E-mail a friendDr. Neil deGrasse Tyson
airdate February 13, 2009
As a kid in the Bronx, Dr. Neil deGrasse Tyson was expected to become a star athlete. Instead, he overcame the misperceptions of a young person of color and became an astrophysicist and the youngest-ever director of New York's famous Hayden Planetarium. Tyson also works with the American Museum of Natural History, writes a column for Natural History, and is an award-winning author, with titles that include The Pluto Files. He's involved in several programs that bring science to inner-city schoolchildren.
New York's Hayden Planetarium director explains what astrophysicists are excited about today. (1:40)
Full interview. (13:16)
Dr. Neil deGrasse Tyson
Tavis: Neil deGrasse Tyson is a noted astrophysicist, of course, well-known to PBS viewers for so many terrific projects over the years. He is also, of course, the Director of New York's famed Hayden Planetarium. In April right here on PBS, you can catch his all-new special chronicling the 400-year history of the telescope. But in the meantime, you can pick up his new book, "The Pluto Files: The Rise and Fall of America's Favorite Planet." Neil, nice to have you back.
Neil deGrasse Tyson: Well, thanks for having me again.
Tavis: I've been waiting to have you here so I could beat you up.
Tyson: (Laughter) Don't tell me Pluto is your favorite planet too.
Tavis: You started all this Pluto hate. You are the Pluto hater. You are a Pluto hater and I don't like it.
Tyson: Pluto had it coming. I just want you to know that, okay?
Tavis: You are a Pluto hater, man.
Tyson: Don't kill the messenger here.
Tavis: What's up with the hate on Pluto?
Tyson: Pluto is just an oddball, you know, and we've known it from the beginning. That's the thing. Ever since it was discovered in 1930, they said it's kind of small. You know, its orbit is kind of weird. It crosses the orbit of Neptune. No other planet crosses anybody else's planet's orbit, right?
It's mostly ice by volume. It's mostly ice and it's little. There's seven moons in the solar system bigger than it and it orbits not in the same plane with the rest of the planets. It's tipped out of the plane by 17 degrees and you're thinking, "What are we gonna do with you, Pluto?"
So we kept it in the ranks, right? All right, Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto. We kept it until we started discovering other objects in the outer solar system in the 1990s that kind of looked like Pluto. They had tipped orbits, they crossed the orbit of Neptune, they're icy, they're small, so maybe Pluto wasn't the ninth planet. Maybe it was the first object discovered in a new swath of real estate in the outer solar system.
Tavis: But if they knew all of this or half of this back in 1930, why did Pluto get elevated in the first place just to get demoted so many years later?
Tyson: I know. That sounds mean, I know (laughter).
Tavis: Pluto got played (laughter).
Tyson: Pluto got played.
Tavis: Pluto got played.
Tyson: Pluto got played. The thing is, it's hard if not impossible to have a class of one. Any classification scheme has got to have at least two objects in it so you can generalize what the properties are that you're collecting for that category. So if Pluto was alone out there, you're not gonna orphan it. It's got no family. You grandfather it in. You say, "Pluto, all right. You look a little weird, but you're one of us, but don't tell anybody," you know.
Even textbooks, right on up through the 1970s and 1980s, they had whole chapters on the planets and then one of the chapters was Pluto and the other vagabonds of the solar system, and we lump it together with comets and asteroids and all the rest of the debris that's flying around the sun.
Tavis: Two questions about this. One, tell me about how you got connected to generating so much media about what you had to say about Pluto, and then help me understand just the media trajectory on how this Pluto file - how this thing - came to be.
Tyson: Well, that's what it is. I had this file of conversations that I had with really angry third graders as well as their school teachers and parents and -
Tavis: - and Tavis Smileys.
Tyson: (Laughter) Apparently, yeah. So the reason why I stepped in this at all was because back in 2000 when we reopened the rebuilt Hayden Planetarium at the American Museum of Natural History, there was a huge exhibit on the universe. We looked at the new objects discovered in the outer solar system and we said, "Wait a minute. Rather than just list Pluto with the rest of the planets, let's group it with these other icy bodies." That's all we did.
Well, a year later - it took a whole year for it to get noticed - the "New York Times" discovers this. Page one story. "Pluto Not a Planet. Only in New York." Boy, that's when my life basically went to hell.
Tavis: (Laughter)
Tyson: That's when the hate mail rolled in, the inbox flooded and my life was never restored after that.
Tavis: Some of the email, to say nothing of the fun that the cartoonists in the paper -
Tyson: - cartoonists, yeah. The cartoonists, op ed writers, everybody had fun with this apparently. So I have in there scans of some of the letters that I got from the kids. You had to scan those because they were like crayons scrawled, "Put my favorite planet back, Dr. Tyson, and here's what it looks like." One of them drew a picture of it. You know, there it is.
Tavis: What did you make of all the fallout, to say nothing of the fact, to your point, that it took a year for this thing to hit anyway?
Tyson: Yeah, well, the fallout had another round in 2006 when the international community of astrophysicists voted on what the nomenclature should be. In that vote, Pluto officially got demoted from planet to dwarf planet. Everyone weighed in. Everybody chose up sides. It was primarily Americans really. I haven't seen this kind of reaction in Europe, so I blame the dog, Disney's dog, Pluto.
Tavis: Disney's dog. That's what did it, yeah.
Tyson: When do you first learn - oh, you got the picture (laughter). I did my pilgrimage to Disney World actually and I said, "I got to tell Pluto in person." I apologized, he forgave me and we were buds at the end of it.
Tavis: On a serious note, what does this mean in your field of study?
Tyson: Excellent question.
Tavis: What does this really mean?
Tyson: That's an excellent question. First of all, we don't normally vote on science. We just let the data show itself. So it was more controversial than typically something like this would be. But what it says is we're learning so much more about the solar system that we're in need of a new lexicon to account for its contents that we don't currently have. So I think the time will come, especially since we're now discovering exoplanets, planets in orbit around other stars, other solar systems, other star systems.
You don't want a classification scheme that only works in your back yard. Ideally you'd have a classification scheme that could embrace the entire universe of planets that are out there. We don't have that yet. So whether Pluto is a planet or dwarf planet or plutoid, in the end, I think that's all gonna shake out because what you want is a vocabulary that embraces the richness of knowledge that we have gleaned about the planets only in recent decades.
In the old days, they were just points of light on the night sky, so one word was just fine. They're all planets. They're just moving against the background sky. But we've been there. We're in orbit around them. We plunged into their - photographed their rings, magnetic fields, the moons.
Tavis: Is there any reason to believe that any of the other planets are about to be demoted or, conversely, are there about to be some new planets who get invited to the club?
Tyson: Okay. So we're looking at earth next (laughter).
Tavis: (Laughter) That was a good one, that was a good one.
Tyson: Some people are worried about this. First of all, size is not an issue because, in fact, Jupiter is more bigger compared with earth than earth is compared with Pluto, okay? So in other words, if we lived on Jupiter and we looked around and said, "How many planets are there?", we'd say there are four, Jupiter, Saturn, Uranus and Neptune, and everything else would just be debris. So it's not really about size.
It's about properties and, as it stands now, these definitions that have come forth will actually handle everything we know about in the solar system. We're pretty stable there. There are other round objects in the outer solar system. If you are round and you orbit beyond Neptune, you're not only a dwarf planet, but you're also a plutoid. That's an extra little sort of sub-class of round object that's icy in the outer solar system.
So, no, everything is pretty secure at least for a while, but I'm still sort of chomping at the bit for a richer lexicon to capture the full breadth of knowledge that we're treated to by our space probes.
Tavis: Beyond "The Pluto Files," what is the most exciting thing for you now? I mean, what are astrophysicists talking about at the annual astrophysicist convention? I mean, what's happening in the solar system now that you guys are looking at that's fully exciting?
Tyson: There's good stuff. Well, first, start in the solar system. We're looking for life, life as we know it, life that likes liquid water because every place on earth where there's liquid water, there's life. Even the Dead Sea. There's not like fishes, but there's like bacteria doing the back stroke in the Dead Sea. There's bacteria that thrives in all kinds of environments, the kind of environments that we find on other planets.
Recently, there was methane on Mars discovered. Methane, this is the gaseous effluences of farm animals, okay? This comes out of them, right? That's the product of bacteria digesting their food in their digestive tract. So bacteria under those conditions gives off methane. We find methane on Mars, we think, coming out of the sides of cliffs where there might be an aquifer. We're thinking maybe there's life there. And there are other choice spots in the solar system where that can be the case. It would transform biology if we found life. That's in our back yard.
In a large-scale universe, we still don't know what dark matter is. Eighty-five percent of all the gravity in the universe is traceable to something we know nothing about, not made of any "normal" ingredients, that also the universe is accelerating in its expansion. We call that dark energy, but we don't know what that is either. We can measure, but we don't what it is. It's a profound frontier of ignorance and, in science, ignorance is good because you're drawn to it because that's where the next discoveries will come.
Tavis: I know a lot of scientists by that definition (laughter). I may be called a scientist by that definition. Before I let you go, though, I mentioned a few moments ago the telescope special that you're -
Tyson: - yes. Thanks for commenting on that. Well, this year, 2009, is the 400th anniversary of the telescope, of Galileo looking up with the telescope. The telescope is extraordinary among all scientific instruments for the following reason. It enables us understand our place in the universe, so it's a telescope special.
I didn't actually create the product. There are like producers and directors and folks. I simply narrated it. But there's a whole team of people who are very talented, who went all around the world, but you'll hear my voice in the program. I felt very strongly for that because I had my first telescope when I was a kid.
And by the way, this year, it's the international year of astronomy for that very reason and, in April when this program airs, there's a goal that, in a ten-day stretch in April, we want to get all six and a half billion people in the world to look through a telescope at least once. Ambitious, but I think an important goal.
Tavis: I'm headed to Philadelphia in a little bit. There's a wonderful Galileo exhibit in Philadelphia right now.
Tyson: Yes, yes. I think they got his original telescope on display there. That's correct.
Tavis: They do.
Tyson: It's a tabletop telescope that transformed the world.
Tavis: So I'm going to see it. I'm gonna check it out.
Tyson: Excellent.
Tavis: Anyway, we'll check out -
Tyson: - take a look through a telescope on your way.
Tavis: During that ten-day period.
Tyson: And when you're looking at heavenly bodies, make sure it's the ones in the sky (laughter). Oops, can I say that on TV?
Tavis: He said, "Can I say it?" I think you already did. And secondly, I don't need a telescope for that. I got these for that (laughter).
Anyway, before I get myself in any more trouble, Neil deGrasse Tyson's new book is called "The Pluto Files: The Rise and Fall of America's" - and Tavis's. I added that - Favorite Planet" - that's not really in there. Anyway, Neil, nice to have you here and we will check for the telescope special on PBS.
Tyson: Thank you, sir. All right.
Back to February 13, 2009