Steven Block is destined for the very highest honours in science, according to at least one Starlab expert in biophysics.What’s more, it is confidently expected that Block’s obsession, Motor Proteins, will be the next big thing as far as research projects go.

In the course of the interview Block tells Shebang that he was a student of Richard Feynman, the Nobel prize-winning physicist, and Max Delbrück, also a physicist but one who moved towards biology and won the 1969 Nobel prize for Medicine.

Prof. Block, who fairly recently moved to Stanford University from Princeton, was interviewed at a conference in Banff, Canada, during August 2000.

[Interviewer, Jack Klaff. Grateful acknowledgements, for editing help and advice, to Prof. Jack Tuszynski and Dr. Kezhou Zhang]

Klaff: You use gags in your papers and presentations. . That’s a good way to begin actually. I noticed one of your papers is entitled "50 Ways to Love Your Lever."

Block Oh, my God, you've actually read stuff I’ve written. [Laughter] Now I'm impressed. Yes. Well at least you got it.

[Laughter] Half the people come to me and they don’t get it.

Klaff: They’re also not as old as I am. [Block’s title is a pun on the Paul Simon song ‘Fifty Ways to Leave your Lover’. The lever he refers to is the stroking arm of a motor protein] Sadly we’re doing the interview before you give your paper, but humour’s a very big part of your presentations from what I understand.

Block Yes, I’ve been lucky enough to have been asked a few times to speak in public context - not just to scientific audiences - and people, I’ve discovered, really want to embrace science.

They really care about science. They don't always have a way of wrapping their head around it because scientists just don't go the extra mile to try and explain to them what the hell is going on. And I’ve found that, if you try to put things not into simplistic but simplified terms, they will meet you half way and they get very excited about some of the things that are going on.

I think they’re naturally well disposed towards science. In the United States there is a dichotomy: people are terrified about science because they think its going to be our ruination. And there are other people who feel that if you don't have the keys at least to technology, the Internet and science then you'll be locked out of the 21 century. So there's an increasing schism that I perceive in the United States between those who are embracing technology and almost a kind of ‘lead eyed’ group, and they’re both wrong to a certain extent. One is wrong to assume that science is the source of all good and the other is wrong to assume that science is going to be the source of all evil.

The truth is rather in between but my way of thinking is it's the only game in town. For better or worse, that’s what it is.

Unless you’re a very devout leader of religion there's really nothing else for it. Science is the rational way of understanding the universe, and there are no other rational alternatives; there are other alternatives but they’re not rational.

Klaff: Yes, promoting greater public understanding of science, that’s what we do. Actually I have an arts and humanities background, as you know. [Klaff is also a playwright and performer]

Block Mmm - incidentally, when I was in London last I had occasion to see the play ‘Copenhagen’ and I was so impressed at how someone had done such a good job of presenting not only the quantum mechanics but the duality and how this interfaces with human emotion. But I was totally wrong because at the end of this I got up and said, "This is fantastic but only in London could you get away with something like this. Something like this would never, never make it on the New York stage." [Laughing] And then later it moved to New York and it was successful.

Klaff: Best play of the year on Broadway.

Block And well deserved.

Klaff: Maybe I should mention that I was at the Niels Bohr Institute in Copenhagen last month, to interview Abraham Pais [Physicist and author - biographer of Einstein and Bohr] [See Shebang Archives]

Block That's fantastic. I’d love to read that.

Klaff: He was a wonderful man.

Block He was. And I was at Princeton you know before I came to Stanford last year. [Pais had been at the Institute for Advanced Study for a long while and had written a great deal about Princeton] So I spent the last 4-5 years at Princeton.

Klaff: Where?

Block I was in the Molecular Biology Department at Princeton.

Klaff: I’ve been a visiting professor at Princeton a couple of times. That's why I recognised you.

Block: That's why our faces are familiar.

Klaff: You yourself are very clear when you speak and not all scientists are good at this. Even at a high-level conference like this, even when you’re asking questions, I understand immediately what you are saying, about stuff that in fact is way beyond me.

Block I had a great time this year; I was asked - I was deeply honoured - I was asked to give the Bethe lectures at Cornell. Each year they have one person who comes and gives a set of 3-4 lectures at Cornell University in honour of Hans Bethe who’s now well into his 95^th year I guess. And one of those is a public lecture and one of those is a scientific a physics colloquium. And one of them in my case was a biophysics lecture.

So on the one hand I had to talk to a bunch of people who were primarily biologists and on the other hand an audience that was made up primarily of physicists and then finally everyone and their grandmother.

I think clarity is clarity, and that if you listen to some of the greater physicists I‘ve heard speak - for example when I was a grad student at Caltech, Feynman was there at the time, and he's an example of someone who one holds up as a magnificent speaker. He had a way of putting things sometimes by analogy, but he wouldn't strain metaphors to the point where they were practically breaking: he would say, "It’s a bit like this".

But by posing a problem in that way which he'd give you something that at least you could wrap your mind around. He might say, ‘You know, like an ice cream cone, OK so its not like an ice cream cone because it’s not perfectly coned maybe it’s got flat sides" or "It’s not perfectly like ice cream because it melts but it melts in a funny kind of way." But he'd allow you to bring it to some level of understanding. He would make you think as if the problem were your own.

Klaff: Since it’s such a privilege to talk to someone who was actually at his lectures, could you tell us about that Chinese meal analogy; the fact that an hour after you’d heard Feynman, you were hungry again.

Block That's right. It’s like the famous Chinese meal analogy; that was true, and I think the reason was that he thought in ways that were so deep, you know, that in the end he'd make you feel that you thought you'd understand it but you didn't. And this might have happened with his students.

To this day, most of the physicists I know have Feynman’s book ‘Lectures on Notes in Physics’ and keep it by their bedsides, and they will read a chapter as practising physicists, and they'll go back to it and they'll derive great enjoyment from his presentation.

But it’s a lousy way to learn it for the first time. So by all accounts that’s how the Chinese meal analogy came to be used. Students were not able to pick up the material, and I think partly because that's not actually the way you learn the field.

But Reading Feynman is the way you appreciate it once you’ve already learned it.

Klaff: Your journey from that, from physicist to biophysicist -

Block Yes.

Klaff: You went from matter to life? I mean I'm generalising.

Block I actually have a slightly interesting life story, which is probably irrelevant for your purpose.

Klaff: No, absolutely relevant.

Block: So you might be interested in how a person becomes a scientist for example.

Klaff: Absolutely

Block Well in my case, first of all my father is a particle physicist and so I grew up in the world of physics and the world of thinking about science and solving problems. And I got carted around the world quite a bit because I lived everywhere in the world where there's an accelerator. Which meants in the early days of Berkeley the Tevatron and then later at Brookhaven on Long Island and then at CERN in Geneva and DESY in Hamburg. Every place but Russia, we drew the line there. Fermilab in Chicago, in fact I went to high school in the Chicago area because that was near Fermilab and also Argonne where there was another accelerator.

Klaff: Experimentalist?

Block He's a particle experimentalist and that's actually one of the reasons why I went up to England. Sort of ironically, he spent what turned out to be about a 10-year period at CERN. CERN will pay - as a benefit for the sons and daughters of their faculty - to go to University. But they will only pay for the member nations of CERN and England is a member nation and the United States is not; so it behooved me to go to a British university. I'd actually spent 1 year at the University of Washington in Seattle.

I was an unreconstructed hippie, I was an antiwar activist, all my friends were going to prestigious east coast colleges, Harvard, Princeton and Yale and I decided I didn't want any part of that.

First of all I wanted to learn Chinese and I’d watched one too many Jacques Cousteau films and so I wanted to become an oceanographer. And there is only one place in the United States that simultaneously offered undergraduate degrees in oceanography and the Chinese language and that was the University of Washington. So I went off there for a year, but then my father said, "Well perhaps you'd like to go to a university in England, it would save us $20,000.00 a year."

So I wroterode off completely out of the blue to Oxford and said, "Are you interested?" and they said, "We don't accept transfer students. If you’d like to come then you have to take the equivalent of A levels or even S level exams. You have to go through this central college clearinghouse and go through interviews and when - as in if - you pass all these things we'll consider you as a student at one of the universities. So I was young, naïve and stupid and I said, "OK throw your exams at me I don't care," and the next thing I know I got accepted at Oxford and Cambridge.

Klaff: Wonderful.

Block And I was totally naïve, because if I’d have had any sense at all I would have gone to Cambridge because they were much better in science - and particularly better at physics at the time. But I had heard a bit more about Oxford and it was interesting to me. It actually turned out to be a transforming experience in my life. I had a fantastic time. I learnt a lot of science there. I spent 3 years at Oxford, read physics, eventually got a degree. My old tutor is still there a guy named Ian Aitchison. There's a Quantum Mechanics text by Ian Aitchison and I was the test case for that.

Now, as you know, in the English system - certainly back then - you studied only one subject alone and Oxford was even more specialised than Cambridge. There was no tripos. So I went to read physics and even the maths I learned were within the confines of the physics department. You didn't even go to a mathematician to learn math. At the end of my 3 years there I really decided, I decided 2 things. One is, I looked at particle physicists and I saw them going into collaborations involving 200 - 300 people, I didn't want to be a tiny little cog in an enormous machine.

The other thing is, I’ve always been fascinated by biological problems and I thought that perhaps I could do something biophysical, the problem was there was no opportunity at Oxford to get any exposure to biology at all.

So out of the blue I wrote off to ex-physicists who had become biologists and one of those was the late Max Delbrück., And I became Max's last student.

Klaff: No!

Block I am indeed Max's last student.

Klaff: My God!

Block: And Max, I owe him an enormous debt of gratitude. What he did is, this student wrote him out of the blue from nowhere.

He said, "Look, in the summers I teach this course at Cold Spring Harbor Labs. Why don't you come and take this summer course? You can work in my laboratory, we'll see how you do." And I literally flew from Oxford directly to JFK, I took the bus to Cold Spring Harbor. I spent the summer with Max. I had a magnificent summer; it was a transforming experience in my life. I got all excited about biophysics and at the end of the summer Max comes up to me and he says, "Well you know , you really need to learn some serious biology, you need to read Watson’s book, you need to work your way through."

Klaff: Not ‘The Double Helix’?

Block Not ‘The Double Helix’, ‘The Molecular Biology of the Gene’. Max said, "You need to read some books on molecular biology, you need to take a couple of courses and then you'll be primed for graduate school in biology. You need a year off basically to do this. What you could do is you could come out to Caltech and work as a, basically a dishwasher in my lab, make the media, attend some classes while you’re at it, get exposed to the whole thing. And then at the end of that year you can apply to graduate school."

I said, "That's fantastic Max, I would love to do that." He said, "There's only one problem." "And I said, "What's was that?" And he said, "Well I don't have the money to support you right now." And I was about to say to him, "Well you know , I’ve got some money in my savings and I’ll ask my parents, I’d love to make this happen, this is my future."

Max said, "Wouldn't hear of it." He called back to - I think it was the University of Konstanz in Germany.

He had been asked as a Nobel Laureate to come and give a fancy set of lectures. He'd turned them down, he said, "No, I'm coming after all." He took his entire honorarium and turned it into the Steve Block Fund.

Klaff: You were clearly an outstanding student.

Block Well, Max was clearly an unbelievably generous individual.

Klaff: And, again, we have the privilege of talking with someone who knew him personally, so please, can you tell us something about him?

Block Max was a truly charismatic individual and arguably one of the last of his generation in some sense to have founded an entire school of thought rather than merely being a scientist who was led by example. Niels Bohr of course was another one. In fact Max was a member of the Copenhagen school of quantum mechanics, and he derived that dealt with Delbrück scattering in quantum mechanics; that was something that Max had solved.

Much as Bohr managed to bring a whole group of people together and served as the nexus for a set of social, scientific and other levels of communication, Max was by analogy that sort of thing in the early days of molecular biology.

He got his Nobel prize for - of course - the Delbrück fluctuation test, which is actually almost a trivial spin off its just a statistics test, it’s nothing significant. But he got the Nobel Prize because he literally founded the whole thing. Jim Watson had such respect for him that he literally openly wept at his memorial service at Caltech.

Max ruled by sheer force of will and he didn't suffer fools lightly. He was famous for sitting in the front of the lecture theatre and if someone was saying something he didn't like he would raise his hand and ask them a rude question. Often if he was bored with a lecture, even though he sat in the first 2 rows routinely he'd get up half way through the lecture walk out the room. Just leave.

Klaff: What did he look like for you? What kind of a figure was he for you?

Block Well I was in awe of him. He was both a tyrant and a grandfatherly figure in this bizarre amalgam that's impossible to put into words.

But I can tell you in my case, for example, he not only raised the money for me to come out to Caltech, but at the end of the year - largely thanks to Max's letters of recommendation in my new-found field - I got accepted to graduate school virtually everywhere. And I didn't know what or where to go. Was I going to go to Harvard? Was I going to go to MIT? Was I going to stay at Caltech?

So Max would see me walking down the hallway and in his usual way he would say "Steve, I vant to see you." [German accent]

So he pulled me into his office and he sat me down and he looked at me and said, "Vell, I’ve decided you go to Colorado." And I said, "Why should I go to Colorado Max?" He said, "I vant you to vork for Howard Berg"

And it turns out Howard Berg was also an ex-physicist - actually Howard Berg had worked on the hydrogen maser with Norman Ramsey for his graduate work, Ramsey got the Nobel Prize for that. [The atomic hydrogen maser is among other things the basis for the world’s most stable atomic clock]

Berg got involved in Biochemistry and is today a leading biophysicist. He's at Harvard now. He actually went from Harvard to Colorado then Caltech and back to Harvard. At that time he was at Colorado.

Max was an enormous admirer of Berg's success and he literally sent me off to go work with Howard. It was an arranged marriage. I arrived at grad school in Colorado in 1975 only to discover that most of the graduate students were doing the usual lab unusual rotations. They spent a few months in one lab or another before they settled down. Not me:, there was practically a desk there with my name on it. I was sent to work with Howard Berg and with Howard Berg I worked.

Klaff: So you were a Magna/Summa cum Laude student all the way through?

Block Well, not really. I think I took the Blanche DuBoisblah de blah kind of approach. I’ve always relied upon the kindness of strangers. [Laughing] Or if they weren't strangers I'd try to make them my friends and then rely upon their kindness. Max literally sent me to work for Berg and Berg got me interested in bacterial senses and then later in motors and in fact I worked on the rotary motor that makes bacteria swim, while I was with Berg's lab. So that's my experience and that's how I got from physics into biology.

Klaff: And the juice? The thing that gets you up in the morning? I mean I know you guys are all academics.

Block Well you know I'm not an engineer. , I have absolutely zero interest in curing. I'm not a doctor either. I don't want to cure anybody's disease although I'd love to see disease cured. I don't want to build any widgets although I love widgets and I love to play with them. What gets me up in the morning is I really have a passion for understanding how things work.

When I was a little kid I use to try to take apart watches and long before I could put them together I'd have little screwdrivers and I’d just take these old watches and Id take them all apart. I would do this when I was 3 and 4 years old as soon as I’d learned how to use a screwdriver, but by the time I was 10 or 11, I could start putting them back together again. And then I finally began to understand, you know, what an escapement mechanism is.

Klaff: My Dad had a watch-making business.

Block Wow! Great, so you know. So I love - I just loved little widgets. And to me the ultimate little widgets are nature’s own. The little engines that drive for example these rotary motors in bacteria. The motors that make our muscles contract, the motors that move our organelles. And really I have a passion for understanding how this stuff works because it is at once mechanical. I come from a physics background and I think in those kinds of terms -and yet at the same time a biological and it really serves as an indicator of what we really are. You think about it for a moment, what are the things that distinguish the inanimate from the animate? What is life? I mean this is the question that people ask over and over again.

Klaff: It's the title of Schrödinger’s book and close to the title of the book I am doing with Professor Jack Tuszynski here at Starlab, via Shebang: "I Want to Know What Life is."

Block Yeah, and so you think about back in high school, and people would talk about what the difference is between living and dead things and one of the differences is that they would reproduce. Well we know a great deal about DNA today and how the information is encoded. One is that they respond to stimuli. Well, I got into biology by working on sensory transduction and its one of my passions to this day, understanding how we see, how we hear, what the physical limits are to sensation and so forth. I’ve actually written some articles on this subject and I gave an entire lecture on it as one of the Bethe lectures - 'The Physical Limits of Sensation'.

Klaff: Absolutely.

Block And the other thing that would teach you is that not only do they reproduce, and not only do they respond to stimuli but they move. Even a plant is a riot of activity if you look at it at the microscopic level, if you look inside its cell I mean it’s a sessile sensile organism but, you know, if you look at it through a hand lens you can see things moving about. Its a different kind of motion from just dropping a rock and watching it fall under gravity. It’s hard to get very specific about it but everyone has a common, sensible notion of how very different living things are from the inanimate and so I'm interested in things that make living things alive. That's what a biologist does, we study what is life. And we oftenalways seem to put it in other terms. B but we always come back to this notion of what it is, what is this extra thing, and I think that even Indians with their pantheism were more on the track than not. There's this notion that there's something very special about the assemblies of molecules which become sufficiently complex that you call it living.

Klaff: Right. So you start with particle physics and you go up the scale, and you go up the scale in terms of size and then you get to molecules and then you get to something called life?

Block Yeah, and there's a big gap between molecules which are done on the nanometer scale and cells which are up here on the micron scale. There are 3 orders of magnitude of stuff in which this is terra incognita - this is the great void of our understanding. How do you go from molecules to cells? How do you go from things that don't self- reproduce and don't move into things that do? And you have to build it up in pieces with very complicated machines: machines for copying the information, machines for moving things about and I now take a motor-centric view of the universe.

Klaff: You’re back to thinking that?

Block: If you think about it, you've been exposed already of course to the central Central dogma Dogma of molecular biology. The notion that information flows from DNA to RNA to protein and, but you think about it, what makes us work? What makes us work are enzymes that code for the reproduction of the DNA - for the transcription of the message -and for the production - the translation - of proteins from this. And every one of those enzymes that carries out this central dogma is a motor. It not only gloms glues onto the substrate and does some interesting biochemistry, but it moves unidirectionally along the substrate. And it needs to produce force and displacement - and in fact the forces and the displacements produced by these motors are in many cases larger than the kinds of things that myosins and kinesins produce. Our lab also works on RNA polymerase as a motor and I'll talk about it tomorrow. It produces 6 times the force of kinesin molecules when it moves along. They are not just motors, they are prodigious motors and there's something intrinsically involved if you want to copy information, which is stored in linear form. You have to move along the linear form.

You have to separate chromosomes during mitosis; cells have to divide and move, to migrate, and to become organisms. Every one of these processes requires some kind of motor so that's why I say I take now a motor-centric view of all of biology.

I think that it is true - you can take a motor centric view of how a watch works. A watch, an old-fashioned watch, is ultimately taking stored elastic energy in the form of a spring, and it’s transducing it into a very specialised kind of motion. A regular motion, a motion which is metered kneaded out in very careful ways, and its a very fancy motor. It's the most highly governed motor you can build.

Klaff: Can you give our readers some idea of the energy and the speeds.

Block Well there's speed and there's force and there's displacement, and these are all attributes that motors have. Kinesin motors for example move fairly fast. They move at speeds of about 800 nanometers a second -— just under about a micron per a second. They produce forces that can range as high as 5 or 6 or even 7 piconewtons. A piconewton is a hard number to describe. If you could somehow extract a red blood cell from your body and weigh it on a scale it would bare down on the scale with a load in the neighbourhood of a piconewton or thereabouts.

Klaff: What would help the reader to know would be something like those old comparisons; if an ant were your size it could lift a kitchen — that kind of thing.

Block Yeah, well you know molecules of course are fantastic, because, while ants can move things hundreds of times bigger than themselves, these motors would move things thousands or maybe millions of times bigger than themselves.

I mean I haven't done that computation so it's hard for me to say tell but it's an impressive number.

Klaff: By the way there’s a very clear mechanistic, motor-centric view that I’m encountering a lot this week, as well as a high degree of reductionism.

Block Well I come from a physics background and so I think in reductionist ways. There are biologists you know - Sidney Brenner has made this wonderful distinction between two types of scientists, the clarifier and the

turbidifier trabitifier [??] simply cannot remember what you said here]. And he points out properly that science makes progress only through both of these and that the clarifier is the ultimate reductionist and he's always trying to find something that's so simple.

Klaff: We ran an interview with Brenner’s friend His friend Lewis Wolpert last year,

Block: Oh great. The problem of course is that the clarifier throws the baby out with the bath water and so in simplified model captures some of the essence but not really what you’re after. The turbidifier trabitifier on the other hand — a lot of biologists are this way - always seeks to model the problem in its full complexity and they’re always wondering about what you've left out. And they’re always concerned that there's something else in addition to that, which gives the richness and the texture and everything else.

They’re both right, and in the end you hope to understand them all, but, coming from a physics background, I try to be as reductionist as possible and then add levels of complexity on to that.

And if you ask what are the simplest things you can study in biology, the answer is molecules. One protein at a time. And that's what our lab has done. We've worked out technologies literally for measuring the forces, the displacements and the velocities of one protein at a time.

Klaff: Right. And you look at them with -?

Block Optical traps, light microscopes, position sensors that are good down to the angström level. Our laboratory has to be in a very special space. We're not only in a basement but we're in soundproof rooms and low vibration spaces with filtered air. For example the noise levels in our room are typically below 30 decibels that's much quieter than a quiet office. The vibrations are such that we have everything up on air tables and we’re deep down on bedrock.

If you were to speak as I am right now in the room while the experiment’s going on you'd destroy the experiment because your voice shakes the air. The air shakes the microscope and sends it through paroxysms which are orders of magnitude larger than the limits of the instrumentation - which by the way are now getting down to below an angström a second, that's the diameter of a hydrogen atom.

Klaff: I need you to explain this, please.

Block: The smallest single atom - so we can measure the position of - not a molecule - we actually have to use small beads, small glass spheres actually. If you like puns, it’s like that book ‘"Das Glasperlenspiel"

Klaff: ‘The Glass Bead Game’

Block: ‘Glass Bead Game’ by — who was it?

Klaff: Hermann Hesse.

Block Hesse. And my colleague friend Robert Simmons, Bob Simmons used this as the title for one of his discussions of kinesin or actually myosin because you hook these molecules onto glass beads so it's a glass bead game. We hook molecule kinesin onto the bead, and the bead becomes our reporter about where the kinesin is. And we can measure the position of that bead to within the diameter of a hydrogen atom and we can make that measurement ten thousand times a second.

Klaff: Very impressive.

Block But to achieve that level of stability things may not drift. If the temperature of the room is one degree centigrade warmer on one side of the room than it is on the other just the metals of which the microscope were made will expand suspend and drift and move at speeds which are vastly in excess of that. So we have to be in a temperature-regulated room which is low on mechanical vibrations which is acoustically isolated and we also have to have low dust for the optics and things so by the time we’re done it’s a big deal. And Stanford spent in excess of a million dollars setting up a laboratory that would do this kind of thing so it’s not, it’s not for everyone.

But when you get the apparatus going its perhaps remarkable that you can do things that were only pipe dreams 10 years ago. You can literally take a single protein molecule and watch the steps that it takes!

Our lab is famous for being the first lab that actually discerned the physical steps the kinesin molecule makes.

They measure 8 nanometers and that's 80 times the diameter of a hydrogen atom. 8 nanometers is typically the distance across just a single protein and so to be able to see these as steps in real time in a microscope while they are happening is wonderful - it is a wonderful achievement.

And being able to measure at the same time the forces they produce. And at the same time you’re measuring the displacements and measuring the background levels of the fuel, the ATP [Adenosine triphosphate], means that you can now do what are called force velocity curves...

You know Oone measure of how engines work is to measure how much force they produce as a function of how fast they go. For example electric engines produce their maximum torque when they’re close to stall, when they're barely moving. That's why a subway train which is electric lurches verges out of the station. That’s why your Cuisinart cuisinaire produces such a huge power when you pulse it.

Gasoline engines on the other hand produce maximum torque at 5-6 thousand RPM, which is why you have a transmission and a red line on your tachometer; if you want to get a gasoline engine going you have to get it going fairly fast.

Kinesin motors are yet again different in they have a characteristic shape for their force-speed curve and which is different. And so you can use the shapes of these curves to diagnose the kind of process you have. We make physical measurements and out of those we try to understand how chemistry - fuel in the form of ATPases [the enzyme that catalyzes ATP] - has somehow been coupled by enzymes to the production of force and displacement. So that's the object of the exercise: is to understand the mechanism density — The the word for it is mechanochemical mechano-chemical-coupling. Or, or you'll find some people calling it chemomechanical chemico-mechano coupling. We're not sure who to give first billing to.

The notion is that we eat food, from this we make fuel in the form of this magnificent molecule ATP which is used to power just about everything including ultimately our muscles. We make this in our mitochondria, these specialised organelles which are passed down through the mother and this is used to power everything. ATP is It’s used not only to power the motors, it’s used to make DNA, it’s used to duplicate DNA, it’s used to synthesise proteins, its used to transport things across membranes. It’s used for everything and somehow this fuel is burned, in some sense the word. ‘Bburn’ is a metaphor: , it’s a chemical reaction.

Ultimately that results in the case of kinesin the protein I work on, one of the proteins I work on, making these little steps.

Klaff: There are people who study proteins and people who study genes. You are not a genes guy, even though genes are pretty interesting, in fact some people believe the universe is information.

Block Yes. Well, yes of course information is no good if you don't do anything with it.

So the mechanism by which you use the information is the motor, the mechanism by which you exist is the storage of the information, so in some sense everyone is right.

Or there is no right or wrong. I think you’re right in pointing out that the molecules that are used to store information in DNA, RNA and proteins in some sense where information also resides are -as I was saying earlier - are ultimately synthesised with a set of very specialised enzymes without which you'd be dead.

DNA is no good if you can't replicate it.

Genes are no good if you can't transcribe them.

Transcribed genes are no good if you can't actually make them into the proteins to carry out the function and to do all this requires these wonderful specialised enzymes and we’re just beginning now to understand how they work.

They’re very complicated, they’re much more complicated than the motors myosin and kinesin because they not only carry out motor-like functions. They’ll carry out all this enzyme stuff and make a copy of it and make it faithful and don’t make errors and if they do make an error, they back up and fix the error and go forward again.

Klaff: It sounds like they're taking orders.

Block They do take orders, but, ultimately you know, the information may reside in the DNA but that's a bit like, I don't know I'm searching for some kind of metaphor here:

Klaff: Imitate Feynman — ‘It’s a bit like’

Block Right. In some sense the information in a colony of bees resides with the queen. But the queen would be nowhere without the workers who make the cells, who make the honey, who collect the pollen, and if you’re interested in beehives you could become a queen expert and study nothing but queens and that would be a very interesting thing to do.

But, if you did that, you'd miss out on the wonderful mechanisms bees have for finding flowers miles away and getting back. Or knowing when a storm is coming and getting back to the hive before the storm. They can sense gravity they can sense light, they can sense magnetism.

You'd miss out on all that stuff if all you'd concentrated on was the fact that bees made lots of babies. So if all you concentrated on was the fact that DNA makes lots of copies of itself, you’re missing out on this richness, this rich texture that gives rise to life.

Klaff: BVery beautifully put. And the next step. The future?

Block [Laughter] My crystal ball is no more clear or cloudy than the next man’s.

Klaff: Hilbert [the mathematician] said when he came back he wanted to know about the Riemann hypothesis in a thousand years’ time.

Block I'm not sure you know. This is a field that is moving so quickly, even compared with mathematics at the turn of the century - even compared with physics at the dawn of quantum mechanics. Biology is moving so fast now that I'm loath to predict more than a couple of years into the future about where things are going.

I think that probably in 10, 15, 20 years down the line when you know, gene therapy becomes a reality it may become possible for better or worse that you know we can even think about synthesising simple kinds of organisms de Nov.

There are some organisms, like Mycoplasmamicoplasminortalia, which have perhaps only 500 or 600 genes. , Tthat's all. They’re free living organisms, and of those 500 genes, perhaps 250 or 300 are really truly essential.

It may become possible to put together organisms ab initio.

It may become possible to view organisms with properties borrowed from other organisms or even thought up ab initio.

It may become possible to organise proteins.

There's a lot of talk about nanotechnology. I think most of it is utter nonsense. I think the stuff that K. Eric Drexler and his colleagues have talked about is stuff ed and with nonsense. But on the other hand, I think there is a nanotechnology. , tThere are nanoscale machines, that will be of interest, If we want to learn how to develop these, and build from these, there's no better starting point than biology. You don’t have to sever your head and let it build, let it live on a diamondoid body in the trans-human condition aeons into the next millennium.

That's not what it's all about. What its really all about is understanding intimately how we work and how we’re put together.

When we do that we can make things that are maybe a little bit better or a little bit different, or a little more interesting.

Klaff: Humans or different life forms?

Block Humans andor different life forms. And I think that's where it's really going to go. I don't think people are going to make something that replaces a protein. I think they’re going to learn how to engineer proteins in new and interesting ways.

Klaff: That has good and bad?

Block And that has good and bad consequencesconnotations. Like every other revolution in science there's a dark side and there's a light side, and people talk about all the horrible things that could happen, you know.

I spent some of my summers actually working for a group called JASON which is a set of advisors that consult forto the US government, and all with the security clearance, all worrying about things.

People worry about, for example biological warfare in the future, not right now but when genetic engineering takes hold: what happens when somebody makes the anthrax into something that you can't vaccinate for or that you can't fight with antibiotic?

What if someone unleashes smallpox on the world?

I mean there're some very serious and very real threats out there.

And we’re going to have to come to grips with that just as we lived under nuclear shadow for the latter half of the 20th century, I think we are going to live under a biological shadow for most of the 21st century. And our best defence against nuclear weapons remains the goodness of mankind, such as it is.

As many treaties as we can possibly put into place and the hope that science which brought us this difficulty will also bring us some partial solutions. I think we’re going to have to placemake the same faith in biology, that just as biology maywill bring us badgood things, biology will bring us goodbad things

And its up to us to keep it all in check. But I don't pretend to understand you know how this is all going to be done.

And I think that the people whothat do say they have a great insight into this are full of nonsense.

Klaff: They’re lying

Block: They’re simply deluding themselves.

Klaff: You got involved with all this before it became a revolution.

Block I got involved in it in the 70's before it became fashionable. I think it's very hard to discuss how one scientific revolution is in some sense analogous to another revolution. They all seem to have their own characters.

Klaff: And it’s big news?

Block I think it's big news, but that's not why I'm in it. I'm in it because I just love little toys.

[Laughter]

It’s absolutely big news. I think that’s enough to get excited about. It's the biggest news yet.