Imagineyou'reAlanEustace.You'reinyour50's,you'vegottwoyoungdaughtersandalovingwifeathomeandyou'retheSeniorVice-Presidentof'Knowledge'atGoogle.Butnoneofthatmatterstoyourightnow--becauseinlessthanaminutethegiantballoonstrappedtoyourbackisgoingtoinflatetothesizeofafootballstadiumasitcarriesyouover135,000feetstrai...