arfa brane:
And I'm really trying to tell you that mass and velocity--the attributes of entities, whatever that's supposed to mean--are not numbers.
When you say "attributes", I'm not completely sure what you mean.
Must an "attribute" be somehow inherent in an object, or can it be something that human being associate with the object?
For instance, consider a beautiful red rose. Is it acceptable, in your opinion, to say that the rose's attributes include its redness and its beauty? Or is one or both of those things not an attribute?
Let's assume that beauty is an attribute. Is that inherent in the rose, or is it a property that humans assign to the rose, to describe it and to understand it? If we were to give an alien being a rose, do you think it would be able to examine the rose and correctly assess the "beauty" attribute? Or would we need to explain the human concept of beauty and how it is judged, before the alien could decide on whether the rose has beauty as an attribute?
Next, consider something like the rose's velocity. You say that's an attribute of the rose? Is it inherent in the rose, or does it depend on some kind of human-constructed definition or description as well? What would an alien have to say about the rose's velocity?
I can imagine that an alien would very likely share with human beings some concept of distance and time, although no doubt it would call those things by different names (but a rose by any other name etc. etc.). So, once we established a mutually-understandable language, we could certainly talk to the alien about the velocity of the rose. But that still leaves open the question of whether the rose's velocity is something inherent in the rose, or whether it is just something we can talk about in relation to the rose, using other concepts we have defined.
I'm interested to hear your opinions on all this.
This doesn't mean the mass--real physical mass or real physical atoms--is a number; it means mathematics can only logically treat mass as a number.
When you talk about "real physical mass", it sounds like you're thinking of something inherent in an object. Thus, you would say that somebody could examine a rose and find its mass. But if you and I would say the rose's mass is 200 grams, and the alien says the mass 1570 urgrunts, then what? It seems like we need to understand something of each other's language to convert between grams and urgrunts. And if that's the case, is it still fair to say that the mass of the rose is entirely contained within the rose - or would it be better to say that the most important information about the "mass" of a rose is contained in a bunch of concepts and definitions that are independent of the rose?
Likewise for a numerical amount of charge, or anything else which is physical.
Can you isolate the "charge" of an electron from the electron itself?
You say that "charge" is "physical", but what do you mean? Charge doesn't seem to me to be physical, in the same way that a rose is physical. The rose is something I can pick up and put in a bottle; then I have a bottle full of rose. But I can't pick up the charge of the rose and put it in a bottle, and then have a bottle of charge. So, explain to me in what sense charge is "physical"?
If you mean merely that we can associate a particular number with an object and refer to the "charge of the object", doesn't that make charge a number, rather than a "physical thing"? What's most important about the electrical charge of a rose is the concept we have in our heads about what electrical charge is.
If I'm unfamiliar with roses, you can point to a rose and just label it: "That's a rose, there!". But if I'm unfamiliar with electric charge, you have a LOT of explaining to do before I can understand what you mean by the "charge of that rose, there".
But using numbers for physical things doesn't make the physical things into numbers.
Okay. So tell me what makes "charge" a "physical thing". You must have some working definition of "physical thing" that you're using. Tell me what it is, so I can understand.
James, you have nothing to offer to the discussion. Nothing.
I think you have a very closed mind. But let's give it one last try, just in case.
Here's what I think exchemist and James R keep getting wrong:
They fail to distinguish between a theory, with its mathematical equations, and observations or measurements (always physical things, although you can't put observations in a bottle, but, . . . never mind).
I think that the distinction between theory and observations is
precisely what exchemist and I have been trying to drill into you. Strange that we each think the other has the problem. There must be a communication disconnect somewhere - or a failure of one or both parties to understand something.
I say that when you say "The charge of an electron is 1.6 x 10^-19 Coulomb", you're talking about a
theory about the electron. I can't find 1.6 x 10^-19
things inside an electron. The electron isn't made up of 1.6 x 10^-19
things. I can't extract the 1.6 x 10^-19 Coulombs of charge from the electron and thereby have a bottle that contains just the charge, without the electron. So, I ask: in what sense is the charge a "physical thing"?
As far as I can tell, "charge" is just something we define, and then we use it in mathematical models to describe and predict how an electron will act in interaction with certain other things: e.g. electrical equipment used to measure charge. To build that equipment, by the way, we needed to build in a definition of charge, implicitly. That came from
us, not from electrons or equipment.
Please note: I am in no way arguing that charge isn't real, or that it doesn't actually exist. It is an incredibly useful concept, because it turns out that it is a mathematically conserved quantity in lots of situations. Each time we measure the charge of an electron - with properly calibrated equipment - we find the same answer. But that doesn't imply that charge is a
thing (some
stuff) inside the electron, any more than the beauty of a rose is a thing inside a rose.
The theories do not tell us what the physical things are, because theories use mathematics, and so the physical quantities are translated into mathematical quantities.
Please explain to me how it is possible to "translate" a physical quantity into a mathematical quantity? What do you mean by "translate", in that sentence?
If the charge of an electron is a physical quantity in the electron, how could we possibly "translate" it into the number 1.6 x 10^-19 Coulomb? That would mean taking some
stuff and making it go away, only to be replaced by a number on a computer screen, wouldn't it?
But maybe by "translate" you mean something more along the lines of: we make a particular measurement, using calibrated equipment, and then assign a number based on the readout on the equipment, which has built into it a human-generated concept we call "charge". We then associate that number (1.6 x 10^-19 Colomb) with the physical thing (the electron in the machine).
It is interesting to me that you said "translated" rather than "transferred" to "converted" or "moved". That implies to me that, despite what you keep saying, you understand that the charge of an electron is conceptually quite different in character from the electron itself. Am I wrong?
This in no way means you can conclude that a theoretical physical quantity, such as mass or momentum, is just a number. It is theoretically just a number, but that can't be objectively true because mass and momentum are different physical things even theoretically, whereas "just numbers" are always "just numbers".
Tell me how
you go about distinguishing "physical things" from "just numbers". What's the simplest test you can do to tell the difference?
As an example, if "electric charge" is a "physical thing", tell me how your test distinguishes between charge being "just a number" from charge being a "physical thing".
Concluding that something physical is a number because a theory uses mathematics, is just wrong.
Maybe. What do you mean by "something physical"? That seems to be the sticking point, here. Explain it to me. How should I go about telling the difference between "something physical" and "just a number"? How can I tell, for instance, that the velocity of a rose is "something physical" and not "just a number"? How can I tell that the mass of a rose is "something physical" rather than "just a number"?
Mathematics does not say anything about where mass came from, or what it "really" is. Nobody knows what anything physical "really" is--see Feynman.
But your entire argument hinges on your knowing what "something physical" is, and what it is not.
I hope you appreciate the problem. If what you say is true, then the distinction you're trying to make is impossible to make. Your argument defeats itself.
Understanding physics involves understanding mathematics; physics is about real things, mathematics really isn't, unless we say so.
I agree that physics is about "real things". Physics, for example, can describe an electron and predict how it will behave in future, under various conditions. But it does that by using a mathematical model of the electron.
In what sense, then, is the mathematical model not about a "real thing"? Explain it to me.
