical observations, that is really embarrassing. Regarding non-falsifiable theories; there’s not a physicist that thinks theories should not be tested. A lot of work is done to make these theories testable. Unfortunately, they are often only testsble on open problems since the limit of these theories just reduces to GR for instance.

jMyles 6y ago

> IMO the most embarrassing problem in physics is people pushing non-falsifiable, unscientific theories (multiverse). Is this a not-so-subtle dig at Beacham and other experimentalists who make room for multiverse? Or do I jump to the wrong conclusion? Two questions for you: 1) Does 'falsifiable' in this context per se mean that there needs to be some particle physics experiment that can be designed to test the theory? Is there no room for theoretical physics? Is Rovelli, for example, per se barking up the wrong tree by this measure? 2) Aren't these theories reasonably falsifiable insofar as they'll eventually result in experiments designed to map out the possible domains of the space? eg, what if we build a much higher energy collider and finally find real evidence of the super-symmetry particles?

lmm 6y ago
> 2) Aren't these theories reasonably falsifiable insofar as they'll eventually result in experiments designed to map out the possible domains of the space? eg, what if we build a much higher energy collider and finally find real evidence of the super-symmetry particles? Would you treat not finding super-symmetry particles as falsifying those theories? AIUI those theories admit the possibility of such particles but also the possibility of such particles not existing, so they're not actually falsifiable that way.
- l33tman 6y ago
  Most theories' predictions are not open ended. It's possible to exhaustively search the prediction space to falsify them (up to an experimental standard that you need to agree on). I'm by far not an expert on super-symmetry but from what I've seen the prediction space of the most common SUSY models is getting continuously boxed in.
- andi999 6y ago
  I think super symmetry is almost falsified. People just cling to it because there is (almost) nothing else. If any new theory comes around without supersymmetry (but other predictions) people will jump ship.
throwaway3699 6y ago
Science is defined by testability. A theory that can't be tested is just pseudoscience, unlike a theory that just can't be tested right now due to technological limitations.
- JimBlackwood 6y ago
  It would be pseudoscience if it were to be seen as or communicated as fact. It’s not. Any newly observed fact can falsify these theories. It just takes a long time. There’s still tons of open issues on General Relativity too. So far though, it seems to have passed every test. Would you call GR pseudoscience too then? Since it’ll likely never be fully verified.
  - boomboomsubban 6y ago
    > would be pseudoscience if it were to be seen as or communicated as fact. It’s not. Pseudoscience is something labelling itself as science while not adhering to scientific standards. Claiming it's a fact would be a dead giveaway though. Relativity has been experimentally tested and made accurate predictions, it is impossible for it to be "fully verified."

piokoch 6y ago

So very true. The ideas mentioned in the article does not sound appealing to me: "In this picture, the curvature of space would constantly fluctuate on extremely small scales, well beyond anything we could hope to measure" "Her model is based on the idea that extra dimensions, beyond the three of space and one of time that we witness, might be hidden out of sight." Instead of cosmological constant "novel" approaches relay on something that could not be observed, even in principle. That does not sound like a good approach. My guess is that they try to make some assumptions, figure out math around it, hope that it will somehow stick nicely, which would give hope that there is something in it. Indeed, it seems that math "likes" to describe our universe, some mathematical theories (Riemannian geometry, group theory) fit physics wonderfully. The problem is that for physics math is just a language, it is unlikely that language alone will give us answers without understanding physical phenomena itself.

lmm 6y ago

How surprised would you be if it turned out we really did live in a multiverse? Would you expect things to look different if we did? Do you think it's extremely implausible a priori? I find multiverses far more plausible than futzing constants, because the universe in general seems to be absurdly big but simple and consistent physics-wise. Smaller but more fiddly/complicated models seem much less plausible, just judging by history.

boomboomsubban 6y ago
How would one develop an experiment that would result in evidence we live in a multiverse? Demonstrating observable phenomena is a result of something outside this universe seems like a logical impossibility currently. Philosophically I find the idea of the multiverse probable, but making it science is a separate thing. edit poor word usage.
- akvadrako 6y ago
  Science doesn't prove anything so it's not really relevant to the question of the demarcation line. A theory involving a multiverse can make observable predictions even if the other regions are not accessible.
  - boomboomsubban 6y ago
    >Science doesn't prove anything I should have said evidence rather than proof, my mistake. >theory involving a multiverse can make observable predictions even if the other regions are not accessible All those predictions would serve as evidence for the same theory without involving a multiverse.
    - akvadrako 6y ago
      The multiverse is not some addon that can be removed easily; it's just another prediction of the theory.
      - 6y ago

atoav 6y ago

I see these multiverse theories more as a philosophical idea than anything empirical. To explore the different variations of our own world can also be intersting to understand what's going on (e.g. what if $variable in the beginning of the universe would have been slightly altered). But yeah more in the world of thoughts than anything else.

DavidSJ 6y ago

If you're referring to the Everett multiverse (although the OP was not, so maybe you're not), then its status is not so different from that of the unobservable portion of our own universe. That is, if we take the simplest known cosmological model consistent with our evidence, its equations predict space and matter outside our observable universe. That cosmological model is falsifiable in that it makes other predictions besides this one, many of which can be (and have been) tested, but this specific prediction cannot be directly tested. Similarly, the equations of quantum mechanics predict multiple "worlds" (although I find this term unfortunate: the state of the "multiverse" is always just a single point in Hilbert space, and it only seems like there are multiple "worlds" when we imperfectly try to map that physical state onto the intuitive level of everyday experience). That specific prediction cannot be directly tested, but other predictions of the equations can be, and have been. There is essentially no dispute about the math. The dispute is whether to deny the reality of something which is right there in that math, akin to denying the reality of a universe beyond that which is observable.

simiones 6y ago
The multiverse usually refers to multiple universes each with their own big bang, existing in regular space, but outside our light cone. It is a completely unscientific theory, in the sense that there is no chance of ever proving or denying it, by its very construction. The many worlds interpretation is completely unrelated, and it doesn't suffer from this problem of being unfalsifiable even in principle. However, I would also not say that the MWI is a straightforward deduction from the laws of QM. It rejects the most visible effect of those laws (the Born rule, i.e. that they predict probabilities of classical events and not certainties) and replaces it with an infinity of "worlds". Even worse, it still doesn't explain WHY we can only "see" one such "world", while elementary particles can "see" all of them (i.e. it doesn't solve the measurement problem any more than Copenhagen interpretation). And there is also debate on how plausible it is to even define the "probability of a world", so whether MWI is actually consistent with the Born rule is somewhat in doubt.
- DavidSJ 6y ago
  it still doesn't explain WHY we can only "see" one such "world" It's just that there's one of us in each world. The one in this world sees this one. The one in that world sees that one.

jw1224 6y ago

> IMO the most embarrassing problem in physics is people pushing non-falsifiable, unscientific theories (multiverse) The Big Bang itself is a non-falsifiable, unscientific theory. We cannot prove it happened in the way we think it might have. The Big Bang created a universe of cause and effect, yet has no cause itself. All known laws of physics fail to work in the early moments of our existence. “Give me one free miracle, and science will explain the rest” (— maybe Terrence McKenna? I can’t remember)

simonh 6y ago
We can literally see the big bang happening, in the form of the CMB. That's the actual light from the big bang. Just because we don't understand it's cause yet doesn't mean we won't, and doesn't mean it didn't have a cause.
- Daho0n 6y ago
  This is a tad disingenuous IMO. We can't "literally see the big bang happening". That's is like saying we can see the explosion of a stick of dynamite that exploded inside a mine because we see a dust-cloud and hear a boom a split second later at the mine entrance. We are standing outside the mine, talking about the effect of the dynamite. We see the effect (electromagnetic radiation or "the dust-wave"), not the cause or the event itself.
  - simonh 6y ago
    I don't see how it's disingenuous, that's literally what it is. It was even predicted well in advance of measurement. If you see the flash and hear the boom, how can you credibly say that was not witnessing the event?
    - Tenoke 6y ago
      The CMB is an observation well matching what you'd expect with a Big Bang but it is not the Big Bang itself and one can make other theories to try and explain it.

simonh 6y ago

Sexy exciting SF theories like the Everett Multiverse get a lot of press, but they are sideshows when it comes to bread and butter physics. No actual enquiries into physics or our understanding of the universe are being obstructed by it, so I don't really see how it's a problem.

GoblinSlayer 6y ago
Well, your life is not affected whether Earth is flat or not either.

Tenoke 6y ago

If you had added the right constant or few you could've proven geocentrism in the 1600s and said that "The fact that some futzing constant needs or doesn't need to be added" doesn't prove the model is wrong.

JesseMReeves 6y ago

„During March and April 1959, at Wheeler's request, Everett visited Copenhagen, on vacation with his wife and baby daughter, in order to meet with Niels Bohr, the "father of the Copenhagen interpretation of quantum mechanics". The visit was a complete disaster; Everett was unable to communicate the main idea that the universe is describable, in theory, by an objectively existing universal wave function (which does not "collapse"); this was simply heresy to Bohr and the others at Copenhagen. The conceptual gulf between their positions was too wide to allow any meeting of minds; Léon Rosenfeld, one of Bohr's devotees, talking about Everett's visit, described Everett as being "undescribably [sic] stupid and could not understand the simplest things in quantum mechanics". “ Source and original source here: https://en.wikipedia.org/wiki/Many-worlds_interpretation https://en.wikipedia.org/wiki/Many-worlds_interpretation Everett spent 4 years doing graduate studies, taking his first physics courses then and coming up with his many-worlds dissertation within a single year (137 pages ’typed’ (according to current historical records) by his later wife Nancy Gordon). He pretty much left physics afterwards, for doing weapons research(!) for the Pentagon. Many-worlds sounds like what an overconfident ‚pragmatic’ college graduate would come up with even to those who don’t do physics. Is it just my impression or is it mostly US-Americans who are pushing many worlds into physics?

simonh 6y ago
Not at all, Stephen Hawking was a proponent of the idea, as is David Deutch, another British physicist. It has plenty of proponents, or at least those unwilling to discount it, on both sides of the Atlantic.

garaetjjte 6y ago

I'm not a physicist and I don't really have an opinion there, but that's funny. One side argues that pushing multiverse is unscientific, while other side argues exactly the opposite, that pushing Copenhagen is unscientific. https://www.lesswrong.com/s/Kqs6GR7F5xziuSyGZ/p/xsZnufn3cQw7tJeQ3 https://www.lesswrong.com/s/Kqs6GR7F5xziuSyGZ/p/xsZnufn3cQw7...

8bitsrule 6y ago
Different physicists will have different preferred ways of explaining (interpreting) observations. Given the same observations, competing theories/interpretations/models will arise. How to choose between those that don't conflict with any of the evidence? A famous scientist, Arthur Eddington, did a lot of work on what he called 'Fundamental Theory', an attempt at unifying everything. It went over 'like a submarine with screendoors'. After I'd looked through the book for a couple of hours, I asked a seasoned quantum theoretician if there was anything particularly wrong about it. 'No'. Then why hadn't I heard of it, why didn't anyone take it seriously? 'Because they didn't like it.'