【背景介绍】

根据科学家实验表明，蹦极这种极限运动会让你感觉时间是增长的。在每一秒你坠落的时间里，你所有平时观察不到的细微统统被你记住，从而让你感到时间增长。这到底是怎么回事？请听几位科学家的讨论。

【听力原文】

STEVE INSKEEP, host:

If you're doing something adventurous this summer, like, say, bungee jumping, it may make your heart race. And we have a story this morning about what happens in your head while your heart is racing. It comes to us from RADIOLAB.

(Soundbite of music)

JAD ABUMRAD: Morning, Steve.

INSKEEP: Hi, Jad. That's Jad Abumrad from WNYC.

ROBERT KRULWICH: And this is me, Robert Krulwich. And RADIOLAB is well, it's a show where we get curious, we explore big ideas...

ABUMRAD: And sometimes we get a little dangerous. In fact, like for this story, we fell off a house.

INSKEEP: Fell off a house? You didn't.

KRULWICH: Not really.

INSKEEP: OK.

KRULWICH: But a guy we know did. His name is David Eagleman. He's a neuroscientist from Baylor College of Medicine. But back when he was a kid...

ABUMRAD: How old were you just to, sort of?

Mr. DAVID EAGLEMAN (Baylor College of Medicine): I was, I was eight years old.

ABUMRAD: He had an experience which he says changed his life.

Mr. EAGLEMAN: Yeah.

ABUMRAD: He was playing in his subdivision in Houston. And there was a house nearby...

Mr. EAGLEMAN: ...that was under construction, and my father told me not to go climbing around on the house under construction, but I was a boy so I did and I was looking at the edge of the roof and I stepped on it but in fact it was tar paper hanging over the edge, and I, and I fell.

KRULWICH: Oh, so you stepped onto the air, in effect. You just went shwoooh.

Mr. EAGLEMAN: Exactly. (Soundbite of music)

Mr. EAGLEMAN: And what happened was the event seemed to take a very long time. I thought about whether I had time to grab for the edge of the roof and I realized it was too late for that.

(Soundbite of music)

Mr. EAGLEMAN: So then I was looking down at the ground as the red brick floor was coming towards me. And I was thinking about "Alice and Wonderland," how this must be what it was like for her when she fell down the rabbit hole.

KRULWICH: Hmmm. How long by the way was it from the top of the roof to the ground below?

Mr. EAGLEMAN: Point eight six seconds. (Soundbite of laughter)

Mr. EAGLEMAN: That's how long it takes to fall twelve feet. I calculated that later.

ABUMRAD: That would be one-one thousand - and this whole experience left David Eagleman with a question that he could not get out of his mind.

Mr. EAGLEMAN: What happens to people when they're in a life or death situation and they have these thoughts that seem to take a long time? So at some point I realized I needed to study this.

ABUMRAD: How would you even study that?

Mr. EAGLEMAN: Well, the first thing I did, I took my entire laboratory to Astroworld.

(Soundbite of Astroworld theme music)

Mr. EAGLEMAN: Which is the amusement park here in Houston. And we went on all of the scariest rollercoasters and we brought all of our equipment and our stopwatches and had a great time, but it turns out nothing there was scary enough to actually induce this fear for your life that appears to be required for the slow motion effect.

So I searched around and I finally found something called SCAD diving.

ABUMRAD: SCAD diving.

Mr. EAGLEMAN: Stands for Suspended Catch Air Device.

ABUMRAD: Where do you do that?

Mr. EAGLEMAN: Turns out it's illegal in Houston but I found one in Dallas.

(Soundbite of laughing)

Mr. EAGLEMAN: So we made a road trip up to Dallas.

Unidentified Man #1 (SCAD Instructor): Alright, jump number one.

ABUMRAD: And we actually found a reporter in Dallas who agreed to give this a try.

Unidentified Man #1: ...on, and then Ill put this on over the harness.

APRIL: No ones ever died on this thing, right?

Unidentified Man #1: Nope.

ABUMRAD: This is April.

APRIL: I feel like my heart's in my throat.

ABUMRAD: She's very brave.

Mr. EAGLEMAN: You ride up to the top of this tower in this very rickety little elevator type of thing.

APRIL: Okay, we're riding up in the elevator right now.

Mr. EAGLEMAN: A hundred and fifty foot tall tower.

APRIL: It's not too fast.

Mr. EAGLEMAN: Climbing up and up and up.

APRIL: It doesn't seem that far when you're down there. Up here it seems really far.

Mr. EAGLEMAN: It's like a fifteen story building.

Unidentified Man #1: Yeah, we're halfway.

APRIL: Oh man. OK, this is just halfway, I'm already freaking out.

Mr. EAGLEMAN: And...

APRIL: My hands are starting to shake.

Mr. EAGLEMAN: ...at the very top youre suspended.

APRIL: Like this?

Unidentified Man #1: Yup.

APRIL: OK.

Mr. EAGLEMAN: You're hooked up to a carabineer.

APRIL: (Unintelligible)

Unidentified Man #1: Sit all the way back. Lean back.

KRULWICH: Okay, so I want you to imagine this: You're up in the sky. You are facing the clouds, not the ground. You are attached to something which is about to be severed. And you will fall totally free into the void, unable to see what's about to happen to you, presuming a net, maybe.

APRIL: Oh God. OK. Don't let me die.

ABUMRAD: Three, two...

APRIL: Really nervous right now.

Mr. EAGLEMAN: And...

APRIL: Aaaah!

ABUMRAD: Okay wait, wait, wait, wait. One thing I forgot to mention. April actually wasn't part of David's study, but if she had been, she would be wearing around her wrist this little device.

Mr. EAGLEMAN: New device called the perceptual chronometer.

ABUMRAD: It's about the size of a watch and it flashes numbers super fast.

Mr. EAGLEMAN: Yeah, yeah.

ABUMRAD: Way too fast to see normally. But the thought is, if April falls and everything starts to slow down, well, then these numbers should slow too. So that if she looks at her wrist as she is falling, she should be able...

Mr. EAGLEMAN: To now read the watch that would be impossible under normal circumstances.

ABUMRAD: Back to April.

APRIL: Really nervous right now.

ABUMRAD: Three, two...

Mr. EAGLEMAN: And...

APRIL: Aaaaah! Oh my God. Oh my God. Oh my God, that's the scariest moment of my life. Oh my God.

Mr. EAGLEMAN: I should probably tell you guys the results of the study, but...

ABUMRAD: (Unintelligible) people report that time slowed down enough for them to read the number?

APRIL: I'm alive.

Mr. EAGLEMAN: No.

KRULWICH: No?

Mr. EAGLEMAN: Turns out when youre falling, you don't actually see in slow motion.

ABUMRAD: Aww.

Mr. EAGLEMAN: Yeah. It's not equivalent to the way a slow motion camera would work. Even though people feel like it's going in slow motion, it's something more interesting than that.

(Soundbite of chime)

ABUMRAD: 'Cause here's the thing, right after people did the jump, he would ask them...

Mr. EAGLEMAN: How long they thought their fall took.

ABUMRAD: The right answer, if they'd had a stop watch...

Mr. EAGLEMAN: Just under three seconds.

ABUMRAD: But what people would say...

APRIL: How long, when you were falling, how long did it...

Unidentified Man #2: (Unintelligible)

APRIL: Ten seconds.

Unidentified Woman: It felt, it felt like - time was stopped.

ABUMRAD: So how do you explain that? Like times not slowing in the moment but seems to be slowing after the moment?

Mr. EAGLEMAN: Well, I came to understand that it's a trick of memory. Normally our memories are like sieves. Were not writing down most of what's passing through our system.

ABUMRAD: But he thinks that when you go...

APRIL: Aaaah!

ABUMRAD: You know, life or death moment.

APRIL: Oh my God!

ABUMRAD: In that instant, our memories go wide open.

Mr. EAGLEMAN: Because that's what memory is for. It's for when everything hits the fan. You want to write it down and remember it.

ABUMRAD: So all of it goes right to your hard drive - the clouds, the feeling of the air. Oh look, there's a guy in a blue shirt.

Mr. EAGLEMAN: So when you read that back out, the experience feels like it must have taken a very long time.

KRULWICH: Hmmm.

Mr. EAGLEMAN: It must have.

KRULWICH: Normally the trivial stuff gets dumped but in this situation it gets written.

ABUMRAD: And then you realize how much trivial stuff is in there.

INSKEEP: Which makes you wonder, Robert and Jad, how we'd feel if we remembered all that stuff all the time.

KRULWICH: You'd be totally consumed by memories. You'd...

ABUMRAD: Buried.

KRULWICH: Yeah. You'd look at an egg and you'd see all the veins in the egg and you'd see the white and you would see the borders and you'd think...

ABUMRAD: You wouldn't be able to forget it.

KRULWICH: Having an experience like this creates a surfeit of memory - too much to remember.

INSKEEP: Well, Robert and Jad, I don't know what to make of this, but if feels like this story took about three times longer than normal.

(Soundbite of laughter)

INSKEEP: Thanks very much for sharing that one with us.

ABUMRAD: Thank you.

INSKEEP: That's Jad Abumrad and Robert Krulwich from the show RADIOLAB, a production of WNYC. And you can explore RADIOLAB at npr.org.