Time Is Constant, But How We Perceive It Varies Time seems to slow in the summer. And how we measure time has changed dramatically over the centuries. We used to tell time by the sun and the stars, and our first clocks had no minute hand. University of Rochester professor and NPR blogger Adam Frank talks about the social construct of time.

Time Is Constant, But How We Perceive It Varies

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NEAL CONAN, host: This is TALK OF THE NATION. I'm Neal Conan in Washington. Everyone knows that time is precise and remorseless and, yet, variable. We measure down to tenths of a second at the end of a basketball game, while baseball measures time by innings.

The solstice earlier this week reminds us that we used to tell times by the sun and the stars. Our first clocks had no minute hand. As I speak, a big, red digital clock in front of me counts down minutes and seconds. Right now, the time remaining in this segment of the program - 11 minutes and 47 seconds - is the most significant thing in my life.

For somebody else, maybe it's the length of a vacation or a baseball season or the time left in the school year, maybe the length of a deployment. What's the most significant measure of time in your life? Give us a call, 800-989-8255. Email us, talk@npr.org. You can also join the conversation on our website. Go to npr.org. Click on TALK OF THE NATION.

Later in the program, another film from the SilverDocs Festival, Mimi Chakarova on her documentary "The Price of Sex." But first, time. Adam Frank joins us from member station WXXI in Rochester, New York. He's a professor of astrophysics at the University of Rochester and writes for NPR's 13.7 Cosmos and Culture blog. Nice to have you with us today.

ADAM FRANK: It's a real pleasure.

CONAN: And let me ask you that question. What's the most significant measure of time in your life?

FRANK: Probably the time it takes for my email box to fill up, which is, you know, maybe minutes.


FRANK: After I've sent all those emails and think I've cleared it out and then to watch it fill back up.

CONAN: It is a curious thing that it can seem so second-by-second-by-second and at the same time stretch out or compress.

FRANK: Well, I think the important thing to understand is that that is a very recent invention in our experience of time. One of the things I think it's really important for people to understand, that the experience of time that we have or that anyone has at any particular moment in history is an invention. It is neither God-given nor physics-given, and it is very much, you know, a social construct that is built both out of the science and the technology of that culture.

And it has very specific needs for economics and for politics. And so there's nothing - I often in my class will ask people to tell me what time it is, and someone will take out their cell phone and say, you know, it's 1:17. And the question I ask them is: What is 1:17? That number wouldn't even have made sense 500 or 1,000 years ago.

You know, since there were no clocks, essentially, then, or most of humanity didn't live with any kind of mechanical timepiece, 1:17 would have no meaning at all. Yeah, it's always changing.

CONAN: Yeah, I understand that, but you say it's a social construct. A day, 24 hours, roughly, well, that seems a pretty natural phenomenon.

FRANK: Well, it's certainly true that, you know, the boundary conditions, so to speak - you know, there's essential facts about our experience of time, which is that, you know, the sun rises, and the sun sets.

But the idea that the day is 24 hours, right, that already there, that abstraction into - you can take this experience of, you know, my room gets light in the morning and then later on, you know, at some time later, it gets dark, and then I'm tired, you know, laying the 24 hours on top of that is the part, the social construct.

That is the part that came up - we are a scientific society, so certainly that is the way we've used time, but essentially, you know, there's this elemental experience of time, which is the sun rises and the sun sets.

CONAN: And Earth goes around the sun, well, just about once a year.

FRANK: Right.


FRANK: And actually, it's the - you know, what's interesting, if you look at - again, if you think of the way that society uses time, that each society has - uses specific needs for time and builds its sense of time and forces it sort of on its people is looking at the division between lunar calendars and solar calendars.

You know, 12 months measured by the moon doesn't fit in to a yearly journey of the sun. And so it's been that there's, you know, about a 30-percent different, you know, 30 percent of a day that doesn't fit. And, you know, much of the history of calendars has been trying to figure out what to do with that mismatch and again because of, you know, very much for both political reasons.

You needed to have your - you didn't want, you know, your summer festivals sliding into the winter. And for economic reasons, also is that you need to know, you know, at what time of year to have your harvest or to have your trading days, et cetera.

CONAN: You can even get into tremendous theological problems, when to set Easter, for example.

FRANK: Exactly. That was an enormous problem for the church during the Middle Ages is that Easter was sliding through the calendar, and they needed calendar reform in order to match those. And that's a very nice example of the way - you know, there are these brute facts of nature that we're given about, you know, the movement of periodicity.

That's really what it's about, right. What we find is that there are periodicities. You know, the moon changes, goes from, you know, one shape to the next shape, et cetera, over about 29 cycles of the sun. But really what we're - the elements, the elements we're dealing with are these periodicities.

We lay down on top of that these sort of social structures based on whatever technology we have at that time and the needs and what we can invent out of the technologies for social organization.

CONAN: For example, time zones, I mean, time back in colonial days was, you know, the clock on the church tower or maybe city hall kept the clock, and the bells rang more or less when they were supposed to. Then the railroads happened.

FRANK: Right, and that's a really fascinating example of how technology - and another way to think of technology is material engagement. It's what we do with the stuff we find, right. And once we built machines out of, you know, iron and wood and - that could move fast enough, suddenly local time, you know, was not enough, right.

It used to be that Philadelphia had its own noon that was different from New York City. And, you know, in 1770, it took about a day and a half. That was the fastest you could get from Philadelphia to New York. By 1880, you can do it in three hours, and suddenly now the difference between noon defined in New York in the Grand Central Station and noon defined in Philadelphia at their train station meant a lot if you had to make the 5:05.

So simultaneity, the idea that everybody experiences the same moment, is a very radically new idea.

CONAN: We have this from Pat, in Fargo. My time is measured in seasons. I am seasonally employed, so seasons mean a lot in my life. Also, the hours left in my shift during an average day: eight hours, then I get to go home. So seasons, though, seem - well, that seems pretty venerable.

FRANK: Well, except one thing that's really interesting if you look at the history is the fact - one of the problem with seasons, especially if you think about work life and getting paid, is that the days are shorter in the winter than they are in the summer, right. And that caused enormous problems for people who were getting paid - you know, in guilds who were getting paid for a day's work.

What did a day's work mean when there was so much less sunlight during the wintertime than there was during the summertime? And it's the invention of clocks, around 1300, that just radically transformed the way people experienced time because now there was this abstraction of 1:00. You know, when the bell strikes one, that's when you're supposed to be back at work.

That shifted the way everybody began moving through their day. Before that, there was a lot of flexibility. There was the sort of sense of, like, oh it's sunrise, sometime after sunrise you're supposed to show up. But by the time clocks - and the clocks sweep through Europe.

They first are introduced around 1307, and then within 100 years, every town and village in Europe had a mechanical clock. And usually, there were no minute hands on these clocks, and actually, in the beginning, they were just bells.

But by the 1400s, people now are beginning to live the clockwork life, right. They're beginning to have - they're beginning to have to show up at this abstraction of when that bell hits five, that's time for you to stop, not sort of like, well, it's, you know, the evening shadows are getting long.

CONAN: Let's get some callers in on the conversation. What's the most significant measure of time in your life? 800-989-8255. Email again is talk@npr.org. Shelly's(ph) on with us from Chico in California.


CONAN: Hi, Shelly.

FRANK: Hi, Shelly.

SHELLY: Me, I tend to measure time by what's happening with my kids, how old they are, how old they're going to be, how much further until high school, how much longer till college. In the big pictures of things, I think of it like that, how many more months until school starts.

But then I think for the smaller things, it's very much about my deadlines: 15 minutes until I have to catch the bus, or 12 minutes until that. And we kind of run our whole world around the bus that we use the most.

CONAN: The school bus or the city bus?

SHELLY: For me, it's the city bus. My children and I are visually impaired, all of us. None of us see well enough to drive. And so we take the city bus everywhere. And so our whole basis of things is by the schedule of which route we're going to take.

And so we have this whole language based on that. You know, it's 10 minutes until the 8, or it's 15 minutes until the 15, or and if you're listening, people who don't ride these buses think that all of the numbers relate to time, but they don't. They have to do with which buses and what time they're coming.

FRANK: Schedule, right.

CONAN: Schedule. Go ahead.

FRANK: And that's actually a very important point because essentially, you know, the minute hand did not appear until the late 1700s, and it was very much tied to the development of factory and factory life because people didn't minutes beforehand, right. You didn't need to have a - go ahead.

SHELLY: Oh, I was just going to say for us, it doesn't really matter what time it is on the clock. It's are we late, or are we on time, is the bus late, or is the bus on time. And then how understanding the people that we're bussing to are going to be if, you know, we're not - we have a fabulous bus system, but it is kind of a rural area. So it can be kind of challenging.

FRANK: But I think the important point - I agree with you, it's not really the - you know, what matters is your experience of a unit called a minute, right, because beforehand - you know, you know if you think you're late, you know, or if you're standing there waiting, you think you've made it on time, right. And then, you know, you look at your watch, or, you know, you find out that it's now - that the time for the bus to come has passed, you feel those minutes pass.

SHELLY: (Unintelligible) the driver thinks it is, too.

CONAN: It's interesting. I, for a while, did broadcast baseball games, and the time between innings, 90 seconds, I developed an exquisite sense of exactly how long 90 seconds was because you had to a lot in those 90 seconds, including get up and visit the facilities or go get a soda or whatever it is you were going to do, but you had to be back in front of the microphone exactly 90 seconds later.

FRANK: Right.

SHELLY: Well, I'll say things to my kids a lot about a quick minute, it's a quick minute, or it's going to be a long hour based on our ride through it. And my youngest son is very literal. So for him, once he started to understand about time, he thinks I'm crazy because all minutes are the same, you know, as far as with the clock. He's very fascinated by the clock.

FRANK: Well, you bring up an excellent point.

SHELLY: One time, the weight fell off of our cuckoo clock. So the second-hand thing started going really fast, and he had a panic. He was like: Mom, we're going to run out of time. Get the weight back on there. Because he thought that ran all of time.


FRANK: Right.

CONAN: Well, Shelly, good luck, and I hope you make the bus.

SHELLY: Yes, I actually am going to be catching it in about 12 minutes.

FRANK: Exactly, right, yeah, right, in 12 minutes.

SHELLY: Well, I'm going to attempt to catch it in 12 minutes. Thank you very much. You have a great day.

CONAN: This from Bella(ph): Every time one of my daughters has a birthday, I'm reminded of how quickly time passes. When the kids were younger, I couldn't wait for them to achieve the next milestone. Now that they're teenagers, I want desperately to stop time so that I can enjoy them just a little bit longer.

We're talking about measures of time with Adam Frank, who is a blogger for NPR's 13.7 Cosmos and Culture blog and author of the forthcoming book "The End of the Beginning: Cosmology, Culture and Time at the Twilight of the Big Bang."

What's the most significant measure of time in your life? Give us a call, 800-989-8255. Email us, talk@npr.org. Stay with us. I'm Neal Conan. It's the TALK OF THE NATION from NPR News.


CONAN: This is TALK OF THE NATION from NPR News. I'm Neal Conan in Washington. Time seems to slow down in the summer. School's out, vacations start. We may measure time by mile markers or sunsets rather than email messages and minutes until the next meeting or the next station break.

We're talking today about time. What's the most significant measure of time in your life, 800-989-8255. Email us, talk@npr.org. And you can join the conversation on our website. Go to npr.org. Click on TALK OF THE NATION.

Our guest is Adam Frank, a professor of astrophysics at the University of Rochester. He's been thinking a lot about the concept of time lately with that new book coming out, "The End of the Beginning: Cosmology, Culture and Time at the Twilight of the Big Bang."

We have an email from Pat(ph) in Anchorage. As a professional pilot for 32 years of my life, so far, the time of significance for me is hours I have spent aloft. It is said that the time you spend piloting an aircraft is added to the time allotted to your life. With my some-25,000 hours of flying time, the extra 1,000-plus days is a bonus. I wonder when they are coming.

FRANK: Right, when you get to, you know, turn them in, essentially.

CONAN: Exactly, when the guy with the scythe comes up. Oh, wait a minute, I forgot your added air time.

FRANK: Here's your coupon, yeah, your get 3,000-hours coupon back.

CONAN: Let's go to Tiffany(ph), Tiffany with us from Portland.


CONAN: Hi, Tiffany, you're on the air.

TIFFANY: Okay. The most significant measure of time in my life has been my mornings. At the beginning of every day, my lovebird's cage is in my bedroom, and I leave the door to that cage open. And he's the one that wakes me up because I'm fortunate enough not to have to really set an alarm, unless there's absolutely something pressing that morning.

So he's the one that comes out of the cage, lands unfortunately on my face and then tries to burrow down into the covers because he likes to sleep with me. It's not like we're getting up. It's his choice to just suddenly come into the bed.

CONAN: And is that as a result of the sun waking him up where he was before?

TIFFANY: I don't think it's the sun because it's usually around 7:30 right now, in the summer. So the sun's been up for a couple of hours by then. And he tends to be a bird that likes to just snuggle, being a lovebird. But I think what it is is it's for him just time to get into the bed and, I don't know, be warm. I really, I can't ask him. He won't answer.


FRANK: Because he's a bird.

TIFFANY: But he does have that freedom, you know, to come and go as he pleases. So that's what he does. He gets up, comes into the bed and goes right back to sleep.

FRANK: It sounds like you have the freedom also, though, that you've been able to sort of lift off the, you know, the sort of socially imposed time of, like, you know, the buzzer goes off, and NPR comes on on your radio at 7:30, and it's time to get up.

TIFFANY: Right, right. And, you know, what's really weird, though, is that the bird right now, it's usually 7:30 every morning. That's his thing. And so he has his own clock going on. In the winter, it's actually earlier, which is very strange. He'll get up around 5:30, 6. I don't know...

CONAN: Well, it sounds - do you know any bird psychiatrists?

TIFFANY: Pardon me?

CONAN: Do you know any bird shrinks?

FRANK: Bird whisperers.

CONAN: Bird whisperers, that's what she needs.

TIFFANY: Well, he's on my shoulder right now. We're driving back to Portland. It's a - it's a lovebird. So he wants that warmth. I think in the winter, he wants the warmth earlier.

CONAN: That's possible. Tiffany, drive carefully.

TIFFANY: Pardon me?

FRANK: With a bird on your shoulder.

CONAN: Drive carefully.

TIFFANY: Well, thank you.

CONAN: Here's an email from Jim(ph): A truck driver, I live a 14-hour clock. It can vary what time it starts, but once it starts, there's no stopping it. I think that's the length of his allotted driving space.

Justin(ph) tweets: I experience time by the album. It takes approximately five CDs to get from Atlanta to Nashville, 10 to get from Nashville to Columbia, South Carolina. But Adam Frank, just going back to the concept of the bird getting up when the bird wanted to, before we had constructs like alarm clocks, we slept differently than we do now.

FRANK: Right. And that's really - that's one of the most significant things about the change or how technology has changed our experience of time. Before artificial illumination basically, you know, robbed us of the night, it used to be that people - you know, when the sun went down, candles were expensive, and you went to bed, right. So most people went to bed pretty much after the sun went down.

And they'd go to sleep, and around the middle of the night, somewhere around midnight or one, they would wake up again. And the first period of sleep was called first sleep, and then you'd, you know, sort of wander around a little bit, do whatever you did, and then you went back for your second sleep.

And you can see this in diaries from people in the 1500s and 1600s, and then once artificial illumination came to dominate, which is around the beginning of the 1800s, that whole pattern was shifted, and first sleep went away. And now if we wake up in the middle night, if we go to sleep and wake up in the middle of the night, we feel that we've had a bad night's sleep, and we don't understand that that is actually our natural sleep.

So even something as elemental, when we come to time, as our patterns of sleep has been shifted by sort of what the culture and its technology allows.

CONAN: Let's go next to Finlay(ph), Finlay with us from Newbern in North Carolina.

FINLAY: Hey, fascinating subject, fellows. I'm a musician and also a classical music announcer on one of your affiliates, Public Radio East here in eastern North Carolina. And as a musician, time is obviously very important because when I conduct, when I perform, it's interesting, and a lot of other musicians have told me this, too, if it's a really good performance, no matter how long clock time it is, it seems like it goes by in just a couple of minutes.

But if it's not so good, you know, and the (unintelligible) starts to come out, it just takes forever.

CONAN: I'm glad that doesn't happen in radio.


FINLAY: Yeah, but it's that perception of time as a musician - because as a musician, of course, you kind of control time. You know, you...

CONAN: I was going to say, maybe the most important measure of time is 3:4.

FINLAY: Or 4:4 or...

CONAN: Whatever it happens to be, yeah.

FINLAY: Subdivided infinitely. And also when I'm playing music on the air, recorded music, the most important aspect of time is how much I have to fill before I get the feed from NPR.


CONAN: Yeah, I'm familiar with that, too.

FINLAY: You know the feeling?


CONAN: I've been there, yeah. All right.

FRANK: Well, it's interesting that the anthropologist Stephen Mithin(ph) says that perhaps the thing that keyed our intelligence - you know, no one understands why it was 50,000 years ago, suddenly we began culture, suddenly we became self-aware. And Stephen Mithin has said that it's actually singing and music that may have been instrumental to our sort of awakening to ourselves and the development of culture.

So it may be that that sort of very personal, very elemental experience of time that we have through music, or sometimes sports will also do that, you'll have that, you know, you'll be in the flow, or writing. I know I certainly have this as a scientist when I'm doing calculations. Hours will go by and I won't even know what happens.

And, you know, that is sort of our - that is something more elemental than what gets imposed on us by the culture.

CONAN: Finlay, thanks very much for the call, and good luck.

FINLAY: All right, brother, take care. Great program.

CONAN: Thank you. This from Jennifer(ph) in Bellville, Mississippi, I think: I'm 37 weeks pregnant. So right now, I measure my time in weeks.

FRANK: Congratulations.

CONAN: And in kick-counts. So - and that's, yeah, another measurement and one that's - the nine months and, of course, not necessarily a precise measurement, either.

FRANK: Right.

CONAN: This from Richard(ph) in Boise: I've always been fascinated that time and weather are the same word in Spanish, tiempo. As time is a measure of events, it seems that before mechanized time, the weather must have been the communal events that were the basis for a common idea of time.

FRANK: That's fascinating. Certainly when you look at other cultures, when you look particularly at agrarian cultures, what you find is this idea of an abstraction of time doesn't occur at all, and the day will be divided into these sort of flexible units that really are named based on what you do with it.

So, like, the Kosovo people in southwest Ethiopia have a word called (unintelligible), and that is basically when the cows come home, right, when you go get the cows. And it's not like that happens at 5:00. It happens when you go get the cows, right. So it sort of floats. And it's only more recently that we've had this sort of imposition of sort of the abstraction.

But yeah, earlier on, people were very much - they floated on time based on what happened and what they were doing.

CONAN: Let's go next to Ruth, and Ruth with us from Marietta, Ohio.



RUTH: When I was a child, the time from Thanksgiving until Christmas was interminable. Now, Thanksgiving, Christmas is next day. And when I was a child, birthdays took forever. And now I know that something's going to happen in a year, and it happens right away. And I'm really curious.

I know there's been discussion and studies on why time compresses as you get older. I would really like to hear you discuss that.

CONAN: Adam Frank, any ideas?

FRANK: Well, there is - there's definitely been research that shows as you move on with your life, you know, that things become compressed. One reason is you have so much memory built up.

I mean, I think one of the reasons why childhood, our memories stand out so vividly, you know, from Proust on, you know, marking that, you know, acknowledging that, is that we have so little memory built up of it, that, you know, these experiences of time, the movement through time still seems very new.

Then there's also the fact that as you move through your life, you're getting closer towards the end of your life, and there's the recognition of that. And so there's a sense also there of the dimming, in some sense, of that role ahead of you. And that also contributes, just that you've lived a larger fraction of your life already.

CONAN: Interesting, we have an email to that point from Kevin in Knoxville: I have liver cancer and will be dead within a couple of years and in many ways don't measure time. Why bother? But I'm also a personal chef, and when I cater a party, every 10 minutes matters. It's a question of circumstance. So that time is that how much time we have left, our three-score intent, as it used to be measured.

FRANK: Well, I think certainly - and, you know, different religions point to this, as well, like, you know, within Buddhism, there's this idea that, you know, well, you don't have lunch at 2 o'clock, 2 o'clock is having lunch, right? And it's very much sort of how we turn, you know, what our attention is in our movement through the day, you know, again, this idea that the culture imposes upon us certain temporal structures because - you know, for a variety of reasons. And when we adhere to those then we're very much in this sort of, you know, step-by-step experience of time.

But we all have these moments sometimes. You know, it could just be when we're doing the dishes or we're, you know, we're walking through the woods and we see a sunset, when suddenly that whole veneer of that structure just drops away and, you know, we have an encounter of - you know, a word that could be used like sacred, you know of somehow the world sort of - and time stands out on it's own. And if you're brought - when you have experiences of your own mortality, I think that, you know, that again, that veneer, that social veneer will really drop away.

CONAN: Ruth, thanks very much for the call. Let's see if we go next to Bob, Bob with us from Fort Meyers.

BOB: Hi. You know, I live in a very strange world, time-wise. I work in TV news, and we go out and shoot news stories all day and then come back and edit them. And so I - a couple of strange things happened in my life. One - or happen in my life everyday. One is that we go out and we'll cover a story which may take two hours, three hours to develop, and then we have to condense it down to a minute, 30. So we're shrinking time constantly.

FRANK: Right.

BOB: The other part is that I live in a universe that's a 30th of a second long, because every frame of video is divided into 30 parts, 30 frames per second - I'm sorry, not every frame, every second is divided into 30 parts. So I have to be very aware of what happens within each one of those 30ths-of-a-second, because when you look at it that way, a lot happens within one second. And we have to be very careful about that.

FRANK: Well, it's interesting. You know, that really points out this idea of how time shifts from - and the experience of time or the uses of time shift from one culture to the other. You know, computer-generated trading now is another example, where you know, we never thought about milliseconds before. It wasn't milliseconds. Who needed a millisecond? But now, suddenly, you know, there are we do have to pay attention to that, or the consequences can, you know, if we don't pay attention, it can be dire.

So, you know, as culture moves along, its uses of time, its structures for time change. And, you know, I think the really important thing to understand, it's going to change again, that, you know, if you're not happy with the time you have now, you know, it will most likely change. And one thing that's interesting is the way people opt out of their cultures time, people who do - say, lifestyle entrepreneurs, people who have started businesses not because they want to become millionaires, but because they want to have control over their own time.

And so, you know, they're building it they just want to live, you know, they just to want to have enough money to live, and so they're building businesses, essentially, to free themselves from, you know, that structure that we're, sort of, we're taught very early on. You know, when you're a kid, right, what happens is you go to school and you learn that 9:00 AM is for math and 10:00 AM is for history. And if you still like doing math, stop doing math because, you know, it's time to do history. And that follows us our whole life. That's the way we suddenly - essentially structured our, you know, our culture.

CONAN: Bob, thanks.

BOB: Thank you.

CONAN: We're talking about time with Adam Frank. You're listening to TALK OF THE NATION, from NPR News. Another sense of the word, when did we start thinking about killing time?

FRANK: That's a fascinating idea, and actually if you - one of the really fascinating parts of the book, as I was studying or doing the research for it, was looking at the beginning of industrialism and when people started being clocked in work. And actually, this began with a man named Ambrose Crowley, who, in the 1700s, developed the first factory model for iron production. And he had this long rule book called "The Rulebook of the Crowley Iron Works," and it set out all the things you had to do with your time. And it was very specific about people who were killing time, who were fooling around, who were wasting Crowley's time.

And, you know, that was the first time you'd get docked, the first time and that you can see, in print, someone - the rules being set outside for you being docked for not being productive. So, I think killing time is actually what people did quite a bit, you know, before the imposition of clocks with minute hands, etc., but, you know, with the recognition that this is not something you want to have happen comes with the imposition of the industrial model of, you know, you might it call it a punch-clock universe.

CONAN: Here's Scott emailing from Mountain View, California. We're theater people. Time is measured in titles. Was that during "Hamlet" or was it "Sweeney Todd"? Smaller units are rehearsals, tech week, after opening, everything centers on opening night and every day is centered on curtain time. We all hope to make it all the way to closing night, and then we move on to the next (unintelligible). So, yeah, the run of a play is the necessary and significant measure of time.

FRANK: That's fascinating, yeah. So that - you know, your time is organized around your activity, there, in that case. They're almost - in that case, they're almost looking back to what the Kosovo people are doing, right?

CONAN: Mm-hmm.

FRANK: That they have their - you know, there's that social time, but really, they have their own internal structure of time, that what matters is where they are in that structure.

CONAN: Here's another email from Don in San Ramon. My regularly scheduled six-month dental appointment is a good wake up to wonder what I've accomplished in the last half year. Fortunately, I don't dwell on it for too long.

FRANK: Ouch.

CONAN: A tweet from Forest Fisk: As a photographer, I measure time by photo albums of events. If I'm not doing something new, no pictures. Then time seems to fly. And let's see if we can go to Michael, and Michael's with us from San Antonio, in Texas.

MICHAEL: Hey, how you doing?

CONAN: Good, thanks.

MICHAEL: Well, it's really funny. My - I work from home, and my measure of time is actually NPR. If I - Diane Rehm's horns come on, it's 9 o'clock and I need to get up. Eleven o'clock is FRESH AIR, so I hear, you know, Terry Gross telling you FRESH AIR from Philadelphia, and 3 o'clock is THE WORLD (unintelligible) o'clock is TALK OF THE NATION. It's these little audio mnemonics that kind of keep my sensibilities about me, and it's kind of funny when there's a pledge drive or something going on. I'll be back here and I'll listen to the Internet version of, you know, WNBR, and it really throws me off because it's kind of out of sync with the San Antonio stuff. So NPR is my radio and my timepiece.


FRANK: That - I think that's actually a hugely important point, because what you're doing is - and this is something I found when I was, you know, doing my research - is that you're living on a shared time, and it was actually radio that first taught the world how to live on shared time. You know, radio it wasn't until like 1920 or so that radio broadcasting, that people - the first attempts, the first radio station was KDKA. And...

CONAN: Oh, you can get into a lot of arguments about that.

FRANK: Okay, all right - well, the early - what's important for this point is that the early radio - there weren't structured days. People kind of played what they were playing whenever they wanted to play it, and it was - at least in my reading - it was John Brinkley who was actually kind of a quack doctor who sold Viagra for his time. That first - for his radio - he had a radio program that he structured his radio day, and that everybody knew at 7:00, that would be time for music.

CONAN: Time for music Michael, thanks very much for the call.

MICHAEL: Love the show. Thanks.

CONAN: Thank you, Adam Frank we appreciate your time today, too.

FRANK: My pleasure.

CONAN: Adam Frank, a professor of astrophysics at the University of Rochester, and he joined us from member station WXXI. Coming up: "The Price of Sex," a documentary on the terrible cost of sex slavery. Stay with us. It's THE TALK OF T HE NATION, from NPR News.

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