Notes for 11/13/2025

 

11/13/2025

[Philosophy Club every Tuesday at 5:00pm in CAS 436 ("The Cave")]

[Challenge for today: Try to think of (and possibly ask) at least one question.]

Assuming you could travel into the past, is there anything in your own life you’d want to try to change?

In the Grandfather Paradox, how, exactly, does “chronology protection” work? What prevents you from killing your grandfather?

 

 

 

Bootstrap “paradox” (is it really a paradox?)

Could you write a novel that you merely copy from the future?

Time is the measure of change.

 

Is time possible WITHOUT change?

 

In the absence of something that changes that can serve as a “clock” there can be no passage of time. For time to pass is for time to pass relative to some changing thing that “measures” (or observes) it.

 

If all “clocks” were to stop and nothing existed by which the passage of time could be marked, then it makes no sense to talk about time PASSING at all.

 

Sydney Shoemaker’s frozen regions thought experiment

 

 

Suppose the universe was divided into three regions, each of which experiences a “local freeze”

 

During a local freeze, the frozen region has no changes taking place within it

 

A local freeze lasts exactly 1 year.

 

Region A: Experiences a local freeze every 3rd year

 

Region B: Experiences a local freeze every 4th year

 

Region C: Experiences a local freeze every 5th year

 

What happens during year 60?

 

One answer (that says time is impossible without change) is that there is no such thing as DURING year 60. There is no sense in the suggestion that all regions are frozen for the SAME TIME.

 

 

Another answer is that we have good inductive reasons to think that all three regions are frozen for one year.

 

The second view depends on thinking that time is passing IN a frozen region (measured within it), while the first depends on thinking that time is only passing FOR a frozen region (measured only from outside it – an external vantage point).

 

 

If we take the first view, we have to say that the pattern “resets” since there is (and can be) no such thing as a “universal freeze” (because there is no external vantage from which the passage of time can be measured).

 

The second view holds that there is a difference between measuring the passage of time and the passing of time.

 

What makes it true that one year has passed?

What could make it true that 1 year has passed rather than 1 second or 1000 years?

 

Correspondence theory of truth: Truth is correspondence with the facts.

 

What are the facts that determine HOW MUCH time has passed in this thought experiment?

 

 

Analogy:

                                   A           B

                       1     2     3     4     5     6    

Suppose we ask “how far apart are A and B? 

On the first line, the question makes no sense because we are presupposing a measure of length in the question.

In Shoemaker’s frozen universe scenario, we do the same, only with a measure of duration.