problems

1. time travel

Ted Chiang describes a device in What’s Expected of Us:

By now you’ve probably seen a Predictor; millions of them have been sold by the time you’re reading this. For those who haven’t seen one, it’s a small device, like a remote for opening your car door. Its only features are a button and a big green LED. The light flashes if you press the button. Specifically, the light flashes one second before you press the button.

The heart of each Predictor is a circuit with a negative time delay — it sends a signal back in time.

A.

Determine whether each of the following continuations may be interpreted as a consistent time travel scenario. Please make sure to explain why.

1. You resolve to beat the Predictor by pressing the button even before you see the flash. When you attempt to do this, the flash immediately appears, and no matter how fast you move, you only manage to press the button once a second has elapsed.
   

2. You resolve to beat the Predictor by pressing the button before you see the flash. When you attempt to do this, the flash immediately appears, but you manage to press the button even before the second has elapsed.
   

3. You resolve to beat the Predictor by not pressing the button after the flash appears. You wait for the flash for a while, but it never appears. So, you pretend you are about to press the button by quickly moving toward it. The flash appears, but the inertia of the moment leads to you to accidentally press the button just one second after the flash.
   

4. You resolve to beat the Predictor by not pressing the button after the flash appears. You wait for the flash for a while, but it never appears. So, you briefly resolve to press the button with a view to changing your mind immediately afterwards. The flash appears but you almost automatically change your mind and refrain from pushing the button.
   

B.

How can the Growing Block Theorist make sense of the consistent time travel scenarios described above?

2. time and modality

The A-Theory of Time answers two questions in the affirmative:

1. Are there objective differences between being past, being present, and being future?

2. Are present events and objects more real than past or future events and objects?

Consider now the distinction between being actual and being merely possible. There are actual human outposts in the Artic, but human outposts in Mars are merely possible, they are not actual. On the face of it, we face two questions:

1. Are there objective differences between being actual and being merely possible?

2. Are actual events and objects more real than merely possible objects 

A.

Please outline modal counterparts of the A- and B-Theory of time.

B.

Assess the plausibility of each view you have outlined.

3. presentism and time travel

A.

How would a presentist recount Ted Chiang’s What’s Expected of Us? Consider some potential difficulties for a presentist reconstruction of Chiang’s scenario:

1. When you press the button of the device, there is no such event as a light flash one second before, much less a signal sent by a circuit with negative time delay.
   

2. How could there be genuine causation between a present event, which triggers the emission of a signal by the circuit with negative time delay, and a past event such as the light flash? That is, how can an event cause something that does not even exist?

B.

To what extent is the Growing Block Theorist better off than the presentist, if at all? Please justify your answer.

4. thank goodness it’s over

A. N. Prior offered an argument against the B-Theory:

I have a very good friend and colleague in Australia, Professor Smart of Adelaide, with whom I often have arguments about this. He’s an advocate of the tapestry view of time, and says that when we say ‘X is now past’, we just mean ‘The latest part of X is earlier than this utterance’. But when, at the end of some ordeal I say ‘Thank goodness that’s over’, do I mean ‘Thank goodness the latest part of that is earlier than this utterance’. I certainly do not; I’m not thinking about the utterance at all, it’s the overness, the pastness of the thing that I’m thankful for, and nothing else.

Consider the occurrence of a very painful event at a given time. Before the event, the subject experiences different degrees of anxiety as the event comes closer. The event itself is very painful, and after the event, the subject experiences different degrees of relief as the event recedes further into the past.

A.

How would the A-theorist account for the difference in attitude across time.

B.

How would the B-theorist account for the difference in attitudes across time.

C.

Reconstruct and assess Prior’s argument for the A-Theory in light of your answers.