(Seattle)SearsTower:. It is feet high.ColumbiaCenter:Let = the modelheight.The modelshouldbe about incheshigh.WhyThereAre No 12-Foot-Tall Giants
Why are thereno -foot-tallgiants?One explanationfor this is a matterof similarfigures.
Let’s supposethat thereis a -foot-tallhuman.Comparethis giant(?) to a -foot-tallperson.Now let’s
applysomefactsaboutsimilarfigures.
The scalefactorrelatingthesetwo hypotheticalpeopleis. Hereare someconsequencesof this
scalefactor.
Alllineardimensionsof the giantwouldbe timesthe correspondingdimensionsof the real person.
This includesheight,bonelength,etc.Allareameasuresof the giantwouldbe timesthe correspondingarea measuresof the real
person.This includesrespiration(breathing)and metabolism(convertingnutrientsto usablematerials
and energy)rates,becausetheseprocessestake placealongsurfacesin the lungs,intestines,etc.
This also includesthe strengthof bones,whichdependson the cross-sectionarea of the bone.Allvolumemeasuresof the giantwouldbe timesthe correspondingvolumemeasuresof
the real person.(You’ll learnwhy in Chapter11.) The volumeof an organismgenerallydetermines
its weightand mass.Whatkindsof problemsdo we see for our giant?Hereare two severeones.
- The giantwouldhavebonesthat are timesas strong,but thoseboneshaveto carrya bodyweightthat
is timesas much.The boneswouldnot be up to the task.In fact it appearsthat the giant’s own weight
wouldbe able to breakits bones.
- The giantwouldhave timesthe weight,numberof cells,etc. of the real person,but only timesas
muchabilityto supplythe oxygen,nutrition,and energyneeded.
Conclusion:Thereare no -foot-giants,and someof the reasonsare nothingmore,or less, than the ge-
ometryof similarfigures.