[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Alexander



binder@zk3.dec.com asks:

>Humans walk at about 2.5 to 3 MPH.  The average human can run in a
>short burst at speeds well in excess of 10 MPH, and a trained  
>sprinter
>can achieve over 20 MPH.  (A 10-second 100-yard-dash is an average
>speed of 20.455 MPH.)  How do these figures stack up against the
>numbers Alexander puts forth?  What's our "dimensionless speed"?   
>And
>how does the ostrich stack up - ostriches don't *walk* much faster  
>than
>we do, yet they can run at 40 MPH or so.

Alexander indicates that humans can hit a dimensionless speed of  
nearly 3 (his figure 3.10); he cites a maximum human speed that  
translates into 22 mph. He claims to have timed running ostriches at  
"a little faster" than the equivalent of 31 mph, which isn't too much  
different from the figure you cite. However, in his figure he only  
has two data point for ostriches and they are both below a  
dimensionless speed of 1.0, which makes me doubt he has their top  
speed in the analysis. I strongly suspect there is better and more  
recent literature on this because the book is dated 1989. Perhaps  
there is something in the dinosaur tracks symposium volume, which I  
don't have. Anybody up to speed on this stuff?