MS. DIANE REHMThanks for joining us. I'm Diane Rehm. Simon Garfield says his fascination with maps began as a child traveling to and from school on the London Underground.

MS. DIANE REHMThe subway map was how he knew where to get on and off. Maps became not just a tool to get around, but a representation of the world yet to be discovered.

MS. DIANE REHMSimon Garfield is the author of a new book titled "On the Map: A Mind-Expanding Exploration of the Way the World Looks." He joins me from the BBC studios in London. I do encourage you to be part of the program. Join us on 800-433-8850. Send us your email to drshow@wamu.org. Feel free to follow us on Facebook or Twitter. Simon Garfield, welcome to you.

MR. SIMON GARFIELDGood morning, Diane.

REHMSo glad you could join us. You know, you say that maps tell our stories. What do you mean?

GARFIELDWell, you know, we look at digital maps now and we see them on our phones and we go in our cars and we have GPS and you know, think, okay, you know, you're absolutely right about the tube maps. It gets us from A to B and it's the same with these.

GARFIELDBut actually, if we look at them in ten years' time, they're going to look fairly similar. We look at them in 20 years' time and they're going to look very similar as well.

GARFIELDWhat we're losing by looking at those is all the great history that we have from printed maps and printed maps tell a story from, you know, 2,000 years ago really, from the ancient Greeks and, you know, the Great Library of Alexandria what they knew of the world and all the way through.

GARFIELDAnd they have political angles and they have great personal angles and they can reflect great personal tales or big, grander schemes. They tell you about wars. Now, none of this would be possible on the digital maps so the attempt of the book really is to look back and to tell some of the great stories through printed maps.

REHMBut at the same time, you actually use current technology to look back. You visited Google, for example, when you were researching the book so what did Google mean to you?

GARFIELDWell, you know, despite the fact that I love all the old maps, I, you know, like, I imagine the vast amount of your listeners, you know, benefit from the new technology as well. And if I'm in a car alone, I do use GPS. If I'm, you know, walking around a city that I'm not hugely familiar with, I will open up the map on my phone.

GARFIELDSo obviously, Google is fantastically important and I was privileged when they let me in and they told me that they never expected to have as much responsibility as they have now. You know, as we all know, Google began with search and that was the big thing and then they thought, oh no, what can we do, you know? Everyone's looking at us. We can show them maps as well.

GARFIELDSo they search and they get a picture now. Now, of course, they are, without any question, the most dominant digital player. We only have to look at the disaster that was Apple Maps, when they tried to produce their own maps last September, to know how important and how significant Google is.

GARFIELDAnd also, you know, we kind of realize that actually now they are essentially -- there are lots of other mapping companies and lots of other digital mapping companies, but it is the first name that you think of when you think of maps. And I think the, you know, the reason I went to see them was to talk about, really, their responsibility.

GARFIELDAnd they told me this fascinating story that, you know, that they got one thing wrong on their map and it started a small war. So they had actually given a region more area, you know, on their maps, actually more space, more land than they should have had. And there was a little local difficulty as a result of that.

GARFIELDSo, you know, fantastically important and, you know, I'm fascinated by what we gain from digital maps and really kind of what we lose. And, you know, if we can have them both at the same time, then it's a win/win. My real concern is that we're going to forget about the old stuff. We won't be able to read a map, all those things.

REHMBut I want to take you back because, in a sense, what you're suggesting, and scientists have indicated the same thing, that maps have been as important and even more important to human development than even language.

GARFIELDYeah, that's why I'm -- so people such as Richard Dawkins and he's not alone, have supported the view that before we could speak, we could draw so we could indicate, you know, where, if we were on the African Plains, we could indicate where the elk was, where we have to throw our spears to eat that evening.

GARFIELDThe way we did this, initially, it is thought, was not through language, but it's through drawing, either in caves or you know, in the dirt whatever. And he speculates whether it wasn't that ability, that spatial awareness, that expanded our brains and expanded our brain power and a single thing that elevated us from the apes into Homo sapiens. So maps absolutely define, you know, what makes us human.

REHMSo go back in history to the Greeks, to the beginnings of real mapping, and you've got Ptolemy and you've got Eratosthenes, who are two of the great mappers.

GARFIELDYeah, Eratosthenes and you pronounced him right and some people don't and so that's great. Basically, so both of these great geographers really developed the art of geography. Geography wasn't a significant science until about 2000 years ago.

GARFIELDAnd what they did, well, they were based at the Great Library of Alexandria and what they did was something that really had never been thought of as important before, which was to try and imagine how the world looked. And the way they did this was a mixture of things really.

GARFIELDIt was essentially based on travelers' tales so navigators, other sailors would come in to Alexandria, which was essentially the, you know, the trading and the cultural capital of the world. And they would have their maps confiscated often and they would maybe sail away with duplicates or maybe wouldn't sail away with anything.

GARFIELDAnd their maps, and wherever they would come from, they would be sort of collated, if you like, to expand the sum of human knowledge. And these would be added to what we knew of celestial guidance and they would be formulated into a description of what island or what country lay next to where.

GARFIELDNow, some of this is fantastically inaccurate, obviously, if you're looking at the, you know, the Greek and Roman Empire, they knew all about that, some of it less so. So we knew about three continents. We knew about Africa, which was then named Libya. We knew about Asia and we knew about Europe.

GARFIELDAnd I'm always amazed about how much we got right. You know, it's quite easy to say, oh, you know, this was misshapen. And they thought Africa was much larger than it actually was, but actually what they got right is sort of extraordinary.

GARFIELDWe don't have, however, the original maps. It's not even clear.

REHMBut how do we know what happened when they got things wrong? I mean, if they had Africa, Asia and Europe, they left out a great deal so I mean, how did they manage their navigation or did they make it up as they went along?

GARFIELDWell, I mean, you know, we make great sorts of discoveries by not knowing where we're going...

REHMExactly.

GARFIELD...so there was a, you know, that was a very sort of significant part of the world. I mean, what they did classically was not sort of, you know they were interested in trade. They weren't interested in the world for sort of educational purposes. And we don't know exactly what they knew because the maps don't exist and what we have essentially is from people like Ptolemy.

GARFIELDThey drew up atlases, but without the maps so what we had was what was handed down and were essentially the indices. So we knew what lay in relation to, you know, to what and that was the key. And then in Victorian times, you know, we could reproduce and there's a lovely picture of a book, of a sort of a Victorian reproduction of what we think Eratosthenes knew.

REHMNow, there's one error that you say is your favorite cartographic error and that was the Mountains of Kong. Explain what that is.

GARFIELDOkay. Well, we're jumping forward now really...

REHMRight...

GARFIELD...to the 19th century and the Mountains of Kong were a region of mountains that appeared on maps for a period of about 100 years. They began appearing in 1798 where a very famous English cartographer called James Rennell, who had mapped India, and was sort of, you know, regaled as one of our great geographers.

GARFIELDHe tried to illustrate the travels of Mungo Park, who was a great African explorer and he put in -- for reasons that we don't quite know about. He may have just seen a few mountains. There might have been a lot of fog. He heard that there were mountains in the distance. There may have just been hills and he mapped essentially the Mountains of Kong, which expanded from the west coast, the very extreme west of Africa, essentially like a belt across the whole of Africa.

GARFIELDNow, the problem with maps in those days was that unless you were, you know, also exploring Africa...

REHMWe've got to take.

GARFIELDWe'll come back to that.

REHMWe will come back to that one after a very short break. Simon Garfield is with me. His new book titled "On the Map."

REHMAnd if you've just joined us, Simon Garfield is with us from a BBC studio in London. He's the author of the new book. It's titled "On the Map: A Mind-Expanding Exploration of the Way the World Looks." And just before the break he was talking about what he calls his favorite cartographic era that was made many years ago. It is the mountains of Kong. Now go on with your explanation, if you would, Simon.

GARFIELDOkay. So the mountains of Kong began in 1798. Now, what's remarkable about this is, well, not only did they not exist and you can still buy -- I mean, you can still buy old maps and they all know, and that sort of thing, and they stretch for thousands and thousands of miles. And they're very boldly on the map as well. But the thing that I love about it, most of all, is that unless you were fortunate to actually travel to Africa, which most people in the 19th century, you know, hadn't seen, you wouldn't know that they weren't there. You would just take it as sort of gospel.

GARFIELDYou know, we tend to regard things on maps as true. You know, so we would read maybe a biography and think, okay, that's sort of conjecture. But on a map, it has a certain authority and that I think holds true even now. So for 100 years, people thought, well, okay, we're going to add a little bit to this map because someone else has come back and we've got a little bit more explanation about, you know, what Africa looks like. But obviously, we're going to keep the mountains of Kong there.

GARFIELDAnd I always like to say this is sort of a kind of Wikipedia entry, you know, of its day. But someone will put something up there that was wrong, it would then appear, that fact in, you know, a thousand school essays until someone pointed out actually, no, that wasn't the case and then you had to correct it. And so it took until 1889 until a French army officer, who was called Louie Gastovbinga (sp?) or binja, actually went to Africa and found that actually not only were -- did the Mountains of Kong not exist, but he said, I think it was a -- he said, on the horizon not even a ridge of hills.

REHMOh my. Oh my.

GARFIELDAnyway so -- and then we had great instructions to take them off the map and -- but even in 1890, I think a Rand McNally map of Africa had the Mountains of Kong on it.

REHMOh my.

GARFIELDSo unfortunately, no longer there, but if you want to see them, they are on old maps.

REHMAll right. Now I'm jumping around in our time sequence here, but here's an email from Ernest in Silver Spring, Md. who said, "How did the ancient Polynesians make such extraordinary voyages without maps?"

GARFIELDWell, interestingly enough, I mean, we, you know, we use maps all the time. And in the West and, you know, England and America we love maps. It's part of our culture. So many other parts of the world, even now, it's not part of their culture. I will answer the Polynesian question but an interesting sideline to that is I was talking somewhere recently about the book. And someone came up to me and said that they were in the British Army. They went to Afghanistan and they didn't have proper maps because it simply wasn't part of the culture. And that exists even now.

GARFIELDSo the Polynesians, they basically felt that they didn't need maps, you know. They were sort of going on their travels for trade reasons. And they guided themselves by the heavens and by the stars and by the north stars and everything else. And, you know, they sort of knew -- and they had other things, you know. It was obviously in their blood. They knew if they sailed for a certain amount of time, you know, from the main land they would get to a certain point. And then they would have to change their sails. So it was a mixture of experience and the heavens.

REHMAnd of course I must ask you about Columbus and his voyage and how he ended up in one place thinking it was another. To what extent was that the fault of faulty map making at the time?

GARFIELDI think it was probably a mixture of things. I mean, he was -- you know, we mentioned Ptolemy and he was still pretty much guided by what Ptolemy thought the world looked like. And this was now, you know, we've been out 1400 years away from Ptolemy. But that's all the knowledge we had. So it was on the edge of what we know as a golden age of (word?) . So it shows how little we knew of the world. It suited him when he was trying to raise money for his voyage to think that it was a much shorter -- you know, a much shorter journey than it was.

GARFIELDAnd you're right, he got it wrong by, you know, thousands of miles. And, you know, here you are, you know, you're the lucky recipient of his mistake really. I mean, that's sort of the -- you know, in a way also that's sort of the joy of good maps and the joy of errors as well. I mean, the biggest -- but I mean, if we're talking about Columbus, you know, the biggest -- you could call it an error, I suppose -- is why, you know, the U.S. isn't called Columbia perhaps and why it's called America.

GARFIELDAnd the reason for that was, again, it's down to maps, you know. The man who drew up a hugely influential map in 1507 -- and the Library of Congress recently purchased this map -- Martin Waldseemuller, got misinformation about the new world. So he was the first to put the new world on -- he wasn't the first to put it on a map but he was the first to put it on a widely seen and hugely influential map.

GARFIELDAnd he had seen some letters from a man who knew Columbus and had helped finance Columbus' mission called Amerigo Vespucci. And he thought that Amerigo had got there first. And so he explains in his map, this is named after Amerigo, the first time Amerigo appeared. You know, it was the bottom sort of left-hand corner of the huge world map. And it was the first time it appeared and he realized his mistake, I don't know, five years later. And by then it was too late. People were already calling it America and it already appears on other maps.

REHMHelp me to understand how we came to have a globe.

GARFIELDWell, the importance of a globe really was that a map is a two-dimensional object and we live in a three-dimensional world. And so if you're sailing on the seas we know that the earth curves and that the sea, you know, isn't a sort of straight line. And we thought, well, wouldn’t it be a fantastically useful thing to actually depict the world as it really was rather than just as a two-dimensional object? So it's sort of really as simple as that.

GARFIELDI saw as simple as that. Actually trying to put a two-dimensional object on a round -- on a circle really is fantastically hard -- on a globe is fantastically hard.

REHMHow long did that take? How long was it before that two-dimension became three?

GARFIELDWell, the first one we know of is from the 15th century. There were sort of other spheres. The earliest existing example is from the 15th century. That's the last one -- I mean, that's the earliest one that we have now. And the chances are there were some before then. But I was kind of interested -- I mean, as you say, you know, how does a globe come about? How do you make a globe? And I went to see a contemporary globe maker. Globes now -- you know, they used to be in every classroom.

REHMOf course.

GARFIELDEvery boardroom in America had a globe.

REHMRight.

GARFIELDIt was a symbol of power. You could hold the whole world in your hand. You can spin it and stuff. Now, again, because we have Google Earth on our maps -- on our computers, you know, it's seen as a less significant thing. We don't need it to gad about. But I did spend some time with a British globe maker who was trying to sort of reinvent the importance of globes and make those. And he said, you know, he began from scratch and it took him four years to make his first globe that actually worked.

REHMHere is an email from Mike who says, "I use to participate in a competitive outdoor sport called orienteering. The sport involves finding your way around an outdoor course with the aid of a map and compass and trying to complete your way around the course in less time than your competitors. Could you please comment on some aspect of orienteering, assuming you're familiar with that sport."

GARFIELDYeah, I mean, when I was at school, that was an option. If you didn't want to play rugby or soccer or get muddy and, you know, a competitive sport, you could go out on your own with your maps and try and find your way back to the school or the car or the countryside or...

REHMAnd you did that, I'll bet.

GARFIELD...wherever it was. I did that a little bit until I realized actually it was -- it's actually a lonely and slightly scary occupation, as well, way to spend an afternoon because if you got it wrong you might not find your way back. But yeah, I mean, see, I think this is a dying art. I think now if you go to schools -- you know, your emailer said, well, you know, they used to do this. And I'd be very surprised if it exists sort of in the same way. But I think a fantastically important skill, and I think this is something that we're losing.

GARFIELDYou know, we now get all our maps for free. By and large we can find our way around the world, you know, just using satellite navigation. And, you know, as we said at the top of the program, you know, either on our phones or, you know, other GPS devices. I know for a fact the mountain rescue people, for instance, hate GPS. They hate the fact that GPS is available to everyone, I should say, because what happens is people go out and they think they can just find their way on the phones.

GARFIELDAnd they might find actually when they get out there that the phones don't work because the weather is bad or the signal just doesn't reach them or they run out of batteries. Even worse, you know, you kind of think, oh, well, we'll find a way home with this. And actually, you know, the significance of being able to read a map and actually find your way back just, you know, using a paper map, I think we're losing that. And I think that's, you know, a really great loss. And I don't think it's being taught right. Again, talking to people, it's just not being taught in schools the way it once was because people don't say it's that important.

REHMAnd, you know, I am one of those people who has great difficulty reading maps, and I'm talking about paper maps. We were traveling years and years ago with dear friends and my husband and I took turns sitting in the navigator's seat. And I was terribly embarrassed because we were in a foreign country and I just had a terrible time with that map. Now today with GPS we would assume that that would be different. But I agree with you that learning to read maps is a very important skill. And you're listening to "The Diane Rehm Show."

REHMWe have many callers waiting who'd like to talk with my guest Simon Garfield. He's the author of a new book. It's titled "On the Map: A Mind-Expanding Exploration of the Way the World Looks." So let's go first to Sanibel, Fla. and to Leah. Good morning, you're on the air.

LEAHWell, good morning. My name's Leah Quinn and I'm actually from Hawaii. And so when your guest talked about the way that Polynesians actually were able to get around the Pacific, not just Hawaii but to many, many islands, it wasn't just by using the stars. It was a very in-depth knowledge of the current. And in fact, the Hawaiian Polynesian Voyaging Society had a voyage that was documented in National Geographic in the late '70s where they replicated an ancient canoe, you know, and took it to Tahiti and back again with no instruments whatsoever.

GARFIELDYeah, absolutely right. Now that's a very good point but it's sort of -- you know, it is that kind of intuition. So they knew by experience of the currents and it was -- you know, that's what I sort of really meant I think by it's sort of in their blood I think. And I've seen that -- I've seen, you know, some of the rafts that they recreated and they are sort of extraordinary things. It's not just a question of how you got around but how you actually survived on the open seas on those things as well is extraordinary.

REHMLeah, I'm glad you called. To Clinton, N.Y., good morning, John.

JOHNGood morning, Diane. A great show.

REHMGood.

JOHNI'd like to make a comment and ask the author to comment also on this. My son is a junior at Dickinson College majoring in archaeology but he's the GIS consultant to the Barrington Atlas, which is edited by Richard Talbert, a professor at the Ancient Mapping Center at the University of North Carolina Chapel Hill. And I'd like the author to comment on how we're still reconstructing the reality of the ancient world. And the tremendous effort that has gone into the Barrington Atlas, which is, I think probably the most accurate source of that information on the ancient Greek and Roman world that is.

JOHNAnd also the role of GIS which also can produce things in three-dimensional factors that might replace what we now refer to as physical globes.

REHMAll right.

GARFIELDYep, no, I mean, fantastically important. You know, I've talked a little bit about, you know, satellite in terms of GPS and -- well, the GPS in terms of our phones and use in our cars. But obviously, you know, the value of satellites and GIS, you know, Geographic Information Systems using the new technology allows us to do extraordinary things online. And, you know, we now -- not only do we, you know, get around far more accurately in planes using it kind of far more, and it becomes, you know, far more trustworthy.

GARFIELDBut as you say, we can kind of recreate these ancient worlds in far more kind of actual ways than we ever could. So I don't want to seem like a sort of naysayer, you know, someone who actually doesn't like the new technology because I realize it's values. I'm just very, very careful that we don't also lose what we have, that we're not just looking for geographical accuracy, you know, to make sure we get absolutely everything right.

GARFIELDBut also we're looking, you know, as we said at the beginning, an idea of what makes us human, an ability for maps to tell our tales and to have personality and individuality. And that's what's very important to me. And I think if we can have them both that would be the ideal.

REHMLet's hold on to the question about the Barrington Atlas and ancient worlds until we take a short break here. When we come back, John, we'll have Simon Garfield address your question.

REHMAnd just before the break our caller John, in Clinton, N.Y., posed a question to my guest, Simon Garfield, whose new book is titled, "On the Map: A Mind Expanding Exploration of the Way the World Looks." He asked about the Barrington atlas and the mapping of the Ancient World. Simon?

GARFIELDYeah, I mean it's a fantastic project. I think, if I’m right, developed by Princeton or at least published by Princeton. You know, I should say it's kind of a hundred page large-scale atlas. And what's so wonderful, I mean, it's a physical atlas. I think it comes with a CD-Rom, as well, to help you sort of find your way around. And, you know, the wonderful thing about something like the Barrington atlas, which has, you know, a vast amount of scholarship kind of attached to it and in it's making and it goes from, I think, 500 B.C. up until 49 A.D. or so, 50 A.D.

GARFIELDNo. Actually it goes later. I think it goes to 600 A.D. It attempted to get the kind of physical aspect of the way, you know, for instance, Ancient Greece looked as well, which is a kind of, you know, a wonderful thing. Which, again, on digital mapping, again on our computers, you sort of lose. You know, you can have an element of contours, but it's much, much harder. And unless we're looking 20 years ahead, maybe we'll have kind of 3D maps on all our computers. So fantastically valuable in that, but it's a rarity. And it's a beautiful rarity. And I think probably, you know, a prize-winning one.

GARFIELDBut I don't think we pull down, you know, I call them kind of shoulder-dislocating atlases in the same way that we once did, you know. Our world has shrunk in a way. So the Barrington atlas is a sort of historical document, but I think our world has shrunk. If we want to find our way around now, we used to go to atlases and now we don't. And I think we think that the world is sort of somehow smaller because of it. You know, we are always at the center of maps. It used to be we were very, very insignificant. Now, you know, we go to our computers and we are always in the middle of it.

GARFIELDIt is, of course, a slightly egocentric way of mapping in a way, rather than having to find our place on a large atlas, now we think we're in control and I'm not sure we are.

REHMAnd taking that even a step further, in your book you go into the mapping of the brain. So you're not just talking about the geographical world. You're talking about humanity and how its own brain begins to be geographically located.

GARFIELDYeah, I mean it's, you know, we talked about sort of Ancient Greece and what they knew of the world then. We've only been able to understand the inside of our brains, the mapping of our brains fairly recently really. You know, it's through sort of high resolution scanning that we've really been able to understand not only that, but also then that sort of makes us think about the spatial abilities and spatial awareness. There was a fantastic experiment conducted in London, not so long ago, into London black taxi drivers.

GARFIELDAnd we had a fairly good idea, you know, 10 or 15 years ago about the hippocampus and the way our ability to understand space and what lay ahead of us was sort of developed in, you know, a certain part of the brain. But it was quite hard to prove this really and to look at how it really developed. So an enterprising researcher got the brains of a number of deceased taxi drivers and found -- because they had stored the London A to Z in their brains, so that part of their brain had expanded greatly. I mean, sort of beyond, you know, beyond anything that they expected to find.

GARFIELDAnd that, again, you know, I wonder that the next question I suppose now is that going to shrink back? Now people no longer have to have that memory, although having said which, if you want a black cab license in London, you still have to have that knowledge in your head, but in 10 years time, the rules may change. They may say, okay, like, forget that. You can just go by GPS, by satellite that's also reliable.

REHMAnd of course, the saying could be said of developing a language as a child and then losing it and what happens to the brain then.

GARFIELDYes, absolutely. We're still at the beginning of this.

REHMYeah.

GARFIELDYou know, we're talking about brains, but I also look at the mapping of Mars, which I find is absolutely fascinating as well. You know, we have an idea of what lies out there, but only -- and again, this is another kind of passive technology. Only really in the last sort of 40 years, really, since the 1970s have we been able to understand the mapping of Mars. You know, we used to think -- and it was very hard to disprove this until NASA sent their space rovers up there. We used to think that, you know, Mars had canals on them and this was genuinely believed. There was a very famous story of a man called Percival Lowell, who set up a huge observatory in Flagstaff, Ariz., and convinced the world that Mars had canals on it.

GARFIELDHis theory was that the ice caps of Mars were melting, that the great, you know, fantastic Martians, weren't they clever, they dug canals to conserve water. And that, again, from a map, is where we get this great idea of Martians and all, and then, you know, this great fear of Martian invasion. It wasn't from people like H. G. Wells and science-fiction. It wasn't from Hollywood. It was from maps.

REHMAll right. Let's go to Phoenix, Ariz. Good morning, Maddie.

MADDIEGood morning. My comment is referencing my experience with my children. I believe it's important to foster that relevance and value of maps early on. So we started teaching our children to be aware of their location since they were very young, you know, knowing their north, south, east and west. And when traveling we prefer the road trips and engage them in the voyage by having them help us navigate. We have three children under 12 and they each get a map. One gets the paper map, the other one gets the Google map on his phone and the other one gets the GPS and we all trade.

MADDIEAnd the goal is for them to enjoy and learn from the traveling experience versus just being a piece of luggage in the trunk and not knowing where they're going until they get there.

REHMMaddie, I think that's just a great idea. And I'm sure Simon Garfield supports your effort. Here's an email from Steven who says, "Could you address the problem of hoaxes in the world of mapping. For example the Vinland map, was that a hoax?" And you have a whole chapter in your book on this.

GARFIELDYeah, it's an extraordinary saga. And it's even more interesting, I think, because, again, we can't be 100 percent sure. So the Vinland map came into play in the 1950s, where an American book and map dealer was on his travels in Geneva and he called in on a dealer that he knew. And he came out, having spent quite a lot of money on this map, which purported to show on a map for the first time, that the Vikings knew of the existence of America, which they called the Vinland or Wineland, about 400 years before Columbus, maybe 500 years before Columbus. And the map was actually made about 50 years before Columbus.

GARFIELDSo an extraordinary thing. If this was true it would, you know, it would sort of turn history on its head. The map would instantly become the most valuable map in the world and everything else. Now, for the past 60 odd years, scholars have been lurking at this map and trying to decide whether it was a hoax or not. Now, it may have been a forgery and there's all sorts of theories about how it might come about, but I talked to one or two experts who have examined the map. It's now at the Beinecke Library in Yale. And they say they probably think it's 80 percent a hoax and a fake and possibly, you know, there's 20 percent of doubt that remains.

REHMInteresting. All right. To Wichita Falls, Texas. Hi there, Kyle.

KYLEMorning, Diane, Mr. Garfield. I want to just say it's really nice to hear the importance of maps. I am a mapmaker in the United States Army, 12 Yankee. I was trained just south of where you all are at, at Fort Belvoir, Va. And using digital mapping software, we're able to create paper maps off our plotters for whatever our customer's needs are, whether it's our unit commander, the squad leader leading his group into the field. So it's often overlooked how essential maps are in the whole supply chain, you know, ammo, food, trucks is one thing, but we'll always need maps and GPS is one thing, but maps will never run out of batteries.

KYLEYou just have to make sure they are built correctly so we don't have any issues or have enough maps.

GARFIELDYeah, that is interesting. If I heard you right at the beginning, you said that you downloaded these maps, you know. So it's sort of the best of both worlds, really. You know, without the satellites, I suppose you could say, well, you may not have been able to obtain these maps at all. Is that correct?

KYLEActually, we have a database at the National Geospatial Intelligence Agency. We have maps from the Geologic Service, Forest and Wildlife, states, whoever can provide a map, we can bring them in and then add our own information on top of it, a route, an operating base, where an airstrip should be, where helicopters will come in, do our analysis on that, tell them you can and can't drive in there, too much mud, too many obstacles for a helicopter. So not just creating the map, but also telling them what they can do with that map.

REHMSure.

GARFIELDThat sounds fantastically important. And the interesting thing about your work there is that you're absolutely adding to our knowledge of the way the world looks.

REHMAbsolutely.

GARFIELDAnd to the map, which will then be passed on. You know, people sort of think, oh, well, you know, the satellites have seen everything. You know, here we are in 2013, you know, we've mapped everything. We've mapped everything in the world, but actually, you know, it's clear from your experience that that isn't the case and you're finding new things and you're logging new things all the time on the map. And that's what I like about, you know, we talked about Google maps. There are a lot of services online where you can network. We can now put our own local knowledge onto digital maps.

GARFIELDAnd that's a lovely kind of personal thing, which I think is very important now, as well.

REHMKyle, thank you for your work. Here's an email from Tim who says, "Have you seen the wonderful map in the Vatican where the beautiful maps are all oriented from the perspective of Rome?"

GARFIELDThat's right. I haven't actually seen them in the flesh. I've seen pictures and I've seen reproductions. I mean, that's another, you know, interesting thing about digital maps. Now, we are at the center of our maps, you know. We enable the location button on the apps and, you know, any logical device. And it's, how do we get from where we are to, you know, wherever we want to go? But of course, you know, we didn't used to be at the center of maps. It used to be Rome, you know, as you say, the Vatican or in the medieval world it used to be Jerusalem and if you're in China, it was (word?). Even then, I suppose, you could argue that it was ego centered.

GARFIELDEveryone thought that they were the most important thing in the world.

REHMExactly. And for New Yorker covers, New York became the center of the world.

GARFIELDOf course.

REHMAnd you're listening to "The Diane Rehm Show." Here's an email, let's see, from Nancy in Cincinnati, "What do you think of Dora's map companion in many Dora stories? Map creates a map for the readers to find their way through the story. I was fascinated with how two and three year olds took to the character and honed their logic skills to use it."

GARFIELDYeah, I mean, we don't have -- I know about "Dora The Explorer," in America. Not such a big thing in the U.K. And also my kids have very similar things, but it's clearly a fantastic way of sort of getting kids interested in the wider world and what lies, you know, sort of beyond their immediate knowledge of house and home and school and all of that. But the great thing, I think, about that show is you sort of go on a quest, you know, that's the...

REHMExactly.

GARFIELD...spirit that underlies all maps, I think.

REHMAnd one last quick question regarding the book, "1491." A book that talked about the Chinese of that era, how they had a vast flotilla which traveled the world and it was their detailed maps which the Spanish and Columbus used to get to the Americas.

GARFIELDYeah, I mean, a very interesting theory. And a very kind of well-argued book, which, again, I would say it was well-argued speculation. And it's something I examined a little bit in the book. But what I love about that, again, it's that idea of finding out new things that you kind of think may be there, may not be there, and, you know, this was, you know, 1491 and onward through the great Spanish and Italian explorers, this is where we really grasp the knowledge of the world and expand our knowledge.

GARFIELDThis is where the wonderful, you know, Dutch atlases came from. And that was sort of the golden period. So I kind of love, you know, all that idea of suddenly during the renaissance, we were -- and using kind of Eastern knowledge, as well, Asian knowledge, as well. We were sort of really developing. And that goes on, you know. We tend to think actually we know everything. It's all been done. Clearly, not the case.

REHMSimon Garfield, he's the author of a brand new book. It's titled, "On the Map: A Mind Expanding Exploration of the Way the World Looks." Simon, we'll be looking at maps differently now and examining GPS in different ways because of your book. Thank you.

GARFIELDWell, that was a great pleasure, Diane. Really nice talking to you.

REHMThank you so much. Thanks for listening all. I'm Diane Rehm.