Weight is an old word is ambiguous. It has several meanings, one of which isa synonym for mass.
The context in which it was used in this case was as a measure of force.BTW I don't discount the doctor's diagnosis as it was relayed on the LHC forum. It wasn't made clear that the Dr reasoned that the link between hair loss a and length of hair was the simple mechanical one. There may have been other factors.
Phil Hall
