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"In the foundations of physics, we have not seen progress since the mid 1970s when the standard model of particle physics was completed." This seems to discoun

"In the foundations of physics, we have not seen progress since the mid 1970s when the standard model of particle physics was completed." This seems to discount the explosion of work in the foundations of theoretical physics. Most notably the many variations of String Theory. Just because the work has not yet produced experiments that can validate them do not mean they are not progress. It's some of the most exciting foundational work that's come for decades.

mindcrime 7y ago
Just because the work has not yet produced experiments that can validate them do not mean they are not progress. The argument I've seen expressed about this, is that these advances should more properly be considered advances in mathematics not physics. Or to put it another way "the math works, but we have no idea if it applies to the real world or not." It's a question for the episemologists, I suppose, whether or not we should consider an advance "real new knowledge" if there's no experimental validation.
Ma8ee 7y ago
For many people that have followed fundamental physics it has become more and apparent that string theory, with its variations, is a dead end. The problem isn’t that no ones has managed to experimentally validate the theory. The problem is that string theory has failed to even make predictions that even in theory could be experimentally tested. Edit: since I’m getting downvoted, is there anything factually wrong with what I have written?
- garmaine 7y ago
  Fellow (former) physicist here. I think you got downvotes because you merely asserted the death of string theory, and didn’t provide any facts. Ironic because string theory doesn’t present any new facts either. Down voters don’t know that what you state about string theory being dead is not just some guys opinion, but a general observation that any unbiased person in the field would infer. String theory was a fad that came and is now out of fashion.
  - Ma8ee 7y ago
    Neither did the comment that I responded to present any facts. So, in the end it is just whose opinion is most popular.
pdonis 7y ago
> This seems to discount the explosion of work in the foundations of theoretical physics. Most notably the many variations of String Theory. Hossenfelder is well aware of string theory, as she says right in the article: "All these wrong predictions should have taught physicists that just because they can write down equations for something does not mean this math is a scientifically promising hypothesis. String theory, supersymmetry, multiverses. There’s math for it, alright. Pretty math, even. But that doesn’t mean this math describes reality." > Just because the work has not yet produced experiments that can validate them do not mean they are not progress. But it's not just that string theory hasn't yet produced experiments that can validate it. It's that (a) direct experiments to validate it are something like twenty orders of magnitude away in terms of energy scale, so not doable now or for the foreseeable future, and (b) every prediction it's made so far that can be tested at energy scales we can probe (such as the prediction that supersymmetry would show up at the LHC) has been wrong.
- pas 7y ago
  Most of those theories have some implications about lower energy ranges. And pushing up energies is a great way to rule out a lot of them. (And some of those theories have some large scale cosmological implications too, so better telescopes can rule out more.) But ... there seems to be a lack of (serious) theories that have easily testable predictions. And this is not surprising, because we also lack easily reproducable but yet unexplained data. (For example the high-energy gamma ray busts are very interesting but we have no idea where do they come from really.)
  - pdonis 7y ago
    > Most of those theories have some implications about lower energy ranges. And pushing up energies is a great way to rule out a lot of them. Yes. The problem is that ruling out is all that's happening. Not one has had an implication about lower energy ranges that has turned out to be right.
    - pas 7y ago
      And that's not necessarily a problem. After all, we can measure things with insane accuracy (LIGO, atto/femto-second laser pulses, neutrino detectors, etc), our theories about the accessible energi regimes are quite good (14+ digits for QED - quantum electro dynamics). At some point it's no wonder we need bigger microscopes to see deeper into reality. Sure, were someone just come up with an even better theory that can be tested easily, that would be great too, but since we have no recipe for that, but we have quite a few for building bigger experiments, that's what most of the particle physicists advocate.
scott_s 7y ago
Yes, she does discount string theory: http://backreaction.blogspot.com/2016/06/dear-dr-b-why-not-string-theory.html http://backreaction.blogspot.com/2016/06/dear-dr-b-why-not-s...

mindcrime 7y ago

Just because the work has not yet produced experiments that can validate them do not mean they are not progress. The argument I've seen expressed about this, is that these advances should more properly be considered advances in mathematics not physics. Or to put it another way "the math works, but we have no idea if it applies to the real world or not." It's a question for the episemologists, I suppose, whether or not we should consider an advance "real new knowledge" if there's no experimental validation.

Ma8ee 7y ago

For many people that have followed fundamental physics it has become more and apparent that string theory, with its variations, is a dead end. The problem isn’t that no ones has managed to experimentally validate the theory. The problem is that string theory has failed to even make predictions that even in theory could be experimentally tested. Edit: since I’m getting downvoted, is there anything factually wrong with what I have written?

garmaine 7y ago
Fellow (former) physicist here. I think you got downvotes because you merely asserted the death of string theory, and didn’t provide any facts. Ironic because string theory doesn’t present any new facts either. Down voters don’t know that what you state about string theory being dead is not just some guys opinion, but a general observation that any unbiased person in the field would infer. String theory was a fad that came and is now out of fashion.
- Ma8ee 7y ago
  Neither did the comment that I responded to present any facts. So, in the end it is just whose opinion is most popular.

pdonis 7y ago

> This seems to discount the explosion of work in the foundations of theoretical physics. Most notably the many variations of String Theory. Hossenfelder is well aware of string theory, as she says right in the article: "All these wrong predictions should have taught physicists that just because they can write down equations for something does not mean this math is a scientifically promising hypothesis. String theory, supersymmetry, multiverses. There’s math for it, alright. Pretty math, even. But that doesn’t mean this math describes reality." > Just because the work has not yet produced experiments that can validate them do not mean they are not progress. But it's not just that string theory hasn't yet produced experiments that can validate it. It's that (a) direct experiments to validate it are something like twenty orders of magnitude away in terms of energy scale, so not doable now or for the foreseeable future, and (b) every prediction it's made so far that can be tested at energy scales we can probe (such as the prediction that supersymmetry would show up at the LHC) has been wrong.

pas 7y ago
Most of those theories have some implications about lower energy ranges. And pushing up energies is a great way to rule out a lot of them. (And some of those theories have some large scale cosmological implications too, so better telescopes can rule out more.) But ... there seems to be a lack of (serious) theories that have easily testable predictions. And this is not surprising, because we also lack easily reproducable but yet unexplained data. (For example the high-energy gamma ray busts are very interesting but we have no idea where do they come from really.)
- pdonis 7y ago
  > Most of those theories have some implications about lower energy ranges. And pushing up energies is a great way to rule out a lot of them. Yes. The problem is that ruling out is all that's happening. Not one has had an implication about lower energy ranges that has turned out to be right.
  - pas 7y ago
    And that's not necessarily a problem. After all, we can measure things with insane accuracy (LIGO, atto/femto-second laser pulses, neutrino detectors, etc), our theories about the accessible energi regimes are quite good (14+ digits for QED - quantum electro dynamics). At some point it's no wonder we need bigger microscopes to see deeper into reality. Sure, were someone just come up with an even better theory that can be tested easily, that would be great too, but since we have no recipe for that, but we have quite a few for building bigger experiments, that's what most of the particle physicists advocate.

scott_s 7y ago

Yes, she does discount string theory: http://backreaction.blogspot.com/2016/06/dear-dr-b-why-not-string-theory.html http://backreaction.blogspot.com/2016/06/dear-dr-b-why-not-s...