 Yes, okay, you're good Sorry about that. Thank you all for being here. I will talk about fixed points. This is quite a strange title, but I hope you will understand very shortly, and it will be about the ontological nature of measurement units This is a work in progress as you will see in the metaphysics of quantities and of measurement because it is scientifically placed The aim is to defend and I will define them later, absolutism against Relationalism, maybe I will say Relationalism, because it's shorter and easier to pronounce And the method I will use is to try and draw metaphysical conclusions from at least partially measurement practices And as you will see, I will focus on some units definitions and mainly on standards, measurement standards And mainly on the way that standards possess their magnitude, their quantities And I will argue, this is the core of the following arguments I will argue that Standards need to be stable in order to have meaningful measurements And that this stability of standards implies an absolutist view of quantities. This is the main argument So I will begin by talking a bit about standards and what many tools are and then on the need of fixed points and on the third and fourth sections, I will display the main arguments Okay, so you have here some chosen definitions of units that you may know already I won't go through all of them, just I pick just maybe one or two. Here you have the formal definition of the metre that is the unit of length which was defined as the distance at zero degree between the axis of two central lines marked on the bar of Platinum Iridium which was kept at the BPM in France So the metre is a distance on a material object And Yes, this one today No, this one. Second, for a short period of time, the method was defined as multiple of wavelength of orange-red emission line in the electromagnetic spectrum of the krypton atom So the first question is What are those terms that I refer to those lengths here? the distance between two axes and a Metrical of wavelength. What are these things that I am referring to? Just to settle some technical terms I'm calling quantities the determinable kinds of quantity like mass or length and I'm calling magnitude the determinate quantities that objects may possess Having a mass of three kilos in ten meters long So Measurement unit This is an assumption which could be criticized Of course, the measurement unit is the magnitude of the quantity So when you want to measure some quantities like x, you have to choose a unit and the unit is little x, the determinate magnitude of the quantity But units as you know already have to be realized that the Not technical term that is there has to be possessed by concrete and manipulable and bearable standards So that measurement systems can be established This is called mise en pratique in the technical vocabulary for instance until 2018 the unit of mass that is Specific mass magnitude was the mass of an object which was called the EPK International of the type of the kilogram So my question now is what is the ontological nature of such magnitude that are defined and identified as measurement units? That is what is it for a concrete object because standards are always concrete objects What is it for them to possess this magnitude of a quantity? As answers we have competing in the physical view The one that I will be criticized that I will criticize here is called relationalism According to which quantities are only relations among concrete objects. That's all you have in the world So there are no absolute mass magnitude Objects just don't possess absolutely their their magnitude So either they just don't exist or When objects are they have magnitude they are grounded in more fundamental facts that are relational okay so For instance my laptop Which is said to to weight? one kilogram and 300 grams What is it for my laptop to have this mass it is only according to relationalism is only or at least fundamentally To be in certain mass relations with other objects for instance to be as massive as another to be two times as massive as and so on So all you have are just objects which stand in certain determinate mass relations Okay On the contrary you have absolutism which claims that quantities are Ranges of absolute magnitude So of course absolute magnitude exists and there are what's fundamental the ground mass relations so To take the same example my laptop as its mass in an absolute manner and Only later only on a grounded level it can stand in Determinate relations So it's only because it has its mass and that my car on its part has also its mass That's the two stand in the relation, okay So my goal is To give I have good reasons to reject relationalism and To defend only a basic absolutist claim that Objects possess their magnitudes absolutely and not in a relational way but I want to commit to Any more specific absolutist views like the one I put here I Don't know yet if Quantities are magnitude are absolute intrinsic monadic properties of objects I Don't know if we should limit them with a second order relations just to put some structure on them and so on I Don't know if Wolf is right With her structure on substantialism, that's all I don't know. I just want to prove I am so to prove that objects possess magnitude in an absolute manner and not fundamentally by entering in some relations but Why focusing as I do on standards on measurement standards? Because they have a very special feature that will be of interest They have to be fixed points and This is a very special characteristic that will allow me to To draw some metaphysical conclusion What are fixed points I will explain it More extensively later, but it's just the fact that when you do measurements when you measure things You have to assume that your standard is the stable realization of the unity of chosen and My main argument or the Common form of the following arguments will be that This stability of the standard cannot be understood from a relational point of view you have to be absolutist to to give some sense of stability and Because standards are just connection nature chosen. They are nothing specific or privileged or Particularly about standard except that they are used as such Well this conclusion about standard will I hope extend to any object So this is just a special case which has nothing special So what are fixed points? Well, basically when you when you want to measure a quantity that mass I will take my sensor An example throughout the whole speech When you want to measure that you have to coordinate numbers with objects and There this requires lots of assumptions, but I will only present three So there's three steps in coordination First you have to choose a scaling convention then you have to produce standards that fits This the chosen scale and then you have you further have to make a stability postulate that would be important to me, so I will go quickly on this because it's well known The scaling convention is the fact that you have to choose a space and target a specific Magnitude of mass as your unit your unit Traditionally this magnitude will be associated or it's accredited the number one But actually there is nothing necessary here. You could choose a unit and say that you're in this tube This is conventional of course because any mass magnitude could be chosen as the unit This convention actually captures once Unit dependent and not objective in your mission of resource Everything else must remain Equivalent when you change your unit. Of course here. I speak of mass, but When you consider other quantities, maybe like temperature Density, I don't know that is quantity that have a less rich structure. They are not additive basically You may need more than just one point of coordination. You may choose Maybe two units. That's bizarre to talk about two units, but that's basically this for temperature you have to Choose the boiling that's not an obligation but traditionally you choose the boiling point of water and the freezing point of water you attribute them to numbers like 100 and zero and then you can coordinate your numbers with temperature states Okay, then once you have defined your unit you still have to produce objects that Realize this this is the A term that I don't want to interpret too strongly that realize the unit This is what's called the misopathic. For example With the old kilogram. Well the standardization is straightforward because the old kilogram was defined as the mass of this object So automatically the following standard is this object I've put an image here Here you have a well-protected Three layers of glass Then only touched right now maybe every 40 years. So This is very stable standard I hope But with the new kilogram which has very recently been defined I will come back to it later by fixing the value of the longs constant Well, that doesn't give you automatically your standard So you have to produce using people balances or what balances I will come back to it later You have to produce a body whose mass is exactly The unit that you have targeted in your definition And then this standard and when I when I when I say standard I will assume that I'm speaking of primary standards and not secondary or copies of replica When once you have your standard, well, you can manipulate it and you can calibrate your measurement instruments and so on but You also need to make a postulate Something that I call the postulate fixity Because this standard needs to be a fixed point fixed point that is You have to assume that it is not At the moment of you of you producing it. It's not only at this moment Realization of the defined unit, but that it will stays it will stay As such it will be stable It will keep on having the same unit the same magnitude that you define as the unit for instance the EPK not only possesses the kilogram the mass one kilogram in 1899 when it was manufactured but later on has to be stable to to Allow for meaningful measurement so three questions now why Why this postulate? How do we make sure of it if we can and What is it precisely this postulate or what it is not more precisely? So basically, why do we need to make this Postulate of fixity what do we need fixed points? Because as I said, we need to assume that when we use the same object as a standard For a period of time we need to assume that Our different and successive measurements will be coherent and will be meaningful suppose for instance that you use this wooden log as the prototype as a standard So at t0 you define it as a math standard. So you define your unit as the mass of this but At a little time it has maybe school on with moisture or maybe it has gained mass because of I know some kind of pollution but later on Maybe you have damaged it or you have used it too much too much. So it has lost a bit of mass but While using it you are also making measurements with it by comparing other objects to it But if its mass has changed in during the time in the interval while you your measurements result won't be meaningful I'll Take an example later well suppose for instance that you You measure how you wait just before Christmas using this and then after Christmas you You wait yourself and you see that you have maybe lost some weight which is very surprising But you cannot be sure if you don't make this postulate that This is not that this was maybe gained some weight So you have to be sure of that Otherwise you could eat all the things you want and just compare yourself with something that's always gained some mass And you will see that in USA that you lost some weight, so it's not very honest So that's why obviously we don't use this as a standard but something made of Platinum Very numb for its stability under certain storage conditions Okay, but there is here a room for controversy because well if you are a radical anti-realist maybe you will retort that This postulate of fixity is actually included in the scaling convention because once you choose the unit and You realize it in an object well Maybe it has no meaning no empirical meaning to say that the standard is fixed or is stable because basically as Do you know our biggest time? Pointed out already. This is something that you cannot strictly speaking verify very good because Any kind of measurement of mass that you do is by comparing objects to the epicae So you cannot compare the epicae to itself So you cannot measure and check its mass So maybe the postulate of fixity is just a convention and has no empirical meaning But I will do here a minimal realist assumption, which I think is quite fair only that Objects massive objects like the epicae have mass magnitude they do have mass magnitude independently of our choice of convention our measurement practice and so on so This implies that the postulate of fixity has no critical status. It means something about this object about the world Even if it's not verifiable Another way to put this is to say that there is an objective Distinction between a change in the scale and a real change in the unit. I Know if you see what I mean by that, but it's quite simple You can at any moment rescale by saying that Well, you you don't measure mass in kilogram anymore, but in the mass of these objects This is rescaling But as long as it is said now then transparent this Who's is no problem? But if the object that you claim to use as the permanent standard Actually changes in mass And this is not a rescaling. This is a real change in mass So if you you think that there is an objective difference between the two then the postulate of fixity has been empirical status, even if it's not not directly Checkable But indirectly it is then metrologist as we will see actually try and check that it is stable otherwise They cannot do meaningful measurements. So this was about the why now about the how There is a well-known epistemological challenge and Charlie puts it like this way Consider in the abstract of someone who has come up with a fixed point where none have yet been established That that is not so different from the Applies of a being who is heard into interstellar space and asked to identify what is at rest In order to tell whether something is fixed one needs something else It is known to be fixed and can serve as a criterion of judgment But how can one find that first fixed point? So this is the well known Problem of circularity I want to unfold here But this problem actually comes from the fact that the predicate fixed or stable if you want is Actually a relative her relational predicates is only Relative to something else that you first Understand assumed to be fixed that you can judge and check and measure is something easy about fixed but As you may hear I used the term fixed twice in this sentence First as something that you can check a vehicle Do I change in weight during the holiday? And second as something that you have to assume in order to make that kind of checks and measurements So you have to assume even if it's not a vehicle You have to assume that your standard is fixed. This is a childhood reading We are in the lunar rocket and if you remember it's on the explorer of the moon That time is about to restart the engine line and said hang on and People don't sense Don't say it in English. It's done. So don't sense. Yeah, don't sense brother carry on. We all would we are holding tight and Later It's funny bluesies and that's all We are done very tight, but to what? This is one of not Actually, you skip the joke about the whiskey Yes So there is a circularity, which is a very important epistemological problem Maybe there is no real way out Except that we could Always make in the comparison procedure to To check that your standard if it's not absolutely fixed because you cannot check that At least is a stable relative to other admitted points of reference But it remains the risk of a common drift Maybe all your reference points are drifting in the same direction together You could also construct a hierarchy of standards This is the case with the killer come the old killer come It was actually very protected into two layers of glass and We only manipulated its six official replicas of official copies It's also the the case for the time If you read the rental He explains that we have a very huge hierarchy of standards to construct what we call the universal time You could also build models to understand What are the factors that could influence the stability or the instability of your standard to make corrections and Finally, what what is or what is not this postulate? Well, we should not conflate it with the metric convention although sometimes in some cases that both are Identified for instance In the current definition of the second it is defined as a fixed number of period of Radiation corresponding to either faint transition of cesium 133 but this definition implicitly as style says Specifies a metric convention for time namely that any two periods of the rubbish of Radiation are equal So this is a metric convention because it tells you Why or which interval are considered equal But as you see it also specifies that the standard the second is stable So maybe in this case there is confusion or Identification between the metric convention on my hand and the postulate of fixity on the other but From a conceptual point of view both are really distinct for instance with the IPK IPK IPK The two are clearly distinct because when you postulate that its mass is stable That it is really stable thanks to the kind of alloy that you used It has strictly no implication as to what counts as an addition of mass and so on or intervals of mass okay, oh Yeah, and also make sure that you You don't say that what is fixed is the unit itself It makes us actually no sense to send to to say that The kilogram is fixed Because the kilogram is the magnitude and magnitude Is not what it is about. I mean, this is not what could change what could change in mass is the standard and the object itself That which possesses magnitude It's like saying that points in space are moving That's bodies who can move in space that is change the points that they occupy Successively but points in space are not My question is what does it mean for a mass standard to be stable If you are a relationist You say that this stability Consists in the fact that the standard holds the same mass relations to other massive objects We have no choice but to analyze the stability as a relational fact If you are an absolutist You simply say say that This ability is the fact that it keeps the same absolute magnitude of mass Just it has the same mass intrinsically, okay Well on the next section I will speak extensively on this About this relationist answer and then if I have enough time I will talk and ask if my arguments must be replaced or complemented if we Go from a token based definition the kilogram is the mass of these objects to units that are defined With reference to levels or constants of nature Maybe that actually doesn't change anything Maybe it does. I hope it does because the arguments are quite nice Well token based units, this is a name given by a handle Well, you know them The unit of mass is the magnitude of this object the unit of length is the length of this object and so on and ultimately as I said the Designated objects serve as standards primary standard. I will display four arguments if I have time Two are based on measurement practices and two are purely metaphysical arguments First argument it's based on based on the fact that we not only measure masses of objects, but we also track How objects lose or gain a mass So suppose we track the mass of an object x over time relative obviously to the mass of the I B K and It ends up in statements like the mass of x is K kilogram less massive as it was before suppose this I Claim that to be meaningful this kind of statement actually requires that the mass of the I B K Be absolutely fixed Not relationally fixed or that its fixity must be understood in an absolutist way so for that You use the standard and you want to track the evolution in mass of this object so You first compare suppose you are in 1899 you compare your log to the I B K and you find that your log is exactly one kilo So the log is in the relation as massive as the I B K But 20 years later you compare it again and the result is 0.9 kilo So your native conclusion will be that the log has lost weight Lost mass. It's now less mass than it was before Well me this is me the native native metrology But obviously and immediately the relation is to be told to me that I'm wrong and that my measurement only mean means that What has changed is the mass collision not the mass of the measure project Because they are not no absolute magnitude So I cannot strictly speaking speak of the evolution of the absolute magnitude of the wooden log But I will answer that okay, but It is the log that has lost in mass Not the E B K that has gained in mass during the internal so maybe We end up only measuring a new relation. I compared the log to the I B K and the relation is now 0.9 okay, but What I want to measure is the mass of W and not the mass of the I B K But obviously the relation is will answer That there is no difference between the two situations If you admit only relations mass relation you cannot make any difference between the two situations where in one it is The W was lost in mass and on the other end it is the I B K which has gained in mass You cannot just do this this make this difference Because there are no absolute magnitude So to answer The relation is this is the first version of the argument okay, but The change in mass is actually measured in kilogram in a specific unit So this means that Even 20 years later when I say that there is a change in relation a change of 0.1 kilogram When I say this to be meaningful I have to assume that that During the interval the kilogram itself hasn't changed Otherwise, I couldn't measure meaningfully the difference in the interval Yeah, so this is just the postulate of fixity. This is nothing new compared to what I said before but the bricks on the argument here is that the IPK stability Cannot consist in a relational stability because The mass relation has changed in the interval So if you are a relationist You said okay, I have to postulate that my standard is fixed is still more But if you are a relationist this fixity could only consist in the fact that it keeps the same relation But you have actually measured that the relation has changed So you cannot at the same time measure change in mass relative to the IPK and be a relationist about the fixity of the standard Okay, I don't know if it's the argument is sound or not, but I hope so. My conclusion is absolutist I think that we have to assume That the fixity of the standard means that it keeps the same absolute And not that it keeps the same mass relation because otherwise we wouldn't be able to measure change Non-change I don't want to discuss but could you just repeat what it means to be the postulate of the fixity for the relationist? We don't go to the metaphysical position you choose To be stable as a mass standard is to keep the same mass But depending on what your option is you analyze Differently what the same math is if you are a relationist having the same math is to keep the same mass relations But you cannot keep the same mass relations if what you measure actually is the change in the relations So the stability can only be absolute I'll skip the objections and responses. Maybe we're going to that Q&A Okay, so my conclusion for this first argument is that If you are a relationist, you assume that the IPK is fixed That is that it keeps the same mass relations to all of the massive objects So if you are if you think that either The IPK is indeed relationally fixed But then you can measure no mass variations And you assume that you are in some sort of a chaotic world where nothing actually changes or You assume as we can see everywhere when you look around that there are mass variations And they can be meaningfully measured So the stability of the IPK must be understood independently of its mass relations that is In an absolute manner Okay second argument There may be a way out for the relationist here because you could say that the stability of the IPK consists consists sorry in this specific relation that the IPK 20 years later is as massive as it was when it was created So maybe the stability of the star that could be relationally understood through some sort of inter-temporal relation like this A relation as massive as between the same object but at two different times And It's good because actually metrologists are trying to check and see whether the IPK is indeed stable or not So actually these kind of comparisons between the IPK now its mass now and the mass it had before could be not directly measurable but could be through model constructing and so on empirically checkable So here I've put a quotation from a series of metrologists in a very famous article Redefinition of the Kilogram and Decision whose time has come they were pushing for shifting to the Planck's constant definition of the Kilogram The IPK they say can be damaged or even destroyed it collects dirt from the ambient atmosphere and must be carefully washed in a prescribed way prior to its use It cannot be used routinely for fear of wear and damage and it seems that its mass This is very strange actually as a sentence It's its mass may be changing with time with respect to the ensemble of PTER standards of about the same age perhaps 50 micrograms per century We cannot be certain of this obviously because We cannot compare the IPK to itself and this would be the only way to be sure of this But I haven't put here the diagrams but when you see the diagrams from the intercomparison There were three names of comparisons in a century and you see that the IPK is drifting away from its copies. That's really weird and we actually didn't understand why And in the last intercomparison I think it was in 2010 something like that The drift just stopped So it didn't come back but to stay at this distance that's really weird and we don't know what But we find those kind of statements that say The standards have drifted off So many micrograms in a century in a century Again my claim is that this kind of statement to be meaningful implies or requires that the mass Of the IPK to be is an absolute magnitude and not a relational fact To prove it I need two premises First that the IPK is only Standard of the kilogram and actually this is true in virtue of the token base definition that I displayed earlier We only have one primary standard of the kilogram one one one and only realization of the kilogram Otherwise it would be simple if you had two Miso practical two realizations of the same unit you could always very meaningfully compare one to the other Then check if it has varied or not Premise be The IPK is a persistent object Meaning that it is the same object as it was Before or when it was created. It's important because What you will see Although obviously this properties could change this mass could change even if we hope not I suppose that you have this kind of relation That the IPK is now It's times less massive as it was 20 years or 100 years ago Here's my agreement First this relation being x times less massive can only be of second order That is it can only hold not between Concrete object that is first order relations, but between states or properties or relations of objects, okay And once I have Established that I will say that the consequences for relationism is Are very bad But this is a crux of the argument Suppose that this relation is of first order So it's related are concrete objects What are they what are it's related? It cannot be the IPK with another standard of mass Another realization of the kilogram because it's the only one Premise a It cannot be that the IPK is compared to itself Not because it would practically Because when you say that the IPK is x times less massive as itself, it is just nonsense An object can only be as massive as it is and it is trivial so You cannot say that Or you could also try to consider That the IPK then and the IPK now are two Distinct objects and then you can have a non trivial relation Being as massive as or being x times less massive as this would be non trivial, but it is forbidden by the second premise Because this is one and only object the LPK not two Time-intext objects So The conclusion is here is that this is a second order relation And that it's related are the mass of the IPK Before and the mass of the IPK now This is not an absolute this conclusion as such this is just About the statute the status of this relation So now now suppose that this relation is of second order Of course, there is an absolutist possibility here. You can say that yes This relation relates The absolute mass of the IPK before and the absolute mass that it has now But if you want to stick or to save relationism here, you could say that No, it's not here that you should say this Yeah If you're a relationist and if you say that The IPK has a different mass before and now has a new mass or a different mass You should analyze this mass of the IPK before as a bundle of relations And also the mass that it has now has a bundle of relations to other massive objects So Here my conclusion is that if you refuse absolutism here, you have to go back to my first argument Because now it is again not possible to understand its Sure stability when you measure other other objects to understand it in a relational way So you actually go back to the first argument when you Postulated that its stability meant that it keeps the same mass relations with other objects so actually the two arguments are kind of walking together to Make sure that if you are a relationist, you cannot at the same time Ground the fact that that metrologists Track and measure the change in mass of other objects And at the same time try to check and measure The stability of the IPK itself But they do But so if they do Relationalism fails to account for this kind of measurement practice Okay I'll be quicker on the two following arguments This is purely metaphysical of this one, which I call the theoretical argument. It's not maybe not a perfect name Imagine let's just suppose that the IPK is Perfectly stable because it is made in a A metal alloy that is perfectly stable A bit like Epicurus God's work, material, but not correctable But suppose also that we live in a world which is criterion Meaning that everything else changes Every other mass changes So if you are an absolutist Well, it's good news because you have A perfect standard a standard which is perfectly stable and this matches your your most The most crazy dreams But if you are this is paradoxical if you are a relationist This is a nightmare because even if The IPK is in a perfect metal alloy Since its relations to all the other objects are constantly changing You have to say that its mass is also constantly changing So this is not an argument. This is just something to That struck me once because From an absolutist perspective, this is really good That you have a perfectly stable standard but from a relationist view, this is a nightmare But maybe the relationist move would be to say that Okay, we don't know if the IPK is actually stable or not Perfectly stable or not, but what we can do is to manufacture I don't know and official copies In the same alloy And this is actually what the meteorologists did in the 20th century And you can periodically compare One to each other to To at least Establish that they are relatively fixed one to another Even if there remains a possibility that there is a common drift that you cannot Empirically assess this This would be as Zhang would say This would be perfectly sufficient to Make mass measurements and to operationalize your concept of mass Okay, so this I would call the Class of the stability class solution from the relationist But now suppose that you manufacture a new copy of the IPK So this means that the IPK gains a new mass relations with a new object That is included in your stability class or stability grid, right? And obviously you won't say that because strictly speaking You don't have the same relations as before because as a new You won't say that even if you are a relationist, you won't say that its mass has changed So I draw from this that The relational stability Of the IPK is Indifferent to the number of its stable relations as long as the relations that it has are stable Stay the same First First part of the argument now the same thing can mean can be done With the type of mass relation that it has suppose now that In your stability grid in your equivalence class if you're reaching out You add a standard for the middle ground now Because for practical reason you need it Well now the IPK also gains a mass relation being One thousand times as massive as this new object that you had And obviously for the same reasons because it's purely practical Not ontologically meaningful You won't say that the IPK before it gains because it gains a new relation Will have change in mass So the IPK Is also stable relationally stable Even if the type of its mass relation changes So actually if you are a relationist You have to say that the IPK is stable as long as There is at least one object with with which it has a stable relation And no matter the number of these stable relations and the type In the the type of those stable relations But the consequences I feel interesting because There is actually nothing privileged about about the objects that it has stable relations with So it actually ends up Being perfectly trivial because all you're saying when you say that all we need are stability class in which we could make intercomparison procedure and so on Actually, all you say is that the IPK is stable because it keeps the same relation with The object with which it has stable relation So it's again completely trivial Now last argument About material standards It's from causal asymmetry Actually, there are practical situations in which You can make Action you can do things to your standard for instance cleaning it washing it that has effects on its mass And as we already Seen It is standard procedure to wash the IPK before using it So and washing it has an effect on its mass I claim that this also puts relationism in serious trouble So to see that suppose Suppose that you are in an initial situation where you have the IPK and one of its official copies k1 That are perfectly equal They are in the relation being as massive as R1 And imagine two possible patterns On the first you clean IPK So this is the first c you clean it while the copy is stored under vacuum and Receives no source of influence whatsoever Then after you compare again the two and the IPK is found to be 99% as massive as k1 I mean it's normal because washing and cleaning it It removes some matter on its surface. So it's normal On the second possible scenario You subject k1 to pollution and we know that when there is too much mercury in the air There is a chemical reaction with the surface of the alloy and some matter is stuck here Stuck here While You know, this should be IPK here While the IPK is stored under after condition Then you make a new comparison and you have the same results Because now it's the copy who has gained in mass Well, this is me the absolutist speaking obviously But from the relational point of view the results both results are the same Okay, so in in both scenarios The same the change in the relations is the same But there are two distinct causal scenarios Because the cause the causes are different In one case we wash in the other there is mercury pollution So the question is how the relationalist could account for the fact that two different causes Produce the same effect. This is not a problem at a such We can't think we can think of two different causes that Sort of converge to the same effect. This is not a such the problem first question This change from a first relation to the second relation between the two objects Is this change ontologically primitive or fundamental? Not reducible and usable in something more fundamental or Does it metaphysically depend on a change in at least one of its related? I think this is a too exclusive and mutually exclusive In the first option You have to think that the the cause be it c or p here Was a cleaning or pollution You have to to think that the cause directly acts on the relation itself Which is hard to to conceive of Just suppose that you can make sense of it So there is a cause who directly changes the mass relation between the two Okay, maybe in the the second option The cause acts on one of the two relays Therefore changing Its relation to the other Okay, well, I will argue that the first option Doesn't work and that we have to Choose the second What first is how to see how something can act on a relation Relations are not anywhere. They're not between the object. I don't know where but a cause is or acts locally So Where is the relation that we that that is acted upon? I don't but let's put that aside If you are a relationist You have in this solution in this first option You have to remain blind as to Which later is acted upon Because you assume that the relation directly acts on the cause directly acts on the relation But this leads to absolute consequences Because you could absolutely clean Instead of the IPK you would clean the copy K1 So this is the same cause But if you clean the other relays later Well, the Resulting relation would be the opposite The change would be from relation R1 to relation R1 Point and or 11 something like that So like you would end up in a in a situation where the same cause Causes two opposite effects and this is Contrary to and determinism Something like that so The relationalists must turn to the second option In which a cause acts on one of the two relays later And changes it in some way Of course You can be here absolutist And you can say that the cleaning for instance the cleaning acts on the absolute mass of the IPK changing it and Therefore changing its mass relation, but if you are a relationist You cannot say this I think that your only way out would be to say that The cause acts on I don't know another more fundamental property of the object On which its mass Its relational mass Depends or supervins or Is rounded I don't know But that would imply that mass Is not a fundamental property, but It rather supervins or depends on another aspect. This is what Martins calls weak relationalism You you keep being a relationist About mass, but you admit that mass is not fundamental And Is grounded maybe on another entity, which may be also relational on his part But my answer would be that you should repeat the same argument on this new quantity, which is more fundamental and so on So I think that the conclusion here is Either that there are nothing fundamental and it's grounding a relation all the way all the way down or that Absolutism is right So maybe we'll speak about Constance and type big definition in the Q&A Thank you No, so questions I don't want to seem to be unfair, but your relation is very stupid Okay All the practice that you describe presume Absolutism All of them None of them try to become your relation is is a some kind of relation is that Is epistemological, but does not really believe in this ontological status of relation The way you argue goes against you were exactly the same So I understand how it could be complicated to to make sense of these Practice for a relationist, but but it's maybe not impossible, but you need a relationist that is more subtle For example, when you say a relationist can tell if mass is a relation Relata Should you should never talk about mass? Even in the relation you should not even talk about massive property of the relata Okay, your standard cannot be understood as a relata that is a standard So You have to understand as the notion of standard in a completely different way If it's if it's related to a something in a box somewhere And I would encourage you to to look at the the standard that's cupidia a paper of rovelli on on on Relative Yeah, the relational not that it's quantum mechanics, but at least Because in quantum mechanics They try to make sense of what would be property of relation that are not connected to the relata by themselves So in that case when you make an argument a relationist cannot say that about this relation A relationist cannot say much a lot of stuff about a single relation You need another relation to talk about the property of the relation because a relation by itself If you don't have access to the if it's not purely an effect of the relata You cannot talk about it directly. You cannot say much About three kilometers. I cannot say which one Is it a difference? Is it it's just three? But with another relation like a causal one or something else or whatever. I don't You can say something about this relations But it's but it's but it's not the same because now you have two relations So you cannot isolate the property of the relation from the fact that the kind of way you used To build another relation to talk about it So so so and that in in if you start like that I think you could avoid the obvious way an absolute case could say But of course you're talking about relata And it makes no sense for a relation if it's just relation are a derivative A derivative aspect of intrinsic properties absolutely But I but I see how the practices you're described the practices to keep something in the box It's clearly The presumed absolutist by default. Yeah By that's the that's the standard way to understand the practice But if if you're serious about okay mass is a relation I'm not sure it's a good idea. I'm just saying Someone would really like to defend mass relation. It's exactly like how do you define Relation in monads, you know, it's not just looking at relata. It's complicated I don't so it's a suggestion But I don't see how I could apply it in this literature I could try I could be could be but I don't I don't why I asked you what what do they mean when they say a quantity is a relation But what do they mean metaphysically about that kind of relation? Isn't just epistemological is the way of the measure quantity or always are they saying something? A mass is a relation What do they mean? metaphysically You you won't find this kind of sentence mass is relation But you will find that the sentence is like There are only mass relations Or sometimes mass ratios Even if it's not meaningful to speak of relations without yeah ratio That's sometimes yeah ratio. It's absolutely a relationist speaks of Speak of mass ratios, which is weird. Okay. Okay, but I don't want to make a case about it So the relationism about quantity today Maybe But maybe they are epistemology No, no, no, it's pure ontology They have epistemological arguments The descriptor for instance says that Well in measurement practice, we only access to comparison So relations so Absolute masses are not Accessible so we should get rid of it because In virtue of some economic principle But there are only mass relations among Let's try to take an easier case. So if you see that distance Is purely relational so it makes no sense to talk about position at all Position is always relations And you would say, okay, I want to operationalize the notion of position. So I need something like a standard of distance, but I There's no related Okay, these relate that makes no sense because position does not exist only relations Spatial relations, you know like this if you want to be a relationist about distance you won't Need positions you will need You will say that you are you you have space intervals Which are the relatives here And that space intervals stand in distance relation in a yeah in distance relation Not that they are distance with the chosen but that's But when I will build my standard doing I will have the same problems according to you the same four arguments should work should go against if you are A relationist that is not really a relationist, but if you are pure relationist if you see I guess you could you would say distance distance makes no sense whatsoever I guess outside of two things you could say for instance without yours your relation is standard could be the relation between the This distance this length And maybe the length between the earth and the sun so you have two space intervals Okay, and your standard would be the distance relation not the distance between the two but the distance the length relation between the two people sure But I don't know and this is maybe maybe the question if you could use A relation as a standard Or maybe not used but reconstruct the whole Theory of length using this as a basic I don't know There is obviously a drawback in this Which is that in practice you attribute Measurements result two objects not two relations, so But that that's the very part of relations They have to buy a new metaphors This relation will not be just Entry conversion of intrinsic property of objects they buy that they're such a thing as Something on the logical the relation that is not in either of the related That's the relationist service relations. I don't know it's a good idea, but It's what they try to argue at least But I don't think that the the relationist Open it here That's stupid, but Your arguments are pretty obvious when you think about it So no, no, but they are extremely well designed, but they should have This the relation is you're describing I've been around for a certain time they should be I cannot see that they didn't see the kind of arguments we proposed. You see Yeah, I don't say obvious the obvious after you explained it to me, of course that that's before but If I pass my life about standard and relations And a different relationism. I should be able to resist the washing and the Acid tree of causality. That's something I should have thought Well, but to just to draw the picture here the Actually most discussed argument against relationism is the escape velocity argument from Which says that we need absolute mass magnitudes In certain cases to explain in a Newton Newtonian gravity to explain Uh, why A body who is living around Big massive objects can exist and escape Or not For instance, you have you you only have two bodies in the universe the satellite If you just have the mass relation between the two and no absolute magnitude On one case The satellite wouldn't escape, but if you double the masses That relation is the same, but the effect would be different Maybe the satellite will crash or escape or So there there are dynamic differences While the relations are not the same So this is the same relationist that I took here as an argument But I Stuck his nose or her nose on practices And I don't think that we need to invent a very clever Metaphysical Fictional situation to to criticize Over questions One half questions About what like someone say like for your four arguments, I just the first one is quite More or less explicit They look like version of transcendent argument in a sense For the meaning of stuff But if I'm a relationist for these kind of situations I think like there is a very There's a Easy way to use strong strategies against transcendent arguments to escape Your argument and say well I just need to believe that there is a fixed point instead that exists But just a useful fiction that I use As a way to fix stuff is speaking But it doesn't mean that the metaphysical in you But it translates metaphysically to what exists in the world And see that most arguments there could be very bad Okay, that's a nice advice Well, partly it is an advice that I should not Say that this is a transcendental argument I didn't say it But in order to avoid this kind of answer maybe I should not I keep I should keep on not saying it And Partly maybe I don't It's you to tell me Yeah, is this assumption realist assumption Compatible with your Strossonian Move or not This is the assumption that objects objectively or really have magnitude Whether these magnitudes are relational or absolutely And this also applies to your standard So when you say that it is fixed that it is stable You are saying something about something is real It's not just a fiction You are saying something about the way you understand that what is fixed I mean because In the first argument you have correctly the principle of fixity was there to Avoid you be able to say well, I don't know which one has changed But It's a question of If you say we're changing belief of We are not changing, it's not a question of which one has actually changed in the world So you claim the right to Make as if One changes and the other This is maybe close to what Dean said Is not very famous but he said In a paper that We have to include This stability aspect in the scaling convention On the choice of the standard Because in this way we have no ambiguity problem When we measure things Maybe that my balance is not right Maybe that the IPK has Gained in mass during the holiday, but I've eaten a lot of cakes and I have less weight Okay, this is anonymous. So It's good Yes, I'm just saying it's a way that our students could answer to that Yeah, okay And another thing if I may just continue another thing One of the things I was That I found here maybe was about the identity of the IPK because So there are different parts of your talk one which was against the one you talked about APK in 1889 being the same as the one in 1989 Sure, you have the same identity but the Because the identity includes the mass Can your object It can keep the same identity so you can say it's the same object, but the mass would have changed and Keep it the same identity So it's not an issue but I don't see why you Couldn't why you have to use a principle It seems to be a bit too strong Pre-premise being It seems to be like too strong for an assumption Well, at least the way you use it I said that it was the same object Yeah While allowing its properties to change Yes, but the argument after one you Use the fact that they have the same If they should have the same mass Because there is this sensation to Consider the two as two distinct objects And if you do that You actually have to choose one as the standard I think that the most natural way to go would be to choose the IPK In 1980 No, it should be an eight other To choose this one the first IPK at the time when it was manufactured To choose this as the standard But this would imply big revision of All the SI brochures of all the definitions become because now you have to say that The unit is the mass of This object which does not exist anymore And you would have to conceive of your mass measurements as comparisons with a vast object Isn't that exactly what we are doing in practice? Up until the change of definition of unit I think that this I didn't put it in the slide but I hesitated to put it in the paper This is Not a good way, but a coherent way to be a relationalist It would be to say that This vast object which does not exist anymore is your standard And obviously it cannot change because it is a Point even maybe Cannot change. It is a trivially fixed And to reformulate the Postulate of fixity by saying something which is not trivial is to say that the IPA now Or the object that now we call the IPA Is in the relation as being as massive as The past object That this is Really not Very finite Yeah, yeah, it is coherent And I try to Find weak spots on this but I didn't And the other question I thought he was about when you are talking about the washing stuff You have to wash this off The IPK is not done But what you wash is The mass you take you are taking away is Not supposed to be the mass of the IPK It is the only IPK You said you said it is the mass on the surface It is not supposed to be part of the definition of the IPK So you are not changing the mass of the IPK The metrologists hesitated When they realized that The unit of mass is the mass of the IPK After being cleaned and washed They hesitated whether they should Notify the definition or not Because it is a matter of designation And they choose not to Notify the definition but only to add To add as a rule That it is only to be used After being washed and cleaned But It is only because there are percussionists And we could We could imagine Not percussionists Metrologists who have A varying standard It is very bizarre because When you see the curve The IPK loses Lots of mass In one or two or three Cleaning procedures And game to game In a few months You can see the curve It is really strange In maybe six months It has gained all That has been washed up That's weird Especially in the vacuum No, it's not in the vacuum Do you only consider the memory In physics I know that the memory in economics Is very different Because It is a stable, fixed point In economics And we have talked about Contemporary economics Is always very flexible Even though I don't have any examples How do you think about Your idea Is only based on physics Or considered or may have many insights This is an important question As to should we admit Of quantities outside the Natural brain What counts as quantity or not But they are Opposite, obviously And in the human or social sciences I would tend to say That there are no quantity at all So Yeah, maybe you give me an example Of quantity in economy I don't know Inflation Growth Measure Domestic products Oh, measures Happiness Index of happiness There's a lot of work But do these quantities have Units, for instance This is the main question In economy Economists Always try to translate Sentences about prices About growth, about inflation In real value Real, income, real Lava and That's Do these real quantities Have units, I don't know Is an employee going to change his sense Is an employee going to change his sense Money? Like a dollar or Yeah, but in Economy theory, you don't have money You don't even have this money You could try to Fake it and say that like The 1990 US dollar It's like the The unit of value I suspect even Economists would say That's some kind of fiction That's some kind of It's a helpful way Most of the time In economical theory, you talk about Value, you don't even talk about Money You never define through the market So it's not that clear What is the unit there? But it's not Mostly not In economical theory No, you have to Take the money away To measure real Value growth I don't have The answer to your question Other questions? I don't want to take the placement The escape argument does not work That's great If there's only two Objects in the universe So you have They are turning Or If the escape Cannot say which one escape Because both of them Become to have an inertial movement at the same time The argument Would say If I put more mass on the big one Nothing happened If I put more mass on the small one Suddenly I can have Escape or not But that makes them stand from a relational Point of view Of mass on the big one So you already presume Absolutism in the argument So show me the argument And if it's that dumb We'll have a paper against it Okay, I will send it to you But I don't want to Write A relation with paper It's to improve The absolutist That already are winning I'm sure In some sense It's got a lot of echoes Of the Substitutism movement Space time arguments Where you have to take the move that says If you're going to make it go through You have to take the move that says Your mistake isn't thinking that those are Two different possible worlds But they're not Even though they seem like they should be They actually aren't I think that's part of what makes this whole thing Difficult Is that maybe somewhere in the background A really dedicated relationist Is going to make some similar kinds of moves In some of these cases What you've actually done wrong Is you think you've described Two different states of the world And they sound like they are And they seem like they are But in fact you failed to describe Two metaphysically distinct possible worlds You've just described the same possible world With different words And I mean that's always I've always found those arguments I wrote my bachelor thesis On periods of space time I've thought about this I spent like a year thinking about Nothing but this for a year I have a hard time because It's really weird It's hard to have intuitions about that It's very hard to have intuitions About But I do think it's two different possible worlds Like what even How do we How do we push back on that I've never had a very good answer For like if that's what someone's response To you is You think you've forced me into a mind But actually you've failed to distinguish Two different states of the universe Like I don't even know What you should say to them If they tell them that Right? The gist of Baker's argument Would be that we could Make this distinction By Exhibiting gravitational effects A difference in gravitational effects In the last part of the paper I have a similar argument That's known as A doubling argument Because if you double all the masses In the universe The relations stay the same But you have two different situations And the relation is just Answers No, they are not Two different situations It's just your intuition speaking So you have to Answer to this No, it's not my intuition It's just not an intuit That those are two different situations But I know Because I can make this difference By showing Potential effects Or in the last part of the paper I Considered that the Kilogram Be defined with reference To the Planck's constant And suppose that The Planck's constant suddenly Changes And then You will have More than a dynamical effect But a metrical effect To Make the distinction between the two situations A shift in the Planck's constant Would preserve all the mass relations Among objects But Changing others Not directly the masses maybe But the masses that you measure Through the Kibble balance Something like that And then you run into all the kinds of stuff That works on about Changing fundamental constants feels a lot like Changing laws It's going to have all the same kind What is really interesting About now that they use constants Is that you connect a lot more stuff So if you change something here You say oh yeah But I will Compensate exactly I have to change more and more stuff around So it's Like if we're wrong about the value of C Like that would be really weird Because that shows up everywhere But if you Based on the Planck's constant Because if your mass ratio is related To the The Planck's constant But Planck's constant appear in Other kind of physics Other kind of None just mass or So you could say oh okay If change here I don't see an effect But I see an effect there I would know that maybe it's the Planck Or something else but still So it's more and more A whole less conception of units And everything works Or nothing works Yeah You could for instance say that If the Planck's constant changes Your mass measurement won't change But your Frequency measurement Changes because of frequency And a constant frequency And mass are tied up in the definition You don't know how to get here But I just did in like 30 seconds How do you How do you do that How do you integrate that into the view that you present here Because you were saying that you wanted When you were talking about standards You were talking about standards like stuff Like those are concrete Do you want to say that then like Planck's constant becomes one of those So you want to talk about You mentioned like you have to make Then you have to fabricate standards So yeah how does that work Just give me 30 seconds So balance Which ties A body with its mass to Some electronic quantum effects Here And you just have, it's not a logic But it's an equation Which is made of a different equation You have an equation that Is relating the mass Here And the frequency Of the body Through the Planck's constant Very basically So you Can just fix the value of the Planck's constant And say that The kilogram is the mass Of a body with such frequency Basically Cool, so you could make A 15 material standard I want to read about how that balance works That's actually super cool, that's ingenious as heck There's a lot of debate As to Is this really a sound relation Between mass and Planck's constant because This is not the same type of relation That we could call a law or something Or a law or something like that This is really Hunt made Yeah it's one thing but it's the speed of The speed of line and meter because In theory that's just some mirrors And move them To get the interference right Cool, but yeah That sounds a lot more complicated than that That's cool Can I just have a really Nice question because I don't Follow this discussion a lot So Could you just say that The standard That we have now is a meter Per kilogram seconds Are always defined in relation To one another The different standards of Different quantities Yeah, so just Meter as far as I understand Meter is defined as The duration No the length of speed of light In one second right Or zero in something seconds I don't know It's something like that right The new one Yeah one Yeah all the seconds right And then the second is defined As But it's not here Yeah I bet you had it somewhere It's like the radiate and the decay So what if you just Changed that You can't define These units Without Other Units Yeah It wouldn't be like a claim You know that's Completely relation Which is that the units are always Relational because I was thinking I don't know I think about physics But if you have the radiate The decay of the cesium Atom right The frequency right Is this like With gravity Zero gravity When does it like Does the gravity actually affect The frequency or not If it does Then it's always With the wobbly There is an extensive Literature on the fact that With the new International system of units Units We wouldn't say that they are Relational between them because They are different quantities If they have relations It's an atomic relations But There is an extensive literature on the fact that Now they are co-dependent And they are not defined Independently one to another So When the units were Defined directly With material objects They were perfectly Independent But now It's based on law Of nature To take the example of the matter You cannot Independently Define the matter On one hand And the second and the other Because what you are Actually referring to as a fixed point Is a speed You should That's why in the new System International I love that The measurement literature I can speak in French Clearly In the System International So units are not Defined independently but Based on seven defining constants So you just have a base Of seven independent Fixed points And on that You have seven co-dependent Definitions Well, maybe the second Actually is more independent Than the other But this is an exception Because it's not actually defined With reference to a constant But Are they circular or Not the co-dependent It just smells circular No, there is not This is holistic But this is not circular Because you have seven fixed points So with seven fixed points You can define Sufficiently seven other things Right? I saw in the practice that you define If stuff really are different So they increase the coherence Confidence Because you have different practices And you need different definition It's circular in the sense It could Matter It could be You could make a circle But you test the co-dependent system As a whole It's all closed Or it's all failure Yeah, I'm not saying it's all coherent But it's impossible to actually Define them independently And the meter example You can't just define it As that stick in France It's also not exactly scientific Well, it was That's a choice They were not forced The new system was a choice So it made some choice Decided to do that The bad consequence Of these new forms of definition Is that you cannot now Measure these constants You cannot because Their value are conventionally fixed If she changed We wouldn't be able to see it Except If If there are I don't know At the verge of the Metrologist community A very resistant little group Who keeps on measuring length With the metal bar Keeps on measuring Masses with the IPK And then maybe they could With using Kibble balances Measure variation H Well, I was Shocked when you put up that quote It's the kind of thing You don't realize how circular it seems Until you point out that it's circular When they say that the mass of the IPK Can't change by 15 anagrams Or something and you're like Wait Obviously now about the new definition We might be allowed to say that But I mean it is Very interesting I really like that argument It's just It's metaphysically impossible to say that On your definition That's literally nonsense Well, maybe it's not nonsense But epistemologically There is strictly speaking The circularity that forbids you To To conclude this statement But they are A statistical causal reasoning That could Allow you to Produce Very good How could you say it's metaphysically nonsense Because It's compared to the one in the past To which we have no access But still exist As a past fact So we cannot check it That's true It's metaphysically nonsense It's just Non-accessible It's Metaphysically nonsense if you don't start putting indexes On every time you use the word Fair enough That's what you have If you do G So 1950 And then G is 2010 Then you're Clear What the heck is a G1950 We have no idea what a G1950 is That's useless But metaphysician Do not care You're right That's a fair point It's almost done anyway Be your time Thank you