Does the Higgs-boson exist?

post by shminux · 2019-05-23T01:53:21.580Z · score: 6 (9 votes) · LW · GW · 48 comments

This is a link post for https://backreaction.blogspot.com/2019/05/does-higgs-boson-exist.html

What do scientists mean when they say that something exists? Every time I give a public lecture, someone will come and inform me that black holes don’t exist, or quarks don’t exist, or time doesn’t exist. Last time someone asked me “Do you really believe that gravitational waves exist?”

Sabine is a theoretical physicists who had gained prominence (and notoriety) through her book Lost in Math, about groupthink in high-energy physics.

In this post she sums up beautifully what I and many physicists believe, and is vehemently opposed by the prevailing realist crowd here on LW. A few excerpts:

Look, I am a scientist. Scientists don’t deal with beliefs. They deal with data and hypotheses. Science is about knowledge and facts, not about beliefs.

...

We use this mathematics to make predictions. The predictions agree with measurements. That is what we mean when we say “quarks exist”: We mean that the predictions obtained with the hypothesis agrees with observations.

...

Now, you may complain that this is not what you mean by “existence”. You may insist that you want to know whether it is “real” or “true”. I do not know what it means for something to be “real” or “true.” You will have to consult a philosopher on that. They will offer you a variety of options, that you may or may not find plausible.

A lot of scientists, for example, subscribe knowingly or unknowingly to a philosophy called “realism” which means that they believe a successful theory is not merely a tool to obtain predictions, but that its elements have an additional property that you can call “true” or “real”. I am loosely speaking here, because there several variants of realism. But they have in common that the elements of the theory are more than just tools.

And this is all well and fine, but realism is a philosophy. It’s a belief system, and science does not tell you whether it is correct.

...

Here is a homework assignment: Do you think that I exist? And what do you even mean by that?

48 comments

Comments sorted by top scores.

comment by jessicata (jessica.liu.taylor) · 2019-05-23T19:04:52.621Z · score: 37 (16 votes) · LW · GW

In this post she sums up beautifully what I and many physicists believe, and is vehemently opposed by the prevailing realist crowd here on LW.

She seems to vacillate between "realism is a philosophical idea" and "realism is false".

This is about realism being a philosophical idea:

And this is all well and fine, but realism is a philosophy. It’s a belief system, and science does not tell you whether it is correct.

And this is simply asserting nonrealism:

If you want to claim that the Higgs-boson does not exist, you have to demonstrate that the theory which contains the mathematical structure called “Higgs-boson” does not fit the data. Whether or not Higgs-bosons ever arrive in a detector is totally irrelevant.

So, she isn't making a coherent argument against realism, she says "it's philosophical" as if it's a counterargument (wat?).

The issue is, when she says something like "That is what we mean when we say 'quarks exist': We mean that the predictions obtained with the hypothesis agrees with observations," that is itself a philosophical idea, subject to philosophical analysis. (What does it mean for a statement to mean something? What's a prediction? What's an observation? How does this idea behave in unusual cases such as the person claiming there's an invisible pink dragon in their garage?) But she's trying to exclude philosophy from the domain of the conversation... which is inextricably philosophical.

This seems like another instance of "people who say they're not doing philosophy are in fact doing bad philosophy."

comment by G Gordon Worley III (gworley) · 2019-05-23T20:10:45.525Z · score: 13 (6 votes) · LW · GW
This seems like another instance of "people who say they're not doing philosophy are in fact doing bad philosophy."

I think a lot of folks hope they can avoid the philosophical tangle and just get on with what they care about and find ways to not have to deal with nasty philosophical problems, especially I think the problem of the criterion. And you can, and philosophy even gives it a name: pragmatism. You can be a pragmatist about whatever you want by putting up a stop sign that says "yep, not going to look at this, going to take it as not only ontologically basic but real so I can avoid dealing with the infinite regress we find whenever we try to reduce everything". And the catch is that we all must be pragmatists about something if we are to get on with anything, since the alternative seems to be uncomputable (again, due to the problem of the criterion and its many guises). So far so good, philosophy work discharged.

But then some people, especially people who identify as scientists and rationalists, have this idea that they don't put up stop signs, they always keep going to the best of their ability, and when reality says "here, enjoy some actual unknowability" this creates serious problems for the person. Their identity is at stake in so much as it is tied to reductionism and realism (or, as is the case with Sabine, some kind of shadow realism? her position is not self consistent as you point out), they suffer cognitive dissonance, and they choose to resolve it by making the same epistemological leap of faith we are all forced to make by the problem of the criterion, but then denying that any leap was made and instead claiming it was just seeing things as they really are, and if pressed on it then doing some weird gymnastics like Sabine seems to do here to try to hide from what knowing even means.

comment by shminux · 2019-05-24T07:27:46.980Z · score: -2 (6 votes) · LW · GW

This comment seems uncharacteristically uncharitable for you, guessing due to a certain level of frustration. Could be misreading it.

She seems to vacillate between "realism is a philosophical idea" and "realism is false".

She does no such thing. She doesn't even use the terms true or false! She says it's not something she needs in her scientific work. You wouldn't be confusing atheism with agnosticism, would you?

And this is simply asserting nonrealism:

She is not saying that something exists or doesn't, just that it doesn't matter for the purposes of of evaluating the quality of a hypothesis.

How does this idea behave in unusual cases such as the person claiming there's an invisible pink dragon in their garage?)

She is doing physics, not linguistics or cognitive science or psychiatry. Or, as in your example, more like sophistry. Russel's teapot has nothing to do with the topic.

This seems like another instance of "people who say they're not doing philosophy are in fact doing bad philosophy."

Pot. Kettle. Her philosophy (or non-philosophy) certainly works for her and for most physicists, look at all the successes in physics over the last century. While certain people are still stuck on logical counterfactuals.

OK, the above was just as uncharitable to you.

comment by TAG · 2019-05-27T12:53:23.580Z · score: 3 (2 votes) · LW · GW

Her philosophy (or non-philosophy) certainly works for her and for most physicists,

Success and failure have to be gauged against what someone or something is intended to do. Science is intended to output knowledge about the world, so ceasing to even attempt that is failure.

comment by jessicata (jessica.liu.taylor) · 2019-05-24T08:18:10.278Z · score: 2 (1 votes) · LW · GW

She does no such thing.

Technically, she isn't asserting nonrealism, she's asserting that the territory is unreferenceable, in saying that statements such as "quarks exist" don't refer to any physical reality, but instead refer to predictions and observations. But that's still a philosophical idea, and the rest of the comment applies.

She is doing physics, not linguistics or cognitive science or psychiatry.

She does physics in her work, and is doing philosophy in this article. Philosophical ideas can be examined philosophically. (I agree that she isn't examining them philosophically, at least not very well)

Pot. Kettle.

Can you be more specific? Are you saying that I'm doing bad philosophy while claiming not to be doing philosophy? If so, which philosophy is bad, specifically? (I definitely think of myself as doing philosophy, and have for most of my life)

Her philosophy (or non-philosophy) certainly works for her and for most physicists, look at all the successes in physics over the last century.

Do you have evidence for this? I think the most generative physicists, such as Einstein, thought of themselves as studying a mostly-external world, and attempting to discern the truth about it (see: Einstein's Philosophy, Richard Feynman's Philosophy of Science).

comment by Charlie Steiner · 2019-05-23T05:33:32.933Z · score: 8 (5 votes) · LW · GW

Hm - would the prevailing realist crowd disagree with this way of using the word?

For example, it sure seems like Eliezer takes more or less the same position here [LW · GW]. I take a slightly more unusual position mathematical truth here [LW · GW].

I still think that things exist, and are true, and are real, and so on. The difference between me and me ten years ago is just that I have an explanation for why I use those words, rather than just repeating them more slowly and louder.

comment by shminux · 2019-05-23T06:43:43.655Z · score: 2 (3 votes) · LW · GW

From Eliezer's post:

was that my beliefs determine my experimental predictions, but only reality gets to determine my experimental results. If I believe very strongly that I can fly, then this belief may lead me to step off a cliff, expecting to be safe; but only the truth of this belief can possibly save me from plummeting to the ground and ending my experiences with a splat.

His statement is that the accuracy of predictions is determined by "reality" and that truth of a belief is measured by its correspondence with reality. Sabine does not make this claim, instead directing anyone interested to talk to the philosophers:

I do not know what it means for something to be “real” or “true.” You will have to consult a philosopher on that.

I said a lot more in the comments in that 7 year-old thread, so no point rehashing it.

comment by Douglas_Knight · 2019-05-23T18:42:44.927Z · score: 6 (4 votes) · LW · GW

Eliezer's post is quite compatible with Sabine's. They may have additional positions that are not compatible, and maybe you know that from their other posts. Eliezer claims a very weak version of realism, while Sabine rejects a strong version. Eliezer claims QCD is true because it predicts reality; whereas Sabine says that she doesn't know what it means for quarks to be real. Sabine does not address truth or reality of theories and Eliezer does not address the reality of objects.

I think that your second quote is misleading. She does not claim to reject the truth of theories, only the truth of objects. That seems like an odd word choice, but the third time she uses "true" it is explicitly about constituent objects.

PS — could you switch the link to https?

comment by Charlie Steiner · 2019-05-23T08:48:36.167Z · score: 5 (3 votes) · LW · GW

Sure, but he also says "Since my expectations sometimes conflict with my subsequent experiences, I need different names for the thingies that determine my experimental predictions and the thingy that determines my experimental results. I call the former thingies 'beliefs', and the latter thingy 'reality'."

This key allows you to substitute in to his previous paragraph, to obtain statements in terms of predictions and experimental results that would be Sabine-approved.

If we think of the philosophical camps as realism, instrumentalism / pragmatism, and skepticism, the state of play seems to be less

"I am a realist, you are a skeptic, let's argue,"

and more

"I'm the true pragmatist!" "No, I'm the true pragmatist!"

I have now skimmed the previous thread, where you also quoted what I just quoted, but said Eliezer was just assuming that there was some thingie out there being reality. The alternative being, presumably, that our observations are not determined by anything that acts like an object with properties, and are instead brute facts.

But the first sentence ("since my expectation sometimes conflict...") is precisely about how he's not assuming an external reality, but instead advancing it as a hypothesis in order to explain observations. Maybe he's not doing it the way you'd like - and maybe I as a biased reader will interpret that statement as a metaphor for something I expect, wheras you'd do the same but get a different result.

comment by shminux · 2019-05-23T14:52:23.263Z · score: 3 (3 votes) · LW · GW

You'd have to ask Eliezer, but as far as I can tell the philosophical difference between his view (realism) and mine (anti-realism/instrumentalism) is that he elevates the concept of territory into an unquestionable belief, and to me it is one of many sometimes useful models. My approach is "there is an observation that sometimes it is possible to make predictions about future observations that are not completely inaccurate", without postulating an external largely immutable source for those observations, called "reality" or "territory". I am quite sure that this is not the view Eliezer would endorse. Sure, the initial impetus for the idea of the external reality is to explain predictability in certain observations, but then it takes a life of its own and becomes a privileged concept in the epistemology of realism.

comment by Wei_Dai · 2019-05-23T16:04:58.382Z · score: 10 (5 votes) · LW · GW

Can you explain your idea more? If the concept of "reality" or "territory" is just one of many sometimes useful models, what are some other useful models?

comment by shminux · 2019-05-25T05:55:22.343Z · score: 1 (2 votes) · LW · GW

If you are asking for a model that is a replacement for the idea of the territory, that is not what I meant. This would be like asking "if you don't believe in God, what do you replace God with?" But maybe you mean something else.

comment by Wei_Dai · 2019-05-25T06:14:28.606Z · score: 11 (6 votes) · LW · GW

In the comment I replied to, you wrote:

You’d have to ask Eliezer, but as far as I can tell the philosophical difference between his view (realism) and mine (anti-realism/instrumentalism) is that he elevates the concept of territory into an unquestionable belief, and to me it is one of many sometimes useful models.

AFAICT, the "it" in the last clause here has to be referring to "the concept of territory" so I'm asking, if the concept of territory is one of many sometimes useful models, what are some other useful models? I don't see how else to interpret this sentence that would make sense, so if that's not what you meant, can you explain what you actually meant?

comment by shminux · 2019-05-26T04:43:21.815Z · score: 5 (2 votes) · LW · GW

Still not sure what you are asking. There are plenty of sometimes useful models, which work well within their domain of validity. "Humans sometimes behave as Bayesian reasoners" is one of those. Well, that one has a very limited domain of validity, but still non-empty. All of physics filled with sometimes useful models, in fact, as far as I can tell, there is nothing else but models. But that's a view few people here are willing to entertain.

comment by Wei_Dai · 2019-05-27T00:52:09.344Z · score: 3 (1 votes) · LW · GW

Thanks, I think I understand your position better now. Would you say that even the concept of "future observations" is just a model, because for all you know maybe all that exists is just you with your current set of memories and observations? If so I'm curious what your views on values and decision making are. If you're agnostic about the existence of everything except your current memories and observations and models, what things do you assign value to, and how do you figure out what actions are better than other actions?

comment by shminux · 2019-05-27T03:21:44.832Z · score: 5 (2 votes) · LW · GW
for all you know maybe all that exists is just you with your current set of memories and observations?

That solipsistic model is not very useful, is it? Doesn't offer any useful predictions, so why entertain it?

If so I'm curious what your views on values and decision making are.

I posted about my views on decision making about a year ago [LW · GW]. That model seems quite useful to me, as it avoids the pitfalls of logical counterfactuals vs environmental counterfactuals, and a bunch of otherwise confusing dilemmas.

If you're agnostic about the existence of everything except your current memories and observations and models

I didn't say I made an exception at all. I just don't like using terms like "exist", "real" and "true", they can be quite misleading. If anything, I would suggest people try to taboo them and see what happens to the statements they make.

how do you figure out what actions are better than other actions?

Like most people, I have an illusion of making decisions. That is the implication from the current best physics models. My linked post above explains how to compare possible worlds, which is the closest one can get to "making decisions" without implying that they have magical free will separate from physical processes.

If what you are really asking is "how do you reconcile Model A you use in the situation 1 and Model B you use in the situation 2?", then my reply is that every model has its own domain of validity and when stretched beyond it, it breaks. There is nothing unusual about it. in physics quantum mechanics and general relativity are very useful yet incompatible models. You can probably name a few like that in your own are of expertise.

comment by Wei_Dai · 2019-05-29T00:10:24.249Z · score: 6 (3 votes) · LW · GW

In your decision making post, you wrote:

>A model com­pat­i­ble with the known laws of physics is that what we think of as mod­el­ing, pre­dict­ing and mak­ing choices is ac­tu­ally learn­ing which one of the pos­si­ble wor­lds we live in.

(I would state this somewhat differently, but let's go with it for now for the sake of argument.)

Do you consider "which one of the possible worlds we live in" to be synonymous with "reality" or "territory"? If so, would you agree that this model is useful anytime we make decisions (i.e., there's not really an alternative model that we can use to serve the same purpose)? If so, it seems like the concept of territory isn't just a "sometimes useful" model but at least one of the most useful models we have, and in fact pretty much indispensable? How does this differ in practice from what Eliezer thinks? I think you were complaining that Eliezer asks whether wavefunctions are real, but couldn't you ask a similar question, namely, does the possible world that you live in contain wavefunctions?

comment by shminux · 2019-05-29T02:59:59.320Z · score: 2 (1 votes) · LW · GW
Do you consider "which one of the possible worlds we live in" to be synonymous with "reality" or "territory"?

I consider the map/territory model to be useful in this case, yes. I don't promote the idea of the territory into anything other than a useful model in this case.

If so, would you agree that this model is useful anytime we make decisions

I wouldn't make a sweeping statement like that, no. But it is definitely useful to consider the person making decisions as a part of the physical world, and not having magical free will, the way the usual decision theories go, while paying lip service to the idea of reality.

If so, it seems like the concept of territory isn't just a "sometimes useful" model but at least one of the most useful models we have, and in fact pretty much indispensable? How does this differ in practice from what Eliezer thinks?

I don't know what he thinks exactly, but my impression is what I had described above, talking about territory while still thinking that the intentional stance is anything more than an occasionally useful approximation. That "occasionally" part does not include decision theories.

I think you were complaining that Eliezer asks whether wavefunctions are real, but couldn't you ask a similar question, namely, does the possible world that you live in contain wavefunctions?

I don't recall complaining about it, but wavefunctions are a mathematical abstraction, obviously. Not a lot of use in asking whether they are really real or only seem real and what not. As for "does the possible world that you live in contain wavefunctions?" question, my answer would be that at the level of coarseness that corresponds to observing someone's actions, "wavefunction" is not a useful abstraction, just like quarks are not a useful abstraction when talking about, as in Eliezer's example, a Boeing 747. The only residue that I expect to find useful from quantum mechanics in the macroscopic world of agents is the inherent unpredictability and randomness at the level of the ion channels opening and closing, which, when combined, result in the appearance of conscious decisions.

Not sure if this makes sense, but thank you very much for being patient and engaging in this discussion, and not just shrugging it off.

comment by TAG · 2019-05-27T13:10:11.925Z · score: -1 (2 votes) · LW · GW

That model seems quite useful to me, as it avoids the pitfalls of logical counterfactuals vs environmental counterfactuals, and a bunch of otherwise confusing dilemmas.

You are "solving" the problem by dogmatically siding with clockwork determinism against free will. That isn't a real solution because someone else could be dogmatic in the other direction, and it is also inconsistent with your anti realism.

comment by shminux · 2019-05-27T14:45:37.231Z · score: 3 (5 votes) · LW · GW

Just a general comment on your style: I have stopped replying to you because you tend to talk at me, telling me what's right and what's wrong, as if you have the monopoly on truth. This may well not be your intention, but that's how your comments come across to me. Just thought I'd let you know. Of course, for all I know, others perceive my comments the same way and that's why they don't reply to me.

comment by TheAncientGeek · 2019-05-27T15:09:09.321Z · score: 0 (3 votes) · LW · GW

Saying that some things are right and others wrong is pretty standard round here. I don't think I'm breaking any rules. And I don't think you avoid making plonking statements yourself.

comment by TAG · 2019-05-25T20:17:43.036Z · score: 1 (1 votes) · LW · GW

... truth of a belief is measured by its correspondence with reality...

I'm not sure if he literally said that, but in any case it's problematical because we have no way of measuring correspondence as such.. we measure predictive ability, and assume it has something to do with correspondence.

comment by G Gordon Worley III (gworley) · 2019-05-23T20:37:16.903Z · score: 5 (7 votes) · LW · GW

For what it's worth I think there is a way to rescue Sabine's bad philosophy. She says:

Look, I am a scientist. Scientists don’t deal with beliefs. They deal with data and hypotheses. Science is about knowledge and facts, not about beliefs.

And from a certain point of view this is right, science is pragmatic and about ignoring large parts of problem space in order to act as if we did have the ability to know facts directly. And it works pretty well as far as it goes, as the modern world makes clear with all it has enabled us to do and have that did not happen without science.

There are still some technical problems here. Claiming that "scientists don't deal with belief" is sort of like trying to say "scientists are not embedded agents [LW · GW]" which is just nonsensical given what we observe about the world. But if we squint we can see this as more saying science is not about the folk notion of belief, i.e. it's not about all your thoughts, regardless of how well they predict future experiences. I also think when she says that science is about "knowledge and facts" she doesn't necessarily mean what a philosopher would mean by knowledge (a kind of belief that is believed to be correlated with "reality" or at least predictions of future experiences) or facts (universally, eternally true statements), but instead a folk version of these where knowledge some set of accessible facts that can be called up when needed and worked with and facts are statements that accurately predict the world up to the limit of our predictive abilities (and if she lacks a subjective, probabilistic model of knowledge, maybe just statements that predict future experiences 100% of the time).

And in this way it's not at all at odds with philosophy, although it is antagonistic. Speculating, it seems Sabine is hoping that philosophy can remain a separate magisterium she doesn't have to deal with by carving out hard lines between it and science, and although she's clearly not a strong philosopher or else she would have chosen her words more carefully (although I am reading them out of full context, so it's possible I am the one being insufficiently careful!), this is a stance a large part of Western philosophy took for most of the 20th century before it was proven unworkable since no such hard line can be made to exist.

As I like to think of it, we are all philosophers whether we like it or not, whether we know it or not, and whether we're good at it or not. We can wish it were otherwise, but the world we are embedded in is not shaped such that it could be, so even if we want to be pragmatists and avoid dealing with many deeper issues in philosophy, we should at least be honest and upfront about that, rather than what Sabine seems to be trying to do, which is slyly dismiss the need for philosophy rather than simple admitting to her pragmatism so she can get on with being a scientist.

comment by steven0461 · 2019-05-23T19:32:53.560Z · score: 4 (3 votes) · LW · GW
That is what we mean when we say “quarks exist”: We mean that the predictions obtained with the hypothesis agrees with observations.

That's not literally what we mean. I can easily imagine a universe where quarks don't exist where Omega intervenes to make observations agree with quark-based predictions in response to predictions being made (but not, say, in parts of the universe causally inaccessible to humans). Maybe this is a strawman interpretation, but if so, it's not obvious to me what the charitable interpretation is.

edit: by "quark-based predictions" I mean predictions based on the hypothesis that quarks exist outside of the mind of Omega, including in causally inaccessible parts of the universe

comment by shminux · 2019-05-26T23:12:57.456Z · score: 2 (1 votes) · LW · GW

Certainly we can imagine this Russel's teapot universe, where pink unicorns frolic between the stars smiling conspiratorially while hiding from human senses and tools. These kinds of universes exist in human imagination, and are useful in some contexts, but not in physical research. Certainly a lot of physicists, contrary to what Sabine is saying, mean more than "the predictions obtained with the hypothesis agrees with observations" when they say that something exists. Hence all the interpretations of quantum mechanics, for example. My charitable interpretation of what you quoted is something like following Occam's razor, which would imply that there is no need to add Omega to the mix, or assume that the universe is wildly different beyond the cosmological horizon, unless there is a relevant hypothesis with enough predictive power.

comment by TAG · 2019-05-27T13:14:09.188Z · score: 1 (1 votes) · LW · GW

What these thought experiments are useful for is emphasising the lack identity between prediction and correspondence.

comment by TAG · 2019-05-27T12:25:43.888Z · score: 1 (3 votes) · LW · GW

It's certainly not what I mean by "exist". Sabine is offering a new definition, and the problem with new definitions is that they don't solve old problems.

comment by Kenny · 2019-06-14T02:33:42.227Z · score: 3 (2 votes) · LW · GW

I'm confused:

In this post she sums up beautifully what I and many physicists believe, and is vehemently opposed by the prevailing realist crowd here on LW. A few excerpts:

Look, I am a scientist. Scientists don’t deal with beliefs.

Can you point out a specific an example of "the prevailing realist crowd here on LW" or, if you don't want to unfairly single out a specific example, concoct a charitable facsimile? (The fragment "is vehemently opposed by the prevailing realist crowd here on LW" seems hostile, I'd guess due to frustration, but I'm uncertain so I'm curious as to the relevant motivations for you to use it.)

Obviously scientists deal with beliefs. You're claiming (and I believe you) that both you and "many physicists" don't believe that philosophical realism is true (or 'true') or useful (or that it's a 'wrong question'). And, presumably, you and Sabine both believe that the theory that predicts that Higgs-bosons 'exist' is the best available theory for predicting anticipated experiences.

Maybe I've been drinking the Kool-Aid David Chapman's been giving away for too long, but obviously, being something inside { reality / the universe } I have no privileged access to whether any particular beliefs are ultimately or perfectly true or that the objects of those beliefs are likewise ultimately or perfectly real. But if sure seems like we've been able to get closer and closer to true beliefs about what's real. On the gripping hand, we also seem 'doomed' to run up against the inevitable nebulosity of our beliefs.

So, I'll try to answer the questions that both you and Sabine seem to find so frustrating:

  • Does the Higgs-boson exist? – Yes, it seems to exist (i.e. to be a real particle). We have pretty strong evidence that it's been detected and the evidence strongly suggests that its properties match our predictions.
  • Do black holes exist? – Yes, they seem to exist. We've even been able to recently generate an image of one (relatively) nearby!
  • Do quarks exist? – The best theory of particle physics suggests that they do but currently we don't expect to be able to observe them 'freely', i.e. not bound within other less elementary particles, with our available tools, so the evidence of their existence is more indirect than we may otherwise hope to someday have.
  • Does time exist? – Yes, in the sense that we don't have much of an ability to understand anything without, essentially, assuming it exists, tho we do know, and have strong evidence thereof, that it's weirder than our intuitions would otherwise lead us to believe (e.g. it can 'dilate', even in ways we can precisely measure, in certain circumstances). But there are somewhat plausible ideas by which time may not be 'ontologically primitive' relative to some deeper understanding of the (observable) universe, e.g. timeless physics.
  • Do gravitational waves exist? Yes, they same to exist, and we have evidence that's consistent with their existence according to our best theories of physics.

Sabine wrote:

Look, I am a scientist. Scientists don’t deal with beliefs. They deal with data and hypotheses. Science is about knowledge and facts, not about beliefs.

That's just wrong. There is no knowledge, there are no facts, there is no data, nor hypotheses, divorced from or somehow separate from beliefs. It's a belief that facts, or knowledge about them, exist, that statements of or about them are true. Indeed, I don't know what a fact is or what knowledge could be if they were not also true. A statement of fact can be false, i.e. not true, i.e. a statement of something that is not a fact.

Sabine's last paragraph:

Here is a homework assignment: Do you think that I exist? And what do you even mean by that?

You seem to be arguing that the correct answer is no, Sabine Hossenfelder doesn't exist. I know of no theory, and definitely no mathematical framework, that predicts (specifically or even in general possibility) that she does. According to the best theories of physics there are only quantum fields and space-time. QED

Except, that's silly – of course she exists (and is real), at least as far as I can tell!

I think I may have demonstrated that I'm not in fact a philosophical realist. But I think that's wrong too. I strongly suspect that the universe (reality) is ontologically independent of my, or anyone else's, consciousness, or any ideas, beliefs, facts, or knowledge we may have with regard to it. I'm pretty sure we haven't measured or observed any such ontologically primitive elements, and I'm agnostic as to whether we (or anything else in the universe) will ever be able to do so. I wouldn't be surprised if it was actually impossible to do so. But I do believe they're real and that they exist.

As to everything else tho, e.g. the Higgs-boson, quarks, black holes, let alone planets, species, individual people – obviously those are not ontologically primitive and so the degree to which they are 'real' and 'exist' is nebulous. (Unless of course Platonic realism/idealism, or mathematicism, is true (or maybe even also true), in which case everything imaginable (and more) 'exists' and is 'real'.)

comment by TAG · 2019-06-14T15:57:08.222Z · score: 1 (1 votes) · LW · GW

Look, I am a scientist. Scientists don’t deal with beliefs

That's absurdly wrong under some interpretations of "belief". I would assume that what Sabine means by belief is some combination of certainty and not being based on evidence.

obviously those are not ontologically primitive and so the degree to which they are ‘real’ and ‘exist’ is nebulous

It's not obvious that being complex or a compound makes something less real.

comment by Kenny · 2019-06-15T00:19:42.254Z · score: 1 (1 votes) · LW · GW

I'm not sure what conceptions of 'belief' you have in mind in the first part of your reply. Are you claiming tho that Sabine, and other physicists, as shminux claims, don't have beliefs as would be commonly understood? Even about physics, or the accuracy of the mainstream theories in that field? I admit to being confused as to exactly what point shminux, or Sabine, are trying to make tho.

I would assume that what Sabine means by belief is some combination of certainty and not being based on evidence.

I find it hard to imagine what Sabine or shminux could have in mind if what you write is true. They, apparently, would claim that the some physics theories are accurate. In what sense do those claims not correspond to beliefs, e.g. that the theories actually are accurate?

Maybe you're on to something about this whole discussion being confusing because the participants, particularly Sabine or shminux, aren't explicitly discussing degrees of certainty or amounts and strength of evidence. For example, it certainly seems completely reasonable to reply to "Do black holes exist? Are they real?" with something like "They're predicted by our best theories of physics and we have pretty strong indirect evidence of their existence, in specific places (in space-time), so we're reasonably certain that they do in fact exist and are real. For one, we've generated an image of one that's relatively nearby and all the methods we used to do so seem, as far as we can tell, to be eminently reasonable based on everything else we know (and believe to be true).".

It's not obvious that being complex or a compound makes something less real.

Sure, if by "the Higgs-boson, quarks, black holes, let alone planets, species, individual people" we 'only meant' something like a (Vast) group of quantum field excitations (or similar). But, as far as I can tell, we mean very different things by each of those different words or phrases. It seems pretty obvious to me that the 'reality' of a species is a very different thing than the reality of an individual, and neither are always clear in every situation. During speciation, it's not clear when one species has become many – so the 'reality' of the species, one or many, seems less real to me, in that specific situation anyways. Similarly, victims of brain trauma are often described as 'like another person' – that seems to clearly infringe on the 'reality' of personal identity, which seems like a pretty important component of personhood. Generally, the degree to which a concept or category is nebulous seems to match how 'real' it is, or seems.

comment by TAG · 2019-06-15T08:00:57.501Z · score: 2 (2 votes) · LW · GW

They, apparently, would claim that the some physics theories are accurate. In what sense do those claims not correspond to beliefs, e.g. that the theories actually are accurate?

These claims-to-accuracy are not beliefs in the sense that they are based on evidence and are subject to revision, and are therefore not certain.

It seems pretty obvious to me that the ‘reality’ of a species is a very different thing than the reality of an individual,

There may be some issues about the classification or demarcation of complex entities , but they are not necessarily the same as issues about the existence of entities.

For instance, there was confusion about whether the platypus was a mammal or marsupial, but no dou t that they exist.

comment by Kenny · 2019-06-15T21:36:31.963Z · score: 1 (1 votes) · LW · GW

These claims-to-accuracy are not beliefs in the sense that they are based on evidence and are subject to revision, and are therefore not certain.

That seems like a really tortured definition/interpretation/understanding of 'belief'. What's the motivation for that? To distinguish these "claims-to-accuracy" as different than religious belief? I'm confused why this rhetorical stance is useful or interesting given that even religious belief is based on evidence and subject to revision, and even very few religious believers claim total or complete certainty.

There may be some issues about the classification or demarcation of complex entities , but they are not necessarily the same as issues about the existence of entities.

I agree with respect to classification but not for demarcation – if it's unclear how to demarcate two entities isn't it unclear whether two entities exist (versus one or none)?

And generally, because of the seemingly inevitable issues with demarcating individual entities of a given class, it's less clear that they exist, or the reality of their existence (as entities of that class) seems less obvious, i.e. they are 'less real'.

I'm suggesting that 'is real' and 'exists' are not binary values but rather magnitudes. Unicorns seem pretty clearly 'not real' and that it is true that they 'do not exist' (and never existed). But the magnitude of their reality or non-existence is not perfectly un-real or non-existent, as even something folk tales that mention them is (very) weak evidence that they might be real or might have existed (or might still exist somewhere).

Here are two of my favorite examples of categories of entities that are somewhat unreal or less 'existential':

  • Tectonic plates
  • The species of dogs, wolves, and coyotes

For tectonic plates, it's not obvious how many exist, thus the existence of some possible plates is uncertain. Obviously the components of plates exist but, at least for some (possible) plates, it's not clear that they do exist or are 'real' – as tectonic plates.

And dogs, wolves, and coyotes can all interbreed, and produce sexually fertile offspring, and genetic evidence of existing (individual) dogs, wolves, or coyotes indicate that they are all genetically intermixed. Are those species real? Do those species exist? Surely, in general, the individual members of those species exist, but do the species themselves exist? Are those species 'real'? It seems clear to me that the 'reality' of those three species is strictly less than the reality of any members of those species.

comment by TAG · 2019-06-16T11:50:24.775Z · score: 2 (2 votes) · LW · GW

Note that I am not defending Sabine's usage, just trying to understand it.

comment by Kenny · 2019-06-17T02:39:13.569Z · score: 1 (1 votes) · LW · GW

I wasn't trying to attack you, or Sabine or shminux either, so I'm sorry if seemed that way to you.

I think I understand their position pretty well – all of the questions they supposedly face about whether the objects of study are 'real' or whether they 'exist' are almost certainly frustrating. Obviously all of those objects are real enough, or likely enough to exist, in the sense that a sufficient cumulative weight of evidence exists and is accepted, for it to be almost entirely uncontroversial for professional physics to study them. On one end of professional practice of their field, just studying the relevant mathematics is a perfectly accepted practice in and of itself. On the other end, there's sufficient observational evidence, especially given the corresponding (accepted) theoretical interpretations, that the study of these objects is by itself relatively mundane and unremarkable.

The annoying real/exists questions are almost certainly interpreted as critical, if not negative, judgements implying that the physicists at whom the questions are addressed are either stupid or naive, or maliciously deceptive, for believing the objects of study as being (sufficiently) real or existing. So I'd expect an almost overwhelming urge for them, the physicists, to want to avoid dealing with such questions or otherwise to be able to themselves imply or aver that such questions are stupid or naive, or even unanswerable (and thus not 'scientific', i.e. worthy of their consideration).

And I'm sure some (small) degree of ill will, on both the part of physicists and the real/exist questioners, is warranted. Asking whether the object of someone's studies are real or whether they exist is almost unavoidably derogatory. And surely some physics will turn out not to have been about or in search of anything that could reasonably be believed to be real or to exist, as has happened many times before.

comment by TAG · 2019-06-19T11:55:47.451Z · score: 1 (1 votes) · LW · GW

That seems like a really tortured definition/interpretation/understanding of ‘belief

If there is an ambiguity in natural language, then an attempt unpick it will look unnatural. Consider a situation where two theories are equally supported by evidence. If a physicist backs theory A over theory B that would be the kind of belief that Sabine is rejecting.. I think.

I agree with respect to classification but not for demarcation – if it’s unclear how to demarcate two entities isn’t it unclear whether two entities exist (versus one or none)?

In this and your other examples, one can adopt an arbitrary classification scheme, and then the question of whether the posits of the scheme exist can be settled straightforwardly. So problems of existence are not problems of existence per se but problems of classification.

comment by Slider · 2019-05-24T09:42:19.143Z · score: 3 (2 votes) · LW · GW

There is a weird kind of reply of "I agree but disagree on the conceptualization" which would correspond here that claims are not tied to the conceptualization used.

For example "Is blood an effective plogiston transfer medium?" The answer is clearly yes but I would still object to the concept of phlogiston being an appropriate concept to handle the phenomenon in question. Some people might refuse to handle malformed questions and for some questions the malformation of the concepts affects the answer to the degree that addressing it is unavoidable.

And guess what if someone insists on using plogiston terminology I might acknowledge that I understand what they are talking about but I am still going to actively direct them to use other kind of terminology. And the reason is not that plogiston is "false" or "doesn't exist". For things like Higgs-boson the defence why it's a productive way to address it's phenomenon is stronger. But the conceptualization isn't an entirely free dimension and the specific failures specific conceptualizations have can be very important. "The current active conceptualization" guides what expectations are on areas we have no data on and thus can't be pure reformulations of measurements. Insisting that concepts are merely reformulations of data would mean you should not expect anything on parts where you don't have data. Sure anywhere you expect something to happen you could plausibly see whether that expectation yields out. But it's not reasonable to declare everything outside of already seen data to be off-limits.

comment by shminux · 2019-05-24T15:28:21.986Z · score: 2 (7 votes) · LW · GW

The way you think about the concept of "phlogiston" I think about the concept of "truth". Useful to a point, but then breaking down when pushed.


comment by Slider · 2019-05-24T18:58:03.830Z · score: 1 (1 votes) · LW · GW

With "plogiston" I can sell how much more attractive this "oxygen" story is. Being anti-realist doesn't teel what would be better or how to do "essential" (whatever that is) things better.

In particular I am worried that there is no acknowledgement of inductiveness. Sure it would be arrogant to know before hand what is the correct way to be inductive by for example priviledging a particular ontology. But insisting that the part of the models/lines where there is no underlying datapoints is unreal or a distraction is like saying that a finite amount of points is as good as a line.

comment by shminux · 2019-05-25T01:10:53.970Z · score: 3 (2 votes) · LW · GW

Sorry, couldn't understand the point you are making, even after rereading your reply a few times.

comment by Slider · 2019-05-25T02:34:54.030Z · score: 1 (1 votes) · LW · GW

When the theory of chemistry has advanced there has become better concepts to handle what used to be handled with the concept of plogiston.

With "truth" there is no replacement, just outright rejection.

You could have a theory of information where certain evidence is enough to secure a conviction. Then an extreme tool view would be that it's just a method to lock people up should you want to do so. There would be no sense that the evidence is "reliable" or "accurate" just damning. Or someone could be interested in if certain evidentiary standards result in certain conviction what that tells of what the law has become, what kind of precedent it sets. The extreme tool view would say that no precedent is formed, there are just people in jail and talking about the "upheld law system" would be nonsense. It would make sense to insist that at any point in time multiple interpretations of the law are plausible so that there is no "one true law". But it would be weird to say that outcome of hypothetical cases would be unconstrained. Cases form precedent, reveal something about the law system and the law system is not just the sum of all cases tried. If your original case doesn't exactly match a previous case you are not without protection of the law. With predictiosn there are principles at stake not just outcomes.

comment by Vladimir_Nesov · 2019-05-25T05:31:04.227Z · score: 4 (2 votes) · LW · GW

"Shut up and calculate" serves as an excellent replacement for truth in most situations. It's about hypotheses/theories and observations, not reality, so within its area of applicability it makes the idea of reality irrelevant.

comment by shminux · 2019-05-25T05:50:39.314Z · score: 2 (1 votes) · LW · GW
"Shut up and calculate" serves as an excellent replacement for truth in most situations.

Definitely. When do you think it is not a good replacement?


comment by Vladimir_Nesov · 2019-05-25T06:44:32.593Z · score: 6 (3 votes) · LW · GW

"Shut up and calculate" no longer suffices when you want to figure out something about reality that is not about prediction of observations (or if you are interested in unusual kinds of reality, where even prediction of observations looks unlike it does in our world). So this concerns many philosophical questions, in particular decision theory (where you want to figure out what to do and how to think about what to do). The relationship with decision theory is the same as with physics: you want to replace reality with something more specific. But if you haven't found a sufficiently good replacement, forcing a bad replacement is worse than fumbling with the preformal idea of reality.

comment by TAG · 2019-05-26T14:55:47.467Z · score: 1 (1 votes) · LW · GW

Realism is more than one thing, because everything is more than one thing. There is a general argument for a reality as the source of objectivity and possibility of error, and there are specific arguments about the posits of successful theories. Set the bar too low, and you end up believing in oxygen and phlogiston, set it too high and you have to defer belief in anything until the final theory. Points in the middle are hard to guess, which is why it's reasonable to ask physicists what they believe in.

comment by Slider · 2019-05-26T16:19:59.243Z · score: 1 (3 votes) · LW · GW

I think part of the idea is that the downsides of "too high" manifest if you need belief in order for something to function. If we design a system where "belief" is not consumed we don't need to produce it. So the question becomes "do we really need beliefs?" as in can we do without. I would imagine a lot of people have accustomed to the idea that "final theory" is not coming or atleast it's not reasonable to expect for it to come. The corresponding more radical idea is that "only suckers believe".

Somebody that takes probablity very seriously might reject from processing any claim with 100% degree of belief and insists on 99% versions. The more extreme stance claims that what your "belief degree" is irrelevant and what matters is your evidence and reasons for that support the idea. Like if a police officer had "reasonable suscpicion" to do something whether that thing suspected was or was not the case doesn't factor in whether it was reasonable to take that action. Truth of the suspicion would be irrelevant evidence.

comment by TAG · 2019-05-27T13:17:53.701Z · score: -1 (2 votes) · LW · GW

I think part of the idea is that the downsides of “too high” manifest if you need belief in order for something to function.

The function of science is to output knowledge about the world, so just giving up on that to simplify things isn't really an option.

comment by Slider · 2019-05-27T14:42:03.800Z · score: -1 (2 votes) · LW · GW

That is an understandable stance but there are other people that see that the main role of science is to produce technologies. In this kind of view if you have a reproducible capacity it is ok to be hazy why exactly does it work. Some "clients" might care about worldview implications but other types of "clients" might not (war machine). It might be a word-semantics matching game but for some people "world appriciation" is a philosophy activty and not a science activity. Sure ontology might be a regular customer of physics, but physics is going to leave the ontology questions to ontology.

I ended up deciding to cut a line of reasoing pertaining how knowledge-pessimistic bread-greedy person might engage in activity that looks like science but doesn't employ knowledge. Express interest if you wish for me to elaborate.

comment by Richard_Kennaway · 2019-05-23T16:05:47.400Z · score: 1 (4 votes) · LW · GW
I do not know what it means for something to be “real” or “true.” You will have to consult a philosopher on that.

I suggest Tarski.

comment by shminux · 2019-05-24T06:45:47.308Z · score: 0 (2 votes) · LW · GW

I suggest Instrumentarski [LW · GW].