What is A Brief History of Time?
{{Infobox Book | name = A Brief History of Time | title_orig = | translator = | image = | image_caption = | author = Stephen Hawking | illustrator = | cover_artist = | country = | language = | series = | subject = | genre = Cosmology | publisher = Bantam Books | pub_date = 1988 | english_pub_date = 1988 | media_type = | pages = | isbn = | oclc = | preceded_by = | followed_by = The Illustrated A Brief History of Time}} '''''A Brief History of Time''''' (1988) is a [[book]] written by the [[scientist]] and [[mathematician]] [[Stephen Hawking]]. The subject of the book is [[cosmology]], the story of the [[universe]]. There are two other versions of this book: The ''Illustrated A Brief History of Time'' and ''A Briefer History of Time''. The Illustrated A Brief History of Time has pictures to help explain its ideas. It was also updated because new information was found. A Briefer History of Time is shorter than the first version and was also updated. This book is very popular and well-known. This book was on the ''London Sunday Times'' bestseller list for over 4 years.<ref name=PBS>{{cite web |url=https://www.pbs.org/wnet/hawking/cosmostar/html/hawking.html |title=Stephen Hawking's Universe |accessdate=2008-06-11 |format=HTML |work=PBS Online |archive-date=2008-06-09 |archive-url=https://web.archive.org/web/20080609214802/http://www.pbs.org/wnet/hawking/cosmostar/html/hawking.html |url-status=dead }}</ref> == Summary == [[File:Ptolemaicsystem-small.png|thumb|left|A picture of what Ptolemy thought about the location of the planets, stars, and sun.]] In this book, Hawking talks about many theories in physics. Some of the things that he talks about are the [[history]] of physics, [[gravity]], how [[light]] moves in the universe, [[space-time]], [[elementary particles]] (very small objects that make up things in the universe), [[black holes]], the [[Big Bang]] (the theory that the universe starte