(I will try not to give away the story(s), but no guarantees.)

I'm going to assume a little license today and combine 'Classics Corner' with 'Mundane Science'.

Science fiction on TV, while scarce in past years, nevertheless, won its share of awards. One of those awards was for "The Outer Limits" episode 'A Stitch in Time". Amanda won an Emmy award for her portrayal of Dr. Theresa Givens.

One of the basic questions of time travel asked over and over is how "The Grandfather Paradox" applies. "The Grandfather Paradox" asks; 'If you travel back in time to a point before your grandfather has any children and you kill him, how can you exist'? Different authors have answered the question different ways. Two authors that I want to mention today are Allen Steele and James P. Hogan.

FBI agent Jamie Pratt is investigating what may be the strangest case of her career. Seventeen men have been murdered over the last 50 years. Located throughout the country, they were all killed with the same gun. A gun belonging to Dr. Theresa Givens. She was only five years old at the time of the first murder and the gun had not even been built yet. Further investigation showed Agent Pratt the secret behind the locked door in Dr. Givens' office and, first hand, the temptations and dangers of undoing the evils of the past. "Every time I use the technique another universe of possibilities slams into my brain."

I highly recommend that you watch the episode if you get the chance.

"Thrice Upon a Time" by James P. Hogan was published in 1980. The story is one that I would call a 'one world - one time' story. Rupert travels to Scotland to visit his grandfather, who has a talent for exotic physics. Sir Charles has discovered a flaw in the law of Conservation of Energy. As they are investigating the ramifications of the discovery, tragedy strikes. A flaw in the theory underlying an experimental fusion reactor threatens the Earth. They must decide if they will save everyone or save themselves.

Many of Hogan's stories take place in the near future. I highly recommend them.

"ChronoSpace" by Allen Steele is an example of my 'many world - many times' story. Two investigators from the future have taken the place of people on the Hindenburg. Their mission is to deliver an eyewitness account of the Hindenburg's last voyage and document the reason why it has been destroyed. The Hindenburg landed and nothing was the same.

These two stories might be called examples of 'accidental' changes to the time line. Isaac Asimov's 'The End of Eternity" is an example of purposeful changes. Technician Andrew Harlan visits different centuries to make Minimum Necessary Changes (MNC) in an attempt to create better societies and prevent humanity from destroying itself. He knows that the ripple effect from a change can have undesired consequences. Proposed changes are carefully studied, checked, computed and double-checked by Life-Plotters, Sociologists, Computers and other Specialists. Messing with destiny is a slippery slope that is even slipperier when you are personally involved.

What is the truth about time and time travel? Nobody knows for sure yet, but it is interesting to speculate.