▁concerned -- des p ite ▁the ▁thin , ▁imp laus ible ▁characters ▁and ▁a ▁general ▁air ▁of ▁ho - hum ▁familiar ity ." ▁ ▁Re views ▁Review ▁by ▁Dan ▁Ch ow ▁( 1 9 8 7 ) ▁in ▁L ocus , ▁# 3 1 4 ▁March ▁ 1 9 8 7 ▁ ▁Review ▁by ▁Bob ▁How e ▁( 1 9 8 7 ) ▁in ▁Fant asy ▁Review , ▁June ▁ 1 9 8 7 ▁ ▁Review ▁by ▁Tom ▁East on ▁( 1 9 8 7 ) ▁in ▁Anal og ▁Science ▁F iction / S cience ▁Fact , ▁August ▁ 1 9 8 7 ▁ ▁Review ▁by ▁Jan ice ▁M . ▁Eisen ▁( 1 9 8 8 ) ▁in ▁Ab original ▁Science ▁F iction , ▁September - Oct ober ▁ 1 9 8 8 ▁ ▁Review ▁by ▁Ken ▁Brown ▁( 1 9 8 8 ) ▁in ▁Inter zone , ▁# 2 6 ▁November - Dec ember ▁ 1 9 8 8 ▁ ▁References ▁ ▁Category : 1 9 8 7 ▁nov els <0x0A> </s> ▁Time ▁travel ▁is ▁the ▁concept ▁of ▁movement ▁between ▁certain ▁points ▁in ▁time , ▁analog ous ▁to ▁movement ▁between ▁different ▁points ▁in ▁space ▁by ▁an ▁object ▁or ▁a ▁person , ▁typically ▁with ▁the ▁use ▁of ▁a ▁hypoth et ical ▁device ▁known ▁as ▁a ▁time ▁machine . ▁Time ▁travel ▁is ▁a ▁widely ▁recognized ▁concept ▁in ▁philosophy ▁and ▁fiction . ▁The ▁idea ▁of ▁a ▁time ▁machine ▁was ▁popular ized ▁by ▁H . ▁G . ▁Well s ' ▁ 1 8 9 5 ▁novel