Is mass a number?

• Mass is a measure of a quantity of substance. It is not the substance itself.

You are blowing hot air to muddy the water in order to not have to admit you are wrong. You are trying to slowly change your statement that "mass is just a number" into something different, by blowing a bunch of HOT AIR!

You are fooling nobody but yourself if you think it's working. You have no idea who you're talking to!

I certainly am not arfa brane, so stop mentioning his views when it's me you're responding to.

You said, "Mass is a measure of a quantity of substance. It is not the substance itself."

NO! Mass is the quantity of substance itself, and you MEASURE that quantity of substance.

You still do not understand the difference between an object and a measure of that object! Learn the difference.

Objects have a quantity of substance, which is measurable using numbers and units! The object has a quantity of substance whether you measure it or not.

What you are claiming is that mass is just a measurement. Measurements don't have inertia! You still don't get it!

Last edited by a moderator:
You are blowing hot air to muddy the water in order to not have to admit you are wrong. You are trying to slowly change your statement that "mass is just a number" into something different, by blowing a bunch of HOT AIR!
I have been consistent throughout this thread.

At this point, we're 80 posts past the post where I wrote this response to you saying "mass is a word for matter":

People often talk about "a mass" when what they really mean is "an object with mass". Objects are made out of matter, so "a mass" is a euphemism for an object made from matter.

But that's not the problem that arfa brane is having here. arfa seems to think that "mass" is something inherent in an object, rather than just being a number with units that we associate with an object.
If the water was muddy for you back at post #100, it should be well and truly clear by now, since I've walked you through the difference between mass (a concept) and matter (substance, physical "stuff") at some length both before and since that post. It should be, but for some reason you're still struggling with a simple concept, just like arfa brane is. Or maybe you're not struggling and you're just trolling. It's hard to tell.
I certainly am not arfa brane, so stop mentioning his views when it's me you're responding to.
You both share the same apparent confusion. Initially, I thought you immediately grasped the point that he was struggling so much to grok. But then, for some reason, you lost your train of thought, or you decided you'd better have a silly argument with me for old times' sake, or something.

Now, though, you really have no excuse for feigning continued confusion. Either you're trolling, just trying to string out a silly argument, or you're actually stupid. You're in exactly the same boat as arfa brane. So don't complain when I compare the two of you. You've also both attempted the same schoolyard ad hominem attacks in response to my careful and courteous attempts to help you both.
You said, "Mass is a measure of a quantity of substance. It is not the substance itself."

NO! Mass is the quantity of substance itself, and you MEASURE that quantity of substance.
The word "quantity" implies number. It's right there, built into the definition of the word. All quantitative measures are numbers. Masses, lengths, time intervals, energies, momenta, dollar values, how many sheep you have, etc. etc. And numbers are, essentially, conceptual. Numbers are not substances.
You still do not understand the difference between an object and a measure of that object!
Strange that I just explained it to you (again), then, wouldn't you say? Am I wrong? How am I wrong?
Objects have a quantity of substance, which is measurable using numbers and units!
There is no dispute that objects are made of substances.
There is no dispute that a "quantity of substance" can be measured.

I say mass is the measurement you get when you measure a "quantity of substance" in a particular way. A quantitative measurement - mass - is a number, with some associated units. Both the number and the units are conceptual.

When you write down the mass of a rock, you do not write down the rock itself. When you throw a rock, you do not throw its mass; the mass is still on the paper where you wrote it down.

How hard is this? Seriously. How many different ways do you guys need this explained? Are you trolling, attention seeking, or actually stupid?
The object has a quantity of substance whether you measure it or not.
If a tree falls in the forest...

I'll leave you to your philosophy. We were talking about physics, I think.
What you are claiming is that mass is just a measurement.
What else would it be?

You can't write down a rock. You can't bottle numbers.
Measurements don't have inertia!
That was never in dispute. Didn't you read my last post? You seem to keep bringing up issues on which we have never disagreed. Why do you do that?
You still don't get it!
Sounds like trolling. Or supreme irony. Hard to tell.

By the way, you couldn't possibly have gone back and reviewed all the posts I pointed you to, in the time taken between my last post and your reply. You're not doing your homework. You need to put in some effort!

"Some men you just can't reach."

I'm done here. I'll leave you to your ignorance. I have no interest in trying to teach someone that has no interest in learning.

The only thing you're interested in doing is defending your BS in order to not have to admit you're wrong.

I'll leave you to your "mass is just a number" and consider you in the same category as George. "Educated idiot."

I'm done here. I'll leave you to your ignorance.
It's more likely that you can't think of a counter to what I just put to you, other than the bald assertion that you must be right and I must be wrong. Or, you're too wrapped up in your own ego and lacking in honesty and decency to bring yourself to admit to anybody else that you were wrong and I was right all along, even though you've now realised that is the case.

So, you're taking your bat and ball and leaving the playing field. That's just fine, though. You jumped into the middle of a conversation I was having with arfa brane and soon made it clear that you hadn't followed the arguments to that point. It seems that you haven't followed any of the ones put to you since then, either.

George is not an educated idiot, by the way. Maybe he was at some time in the past, but any vestige of an education is absent from his current posts. Now he's just another idiot with a one-track mind, as far as I can tell.

Bad form for you to attempt, yet again, to argue by insult, by the way. That didn't work for you the first time. What made you think a second pathetic attempt at the same tactic would go better for you?

Last edited:
James R is wrong about mass being a concept.
An amount of matter has mass, as I've stated previously in the same sense that transparent glass has transparency, or a resistor has resistance, or a red apple has a colour.

The mass of physical objects is a measure of the number of atoms; a number of atoms is NOT A CONCEPT. End of story.

James R would have you believe he's had some kind of insight into the way humans conceive of physics. I say he's full of shit. Do not discuss what mass means with this person.

You have been warned.

arfa brane is wrong about mass being something other than a concept.
An amount of matter has mass, as I've stated previously in the same sense that transparent glass has transparency, or a resistor has resistance, or a red apple has a colour.
I discussed this particular use of language in a previous post.

Yes, matter "has" all these things in "the same sense". The relevant "sense" in which an object "has" mass is that a number can be assigned to it denoting its mass. Similarly, a colour label can be assigned to it denoting its colour. Neither of these things means that mass or colour is intrinsic to objects, as I previously explained.
The mass of physical objects is a measure of the number of atoms; a number of atoms is NOT A CONCEPT. End of story.
Mass is not a measure of a number of atoms. Two atoms of hydrogen do not have the same mass as two atoms of oxygen, for instance.

But, since you mention it ... do you agree that a number of atoms is a number? Wouldn't a "measure of the number of atoms" then be a measure of a number? Wouldn't that make the "measure" a number itself?
James R would have you believe he's had some kind of insight into the way humans conceive of physics.
No. I just understand this stuff at a deeper level than you do. That's all. It doesn't take special insight.

Either you're actually stupid, or you're trolling, or you know I'm right but can't bring yourself to admit it. So, for whatever reason, you're reduced to this silly repetitive bleating you keep doing.
I say he's full of shit.
I'm sure somebody will take your word for it.

Mass is not a measure of a number of atoms. Two atoms of hydrogen do not have the same mass as two atoms of oxygen, for instance.
There it is. Your ignorance tells you that the same number of different atoms has different masses. How do you know this?
You can't work out that means their mass is a measure, that you just made by counting atoms.

You can do that the other way, right? You can weigh some atoms, right?
So that mass, and how it orders the periodic table of elements, is a measure of numbers of atoms, not a measure of numbers.
Unless you're too ignorant to see it that way. Which seems to be the case with you.

Jesus H, what a waste of time.

p.s. you couldn't help yourself when I posted the proposition that the concept of mass is in a human mind. Concepts are things in minds. Mass is a thing in objects, not in a human mind. But you jump immediately to the conclusion that I'm saying mass is a concept, when what I actually said was the concept of mass is a concept. The same way a human brain is . . . a brain.

Last edited:
James is confused about measurement and numbers.
The word "quantity" implies number. It's right there, built into the definition of the word. All quantitative measures are numbers. Masses, lengths, time intervals, energies, momenta, dollar values, how many sheep you have, etc. etc. And numbers are, essentially, conceptual. Numbers are not substances.
I'm a farmer who owns sheep. Some number of the sheep are all in the same paddock. The number can be written down, the sheep are already there.

The number is an abstraction of the things, a value which is not the things themselves: a number not a physical thing.
The symbols written down that represent this measurement of sheep, which is of physical things and requires a physical process so the symbols are written on something physical, is not a number, it's a string of symbols interpreted by a wet computer or brain. Also not a number . . .

A value can be meaningful, but it has to "have units" to be physically meaningful. Information is physical.

What does a physical quantity mean?
Is it always something that can be measured directly, in the sense humans can sense motion, of themselves and other objects such as sheep or tractors, or rocks that have been launched by a certain method?

In electronics you have the obvious abstraction that an ideal resistance, or other quantity, is not available in the real, physical world. The math works the same way because you want to be able to predict what a given combination of ideal components will do, given some defined input and output. But you also see that an input and an output can be chosen somewhat arbitrarily, since you can compare any two voltage measurements and so consider a part of this circuit, a subpart as being "voltage isolated"; Maxwell's laws of electromagnetism let you define either voltage as being at zero potential. It's a gauge theory.

Resistance, capacitance, inductance, are not numbers. They each have Newtonian meaning, because Maxwell came after Newton.

There it is. Your ignorance tells you that the same number of different atoms has different masses. How do you know this?
It would take too long to describe how I know this. In a nutshell, the reason I know is that I've been lucky enough to have had the opportunity to get a decent education, which I grabbed while it was in the offering.

But you can look it up. Periodic tables aren't difficult to find. They often have atomic masses written on them.
You can do that the other way, right? You can weigh some atoms, right?
So that mass, and how it orders the periodic table of elements, is a measure of numbers of atoms, not a measure of numbers.
Actually, the order of elements in the periodic table is based not on the atomic masses, but on the number of protons in an atom of each element.
p.s. you couldn't help yourself when I posted the proposition that the concept of mass is in a human mind. Concepts are things in minds. Mass is a thing in objects, not in a human mind.
You're still stuck in the same error, unable to separate matter (or substance) from the concept of mass, which is a property a quantity of substance has - or, more pedantically, a numerical value that is assigned to the quantity of substance following some kind of specified measurement process.

If mass really was a "thing" in an object, then in principle you ought to be able to separate this "thing" from the object it is "in", and put the "thing" and the object in two separate bottles: a bottle of "thing" (mass) and a bottle of object. But you already admitted you can't do that, did you not?

Here's a mass: "584000 tonnes". Notice how this mass is not associated with any particular object. It is just "pure" mass. Notice, more importantly, that I have written a number with a unit. Notice how the numner "584000 tonnes" just went into your brain and is floating around there. But I didn't just insert an oil tanker or a mountain into your brain.
But you jump immediately to the conclusion that I'm saying mass is a concept, when what I actually said was the concept of mass is a concept.
You can go all meta if you like, but you're just avoiding the main argument. I agree with you that "the concept of mass is a concept". Specifically, it is a concept of a concept. We can go turtles all the way down, if you want to continue.
James is confused about measurement and numbers.
I think that most readers will have decided for themselves which of the two of us - you or I - is confused about measurement and numbers, by now. (Hint: it's you.)
I'm a farmer who owns sheep. Some number of the sheep are all in the same paddock. The number can be written down, the sheep are already there.

The number is an abstraction of the things, a value which is not the things themselves: a number not a physical thing.
I agree. We can't bottle the number of sheep, but we can bottle the sheep themselves. It's no different with the mass of the sheep.
A value can be meaningful, but it has to "have units" to be physically meaningful. Information is physical.
No. Lots of important physical measures have no units, yet they are still meaningful. Consider, for example, the fine structure constant, or a coefficient of friction. The number of sheep in a field is "meaningful", and it has no units.

You're still stuck in the same error, unable to separate matter (or substance) from the concept of mass
No. That's an error you're making, which you compound by accusing me of doing it.

It's a big part of the ridiculous discussion we're having. You keep accusing me of what you're still doing. Gravity exists despite what concepts you or anyone else might have.
I try as I've just done before your latest load of shit, to explain that you're doing it. You accuse me of doing it again. And here we are.

Look the mass of an object made of matter is part of the object. It isn't a concept in a brain. In physics mass density and amount (i.e. number of atoms) of matter are equivalent.

Equivalent James, not "the same thing", but equivalent.

Consider, for example, the fine structure constant
Consider for example, that it doesn't mean anything when it's just a number. It has to be assumed it has physical meaning; besides, how do you find out what the constant is?

Let me guess, it involves measurements, right? "Actual hands on" physics?

At this point, we're 80 posts past the post where I wrote this response to you saying "mass is a word for matter":
80 posts worth of arguing about their interchangeability, when you attach density to either word. Then they're adjectives, not nouns.

Right? Then (the concept of) matter-density is equivalent, with the right ansatz, the right choice of atoms of matter, with (the concept of) matter-density. Lots of experiments say it doesn't make a difference which concept is meaningful. What makes a difference is measurements, information is a physical thing too. Despite James saying a number of sheep doesn't have units, it does, the sheep are all unit sheep, right?

James,

I sincerely want to apologize to you for calling you an "educated idiot." I've been regretting saying that to you because I do not believe that to be true. I simply said that because I was frustrated.

I respect you and I have learned a lot from you. I consider you to be one of the most knowledgeable and level headed individuals on the web.

I don't need a reply from you, I just wanted you to know that I did not sincerely mean those words, they were spoken out of frustration.

What I've been saying all along is there is a relation between physical objects and mass. Many different objects can have the same mass, the relation is not a function.

James writing down 83kg only specifies the mass of a particular object if that information is given. Otherwise it only says at least one object with that amount of matter exists, or may exist. It's a good reason to abandon the idea that mass is a number.

Ghost Appearance,

Thank you for apologising. I appreciate it. I don't see that happen very often on this forum and it is always pleasantly surprising when it does.

arfa brane:

No. That's an error you're making ...
Quite transparently, it is not. All one needs to do is to read my posts and understand. This shouldn't be hard. But you seem irretrievable stuck. I still can't work out whether you're just trolling or actually incapable of understanding the point I've put to you.
Gravity exists despite what concepts you or anyone else might have.
That's a whole separate topic. Let's concentrate on one thing at a time. We can discuss whether theories exist independently of people in some philosophy thread elsewhere, if you like.
Look the mass of an object made of matter is part of the object.
Which part, exactly? Can you get me a photo of just some mass, on its own? Can you extract the mass from an object and bottle it? Why can't you answer these simple questions? Why do you keep ignoring them or avoiding them?
In physics mass density and amount (i.e. number of atoms) of matter are equivalent.
Even definitionally they are not the same thing. Mass density is defined as mass per unit volume. A number of a atoms is ... just a number - something you get when you count things.

You're going further out on a limb with each post you make to this thread. At some point, surely even you will have to realise that the limb you're on can't support the weight of your bullshit.
Equivalent James, not "the same thing", but equivalent.
Weasel words. I suppose you can define an "equivalence" relation between just about any two things you want to.

In terms of height, I'm roughly "equivalent" to an average door, but that doesn't mean I'm a door.
Consider for example, that [the fine structure constant] doesn't mean anything when it's just a number.
Mass doesn't mean anything unless you assume it has physical meaning, either. Meaning is what we humans assign to things. What else could give things "meaning"? Meaning is what is important to us.
besides, how do you find out what the constant is?

Let me guess, it involves measurements, right? "Actual hands on" physics?
It can be measured experimentally, yes. So can the number of sheep in a field.
Despite James saying a number of sheep doesn't have units, it does, the sheep are all unit sheep, right?
Shall we be a bit more formal about this? Suppose I define the "number of sheep" as the cardinality of a set that contains exactly one element for each of the sheep in a field. The elements of that particular set can be put into a one-to-one correspondence with many other sets that "count" other kinds of objects and, indeed, with sets that do not "count" anything in particular. The cardinality of all of these sets is "just a number". Do you agree that a set of three sheep has the same cardinality as a set of three screwdrivers, and a set of three oxygen atoms, and a set of three intercontinental ballistic missiles? In all of these cases, the cardinality - the thing that we "count" - is "just a number".

Surely you're not goint to now argue that numbers themselves don't actually exist. Or are you?

Can we agree that numbers are concepts? (The cardinality of a set is an idea.) Or can't we get you even to agree to that much?

. . . the mass of an object made of matter is part of the object (in the same sense your own mass is part of you, it's why you "feel" gravity all the time).

But James arrives with the wait a minute proposition:
Which part, exactly? Can you get me a photo of just some mass, on its own? Can you extract the mass from an object and bottle it? Why can't you answer these simple questions?
Absolutely nothing in that, is there? You can't bottle your own mass, although you can write down a number followed by "kg". Why is the "you can't bottle it" argument so trivial and what does it contribute?

Why can't we bottle the Higgs boson? Why can't James R see that the bottle argument amount to five eighths of FA? James' next ridiculous argument says a number of atoms is a number. But James, there are atoms, there's a number of them. If you count them they don't turn into numbers FFS.
Even definitionally they are not the same thing. Mass density is defined as mass per unit volume. A number of a atoms is ... just a number - something you get when you count things.
Then there's something about the cardinality of sets. Sets can have the same cardinality, but contain different elements. The elements of a set don't need to be physical, like atoms with mass.

James doesn't seem to understand still, that counting atoms does not mean atoms, or the mass of atoms, is a number. The count is a number FFS. The cardinality of a set is independent of the nature of elements in the set, the mass in a set of atoms is independent of the nature of matter the atoms are a part of.

Mass is not a number. James is lying about that and a few other things.

. . . the mass of an object made of matter is part of the object (in the same sense your own mass is part of you, it's why you "feel" gravity all the time).
We don't feel gravity. That's another error. But that's another topic.

I note that you didn't say where this mass is supposedly located. Is it visible? Can you take a photograph of it?
Absolutely nothing in that, is there? You can't bottle your own mass, although you can write down a number followed by "kg". Why is the "you can't bottle it" argument so trivial and what does it contribute?
It's the basic issue on which you and I disagree. Don't you know what this conversation is about, 200 posts in?
Why can't we bottle the Higgs boson?
We can. It's a particle.
Why can't James R see that the bottle argument amount to five eighths of FA?
Explain why it is, if you can.
James' next ridiculous argument says a number of atoms is a number.
It's right there in your description, silly! A number of atoms isn't your great aunt's favorite hat!
But James, there are atoms, there's a number of them.
Yes and yes. That has never been in dispute.
If you count them they don't turn into numbers FFS.
I agree with this FFS.

Don't tell me that 200 posts into this thread you still don't understand what the substance of our disagreement is (?). It beggars belief.
Then there's something about the cardinality of sets. Sets can have the same cardinality, but contain different elements. The elements of a set don't need to be physical, like atoms with mass.
"Physical" is a weasel word you're using. Its definition can float around and be whatever you need it to be. Try to address the arguments I have put to you.
James doesn't seem to understand still, that counting atoms does not mean atoms, or the mass of atoms, is a number.
Right! Counting atoms is irrelevant to working out what the ontological status of "mass" is.
The count is a number FFS.
All counts are numbers FFS.
The cardinality of a set is independent of the nature of elements in the set, the mass in a set of atoms is independent of the nature of matter the atoms are a part of.
A moment ago you were saying the mass of your set of atoms was "part of" the atoms themselves.

At least try to aim for some level of consistency in your own position. Otherwise, it just looks like you're flailing around without having a clear notion of what you're trying to talk about.
Mass is not a number.
Yes it is.
James is lying about that and a few other things.
I am not lying to you. I honestly believe that mass is a number. The fact that you disagree with me doesn't imply that I'm lying. I could, hypothetically, be honestly expressing a view that is factually incorrect, but that is different from lying. Lying requires knowing that something is false and proclaiming it to be true, or vice versa.

Well, I still believe we have an immediate category error with the concept of mass being a number.

Atoms have mass. Most of the mass is located in the nucleus. The nucleus has a much greater density for its mass than the rest of the atom.

The mass of macroscopic objects depends on the mass of all the atoms, not on how they are arranged. All physical objects, pianos, people, rocks, water or air, accelerate towards the centre of the earth. mostly.

That's what Newton showed; the acceleration does not depend on the "nature" of matter, but the mass or ponderable (weighable) quantity.

That was a while back. James