This bo­ok will pro­vide ans­wers to 200 int­ri­cate qu­es­ti­ons child­ren ask most of­ten abo­ut sci­en­ce and tech­no­logy. The easi­ly un­ders­tan­dable desc­rip­ti­ons will help le­arn all the de­ta­ils abo­ut the key tech­no­logy in­venti­ons of the hu­mani­ty and int­ro­duce the re­ader to the key phy­sical laws as well as such con­cepts as elect­ri­city, mag­ne­tism, ti­me, etc.