Science > Physics > Newton defined mass as the product of a body's density and its volume:
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Science > Physics |
| User: |
"Don1" |
| Date: |
18 Oct 2005 05:28:04 PM |
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Newton defined mass as the product of a body's density and its volume: |
Did he use weight density, or mass density?
Don
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| User: "Harry" |
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| Title: Re: Newton defined mass as the product of a body's density and its volume: |
21 Oct 2005 03:51:45 AM |
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"Don1" <dcshead@charter.net> wrote in message
news:1129674484.620760.210780@g47g2000cwa.googlegroups.com...
Did he use weight density, or mass density?
Don
"THUS air of double density, in a double space, is quadruple in quantity; in
a triple space, sextuple in quantity. The same thing is to be understood of
snow, and fine dust or powders, that are condensed by compression or
liquefaction; and of all bodies that are by any caused whatever differently
condensed. [...] It is this quantity that I mean hereafter everywhere under
the name of body or mass. And the same is known by the weight of each body;
for it is proportional to the weight"
IOW: he assumed mass to be proportional to its weight, but not equal to it.
Indeed, the same mass weighs less on the moon, although he could not measure
that. Very clever.
Harald
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| User: "" |
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| Title: Re: Newton defined mass as the product of a body's density and its volume: |
21 Oct 2005 05:49:07 AM |
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"THUS air of double density, in a double space, is quadruple in
quantity; in
a triple space, sextuple in quantity. The same thing is to be
understood of
snow, and fine d........
*********************************
What will future generations do with our words, preserved forever
within the bowels of the System, assuming some calamity doesn't destroy
it.
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| User: "Don1" |
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| Title: Re: Newton defined mass as the product of a body's density and its volume: |
21 Oct 2005 05:51:47 AM |
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Harry wrote:
"Don1" <dcshead@charter.net> wrote in message
news:1129674484.620760.210780@g47g2000cwa.googlegroups.com...
Did he use weight density, or mass density?
Don
"THUS air of double density, in a double space, is quadruple in quantity; in
a triple space, sextuple in quantity. The same thing is to be understood of
snow, and fine dust or powders, that are condensed by compression or
liquefaction; and of all bodies that are by any caused whatever differently
condensed. [...] It is this quantity that I mean hereafter everywhere under
the name of body or mass. And the same is known by the weight of each body;
for it is proportional to the weight"
IOW: he assumed mass to be proportional to its weight, but not equal to it.
Indeed, the same mass weighs less on the moon, although he could not measure
that. Very clever.
Harald
Yes Harald, that's right; the mass of a body is proportional to the
ratio of its weight (w), divided by the acceleration due to gravitation
(g); wherever it is: Not equal.
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| User: "Jim Spriggs" |
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| Title: Re: Newton defined mass as the product of a body's density and its |
19 Oct 2005 06:50:57 PM |
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Don1 wrote:
Did he use weight density, or mass density?
Why do you ask? Are you interested in the history of physics (a
perfectly reasonable thing to be interested in), or do you think that
answering this question will help you to understand present-day
physics? If the latter, I will just point out that physics has moved on
and even Newton didn't know everything.
--
The world will little note, nor long remember what we say here.
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| User: "Sam Wormley" |
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| Title: Re: Newton defined mass as the product of a body's density and its |
18 Oct 2005 06:02:15 PM |
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Don1 wrote:
Did he use weight density, or mass density?
Mass
http://scienceworld.wolfram.com/physics/Mass.html
Density
http://scienceworld.wolfram.com/physics/Density.html
A measure of a substance's mass per unit of volume.
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| User: "Don1" |
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| Title: Re: Newton defined mass as the product of a body's density and its volume: |
19 Oct 2005 06:13:26 AM |
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Sam Wormley wrote:
Don1 wrote:
Did he use weight density, or mass density?
Mass
http://scienceworld.wolfram.com/physics/Mass.html
Density
http://scienceworld.wolfram.com/physics/Density.html
A measure of a substance's mass per unit of volume.
Did he just look it up(;^?
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| User: "Eric Gisse" |
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| Title: Re: Newton defined mass as the product of a body's density and its volume: |
18 Oct 2005 07:07:52 PM |
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Don1 wrote:
Did he use weight density, or mass density?
Don
Hurry up and die.
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| User: "tadchem" |
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| Title: Re: Newton defined mass as the product of a body's density and its volume: |
19 Oct 2005 07:29:38 AM |
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Eric Gisse wrote:
Don1 wrote:
Did he use weight density, or mass density?
Don
Hurry up and die.
I propose a new quantity - 'Donsity' - the resistance of a person to
learning. The mental 'mess' is thus a product of the donsity and the
volume of posts in which it is evident that no learning has taken
place.
Only vague, non-standard, or obsolete units can be used for expressing
these quantities.
Tom Davidson
Richmond, VA
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| User: "Don1" |
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| Title: Re: Newton defined mass as the product of a body's density and its volume: |
19 Oct 2005 09:05:10 AM |
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tadchem wrote:
Eric Gisse wrote:
Don1 wrote:
Did he use weight density, or mass density?
Don
Hurry up and die.
I propose a new quantity - 'Donsity' - the resistance of a person to
learning. The mental 'mess' is thus a product of the donsity and the
volume of posts in which it is evident that no learning has taken
place.
Only vague, non-standard, or obsolete units can be used for expressing
these quantities.
Tom Davidson
Richmond, VA
Better yet Slim, let's make some new criteria based on a persons
aptitude for physics, rather than the ability to pay. Maybe we could
cull out mule headed donkeys from becoming physicists. Especially those
who don't know things like the true nature of mass, and that inertia is
its measure.
We'd have never got into the metric mess if they'd known that weight
scales weigh weight; not mass.
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| User: "cnctut" |
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| Title: Re: Newton defined mass as the product of a body's density and its volume: |
19 Oct 2005 01:40:48 PM |
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Don1--
I admire your ability and desire to continually swim in a rip tide.
Pace yourself.
Tut
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| User: "Don1" |
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| Title: Re: Newton defined mass as the product of a body's density and its volume: |
19 Oct 2005 04:50:37 PM |
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cnctut wrote:
Don1--
I admire your ability and desire to continually swim in a rip tide.
Pace yourself.
Tut
Tut tut do you believe Newton used mass density to define mass?
He must have used weight density, there was no mass density until after
he invented mass. Mass density didn't exist until the metric system
began messing around with weights and measures. I have to either swim
in this rip tide or let them have their wrong ways with physics.
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| User: "Sam Wormley" |
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| Title: Re: Newton defined mass as the product of a body's density and its |
19 Oct 2005 04:58:35 PM |
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Don1 wrote:
He [Newton] must have used weight density, there was no mass density until after
he invented mass. Mass density didn't exist until the metric system
began messing around with weights and measures. I have to either swim
in this rip tide or let them have their wrong ways with physics.
Density
http://scienceworld.wolfram.com/physics/Density.html
A measure of a substance's mass per unit of volume.
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| User: "Jim Spriggs" |
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| Title: Re: Newton defined mass as the product of a body's density and its |
19 Oct 2005 06:54:19 PM |
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Don1 wrote:
cnctut wrote:
Don1--
I admire your ability and desire to continually swim in a rip tide.
Pace yourself.
Tut
Tut tut do you believe Newton used mass density to define mass?
He must have used weight density, there was no mass density until after
he invented mass. Mass density didn't exist until the metric system
began messing around with weights and measures.
That can't be right. Mass and volume both existed before Newton was
born, as did the quotient mass/volume. Whether people appreciated what
mass was and that there was a need to consider it, before a certain date
has no bearing on what they _are_ (that's a "timeless" are, are/where if
you prefer).
--
The world will little note, nor long remember what we say here.
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| User: "Don1" |
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| Title: Re: Newton defined mass as the product of a body's density and its volume: |
19 Oct 2005 08:46:45 PM |
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Jim Spriggs wrote:
Don1 wrote:
cnctut wrote:
Don1--
I admire your ability and desire to continually swim in a rip tide.
Pace yourself.
Tut
Tut tut do you believe Newton used mass density to define mass?
He must have used weight density, there was no mass density until after
he invented mass. Mass density didn't exist until the metric system
began messing around with weights and measures.
That can't be right. Mass and volume both existed before Newton was
born, as did the quotient mass/volume. Whether people appreciated what
mass was and that there was a need to consider it, before a certain date
has no bearing on what they _are_ (that's a "timeless" are, are/where if
you prefer).
--
The world will little note, nor long remember what we say here.
Nowadays what we say here goes out to more people than in days of yore.
If Newton didn't know about mass density, then he'd have had to use
weight density; unless there was some other kind.
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| User: "Jim Spriggs" |
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| Title: Re: Newton defined mass as the product of a body's density and its |
20 Oct 2005 02:40:42 PM |
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Don1 wrote:
Nowadays what we say here goes out to more people than in days of yore.
Sad but true.
If Newton didn't know about mass density, then he'd have had to use
weight density; unless there was some other kind.
Are you interested in what Newton did (i.e. history) or what mass,
density, etc, are (i.e. physics)?
--
The world will little note, nor long remember what we say here.
.
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| User: "Don1" |
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| Title: Re: Newton defined mass as the product of a body's density and its volume: |
20 Oct 2005 03:18:53 PM |
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Jim Spriggs wrote:
Don1 wrote:
Nowadays what we say here goes out to more people than in days of yore.
Sad but true.
What's so sad about that?
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| User: "" |
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| Title: Re: Newton defined mass as the product of a body's density and its volume: |
20 Oct 2005 04:11:43 PM |
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Don1 wrote:
Jim Spriggs wrote:
Don1 wrote:
cnctut wrote:
Don1--
I admire your ability and desire to continually swim in a rip tide.
Pace yourself.
Tut
Tut tut do you believe Newton used mass density to define mass?
He must have used weight density, there was no mass density until after
he invented mass. Mass density didn't exist until the metric system
began messing around with weights and measures.
That can't be right. Mass and volume both existed before Newton was
born, as did the quotient mass/volume. Whether people appreciated what
mass was and that there was a need to consider it, before a certain date
has no bearing on what they _are_ (that's a "timeless" are, are/where if
you prefer).
--
The world will little note, nor long remember what we say here.
Nowadays what we say here goes out to more people than in days of yore.
If Newton didn't know about mass density, then he'd have had to use
weight density; unless there was some other kind.
He didn't use weight density, since he was using
Kepler's measurements to derive what things weigh,
not volume.
So that's why everything is weightless,
he used two densities to cancel,
to prove that volume doesn't exist.
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| User: "cnctut" |
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| Title: Re: Newton defined mass as the product of a body's density and its volume: |
19 Oct 2005 06:37:50 PM |
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Don1--
To me, mass is simply lumped crap--density is how much crap is in a
specified volume. If you ask me to quantify--then I'm stuck with a
balance device or a spring device to determine the answer. The spring
devise (F=kx) will provide an answer that varies with GMm/r^2 and the
balance devise won't. Either way, I somewhat understand what each
system provides as an answer and any variance won't matter to me when I
purchase my next pound of nails. Of course when I say pound, I mean the
common variety 1/32 slugs not the British $$ pound ;-))
I try in life not to purchase a train ticket if the train has already
left the station--in this case I suspect it has, although my time piece
my not be accurate. I do admire your energy in this area. Years ago
someone once told me my efforts were like a puppy shaking a towel--but
I retired at 47--go figure.
Best Wishes,
Tut
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