MySQL create table error 1067 - invalid default value for 'update_ time‘

Error message :

1067 - Invalid default value for 'update_time'

terms of settlement :
timestamp You must give a default value , To create a successful .

       CREATE TABLE `user` (
         `id` int(11) unsigned NOT NULL AUTO_INCREMENT,
         `name` varchar(20) NOT NULL DEFAULT '' COMMENT ' full name ',
         `email` varchar(30) NOT NULL DEFAULT '' COMMENT ' mailbox ',
         `is_admin` tinyint(1) NOT NULL DEFAULT '0' COMMENT ' Is it super administrator  1 Said is  0  It means not ',
         `status` tinyint(1) NOT NULL DEFAULT '1' COMMENT ' state  1： It works  0： Invalid ',
         `updated_time` timestamp NOT NULL DEFAULT '1970-01-01 10:00:00 ' COMMENT ' Last updated time ',
         `created_time` timestamp NOT NULL DEFAULT '1970-01-01 11:00:00 ' COMMENT ' Insert time ',
         PRIMARY KEY (`id`),
         KEY `idx_email` (`email`)
       ) ENGINE=InnoDB  DEFAULT CHARSET=utf8 COMMENT=' User table ';

Successfully created