Exploring Theories of Time: Simultaneity and Relativity

Imagine that you’re in the hospital for surgery. This kind of procedure is always safe, and always successful — but it can take anywhere from one to ten hours. You can’t be knocked out for the operation, but because it’s so painful — you’ll be given a drug that makes you forget the experience.

 You wake up, not remembering going to sleep. You ask the nurse if you’ve had the operation yet. They look at the foot of your bed, and see two different charts for two patients. They say “Well, you’re one of these two — but I’m not sure which one. One of them had an operation yesterday that lasted ten hours. The other is set to have a one-hour operation later today.”

 So it’s either true that you already suffered for ten hours, or true that you’re about to suffer for one hour.

 Which patient would you rather be?

 Most people would be relieved to find out they’d already had the operation. Normally we prefer less pain rather than more pain, but in this case, we prefer ten times more pain — just because the pain would be in the past rather than the future.

 Christian Tarsney, a philosopher at Oxford University's Global Priorities Institute, has written a couple of papers about this ‘future bias’ — that is, that people seem to care more about their future experiences than about their past experiences.

 Links to learn more, summary and full transcript.

That probably sounds perfectly normal to you. But do we actually have good reasons to prefer to have our positive experiences in the future, and our negative experiences in the past?

One of Christian’s experiments found that when you ask people to imagine hypothetical scenarios where they can affect their own past experiences, they care about those experiences more — which suggests that our inability to affect the past is one reason why we feel mostly indifferent to it.

But he points out that if that was the main reason, then we should also be indifferent to inevitable future experiences — if you know for sure that something bad is going to happen to you tomorrow, you shouldn't care about it. But if you found out you simply had to have a horribly painful operation tomorrow, it’s probably all you’d care about!

Another explanation for future bias is that we have this intuition that time is like a videotape, where the things that haven't played yet are still on the way.

If your future experiences really are ahead of you rather than behind you, that makes it rational to care more about the future than the past. But Christian says that, even though he shares this intuition, it’s actually very hard to make the case for time having a direction. It’s a live debate that’s playing out in the philosophy of time, as well as in physics.

For Christian, there are two big practical implications of these past, present, and future ethical comparison cases.

The first is for altruists: If we care about whether current people’s goals are realised, then maybe we should care about the realisation of people's past goals, including the goals of people who are now dead.

The second is more personal: If we can’t actually justify caring more about the future than the past, should we really worry about death any more than we worry about all the years we spent not existing before we were born?

Christian and Rob also cover several other big topics, including:

• A possible solution to moral fanaticism
• How much of humanity's resources we should spend on improving the long-term future
• How large the expected value of the continued existence of Earth-originating civilization might be
• How we should respond to uncertainty about the state of the world
• The state of global priorities research
• And much more

Chapters:
• Rob’s intro (00:00:00)
• The interview begins (00:01:20)
• Future bias (00:04:33)
• Philosophy of time (00:11:17)
• Money pumping (00:18:53)
• Time travel (00:21:22)
• Decision theory (00:24:36)
• Eternalism (00:32:32)
• Fanaticism (00:38:33)
• Stochastic dominance (00:52:11)
• Background uncertainty (00:56:27)
• Epistemic worries about longtermism (01:12:44)
• Best arguments against working on existential risk reduction (01:32:34)
• The scope of longtermism (01:41:12)
• The value of the future (01:50:09)
• Moral uncertainty (01:57:25)
• The Berry paradox (02:35:00)
• Competitive debating (02:28:34)
• The state of global priorities research (02:21:33)
• Christian’s personal priorities (02:17:27)

Producer: Keiran Harris.
 Audio mastering: Ryan Kessler.
 Transcriptions: Sofia Davis-Fogel.