Welcome to another edition of “Uncle Bing Says So”, the weblog where your friendly Uncle Bing explains whatever is on his mind that day.

I watched a movie the other day called “Safety Not Guaranteed.” The movie was pretty good and I’d recommend it for anyone with Netflix. It’s not quite worth buying the movie, but it is a good little rental. The plot revolved around time travel or, at least, the potential of time travel. That’s one of my favorite subjects for a movie and I went on a kick last year and had Netflix send me every movie that they had with time travel as a plot device. I watched them all over the course of three months and it gave me lots of different ways to think about the subject.

The theory of traveling into the past that I most agree with is the Parallel-Universe theory. In it, time sprouts off a multitude of new universes at every instant in time. And then, in the next instant, another multitude of new universes are sprouted off of each of those new universes and so on. Think of it like a giant tree with new branches and sub branches sprouting off of it. All of these universes are parallel.

A typical movie plot that involves parallel universes, such as in “Peggy Sue Got Married”, would revolve around one key moment in someone’s life and some choice they made. They made a choice that they regret and now, through the miracle of time travel, they have the chance to go back in time and make the other choice. They then get to see their life play out with this different choice, usually with humorous or disastrous consequences.

The Parallel-Universe theory goes on to say that when you travel backwards in time you travel along your particular timeline, like following the branch down the tree. And when you begin traveling forward again, you sprout off a new timeline and move along that one. You cannot move forward along the first timeline that you went backwards along because you created a new timeline with your different choice.

Therefore, you avoid all the annoying problems with time paradoxes that science fiction people often worry about. You know the ones, such as, “What happens if you go back in time and kill your grandfather before you were born?”

With parallel universes, this is not a problem. If you go back to 1930, let’s say, and shoot your grandfather, you and your family will never be born in this new timeline (and in any timeline that sprouts from it). That sucks, but it is not a problem as far as time is concerned. You went back in time along a different timeline that is completely unaffected by changes you make to your new timeline.

Again, think of it like a tree where you climbed down your branch and begin climbing up a different branch. Your old branch is unaffected by whatever you do to the new branch.

Anyway, so that’s the theory I have about time travel and I feel that it is the one makes the most sense. As I often do after seeing a new movie, I log onto the IMDB and browse the chat rooms to see what other viewers think of “Safety Not Guaranteed.”

In one thread, I got into an interesting debate where this guy thinks that going back in time is immoral and is equivalent to mass murder on the scale of the Holocaust.

His point is that, by simply going back in time you will invariably affect your surroundings and change future events. This would happen even by something as minimal as breathing, which would disturb the air around you and affect other things, as is postulated by the butterfly-effect theory. He does not believe in parallel universes and believes that time is just one long string that can be corrupted by time disturbances.

Disturbing the timeline like that, he says, would eventually result in millions or billions of specific people never being born and replaced with millions and billions of other people being born instead. He mourns for that first group of people that will never exist and calls it murder.

I ask him whether using a condom when he has sex is also immoral since it will prevent one specific person from being born plus all of that person’s offspring. That’s like murdering an entire family. I added that it is no different than going back in time and accidentally preventing entire families from existing. He never addressed my point.

He later admitted that he very much opposes time travel being invented for simple fear that someone will use it to go way back in time and he will be one of the billions of people that cease to exist.

I, of course, tell him not to worry about that because the fact that he actually exists today is proof that no one will ever invent time travel and use it to retroactively wink him out of existence. Because, if anyone ever does invent time travel, some fool, at some point in the future, will use it to go back in time and, accidentally or on purpose, change things to the point where he is not born. But since he exists today, that will never, ever happen, not in a million billion trillion years.

Interestingly enough, in the single timeline theory, time travel can never be invented. If it is, someone will eventually use it to go back far enough in time and will somehow prevent time travel from ever being invented. Then, that whole time bubble will disappear and time travel will be erased from the timeline. It may take a hundred years or five million years, but some idiot will eventually do it and erase time travel.

Anyway, so that’s my question to those of you who want to respond in this forum, is time travel inherently immoral for the fact that changing the past will invariably deprive some people of their lives and provide other souls with life instead?

Uncle Bing is the station manager for internet radio station theQuizomatic.com, an eclectic collection of 70s and 80s pop music plus periodic audio quizzes. You can find the station at quizomatic.whooBazoo.com or through iTunes. You can send email to Uncle Bing at bing987@gmail.com