海角大神

Episode transcript

Jessica Mendoza: Welcome to 鈥淩ethinking the News鈥� by 海角大神. I鈥檓 Jessica Mendoza, one of the producers. Today, we鈥檙e releasing the second episode in our new six-part science series, 鈥淚t鈥檚 About Time,鈥� hosted by Rebecca Asoulin and Eoin O鈥機arroll. If you haven鈥檛 listened to our 1st episode, check it out! OK, let鈥檚 get started. 

[Music]

[Montage of clips from different interviews]

Rebecca Asoulin: So the question that we ask everybody: what is your definition of time? 

Tim Wilson: Oh, gosh, that鈥檚 a big question. Ummm....

Dawna Ballard: I absolutely cannot define time. Because time is really so many things, there鈥檚 not just one time.

Dorsa Amir: (sighs) What is time, really? Ummm鈥�.

Tyson Yunkaporta: I don鈥檛 ... (sighs) I don鈥檛 really have one. 

Leah Ruppanner: So the 鈥� I would define time... OK, I鈥檒l start again. 

Dorsa: I鈥檓 really stumped. I don鈥檛 know if I have a definition for you. I kind of want to look up Merriam Webster and just pretend that was my definition. 

Rebecca: This is 鈥淚t鈥檚 About Time.鈥� A series all about...

Eoin O鈥機arroll: Time. I鈥檓 Eoin O鈥機arroll. 

Rebecca: And I鈥檓 Rebecca Asoulin. 

Eoin: In this science series, we interview experts on time. They鈥檒l help us unravel its mysteries.

Rebecca: Because understanding time more deeply can help us make the most of the time we have. 

[Music]

Rebecca: So what is time? 

Eoin: According to Oxford University Press, 鈥渢ime鈥� is the in the English language. We use it all the time. Yet we find it so hard to define.

Rebecca: We spoke to a lot of time experts for this series. And we asked every one of them to define time for us. They all struggled. And when they did finally define it, their definitions were really different. 

Heather Dyke: It鈥檚 so fundamental that most of the time people don鈥檛 think about it, you know? But it鈥檚 always there in the background.

Eoin: That鈥檚 Heather Dyke, a philosopher of time. What she鈥檚 saying is: Time is hard to define because it鈥檚 just sort of there. It鈥檚 such a slippery concept. 

Rebecca: This episode is about diving deep into that concept. We鈥檒l talk to a philosopher, a physicist, and a novelist who have all made it their life鈥檚 work to answer the question: what is time? And maybe by trying to figure out what time is and how it works, we can learn a little about how to reframe the challenges in our own lives. 

[Music]

Rebecca: So I鈥檝e personally always found philosophy kind of baffling. It just never seemed that useful to me in terms of people鈥檚 day-to-day lives.

Eoin: I mean, philosophy is aimed at the most baffling questions. The ones that can鈥檛 be settled by normal science. So if you鈥檙e not baffled on some level, I think you鈥檙e not doing it right.  

Rebecca: Comforting, very comforting, Eoin.

Eoin:  But, you know, I think philosophy鈥檚 also unavoidable. 

Heather Dyke: So as humans, we鈥檙e sort of natural philosophers. We want to understand the world. But there are so many different aspects to our understanding of the world in general, but I think this is particularly true of time. 

Rebecca: This is Heather Dyke again. She鈥檚 a philosopher of time at the University of Otago, in Dunedin New Zealand. Heather says her goal as a philosopher is to understand time in itself. And how time connects to all different parts of our lives 鈥� from the politics of time, to the psychology of time.

Eoin: Heather鈥檚 understanding of time as a philosopher helped her put into perspective a difficult personal decision.

Rebecca: That decision centered around an 18th century manor house in the English countryside. 

Heather Dyke: Well, it was built by my ancestors in the 1730s. Three stories. Big blocks of sandstone, arched windows. It had beautiful gardens.

Rebecca: Just what you鈥檇 expect if you watch any BBC drama.

Heather Dyke: It was full of old, you know, family portraits. And my great grandfather, he was massively into his big game hunting. So we actually had an elephant鈥檚 foot that had been made into a whiskey decanter holder. You know, it was really like a kind of, an old stately home that you鈥檇 go and visit.

Rebecca: Heather moved to the house when she was 12. And she used to visit it before then.

Heather Dyke: It鈥檚 a vast place, but they didn鈥檛 have spare bedrooms for us. So we camped in the garden. 

Rebecca: By 2012, Heather has moved to New Zealand, and lives with her husband and children. And she realizes that she needs to make a decision, because 300 years really does a number on a place. Should they try to save the house or sell it? 

Heather Dyke: My parents were getting elderly and it was kind of crumbling. You know, it had a leaky roof and it had chimneys that were falling down, windows that were falling out.  

Rebecca: Heather decides she wants to try to turn it around which would mean making enough money to keep up the maintenance of the house. So she moves with her family from New Zealand back to England. And they try to make it work. But after seven years of trying, it becomes obvious that the house can鈥檛 be saved.

Heather Dyke: Nobody ever wants to be the generation that gives up and sells up. But there really was no other option. The last Moreland, which was my maiden name 鈥� the last Moreland to make any money died in 1784. That just made me think, 鈥淲e鈥檙e not doing the wrong thing here. We鈥檙e doing the right thing. It should have been done a while ago.鈥�

[Music]

Rebecca: You might be thinking: what does any of this have to do with time? The decision felt like the right thing to do. But it was still really painful. And her philosophy on time actually helped her come to terms with what happened. 

Heather subscribes to a philosophical theory of time called the B theory. 

Heather Dyke: The B theory says that time is a little bit like space, in that the moment that we designate as 鈥渘ow鈥� is no more real than any other moment. 

Rebecca: What she鈥檚 saying is all times exist, regardless of whether we鈥檙e perceiving it or not. So Eoin chatting with me right now in 2021 is as real as Eoin back in let鈥檚 say, 1990.

Heather Dyke: I treat 鈥渘ow鈥� a little bit like we treat the notion of 鈥渉ere.鈥� You know, I鈥檓 here in Dunedin. You鈥檙e over there in, I don鈥檛 even know what city you鈥檙e in. 

Rebecca: California. 

Heather Dyke: California. There you go. Thank you. But I don鈥檛 think that California is any less real than Dunedin just because it鈥檚 not here. Right? And so. So that鈥檚 kind of analogous to how the B theorist thinks about 鈥渘ow.鈥�&苍产蝉辫;I don鈥檛 think that 1733 or 2120 are any less real than this moment now. I just think that they鈥檙e located at different times, just like California is located at a different place from me. 

Rebecca: In the B theory, there is no present moment. We label things 鈥減ast,鈥� 鈥減resent,鈥� and 鈥渇uture鈥� to match up with our perception of the world. But what we consider the present isn鈥檛 special in this theory. I know this is mind blowing. It鈥檚 really counterintuitive to our experience. 

But Heather says it鈥檚 how time really works. And the theory is really comforting to her. So back to the manor house. 

Rebecca: So in the B theory, is it that you were always going to sell the house?  

Heather Dyke: So, no, that鈥檚 not 鈥� that鈥檚 not true. Because... so it is tricky to get your head around this. So just because the time is real, the future time is real, doesn鈥檛 mean that what happens at that time happens of necessity. It happens because of the things that happened before it. And those things can include free choices. 

So take me back to 2012, when we first went there. It wasn鈥檛 then fixed that we would sell in 2019. That came about because of the various choices and decisions and other external factors. Things might have gone differently, but as it turns out, they didn鈥檛. 

Rebecca: For Heather, when something bad happens, it鈥檚 comforting for her to know that our decisions, aren鈥檛 the only reason things turned out the way they did. To her, the future is not totally limitless. Whether or not the theory is true, it resonates with Heather and helped her deal with the pain of selling her family鈥檚 house.

Heather Dyke: So I now can look back on that as a kind of finite closed 鈥� like it was a return journey. Do you know what I mean? Whereas on the way there, it felt like an open future. And I think my B theoretic view of time, it sort of helps me with that, because I don鈥檛 think the future is this kind of open realm. I do think that we are able to affect the future and our choices and decisions matter. They have causal influence, but I don鈥檛 think of it as this kind of open realm of possibility. I think that helps in cases when things don鈥檛 go as planned. 

[Music]

Rebecca: The B theory鈥檚 foundation is built off of physics. In particular, Albert Einstein鈥檚 theory of special relativity. Physics is foundational to many understandings of time.

Eoin: Time 鈥� if it really exists 鈥� is a characteristic of the physical universe. So if we鈥檙e going to find out what time really is, it makes sense to ask a physicist.

[Music]

Ron Mallett: I thought, 鈥淚f I understand Einstein, I can understand how to build a time machine.鈥�

Eoin: That鈥檚 physicist Ron Mallett. He became a physicist because he wanted to build a time machine. Yes you heard that right.  And he succeeded, kind of. He says he actually came up with a design for a real time machine. Well, a real hypothetical time machine, with real science. And lasers!

Rebecca: A childhood tragedy led to Dr. Mallett鈥檚 desire to do that.  

Ron Mallett: My father was a television repairman. And I idolized him. I mean for me, the sun rose and set on him. He was just everything for me.

Eoin: Growing up, Dr. Mallett鈥檚 dad would give him scientific toys, and he inspired his love of reading. Then when Dr. Mallett was 10, his father 鈥�

Ron Mallett: 鈥� died of a massive heart attack. Suddenly, when he was only 33 years old. And it completely devastated my world. I went into a black hole. 

Eoin: His father鈥檚 death plunged the family into poverty. His mom was now a single Black mother, in 1955, with four children to raise. 

Ron Mallett: A year after he died, I came across the book that changed my life. It was H.G. Wells鈥� 鈥淭he Time Machine.鈥�

Eoin: 鈥溾�� was written in 1895. It tells a story of a man who travels hundreds of thousands of years into the future. 

Ron Mallett:  At the beginning of it, it said that: 鈥淪cientific people know very well that time is just a kind of space.鈥� And we can move forward and backward in time, just as we can in space.

Eoin: This quote is from the Time Traveler, the book鈥檚 main character. It鈥檚 part of his explanation of how his time machine works, which treats time as though it were a fourth spatial dimension. 

Ron Mallett: And when I read those words, I thought, 鈥淥h, this is it. This is the thing that is going to allow me to see my father again. If I could build a time machine, I can go back and see him again.鈥�&苍产蝉辫;My mother had kept these all television and radio parts of my father 鈥� and I even tried to put something together that looked like the illustration. I mean, with bicycle parts in this thing. And of course, nothing worked.

Eoin: After all, Dr. Mallett was 10 years old at the time. But that first failure didn鈥檛 stop him. A few years later, he found another book at the Salvation Army.

Ron Mallett: It was a paperback that had Einstein on the cover of it, standing next to an hourglass. 

Eoin: That book was called 鈥�.鈥�&苍产蝉辫;

Ron Mallett: 鈥� and so I got the paperback and I didn鈥檛 understand most of it. But I did pick up the essence that Einstein said that there are ways you can alter time. 

[Music]

Eoin: And so Dr. Mallett becomes a theoretical physicist specializing in Albert Einstein鈥檚 general theory of relativity, using it to create a theoretical time machine. He says he showed that it鈥檚 mathematically possible to use lasers to bend time back on itself. 

To understand how Dr. Mallett does that, we first need to talk about Einstein and his theory of relativity 鈥� there are actually sort of two theories, really. Einstein鈥檚 work is the basis of Dr. Mallett鈥檚 real hypothetical time machine. 

Rebecca: It鈥檚 also the foundation of physicists鈥� modern understanding of how time works. 

Eoin: First, we鈥檒l talk about Einstein鈥檚 special theory of relativity. 

[Music]

Ron Mallett: Suppose that you鈥� re standing in front of a vehicle and a friend who鈥� s moving in the vehicle throws something at you. 

Eoin: Let鈥檚 say the vehicle is going at 60 miles an hour, and the ball that your friend is throwing is going at 10 miles an hour. 

Ron Mallett: Well, if you鈥� re standing outside the vehicle, the object isn鈥� t going to be coming at you at 10 miles an hour. It鈥� s going to be coming in at you with the speed of the ball plus the speed of the vehicle.

Eoin: If you鈥檙e in the car, the ball is going 10 miles an hour. But if you鈥檙e standing outside the car, you鈥檒l see that ball coming at you at 70 miles an hour. In other words, how fast something moves depends on your frame of reference. 

But, by the beginning of the 20th century, physicists had hit a stumbling block. This principle did not apply to light. Light seemed to travel at the same speed, regardless of how fast the observer was moving.

Rebecca: And that鈥檚 weird. Because everything else changes depending on your frame of reference. And so 鈥�

Ron Mallett: 鈥� what Einstein said is that the only way that the speed of light could be the same, no matter how fast the source of light could be, is that something else has to be changing. Space has to be changing and time has to be changing. Time has to be slowing down so that the speed of light can stay the same.

Rebecca: And that is the Special Theory of Relativity. 

Eoin: This was totally revolutionary. It created a whole new world for physicists to explore. Before this, everyone thought time was absolute. Now they understood it was actually relative. (Hence, relativity!) Special relativity became the basis for Einstein鈥檚 theory of gravitation, which he called general relativity. 

Ron Mallett: The special theory says that time is affected by speed. The general theory says time is affected by gravity. 

Rebecca: The general theory was what Dr. Mallett based his time machine math on.

This stuff is complicated. Dr. Mallett has spent his entire career on this topic. Einstein developing the theory. It just takes some time to absorb. 

Eoin: Einstein鈥檚 basic idea was that gravity bends space and time.

Ron Mallett: If gravity can affect time and light can produce gravity, then light can affect time. That was my breakthrough, by realizing that light can alter time.

Eoin: Dr. Mallett proved mathematically that by using a beam of laser light 鈥� 

Ron Mallett: 鈥� it would be possible to twist space and to eventually twist time into a loop. And along that loop, in time, it might be possible to travel back into the past. 

Eoin: Like we said, a real hypothetical time machine. (As in the hypothesis is real! And the math plays out.) But he hasn鈥檛 actually been able to build it. It鈥檚 too expensive. It could cost billions of dollars in the end. 

Rebecca: And instead of finding this infuriating, Dr. Mallett is 鈥� pleased. 

Ron Mallett: For me, the satisfaction is that I actually have achieved the goal that I had, of finding out a way that a time machine could possibly be built based on Einstein鈥檚 work. Unfortunately, it won鈥檛 allow me to go back to see my father 鈥� yet. 

[Music]

Eoin: So what is a time from a physics standpoint? Time is malleable. Before Einstein, time and space were absolute. But Einstein showed us that the real absolute in our universe is not time or space, it鈥檚 the speed of light. 

Einstein鈥檚 theories give us all kinds of new physics and new technologies like GPS, nuclear power, and even those old cathode-ray televisions.

Rebecca: They haven鈥檛 yet gotten us back to the past. But Einstein鈥檚 theories still open up a whole universe of ideas for all sorts of thinkers. In fact, physics is the starting point for this episode鈥檚 third and final story. 

[Music]

Rebecca: I really wanted to talk to a science fiction writer about time. In science fiction, you can kind of hand wave the mechanics of time travel. It doesn鈥檛 need to be possible. You don鈥檛 need to fully know how time travel would work to explore all of its juicy dramatic consequences.

Eoin: Still, science fiction writers often know and incorporate a lot of physics into their stories. Even if a lot of that is left off the page. 

Rebecca: But in a sci-fi story, the answer to the question: what is time? Is ultimately whatever the author wants it to be.

Ted Chiang: Time travel is kind of a literalization of memory. When we think about the past, we are metaphorically traveling back in time.

Rebecca: That鈥檚 Ted Chiang He wrote the short story that the 2016 film 鈥淎rrival鈥� is based on. It鈥檚 called 鈥�.鈥�

Both the film and the story are about a linguist who is trying to make sense of an alien language. Through that work, she begins to understand time as the aliens do. She can remember her future as well as her past. 

Ted has written two collections of short stories. The second collection includes the time travel story, 鈥�.鈥�&苍产蝉辫; In a lot of his work, characters try to come to terms with their pasts.

Ted Chiang: Time travel stories are about how we feel about our past. They can offer a kind of wish fulfillment, you know, giving us an opportunity to make decisions differently. 

Rebecca: And most of the time, these stories 鈥�

Ted Chiang: 鈥� are about regret, about events in our past, decisions we made that we wish we had made differently. 

Rebecca: 鈥淭he Merchant and the Alchemist鈥檚 Gate鈥� is about a fabric merchant in medieval Baghdad. He meets a shop owner who has a time travel portal. The shop owner tells him about three others who have used the portal before the merchant decides whether or not to use it himself. 

In the story, Ted鈥檚 rules of time travel are based on physicist Kip Thorne鈥檚 wormhole version of time travel which obeys Einstein鈥檚 theory of relativity. According to Kip Thorne, even if we could time travel, we can鈥檛 change the past.

But the vast majority of time travel fiction is about people going back and changing their past. Ted is OK with stories like that 鈥� 

Ted Chiang: 鈥� mainly because I think that they are trying to convey a positive message. They are trying to tell people that you have agency, that you can change your life, you can make a difference. I think those are good things for a story to do. But in reality, we cannot go back and do things differently.  

Rebecca: Ted found himself wanting to write fiction that took that less popular route. 

Ted Chiang: I think people don鈥檛 want time travel stories in which you cannot change the past. We usually find them depressing. They are usually couched as tragedies. So one of the things that I was trying to do with 鈥淭he Merchant and the Alchemist鈥檚 Gate鈥� was to write a story about time travel in which you could not change the past, but where that was not a tragedy.

Rebecca: In his story, the fabric merchant had experienced a loss 20 years before that left him hollow. He felt like he couldn鈥檛 atone for his past mistakes. 

I鈥檓 not going to spoil the story, so all I鈥檒l say is it ends with this powerful line: 鈥淣othing erases the past. There is repentance, there is atonement, and there is forgiveness. That is all, but that is enough.鈥�&苍产蝉辫;

[Music]

Ted Chiang: Time travel stories have the potential to help us reconcile ourselves with our past. Because while we cannot change the things that happened to us, we cannot change the decisions that we made, we can potentially change how we feel about what happened to us.

I鈥檇 like to see more stories in which time travel is used as a way of recognizing that even if you cannot change the past, you can change your relationship to the past. You can grow and learn.

[Music]

Rebecca: Sci-fi writer Ted Chiang, philosopher Heather Dyke, and physicist Ron Mallett, all explored different aspects of time. We need to look at different perspectives, because time touches every part of existence. Shifting our perspective on time can also help us make the best of the time we have.

Eoin: So Rebecca, what鈥檚 your definition of time?

Rebecca: I think time doesn鈥檛 have a neat definition. It really depends on the context. And I think back to all our interviews, and I realize why both of us always prefaced the question, 鈥淗ow do you define time?鈥� by saying that it was a really unfair question. It鈥檚 so hard to define.

Eoin: It鈥檚 almost like the more we use a word the harder it is to define. And we use the word 鈥渢ime鈥� all the time. 

Rebecca: Do you have a definition?

Eoin: Before we started this series, I came up with what I thought was a pretty good definition of time. Time, I thought, is the 鈥減erceived dimension of reality along which change occurs.鈥�

Rebecca: What do you think now?

Eoin: Now, I think I have a better definition. Time is this:

[Long pause]

Rebecca: So time is silence?

Eoin: Not necessarily silence -- it鈥檚 the thing that you鈥檙e experiencing as you experience silence. [very long pause round 2]

[Music]

Rebecca: Thanks for listening! We hope you feel inspired to read or watch a good time travel story. Don鈥檛 forget to subscribe to 鈥淩ethinking the News鈥� wherever you get your podcasts and leave us a rating or comment.

Eoin: And share this series with your friends, family, and coworkers! You can find us at csmonitor dot com slash time!

Rebecca: This series is hosted and produced by me, Rebecca Asoulin. My co-host is Eoin O鈥機arroll. It was produced with Jessica Mendoza. Editing by Samantha Laine Perfas, Clay Collins, and Noelle Swan. Sound design by Noel Flatt and Morgan Anderson. With production support from Ibrahim Onafeko. 

This story was produced by 海角大神, copyright 2021.

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