View previous topic | View next topic

One duck in front of a duck..

Page 1 of 1

Chaniphis
1366027.  Sun Nov 22, 2020 7:10 pm Reply with quote

I don't expect this post is a water tight conjecture, more of a general round the houses, what's going on here then?
Just watching some ducklings following in a trot behind mom. They are stepping out at quite a pace compared to their mother, just to keep up. Now if you scaled up the size of a duckling to adult duck yet with the same size-relative pace, the enlarged duckling would be ponds ahead of the adult.
What I am bepuzzled of, is, whilst some might argue that the youngsters have less bulk to convey and as such their muscles can propel them faster, surely the adults should have relatively configured muscles to propel them with as much fastness, relative to their size?
This appears to be, not the case.
I might add, I see a correlation between this enigma and the theory that a sheet of glass 1m x 1m x 10mm has no problem existing supported upright, yet a sheet of glass with the same relative proportions but 1km x 1km x 10m, would collapse under its own weight?
Scaling something up (or down) doesn't mean that its properties scale along with it equally, or so it seems?
This has always troubled me.
Not just because I can't help associating unrelated conditions, but hey, it doesn't help.

 
Celebaelin
1366030.  Sun Nov 22, 2020 8:11 pm Reply with quote

Chaniphis wrote:
Scaling something up (or down) doesn't mean that its properties scale along with it equally, or so it seems?
This has always troubled me.

Nope e.g. height is a linear property (m) but muscle strength depends on cross section (m^2) and mass depends on a volumetric measure (m^3). If this were not so larger creatures would always be stronger and faster in direct proportion to their greater size and this is not so. Larger creatures beyond a certain size actually have a tendency to be physically slower as (very generally speaking) m^2/m^3 i.e. strength per mass decreases.

It depends on shape of course - for a creature composed of pure muscle relative strength per mass is

For a spherical animal πr^2/(4/3 πr^3)
For a cubic/rectangular cross-section animal w. x d./(h. x w. x d.)

 
CB27
1366075.  Mon Nov 23, 2020 8:10 am Reply with quote

It's not simply about dimensions, it's also about the structural mass.

There's a mathematical principle, called the cube square law, which in it's simplest form shows that volume increases at a faster rate than surface area.

 
cornixt
1366093.  Mon Nov 23, 2020 11:25 am Reply with quote

Chaniphis wrote:
surely the adults should have relatively configured muscles to propel them with as much fastness, relative to their size?

You are observing two different situations here though. The mother duck is just sauntering along, the ducklings are exerting themselves to keep up. The mother duck is capable of moving at a much faster pace, but doesn't due to not wanting to rather than being incapable.

 

Page 1 of 1

All times are GMT - 5 Hours


Display posts from previous:   

Search Search Forums

Powered by phpBB © 2001, 2002 phpBB Group