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fandomhigh2005-11-16 01:13 pm
ten-and-chips.livejournal.com) wrote in fandomhigh2005-11-16 01:13 pm
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Quantum Physics 123: Wednesday 16 November
[The Doctor settles in on top of his desk, drinking coffee. He may never sit behind it again.]
Turn in your papers, please.
So today we're talking about the grandfather paradox. This theory is called such because it stems from the idea that if one travelled back in time and killed one's own grandfather before one of your parents' conception, then you yourself would not exist, therefore not having travelled in time and killed him, etc. It's a very cyclical theory. Some use it to say that backwards time travel is impossible, which I personally disagree with, but I'll leave you to make your own decision.
Two things, in my opinion, prevent the grandfather paradox from becoming a loop of insanity. The first is the fact that a paradox of this sort, in my experience, rips a gaping hole in time, which then needs to be fixed. The second is that a person may be encircled by a causal bubble of sorts, which...[a sigh] keeps his or her own self in existence despite changes to the timeline.
Any questions?
No homework, except for the fact that I want you to think about a final project proposal. You're going to examine one of the concepts we've talked about this semester, or for that matter, anything you're interested in that we haven't talked about, in depth. There'll be a paper and presentation to the class, by the end of the term. No final exam, becauseI can't be bothered to write one this will help you focus your thoughts in a far more productive manner.
HOWEVER...I have to approve your topic. Please come to my office hours on Friday morning and we'll discuss your ideas briefly. I'm not going to be in during the afternoon, so if you can't meet me that morning, send me an email and we'll make an appointment.
Also, since Professor Cregg will kill me if I don't mention this to you, come to the Harvest Festival on Saturday. It will be a brilliant time, I assure you.
Turn in your papers, please.
So today we're talking about the grandfather paradox. This theory is called such because it stems from the idea that if one travelled back in time and killed one's own grandfather before one of your parents' conception, then you yourself would not exist, therefore not having travelled in time and killed him, etc. It's a very cyclical theory. Some use it to say that backwards time travel is impossible, which I personally disagree with, but I'll leave you to make your own decision.
Two things, in my opinion, prevent the grandfather paradox from becoming a loop of insanity. The first is the fact that a paradox of this sort, in my experience, rips a gaping hole in time, which then needs to be fixed. The second is that a person may be encircled by a causal bubble of sorts, which...[a sigh] keeps his or her own self in existence despite changes to the timeline.
Any questions?
No homework, except for the fact that I want you to think about a final project proposal. You're going to examine one of the concepts we've talked about this semester, or for that matter, anything you're interested in that we haven't talked about, in depth. There'll be a paper and presentation to the class, by the end of the term. No final exam, because
HOWEVER...I have to approve your topic. Please come to my office hours on Friday morning and we'll discuss your ideas briefly. I'm not going to be in during the afternoon, so if you can't meet me that morning, send me an email and we'll make an appointment.
Also, since Professor Cregg will kill me if I don't mention this to you, come to the Harvest Festival on Saturday. It will be a brilliant time, I assure you.
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After hearing the Doctor's short lecture, Hank raises his hand.
"I see three possible ways to discount or circumvent the grandfather paradox. First, and one we have already covered, any action that the time traveler makes could create a new, 'branching' timeline, completely different from his or her own. This would obviously eliminate the prospect of self-negation, as the time traveler's origin still exists, just not in that timeline.
"Second, a theory I have heard described as the Inevitability of History states that reality is able to 'gloss over' minor paradoxes by repairing or ignoring them, more or less. So a time travelers may kill their ancestors and thereby self-negate themselves, but reality just rolls on. This would not apply to major disruptions, of course, such as setting off a massive nuclear device, but even something as 'minor' as killing John F. Kennedy's assasing prior to the assasination could be repaired by replacing the assasin with someone else.
"Finally, what if time travel is required for certain events to occur 'properly'? To use a previous example, what if a temporal local would have set off a nuclear device had a time traveler not prevented him from ever being born?"
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no subject