Author Topic: Does weight scale as the cube of size?  (Read 5019 times)

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u18b

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Re: Does weight scale as the cube of size?
« Reply #30 on: September 21, 2014, 07:44:55 AM »
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Yes.  It would take 160 boxcars in each dimension to be the size of a full size box car.

And since Volume is a cube, N scale isn't 1/2 the size of HO, it's about 1/6th (when using 87/160).  :)

Jason

Jason, that can't be correct.
87/160 = .54  (which is a helpful scaling percentage when reducing HO plans down to N scale.

That is a looooonnnnnngggggg way from 1/6.

Ron Bearden
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"All get what they want-- not all like what they get."  Aslan the Lion in the Chronicles of Narnia by C.S.Lewis.

wcfn100

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Re: Does weight scale as the cube of size?
« Reply #31 on: September 21, 2014, 11:05:18 AM »
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Jason, that can't be correct.
87/160 = .54  (which is a helpful scaling percentage when reducing HO plans down to N scale.

That is a looooonnnnnngggggg way from 1/6.

There a bit of misnomer IMO that reducing by a percent yields an object that's x% of the original.  That works in one dimension,  but in the case of a track plan when you say reduce 54%, the program is reducing in two dimensions.

The easiest way is to illustrate it.



If you use the green square as the base, between the yellow and blue, which one is 50% the size of the green?  I say the yellow.

Or the way I look at it.  4 of the blue squares will fit in the green square.  So I consider it 1/4th the size (where you would be calling it 1/2 the size).

Talking about N scale size adds the third dimension which along with the above examples, makes it about 1/6th size.  Or in other words,  it takes about 6 N scale models to take up the same space as an HO model (which, by itself, is something that can't be argued).

Jason
« Last Edit: September 21, 2014, 11:15:57 AM by wcfn100 »

svedblen

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Re: Does weight scale as the cube of size?
« Reply #32 on: September 21, 2014, 01:19:33 PM »
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...which one is 50% the size of the green?...

You need to define "size" for this to be a meaningful question. And once you have the question will sort of disappear  ;)
Lennart

nkalanaga

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Re: Does weight scale as the cube of size?
« Reply #33 on: September 21, 2014, 01:27:12 PM »
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I didn't know anyone kept capybaras as pets.  For those who haven't heard of them, from Wikipedia:
"The capybara (Hydrochoerus hydrochaeris) is the largest rodent in the world, followed by the beaver, porcupine, and mara. Its closest relatives are guinea pigs and rock cavies, and it is more distantly related to the agouti, chinchillas, and the coypu."

"Capybaras are semi-aquatic mammals[11] found throughout almost all countries of South America (except Chile[14]). They live in densely forested areas near bodies of water, such as lakes, rivers, swamps, ponds, and marshes,[10] as well as flooded savannah and along rivers in tropical forest. Capybara have flourished in cattle ranches.[6] They roam in home ranges averaging 10 hectares (25 acres) in high-density populations.[6]

Many escapees from captivity can also be found in similar watery habitats around the world. Sightings are fairly common in Florida, although a breeding population has not yet been confirmed.[15] In 2011, one was spotted in the central coast of California.[16]"
N Kalanaga
Be well

learmoia

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Re: Does weight scale as the cube of size?
« Reply #34 on: September 21, 2014, 02:03:20 PM »
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I could see several TRW Headers coming out of this thread, but I don't have means for photo editing at the moment.

(Picture of Capybara) - "We've solved the formula for Scaled Weight."

Weight standard = "LT WHT / (Scale^3)"

A photo of a Green HO scale Box car, a Blue Z scale boxcar and Half of a Yellow N scale boxcar.
"Solve for O scale"

~Ian
« Last Edit: September 21, 2014, 02:11:37 PM by learmoia »

u18b

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Re: Does weight scale as the cube of size?
« Reply #35 on: September 21, 2014, 02:07:30 PM »
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Jason,
Great illustration.

So by this reasoning, wouldn't volume be (approximately) 1/2  x  1/2  x 1/2 = 1/8 ?
Ron Bearden
CSX N scale Archivist
http://u18b.com

"All get what they want-- not all like what they get."  Aslan the Lion in the Chronicles of Narnia by C.S.Lewis.

peteski

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Re: Does weight scale as the cube of size?
« Reply #36 on: September 21, 2014, 02:15:37 PM »
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Jason,
Great illustration.

So by this reasoning, wouldn't volume be (approximately) 1/2  x  1/2  x 1/2 = 1/8 ?

I can easily visualize shrinking a cube to 50% of it size then I see that 2 layers of 4 of the smaller cubes would fit in the original size cube.   At least when it comes to volume.     The weight would probably be also 1/8 of the original weight.
. . . 42 . . .

Cajonpassfan

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Re: Does weight scale as the cube of size?
« Reply #37 on: September 21, 2014, 03:14:45 PM »
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Jason,
Great illustration.

So by this reasoning, wouldn't volume be (approximately) 1/2  x  1/2  x 1/2 = 1/8 ?

N scale volume vs.HO:.54x.54x.54=.157464 or roughly 15.7% (about 1/6.3)
Which explains why I love N scale; the same proportion applies to all three dimensional objects: structures, bridges, mountains.
Must be a slow modeling day.... Time to return to that giant train room  :D
Otto K.

jagged ben

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Re: Does weight scale as the cube of size?
« Reply #38 on: September 21, 2014, 03:24:57 PM »
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I can easily visualize shrinking a cube to 50% of it's linear dimensions then I see that 2 layers of 4 of the smaller cubes would fit in the original size cube.   At least when it comes to volume.     The weight would probably be also 1/8 of the original weight.

Fixed that for you.

up1950s

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Re: Does weight scale as the cube of size?
« Reply #39 on: September 21, 2014, 05:24:07 PM »
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We know we can't scale water , therefore air , almost always having some water in it also can't be scaled . Given that gravity has an effect on anything that has a measurable weight , and gravity is a constant that we can only counter by applying another force , and that only stops or slows its effects , my vote goes to NO , we cannot scale weight . Imaging a penny being squished by a loco , then take a scale sliver of copper under an N scale loco , hell an O scale loco , no way will that sliver change dimensions by 75% or so .


Richie Dost

Scottl

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Re: Does weight scale as the cube of size?
« Reply #40 on: September 21, 2014, 07:46:19 PM »
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I think this thread has given me an exam question...  :D

mmagliaro

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Re: Does weight scale as the cube of size?
« Reply #41 on: September 21, 2014, 09:46:17 PM »
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We know we can't scale water , therefore air , almost always having some water in it also can't be scaled . Given that gravity has an effect on anything that has a measurable weight , and gravity is a constant that we can only counter by applying another force , and that only stops or slows its effects , my vote goes to NO , we cannot scale weight . Imaging a penny being squished by a loco , then take a scale sliver of copper under an N scale loco , hell an O scale loco , no way will that sliver change dimensions by 75% or so .

But wait... you need to scale the density as well.   A copper penny, scaled into the N Scale world, should only be
1/160 ^ 3 =  one 4 millionth as dense as real copper, and I would bet that yes, an N Scale loco could flatten it.

Dave V

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Re: Does weight scale as the cube of size?
« Reply #42 on: September 21, 2014, 10:03:41 PM »
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But wait... you need to scale the density as well.   A copper penny, scaled into the N Scale world, should only be
1/160 ^ 3 =  one 4 millionth as dense as real copper, and I would bet that yes, an N Scale loco could flatten it.

How do you figure?  Are you scaling the electron shells too?  If it contains the same amount of "stuff" (number of atomic nuclei and electron valences), it will have the same mass in the much, much smaller volume so will be millions of times more dense.

mmagliaro

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Re: Does weight scale as the cube of size?
« Reply #43 on: September 21, 2014, 11:06:53 PM »
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How do you figure?  Are you scaling the electron shells too?  If it contains the same amount of "stuff" (number of atomic nuclei and electron valences), it will have the same mass in the much, much smaller volume so will be millions of times more dense.

As a matter of fact, yes.   Everything has to scale down by a factor of 1/160 in order for any of this to make any sense.
In an N Scale world, everything is 1/160 of life size, including atomic particles.  The world itself, and every particle of it,
is 1/160th of life size.

Wow... this whole thing suddenly took a veer off into very existential territory.

Does this mean that from the point of view of an N Scale layout, that the universe itself is 1/160th of life size? 
« Last Edit: September 21, 2014, 11:12:12 PM by mmagliaro »

Dave V

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Re: Does weight scale as the cube of size?
« Reply #44 on: September 21, 2014, 11:47:39 PM »
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So I'm confused...  Are we talking the same number of atoms or no?  Because if we are, and assuming somehow we can impart a much higher energy state whereby we collapse the electron shells inward (not unlike what happens to a neutron star), we still have to have the same number of subatomic particles that make up said atoms, and they all have a mass that cannot be reduced.  In fact, for quarks, we often speak of mass and energy so interchangeably, that we measure their mass in gigaelectron volts.  And tying back to some other posts, those energy levels are quantized and irreducible.

We had a departmental seminar on The Standard Model this week...   :D
« Last Edit: September 21, 2014, 11:51:43 PM by Dave Vollmer »