I Do Not Believe In

Gravity Is So Strong That Space Is Bent Round Onto Itself, Making It Rather Like The Surface Of The Earth. If One Keeps Traveling In A Certain Direction On The Surface Of The Earth, One Never Comes Up Against An Impassable Barrier Or Falls Over The Edge, But Eventually Comes Back To Where One Started.

Why Do We Remember The Past, But Not The Future?

If Aliens Visit Us, The Outcome Would Be Much As When Columbus Landed In America, Which Didn't Turn Out Well For The Native Americans.

Time Travel Used To Be Thought Of As Just Science Fiction, But Einstein's General Theory Of Relativity Allows For The Possibility That We Could Warp Space-time So Much That You Could Go Off In A Rocket And Return Before You Set Out.

As Those Who Have Seen Jurassic Park Will Know, This Means A Tiny Disturbance In One Place, Can Cause A Major Change In Another. A Butterfly Flapping Its Wings Can Cause Rain In Central Park, New York. The Trouble Is, It Is Not Repeatable. The Next Time The Butterfly Flaps Its Wings, A Host Of Other Things Will Be Different, Which Will Also Influence The Weather. That Is Why Weather Forecasts Are So Unreliable.