credit: getty images

credit: getty images

 credit: u.s. army

credit: u.s. army

 credit: ap photo

credit: ap photo

 credit: wikimedia

credit: wikimedia

 credit: nick golledge

credit: nick golledge

 credit: bluehole

credit: bluehole

 credit: don yoshida

credit: don yoshida

 credit: sarah witman

credit: sarah witman

 credit: nasa

credit: nasa

 credit: slac

credit: slac

 credit: nasa

credit: nasa

 credit: reidar hahn

credit: reidar hahn

 credit: reidar hahn

credit: reidar hahn

 credit: dare

credit: dare

 credit: john goode

credit: john goode

National Association of Science Writers

Electronic implants meld body, brain and machine

 credit: john kent

credit: john kent

 credit: f. h. king

credit: f. h. king