I'll admit: the usual version is short and efficient. But it's also the horror-version.
How about a fantasy-version? Or science fiction? How would a surrealist paint it..? Music..?
Invent a timemachine, travel a century back in time and kill your grandfather. Then he won't marry, nor have any children. Childrens children also disappears and so on. Thus your parents no longer exist, and neither do you.
Invent a timemachine, travel back in time and meet your parents when they were your age. Your parents would then tell their children that they would one day travel back in time for a visit. When the children grow up, and reach the day of the timetravel, they need only do one thing to create a paradox: visit grandfather in stead...
Everybody still exist, as you need not kill anyone to make the point. In stead the paradox lurks in memory. The children will remember that something happened and that it didn't. Thus the present is unaltered, but the past is beyond verification. Which also affects the future...
Invent a timemachine, travel back in time and help the dinos survive whatever disaster it was that drove them extinct in prehistoric time.
Thus a lot of small and furry creatures will remain small and furry. A hamster would then represent the highest evolved mammal om Earth. A creature still hiding in the forest, while intelligent reptiles one day invent rockets, leave the planet, colonize the solarsystem, leap from star to star, exploring the galaxy. Earth eventually disappearing out of sight, and finally forgotten...
Mankind would never exist. Yould would then not exist
as a person, not even as specie.
I can't see why a fantasy-version shouldn't be possible. Also I can't think of any right now. But I'm sure it already exists outhere. Do readers know..?
Your suggestions are welcome,
send me an E-mail...
The original version dramatizes more than it explains. The drama obscures the origin of the paradox, in order to illuminate the consequences. Let's look twice, this time without any action.
Travelling a whole century is not necessary to create the paradox. A decade could do it. Or a month, day, hour... In fact, as short as you like. Ultimately we'll end with a single instant in time where you do something that you don't. The naked contradiction.
Clearly not practically possible, not even as a thought-experiment. The ultimate version reveals that our simple experiment is somehow too simple. Our idea of a single time-line is too singular. However, worse problems lurks ahead:
Letting grandfather off the hook does not evade a paradox. It doesn't matter what you do or not, as merely entering in any earlier point on the timeline violates a basic law of nature, conservation of matter/energy. A timetraveller is thus an agent of chaos, as the traveller represent an effect without a cause. (And visiting the future will not avoid this.)
It could seem reasonable to dismiss the whole idea, but it keeps returning. Quite understandable...
Our memories present vast vistas of things once upon a time.
Our imagination offers countless things that one day may be.
Thus, in our minds we already have the concepts of time as a large landscape, our mind travelling anywhere at will. Jumping instantly to anything.
Any regrets about the past also involve the idea of a timeline branching off or twisting.
Any decision about the future also assumes several possible timelines. Thus even the idea of a multiverse is included...
Finally, we're blind to the obvious: We are already travelling in time. We do it all the time. Our present is a moving point.
Only, we are like passengers, moving along the ship. Actually our dream is not of travel, but control of the course...
Traffic-accident on the hyperway
Schrödingers cat or not
Mads Dam, dec 2005