ExposureBlog

It’s not every day that you find new info about friction–you know–that ill-defined resistive force that occurs when you rub two surfaces against each other. 

Lawyers who deal in slip and fall cases can probably recall the safety guy dragging the exemplar shoe across the vinyl tile at K-mart.  The shoe was likely attached to a spring with a kind of device that looked like a horizontal fish scale.  It was supposed to measure drag and thus, well, coefficient of friction.  Anything less than 0.5 was bad. 

Well, if you’re one of those lawyers, this one’s for you.  It seems that the definition of friction has been enhanced.  We now know the minimum distance for friction to occur—about a nanometer.  And now we also know that friction is dependent upon the chemistry of the materials involved.

Okay. That much we all knew anyway.  Tennis shoes seem to have a higher coefficient of friction than flats.  Can’t dance in tennis shoes.  No slide.

Back to the serious stuff.  Now it seems that two objects don’t even have to be in that close contact to create friction.   The official term is friction at a distance, but the distance is still too small for the average jury to see—even with bifocals.  The distance is just a little greater than a nanometer.  Not like twenty feet or something.  Read all about it here.