Now, let us come to this problem that I want to discuss today which is the cell signaling problem. So, if I just to remind you. So, we discuss this sort of last class. So, here was this problem that I have some sort of a chemical which the cell is going to sense ok. And it is trying to if it is an attractant it is going to try move towards that chemical if it is a repellent it is going to try to move away from that chemical and so on. So, we saw this H pylori movies which had we had this H pylori movies where we saw it moving either towards urea or away from H Cl and so on. So, this was the picture that I have this cell the cell has certain chemo receptors on its surface which are proteins which can detect and recognize the chemical. What I want to know is that if I have some chemical source far away at what rate is the cell going to detect these chemicals with the help of these chemo receptors. So, that is that is the basic problem that I will try to answer. So, let me write down the proper question. So, what I want to ask is that what is the rate what is the rate of rate at which signaling molecules which are like your urea or the H Cl in the case of pylori make their way to the surface make their way the surface of the cell or in other words let me say I want to calculate something which is like this rate. So, dn dt so, the number of signaling molecules coming to the surface of the cell per unit time that is what I want to ask at this as far as the cell signaling problems. So, we will make a number of assumptions and I will say. So, your cell could be whatever arbitrary complicated shape right for example, E coli is like this ferrocylinder we saw if you take an animal cell that is soft. So, it can take variety of shapes, but what will solve this for is this model cell which is a spherical cell spherical cell yes. So, let me write down my assumptions. So, I assume that the cell is a perfect sphere the first step to doing a physics modeling of anything is that assume it to be a perfect sphere, but it is not a very hard constraint to relax. Of course, if you take arbitrary shapes writing down analytic solutions becomes difficult, but you can always solve it numerically following the same technique. If you have some other shape for example, well defined shape with some symmetry for example, a cylindrical cell or something like that then you can again do it analytically the maths will just become a little more complicated. So, I will do it for the simplest case which is a perfect sphere and let me say it is a perfect sphere of some radius of some radius. So, that is my model of the cell let us say it has some m number of receptors m number of receptors on its surface which are distributed homogeneously uniformly on the surface of the cell. So, often we will see you will see that for example, even in this cartoon of the E. Coli the chemoreceptors are clustered at the ends of the cell as far as this calculation goes I will not take anything like that into account I will see that the receptors are sort of spread uniformly over the surface and there are m of them. So, because it is a perfect sphere and the receptors are spread uniformly on the surface let me make another assumption that the problem is very good. So, the concentration is spherically symmetrical spherically symmetric. So, the concentration of signaling molecules is spherically symmetric which means that if I write this concentration in general it is a function of the vector r right it might depend on which direction you are looking at and so on, but I will just say that if I make this spherical symmetric approximation it is just a distance away from the cell that is the only thing that matters. And I will assume that you have a source of signaling molecule somewhere which was your pipette in these pylori experiments far away from the cell. So, I will assume a far field concentration I will assume a far field concentration which is C. So, as r tends to infinity I will say that my concentration goes to C naught. So, this is then my thing that I have a cell over here of radius a far away from that at infinity I maintain a concentration of C naught using some apparatus that I have and if everything is spherically symmetric look what I want to solve for is the concentration profile in all of this space in between ok. So, I want to solve for the concentration profile and because I have made the assumption that it is spherically symmetric it only depends on the scalar r not the vector r and this. So, the signaling molecules are being maintained at a constant concentration here they are going to diffuse right they are going to perform a random walk through the space until they hit the surface of the cell and the surface of the cell you have these receptors which are going to absorb the signaling molecule and then respond to that by moving in some particular direction ok. So, the setup is clear. So, because they are diffusing I will solve the diffusion equation for the concentration of signaling molecules del C del T is equal to D Laplacian of C. So, here is my diffusion equation that I will solve. So, let me say that I want to solve it in the steady state. So, when everything has come to nothing is changing with time anymore which means that I will take del C del T is equal to 0 which means that the equation that I am looking to solve therefore, is D Laplacian of C is equal to 0 all right. So, in what coordinate system should I be solving this you can of course, solve it in any coordinate system, but the most appropriate choice given that this problem that I have defined I have a spherical cell and then there is a spherical symmetry is that I will solve it in the spherical coordinate system. So, I write down the Laplacian in the spherical coordinate system. So, what I have the is D into 1 by R square del del R of R square del C del R is equal to 0. So, here is the Laplacian in the spherical coordinates. So, this is what I am looking to solve. So, if I solve this what this means is that R square del C del R is some constant independent of R because del del R of that quantity is 0 which means that I can write down my I can write down my concentration profile as a function of the scalar distance R as sum A by R plus B right. So, if you solve this differential equation properly the solution comes out to be C of R is equal to A by R plus B there is let me put a minus sign ok. In order to determine the constants A and B what I need to do is that I need to specify the boundary conditions of the problem. Now, one boundary condition I have already talked about which is that the far field concentration is C naught that C as R goes to infinity is equal to C naught. So, that will fix one of the constants for me, but I need one more boundary condition. So, and that boundary condition will most naturally occur at the surface of the cell itself surface of the sphere. So, what I will do over here is I will make an assumption I will make an assumption that these cells are these receptors are sort of perfect receptors which means that whatever sort of signaling molecule comes to these receptors gets absorbed instantaneously and completely which means that what the other boundary condition that I will choose is that C at R is equal to A the surface of the cell is equal to 0 ok. So, this is an assumption it is called the perfect receptor assumption perfect receptor assumption and basically it means what I said that once you anything that comes to the surface of the cell gets absorbed ok. So, which means which is why that the concentration drops to 0. We will relax this in a few minutes and we will see what happens when we relax this constraint, but for the time being let me make this simple assumption that these cells are these receptors are perfect receptors ok. So, now let me I have these two boundary conditions let me now put them in this solution and see what I get for A and B. So, if I put that C at R going to infinity is C naught then what that means is that when R goes to infinity this term will drop out and therefore, what I will get is that B is equal to C naught. If I put this condition that C at R equal to A is 0 what that means is 0 is equal to minus A by R plus C naught which means that A is equal to R C naught right. So, sorry I made a mistake this is at R equal to A. So, this is A. So, this is capital A is equal to this small A times C naught. So, what I have if I substitute back this A and B into that equation is a concentration is a solution for the concentration at any R and that turns out to be C naught which is common 1 minus A by R right. So, it satisfies the two boundary conditions at R goes to infinity this comes back to C naught when R goes to A this C goes to 0 ok. So, satisfied my boundary conditions. So, this is how my concentration profile will look like given that I make this assumption of perfect absorbers. So, now from here I could ask that well now that I know the concentration profile I can ask that how many particles makes it to the surface of the cell per unit time. And to do that you can calculate first the flux the flux J of R at R equal to A the flux at the surface of the sphere the incoming flux remember the flux is nothing, but the number of particles per unit area per unit time. So, that from Fick's law is given by minus D del C del R at R equal to A right. So, if I take del C del R then I will get. So, let me see minus D into del C del R will give me 1 over R square. So, C naught by A by A square because I am calculating at R equal to A. So, this is my incoming flux the negative sign simply says that your particles that are coming into the surface and getting absorbed. So, this is my incoming flux and from there if I want to calculate the number per unit time the number of particles per unit time remember the flux is the number of particles per unit area per unit times if I want the number of particles that comes into the surface per unit time d n by d t that is nothing, but the flux at the surface times the area of the surface itself. So, if I do d C naught A into 4 pi A square. So, what I get is nothing, but 4 into pi into d into C naught into A right right. So, this is the number of part in the case where I have the simple diffusion going on and I have these perfect receptors. This is the number of particles per unit time that comes into the comes to the surface per unit time. So, d n d t is nothing, but what I did is minus j at R equal to A into the area of the surface itself. So, which is this 4 pi d C naught A. So, this is a very important limit it is called the diffusive limit it is called the diffusive limit and what it says is that you if you have sort of chemicals which are diffusing and then getting absorbed at some surface like this R equal to the spherical surface at R equal to A and if this process is happening simply by diffusion then this is the maximum number of particles that you can absorb per unit time at this surface ok. So, it provides a limiting case and it is called the diffusive limit. So, as we go along in the course you will see that this we will use this diffusive limit sort of again and again. You might say that you know we we have done this in the sort of more simplistic case which is that I have this perfect sphere and so on and most organisms will not be perfect spheres which is true, but what that means is that what will happen is that this pre factor that I have this 4 pi that will sort of change, but roughly it will be of this order. You will have some correction terms maybe which are of order 1 depending on what geometry of the cell that you choose, but roughly this is going to be your limit the fastest that you can absorb particles providing these particles are simply diffusing ok. If you have other active processes which are being driven and so on then of course, you can go faster than this, but if you are relying purely on diffusion for the signaling molecules to reach your surface of the cell this is the maximum speed that you can achieve. So, let me now just relax this constraint a bit of this perfect absorbance. So, let me say imperfect absorbance. So, it is good to have it is good to have a clear idea of what assumptions you are making whenever you are trying to model. So, that you can if you want you can systematically relax them one by one in order to go closer and closer to an experiment real experimental situation. So, I will not relax the others for now this is spherical and so on, but at least I will relax this perfect absorber approximation the imperfect absorbers. So, I will say that this receptors have some finite rate of absorption, it has some finite rate of absorption of signaling molecules which is let us say k on. So, it will absorb this signaling molecules with some rate which is characteristic of the receptors which I will call as k on and remember there are m absorbers which means that the number of molecules per unit time that gets absorbed the surface of the cell is going to be m if you have m absorbers each absorber is going to absorb with a rate which is k on and the concentration at the surface of the cell. So, you have some concentration at the surface of the cell these molecules will get absorbed at some rate in a given absorber and you have m of those absorbers. So, that is my rate of absorption. I need to calculate this of course, k on and m are some parameters which I say whatever the cell has some number of receptors it has some rate of intake and I need to solve for what is the c of a. So, now, unlike in the perfect receptor case this boundary condition no longer holds right at r equal to a this is no longer equal to c because not a these are not perfect absorbers. So, some molecules will stay there at the surface of the cell ok. So, in a situation like this how would I define my steady state intuitively before we write it down mathematically. I can say that I will reach I will reach steady state when the rate. So, here is my cell when the rate at which these refusing molecules reach the surface of the cell is exactly the equal to the rate at which this molecules get absorbed into the cell then I will reach steady state right make sense. So, the rate at which this get absorbed is this we have written m k on c of a. So, we have written m k on c of a the rate at which it reaches the surface of the cell is the diffusive flux times the area right. So, minus j of r into 4 pi r square or so, if I write in terms of the concentration j is minus del c del r. So, d del c del r 4 pi r square good. So, now, I can solve this I now have an equation for c a differential equation for c d del c del r into 4 pi r square is equal to m k on into c of a. So, I can integrate this let us see I can integrate this between a to r some arbitrary r. So, dc from c of a to c of r and then on the other side I have integral m k on c of a by 4 pi d dr by r square from again from a to r I have just written. So, dc is on one side all the r terms on the other side. So, dr by r square and then hopefully these are m k on c a by 4 pi. So, now, I can do this integration. So, this over here gives me c of r minus c of a this gives me minus 1 over r. So, m k on c of a by 4 pi d minus. So, let me just do the lower limit first minus m k on c of a by 4 pi d. I do this dr integration between a to r if you take the signs correctly and these are all constant m k on c a 4 pi all right. I can now apply the other boundary condition remember the other boundary condition is still valid that c at r going to infinity is c naught. So, if I put r as infinity in this equation c of infinity is c naught. So, c naught minus c of a c naught minus c of a this term will vanish if I put r equal to infinity right 1 by infinity will be 0. So, all I will be left with this term m k on c of a by 4 pi d. So, in this everything is known except for this c of a. So, I can find out the concentration on the surface of the sphere now right. So, I can solve for c of a that is going to be c naught by 1 plus m k on by 4 pi d. So, this is the concentration at the surface of the set when you have imperfect receptors which are in up taking the signaling molecules with that rate. You can check that whether this makes sense right. If this receptors were very good. So, if it sort of absorbed everything that came into it which means that this k on was very high right. So, let me try a few limiting cases. So, high k on. So, let me formally let me write m k on by 4 pi d a this object over here is much much greater than 1. If I take this limit. So, it is almost infinitely large if k on is like infinity then what will the c of a go to what will this equation reduce to 0 right which is my perfect absorber. If my k on was so large that everything got an absorbed I should get back whatever I had for the boundary condition which is c of a equal to c. So, that is good. On the other hand if these were very poor absorbers nothing got absorbed. So, very low k on right or equivalently this this object m k on by 4 pi d a was much much smaller than 1. Then what should I expect what should this c of a go to c 0 right. So, nothing gets absorbed. So, it just stays as whatever the concentration at infinity was right. So, then c of a goes to c naught. So, if this was very small then I can neglect this with respect to 1. So, it goes back to c naught ok. So, the limits work out very nice work out nicely as it should. If you are very good if you are perfect absorbers your c of a goes to 0 if you have hopeless absorbers your c of a just stays at the background concentration nothing gets absorbed ok. So, now that you know this c of a which is the concentration yes why not it can. So, it it up this you have the surface of the cell right where you have this receptor and the signaling molecule comes it can bind to this receptor and cause a cascade of changes which causes the cell to. So, but this thing is no longer free in solution ok. So, the signaling molecule is no longer free in solution it causes the chemical reaction by getting absorbed with the receptor. It can even get internalized in some cases ok what was I saying right. So, now I know this c of a which is the concentration of signaling molecules at the surface of the cell. I can just substitute that here to find out what is this new DND I know what was it in the case of the perfect absorbers. So, for this case it is then just m k on m k on c naught by 1 plus m k on by 4 pi d a right. So, for the case of imperfect receptors this is the rate at which signaling molecules get absorbed by the cell by the surface of the cell ok. The better the better the receptor is the higher k on the better this DNDT higher the number of receptors that you have higher m higher this DNDT and so on. Remember that this rate that we have calculated this DNDT that is going to be limited by this diffusion diffusive limit because this is the best that you can achieve because this is the case of perfect receptors. So, this DNDT is definitely less than this. So, what we can ask is that well if the cell sort of keeps on increasing the number of receptors that I that it has on its surface how efficient is that how better does it do. So, to do that what we will ask one question which is let us say how many receptors would this cell need. So, I will ask how many receptors would it need would it need to achieve half the diffusive limit. So, here is for the maximum speed the maximum rate at which it can take. So, I just say that well as long as I am in the order of magnitude is the same I have done reasonably well right. So, let me say that how many receptors. So, what would be the number of receptors that I need to achieve half this way. So, that is the question that I have asked. So, basically the DNDT that I am looking for the DNDT that I am looking for is half of this maximum rate. So, 4 pi DC A naught by 2 and I want to find the number of receptors m that will give me this rate. So, m k on C naught by 1 plus m k on 4th pi D ok. So, this question is clear I have imperfect receptors with a certain rate at which it absorbs the molecules which is k on. I ask how many of these imperfect receptors would I need on the surface of the cell to achieve this specific speed which is half of the maximum speed I could achieve. So, this is this you can solve. So, 4 pi DC A naught by 2 plus 4 pi D A. So, m k on C this I have put the this C naught and that is m k on C naught by 2 is equal to the right hand side is just m k on C and I want to solve for m. So, the solution for m is then just what m is what is m 4 pi D by k on 4 pi D A by k on right. So, this is the number this is the number of receptors that I would need provided the receptor has a rate k on at which it takes the cell has a size A the molecules have this diffusion coefficient D. This is the number of receptors that I would need in order to achieve half the diffusive limit this by itself of course, does not tell you much what is 4 pi D A by k on. So, what we will do is that we will put in some typical numbers now and see how many receptors does it translate to. So, let me see. So, let us say a typical eukaryotic cell. So, let me take A as some 10 microns right. So, my cell is a sphere of 10 microns which is roughly a cell size as we discussed. Let me take a typical diffusion constant which is again roughly let me say 100 microns square per second I will need a k on for which I use again. So, these are all order of magnitudes roughly in the same correct order of magnitude. So, 10 per micromolar per second and at some point maybe I will also need the size of a receptor.  So, typical. So, receptor is a protein molecule right. So, typically let me say a size of receptor let me call that something SR is some 10 nanometers. So, these are just order of magnitude estimates. So, typically eukaryotic cell, typical diffusion constant, typical uptake rate and some typical size. You can substitute this back here and find out how many receptors that does that translate to me. So, but before we do that. So, for it is so, this is a cell of 10 micron size right. How many receptors would you expect on the surface of this cell? Order of magnitude 100,000 million billion from our estimates of protein numbers and so on in the first class this is just a guess I mean this is 10 to the power of 4. Good we will start off with that and see. So, now, who is going to put in these numbers and tell remember you should put take everything in the right units. So, what is one molar? One molar remember is avogadro's number. So, 6 point let me just say 6 6 into 10 to the power of 23 molecules per liter. 1 liter is what is 1 liter in micron cubed is 1000 cc. So, therefore, someone 6 into 10 to the power of 23 by how many microns cubed 10 to the power of 15. So, 10 to the power of 15 per micron cube and I am talking in terms of micromolars. So, one micromolar is this into 10 to the power of minus 6. So, that is 17 15. So, 600 per micron cubed that is one micromolar. So, this is 600 per micron cubed. So, k on if I if I translate this let me do here that is getting crowded. So, k on if I translate that k on is 10 per micromolar. So, 10 by 600 into micron cubed per second right. Tell me if I am wrong if I am making any mistake anyway. So, that is the only conversion. So, then I can calculate what is the number of receptors ok. So, this is 4 pi into 100 microns square per second with diffusion into the size which is 10 microns divided by k on which is 10 by 600. So, 600 by 10 second per micron cubed right. So, the units work out micron cubed on top, micron cubed on bottom second. So, this gives me a pure number which is as it should. This is the number of receptors I am calculating. So, this is 4 pi into 6 into 10 to the power of 4. Where is 4 pi roughly 12, 12 6, let me say 75, 75 into 10 to the power of 4. So, 7.5 into 10 to the power of 5 receptors ok. So, the number of receptors that you would need to achieve half of this maximum speed maximum diffusive speed is of the order of 10 to the power of 5 receptors on the surface of this 10 micron cell. Is that a large number or is that a small number? So, how would I say that? What is it large in comparison to? Yes of course, it is a large number, but ok. So, let me say that I have this set right on which I have placed this 10 to the power of 5 receptors. Each of them occupy some area. I could ask that given I have these many receptors 10 to the power of 5 which is a very large number. What fraction of the membrane is covered by these receptors? So, what fraction of the membrane is free for other proteins? If this is taking up all my membrane area, then that is pretty bad that is pretty large right. I do not have anything left for any other proteins to do its job. So, that is one thing I can calculate. Another thing I can calculate is that well maybe what is the separation between given I have 10 to the power of 5 proteins, what is the typical separation between two proteins and how does that compare to the size of the protein itself right. If it is of the order of the if it is the same as the size of the protein which means I would need this protein sitting next to each other in order to accommodate these many. There are some measures that yes 10 to the power of 5 is large, but does it really fill up the cell. So, that again we can do. So, let us say let me do the area calculation. I have these many receptors. So, I want to let us say I want to find this covered membrane fraction covered membrane fraction which is how much area is taken up by these proteins divided by the total area of this 10 micron cell. So, the covered membrane fraction is something 7.5 into 10 to the power of 5 into the area of the protein each individual protein I will assume as 10 nanometer square. So, 10 nanometer square and on the denominator is the surface area of the cell which is 4 pi r square. So, that is 100 micron square ok. So, what is that? It might help instead of writing 75 I had some 4 pi into 4 pi into 6 into 10 to the power of 4 then I can cancel off the 4 pi space square. And nanometer square I need to convert to micron square. So, this will be 10 to the power of minus 5 micron square. So, good. So, how much is that? So, 4 pi 4 pi cancels off 100 this becomes 100. So, roughly of the order of 10 to the power of minus 3 right 10 to the power of 2 into 10 to the power of minus 5. So, roughly of the order of 10 to the power of minus 3. So, the fraction of the true I have 10 to the power of 5 protein molecules, but the fraction of the area that it covers out of the total area that is available to the cell this is like something like 0.001. So, it is still pretty sparse and even. So, it is a lot of proteins, but it is still pretty sparsely distributed on the cell, but even with the sparse distribution I have achieved half of my maximum speed. So, you can say that well instead of 10 to the power of 5 I will put 10 to the power of 6, it does not give you an order of magnitude estimate maybe you are at 50 percent it takes you to 60 percent it is not really worth it for the cell. Cell is already doing pretty well even with this sort of sparse distribution. So, actually if you look at you can also calculate the mean separation given these many it comes to around 18 nanometers roughly between two proteins and a typical protein is square root of this. So, it is 3 nanometers size So, 3 nanometer protein separated an inters proteins separation of around 18 nanometers. So, it is by all measures on the surface of the cell it is pretty sparsely distributed. So, if you look at the effect of receptor density. So, this is some particular bacteria which I do not remember. The molecule that is getting absorbed is the virus the colophage lambda k and this is the receptor density on the surface of the bacteria ok. So, when you receptor density is small as you increase the density of course, you get a lot of improvement in the absorption, but beyond a certain point it sort of flattens out. There if you put more and more receptors on the surface of the cell it does not really make that much of a difference to the to the absorption performance of the cell itself. So, that is one lesson the cell does pretty well even with a relatively low coverage of receptors as far as this diffusion limit goes. And then like I said of course, this is majorly simplified with various approximations one can do better. For example, if you look at the distribution of chemo receptors on the surface of the E coli you will see that there are large clusters at these two ends and very few chemo receptors over here. So, if you were to model the E coli as a sphero cylinder then you could take that there is nothing on this cylindrical walls, but there is a large density on this hemisphere and on this hemisphere and then ask that you know what sort of how does that change the calculation. So, realistic to model realistic organisms the spirit is the same whatever we have done for spherical cases you take the appropriate shape you can solve it numerically or in very few cases maybe you can solve it analytically, but this is the this is the crux of it. And this like we discussed this is also true not only for the cell signaling problem, but a similar approach would also work for this diffusion and capture sort of problems. If you are talking about microtubules where these t-bulin subunits are diffusing and are getting captured at the tip of the microtubule you could do a sort of similar calculation and ask that what is the rate at which these t-bulin units subunits will arrive at the tip of this growing microtubule. So, this is these are two concrete examples that I thought I will discuss one is PrEP, the other is the cell signaling next. So, we will continue with diffusion next class and we will talk a little bit about first passage properties of diffusion. All right that is all I have for today.


Hello everyone and welcome back to Conversations with Tyler. Today I'm honored to be here with Anna Kaye. Anna is truly a British institution. She is Director of Landmark Trust, an architectural historian, historian of the Crown Jewels, an expert in 17th century history, a TV personality, and I'm a big fan of her latest book called The Restless Republic, Britain Without a Crown. Anna, welcome. Thank you. Thank you. Very simple question. What's the most plausible 17th century scenario where England remains a republic ongoing? Well, it could easily have happened and I think a lot of people have forgotten that there was a revolution in the British Isles and it was a republic for ten years. But the trouble was, I think the trouble was really that this is a classic situation where there was a lot of unhappiness with what had been the case, the monarchy, but the formulation of a stable republic had yet to be worked out. I think if Oliver Cromwell had lived longer or named a better successor than his son Richard, it could have endured. But fundamentally it was before its time, I would say, and it was not sufficiently deeply rooted. Fundamentally the people didn't want a republic even though one was brought about and so that meant it was always fragile. Would there have been a way without a crown to have put a lid on all the religious disputes? Wouldn't they have just simmered, led to more civil wars, and some kind of consolidation into autocratic power? And in that sense there is no counterfactual where the republic just keeps on running? Well you could say that, but of course there is a kind of counterfactual parallel because in what's now the Netherlands, what was then called the United Provinces, there had been a revolution, sometimes called the Dutch Revolt, that had happened in 100 years earlier in the 1560s, which had both rejected Catholicism and had rejected monarchy and it became something that was governed by a series of states, you know, had some institution called the States General where their representatives met. So it wasn't so much that religious turmoil and republicanism were irreconcilable, but in the case of England the revolution, the throwing off the monarchy didn't have sufficient buy-in from the political nation, let alone the nation as a whole, it was really brought about by an army coup. So I think that meant it was fragile and it was also linked to a kind of strong view held by a minority and very much represented in the army that a kind of very strictly Puritan regime was what was needed and I think that was kind of incompatible with a sort of peaceful set of circumstances because it wasn't widespread enough. So yeah, but I mean you're right, which is these counterfactual avenues you kind of do take you into so many other what-ifs that it becomes a bit fruitless after a while. An even simpler question, if the English Civil War of the 1640s wasn't about having a republic, what exactly was it about?   I think the answer is it was really, in my view, overwhelmingly about religion. There's a historian who works on this period who talks about it and says, you shouldn't think of it as a kind of revolutionary war, it's really one of the last wars of religion. And so that was the biggest of the issues. There was a sort of related secondary issue about the extent of royal power. So that was in the mix, but it wasn't the first issue. Charles I, who was the king who was being fought against by the parliamentarian forces, wanted English religion, wanted the Protestant religion of England to be more elaborate, more like Catholicism in terms of the way it was performed and liturgy and so on. And that was something that was anathema to a lot of very sort of committed Protestants in that tension. How much of that was sincere belief and how much was that simply a kind of arbitrary marker that different interest groups struggling for power fixed upon and actually the civil wars about the interest groups struggling for power? Well, it's an interesting point. I think if you'd ask that question of a lot of historians working a generation or two ago, they would have said it's all about economic forces, it's all about the class struggle, if you like. I don't think that's my view. I think as we live in such a secular age, and I would say in the UK much more so than in the States, where really, you know, church going and religious conviction is very much a minority pursuit. So to reimagine ourselves or to imagine the world of 17th century England, where religion is such a strong force, it involves a kind of mental leap that sometimes people have been reluctant to do. And I think in terms of historians working on this period, particularly in the mid 20th century, really influenced actually by Marxist approaches to understanding the past. It was all seen as, well, this is the rise of this class, this is the mercantile, urban, you know, kind of strand of society trying to assert authority to climb the ladder and so on. I just not at all convinced by those arguments myself. I think religion was very, very strongly held factoring people's lives and you read contemporary diaries and so on. And it really is clear that people felt very strongly that wherever they were on the spectrum between a sort of absolutely kind of Calvinist Puritan or a Catholic in terms of the range that was around at the time, that personal conviction about what was right was really, really a big factor. So I don't mean that it was the only factor, but I think to treat it as somehow a cover for other motives is to do a disservice, I think, to the people of the age. Given how central the 17th century is in your mind, including disputes over the Book of Common Prayer, does it go to Scotland, James as an absentee monarch, when you look at the disputes today over Scotland becoming independent, how do you see that differently than say someone who doesn't obsess over the 17th century? Well, I think the first thing is, I mean first of all, I have to declare an interest because I am a Scott. I was born and brought up in Scotland. But I think that if you're interested in the 17th century, the kind of additional perhaps emphasis that it gives you is first of all the memory of how the Union came about in the first place. Great Britain as a unit was only, in our historical time depth, a relatively recent creation. I mean it was there for a long time, 300 years, whatever it was, or is, but that of course what happened was that a sovereign acceded to two kingdoms. And this happens quite often historically. I mean it happened quite often with other kingdoms or countries in British history. So William III was the King of Britain, Great Britain and Ireland, but he was also the overlord of what's now the Netherlands. George I was the elector of Hanover and none of these things involved a political union. They were just two countries that happened to share a sovereign. And so that's the reason why, of course, although England and Scotland have been part of Great Britain as a political union since 1707, it was never a complete one. The legal systems have always been completely separate, completely distinct, the education systems, much else besides. So although personally I would be very sad to see the end of the Union and very sad to see a breaking apart between England and Scotland. I do think if you think about the 17th century, it does really underscore how much independent identity has always been there in those two nations and how long a history each had before they became a whole. What did Robert Boyle learn from Sir William Petty? Well, this is the real, like, quickfire questions. What did Robert Boyle learn from Petty? Okay, so Robert Boyle obviously was, as a young Irish nobleman, was a student of the New Science in the 17th century. And William Petty was also, they came from very different backgrounds, so Robert Boyle had been brought up, he's the son of an Irish nobleman in Great Comfort and Granger in Ireland and, you know, Silver Spoon in his mouth and Silks to wear. And William Petty had been born the son of a very poor clothier in a town on the south coast of England. And they met both in Oxford and in Ireland in the 17th century, the mid-17th century. And they were both, I mean, William Petty was an older man's senior to Robert Boyle. Robert Boyle came to Oxford as a student in his early 20s, but he was rich and had friends. And William Petty was already a very sort of well-regarded member of the establishment in Oxford University. So he was the kind of older man in terms of experience and in terms of scientific experimentation, which is what was their great obsession. But on the other hand, Robert Boyle was the man with money and with the ability to commission, you know, fund activities and so on. So I think Robert Boyle, sorry, yeah, Robert Boyle learned from William Petty a lot about what was being embarked upon by this group of young men in Oxford in the middle of the, in the 1650s, which was utterly revolutionary really, which was the beginning of what we would regard as proper scientific process and scientific inquiry through experimentation. They were a group who would form the Royal Society when it was reformulated in the early 1660s. And at William Petty's rooms on the high street in Oxford, rooms that still exist, this group of men gathered, Christopher Wren was among them, and they carried out experiments. And so Boyle learned from William Petty a lot of things about the circulation of the blood, about the, about vacuums, about the different characteristics of the human organs, all sorts of things, because they had these amazing broad areas of inquiry. And of course this is an age where until now really the job of anyone who we were considered to be a subscientist in modern terms was to read the works of classical antiquity and to understand what Aristotle or whoever it was had said about the nature of the world. So it was a new dawn and Boyle learned from Petty an approach, I suppose, to inquiring and looking for yourself to understand from how things behaved when you cut them or inflated them or expose them to light, what the properties of the world were. It seems Petty understood Ireland pretty well and he had some sympathies for Ireland. If he had been allowed to simply rule Ireland unconstrained, could he have done much better? Or is the actual problem one that there's simply no way you can rule Ireland at all without cementing in this external elite, which is then going to lead to trouble? Yes, so William Petty is a scientist and an economist as we would term it now and he went to Ireland as a doctor and because he had this very brilliant brain and analytical scientific mind, he kind of diagnosed what he saw as the problems but as the nature of Ireland, how many people lived there, how many had been dispossessed by the wars and conflict of recent times and he undertook this remarkable business of mapping Ireland as part of the redistribution of land, which was extraordinary and horrific undertaking in many ways. But he wasn't a person who had any experience of governing a place. He was hopeless with people. He was rude and abrasive and direct and would tell them that they were ignorant and absurd, in which you may well have been right but as we know in society, governing a place doesn't necessarily work well if you tell. He didn't think he was temperamentally in any position to be a good governor. What he absolutely was was somebody who saw past because it didn't interest him, prejudice and sort of traditional English dislike of the Irish because he was interested in things empirical and he'd also been trained by Catholics to share most English people's horror of Catholics and so I think he was well placed to advise on the business of running Ireland. He wouldn't have been good at doing it himself and had Henry Cromwell to whom he gave this advice and who had been given the job by his father, Oliver Cromwell of Governing Island. Had he been given more time to do that, I think it could have well have been very successful but it was very short lived because when Oliver Cromwell died in 1658, Henry Cromwell lost his position effectively and so the period of time when William Petty and Henry Cromwell were together working on the business of the reconstruction of Ireland was very short but I think the evidence is there, aspirations for it, they thought you could found a university, you could make it this great forward looking nation that could be a kind of model for modernity could potentially have been very productive. It seems there are some monarchs, they don't do much in the way of building palaces. Edward VI, Mary, Elizabeth, is that just random or is there some systematic political economy reason why some monarchs are building palaces and others aren't? Well, it's usually a pretty practical reason. Well, two, one is to do with money and one is to do with scale of your court. So Henry VIII famously by the time of his death had something like 60 palaces but that was partly funded, of course, by the dissolution of the monasteries which involved the government raking in, state raking in huge amounts of money which meant you could build and acquire on a huge scale.  So you needed to have palaces for the Queens because they were separate palaces for Queens for the Prince of Wales and for your other offspring and so on. So Henry VIII built palaces on a great scale. He then passed the palaces on to his successors who, to begin with, inherited a huge patrimony so they didn't, you know, the kind of requirement or the need for more buildings was, you know, had been sated.  He never gets beyond his teens. Mary Tudor is an adult woman but she's married but has no children and her husband is King Spain so he's not really around very much. And of course famously Elizabeth I is a singleton sovereign on married and with no children. So I think a lot of it is about practicality but there's also, you know, you can add into the extent to which you see and there are obviously people who did on top of those more practical issues building as a way of expressing your status. And so if we think of somebody like Louis XIV in France it's clear that over and above many of those practical requirements or questions of means the magnificence of the monarch and therefore of the institution of monarchy and so on was something that he, you know, realized and expressed in buildings on a massive scale. Why concretely do the monarchs wear crowns? Well, it's an interesting point because of course no actual practical job that a crown does. Sure. And it could be a scepter, right? There's many different symbols of status you could invoke. Why a crown? Of course there are also all those other symbols of status. So there are several scepters as an orb. There are spares as rings as a whole wardrobe of regalia as it's known. But essentially it's about the echoing with this amazing sense of continuity of what was done by your ancestors back to the kind of origins of your institution. So it's very interesting that if you look at images of monarchs of England or within Britain going right back into the early Middle Ages they all are wearing a ceremonial thing on their head.  You see it in other traditions which had no connection to no kind of interaction. For example in traditional African societies where you see headdresses in the wearing of some ceremonial thing which denotes a person as being other than those around them more important, more special, elevated. You see it in the archaeology. I mean the earliest English crowns have been excavated from Iron Age graves. So this is before the advent of the written word. So I mean that seems to be a kind of an almost sort of anthropological sort of universality of the idea that you're doing something special on your head is a way of setting you apart. But it also is very, very clearly monarchs doing it because they're predecessors do it. And we see it in the Middle Ages Henry III who was a great long-lived and successful medieval monarch really lionized his predecessor by several generations, Edward the Confessor who'd been canonized by the Catholic Church. So he was a saint and had his, the graves were opened of previous monarchs' crowns which had been buried with them or got out and so on. And of course for all monarchies nowadays it's very sort of, we have essentially a ceremonial monarchy in this country but when you trace them back to a time where monarchs were actually in charge and had executive power, always the challenge was how did you pass it on to your children?   And anointing is part of this which is a big thing, this kind of business of a kind of a sort of holy endorsement of your line but also the passing on of all these objects which when you breathe your last on your deathbed are still there and attention can be drawn to them and then they're put on the head of your successor and your aura passes to him or her. So it's a very interesting cocktail of history and anthropology and sociology in a way. Why is the British monarchy so extremely successful as a global institution including in the United States? So in Elizabeth past many people said oh this is the end of the line that seems clearly untrue. The thing is just going to continue. It's extremely popular. It draws a wide spectrum of interest. What's the marketing genius behind what's going on? Why is it so well known? You look at the royal families of Netherlands, Norway they can speak English but no one seems to care. Yes it's interesting isn't it? I guess it's probably a cocktail of things. I think the, I suppose the kind of balance that's been struck between a non-executive head of state in the form of the monarch and the executive in the form of the the government, the prime minister and so on but without dialing down much of the the bling and the splendor and the ceremony of the monarchy even though the power has gone has turned out to be a very successful formulation. It's interesting because I don't know that it would necessarily have been obvious that that would have worked. There might have been a feeling that it would be absurd to continue to have all these palaces and crowns and state coaches and all this kind of stuff when you're looking at something which is fundamentally part of the kind of ritual of state but it isn't actually exercising any kind of executive authority. It happens to have kind of come to pass that actually that seems to be quite a sort of satisfying separation and there's something about the apolitical nature of the monarchy and how incredibly careful they have to be about that that in a world where everything seems to endlessly be in turmoil in terms of electoral politics and so on to have a certain kind of sense of reassurance about it. I also think that it changes. I mean I think if you've been talking about the success of the monarchy 30 years ago it might have been a different conversation. I think there have been moments where the monarchy has felt very successful. Others where it's felt more fragile. But I think fundamentally and then I suppose you have to layer into that the fact some quite practical things like the monarchy in this country is in an Anglophone country so the language that's spoken is a kind of tradition, Anglosaxon traditions if you like have a certain kind of familiarity around the world which makes a connection. Obviously also I mean long past now but the kind of the sort of skeleton if you like of something which a monarchy which was once an empire that stretched around the world still has kind of connections and associations that makes the British monarchy of interest in places where the Swedish monarchy might not be as it were. So you're director of Landmark Trust how should we as outsiders think about where the revenue comes from? How does it work financially? So we're a charity, a historic buildings charity and our job is to rescue historic buildings that are in a derelict or in a bad way to raise the money to restore them and then we rent them out for people to stay in so we have 200 buildings across the whole of the British Isles castles and dairies and lighthouses and all manner of things fort, artillery fort and we are self financing so the money that runs the charity comes from letting the buildings so if you would just... So you make money? Well we don't, we generate money Yeah, but then we would invest it And plough it back into the mission of the institution So if you were staying in London this week and you weren't staying in a smart hotel you could be staying in a silk workers house in the east end built in 1707 or John Betcham and his own apartment which is in Clark and Well both of which we own and it would be staying in a wonderful historic building sleeping comfortable beds and everything but as well as your money being a way of paying for your stay it also helps us to run our charity and then to go on and to acquire more buildings that would otherwise be lost and we have this amazing stock of buildings in this country Do you grade your renters the way say Airbnb does or if anyone can come in and stay in the castle? We love them all We love them all and we don't grade them If you did something really awful like you know made a pile of furniture and set fire to it we might not rent you another building but we don't grade them we are open to everybody and we as I say we are a charity so we're not we don't price ourselves in a way that makes us available only to the super rich it's all sorts of people come and stay in our buildings and anyone can do it you just go on our website lambmartrust.org.uk and you can choose from any number of wonderful follies and mini castles we've just finished restoring an amazing castle near Inverness for people who go to Scotland maybe following their own routes beautiful building built in 1550 which had no roof and no floors until two years ago and we raised the money through people giving money philanthropically resources, grants and so on to re-roof it, re-floor it to put heat and power in and now you can have your own castle for the weekend is it socio-economic status that in essence stops your renters from trashing the places because if Airbnb had no store system I would be quite worried right whereas presumably you have a narrower set of renters if not higher in income higher in education or historic understanding yeah I mean I think it is a sort of self selecting group of people the nature of our buildings I think you're right which is that on the whole people go to them because they're really interested in that kind of thing and so it would be a counter-intuitive thing then to trash it we occasionally have people who make a bit of a mess but it's pretty rare and I think people respond to somewhere that feels really special and that you know is run by a charity and looked after with great care and there's a nice member of staff who gives you the key or gets in contact with you so I don't know I think people's good nature and recognition I suppose of the specialness of what they're experiencing is pretty good pretty good kind of force for keeping them keeping them behaving themselves Did the income tax and estate tax lead to the end of the era of great country homes? because all of a sudden they became a lot more expensive right? Yes The carrying costs are suddenly much higher Yes I mean it was definitely a big factor at the rise of inheritance tax and various other land taxes I mean it didn't bring an end to them you don't need to go very far in this country to see that that was But many more turned over to groups like Landmark Trust right? Yes, yeah it's true and you know a lot of them were sold off the interior stripped out a lot of the interior sold to the states actually the very interesting phase in the history of British country houses really in the first sort of 20, 30 years of the 20th century where whole rooms are houses that I live in this happened to whole rooms, beautiful panelling from the Tudor period prized off the walls put in packing cases and dealers would sell them to the kind of Randolph Hursts of the world who were recreating an idea of old Europe in new buildings so there were different there were a series of factors at play I think it was to do the First World War I mean the extent of the death trial taken by the First World War the impact that had on these great states in terms of the workforce not just in the kind of the owners of the houses but also the people who were working on the estates was enormous so it did make for a big shift but there's something called the Historic Houses Association in the UK which is a kind of club a trade association for people who are private owners of big historic houses and open them to the public or do public events in them and they have an annual conference and if you go to it you really wouldn't think English or British country houses in trouble I mean there's thousands of people there and their buildings up and down the country where they're busy you know putting in farm shops and you know glamping which is a very big thing in the UK and amazing you know kind of eco projects and so on so it did I mean the taxation system and the kind of essentially the rise of the state as an institution that needed resources to be able to fund things like like you know universal healthcare which is obviously a wonderful thing required the kind of growth of taxation and that definitely particularly particularly in the mid 20th century took a big toll on land owners and big houses Given the standpoint of your job how is it you think differently about say a wealth tax I don't know I don't know that I do think differently about a wealth tax But it's discouraging the creation and maintenance of the asset you're dedicated to popularizing and preserving right Well not necessarily I mean it depends I mean a lot of people who have big historic houses I mean a lot of them have them in charitable trusts so they're and do things which mean that there is public benefit more generally from them and the various sorts of I mean it depends what sort of wealth tax and how it's calculated and what basis of it is but I think there are lots of ways you could formulate something that didn't penalize those who were clearly taking a very kind of responsible attitude to historic buildings I also think that sometimes too much money is an absolute killer of historic buildings you see the absolute ruination of wonderful buildings in for example the wealthier parts of London where every cornice has been stripped out the plaster has been hacked off to be you know redone every 10 years by the next owner and all character and pattern has been lost for them so I think there's something to be said for poverty as a preserver as well as wealth Should Britain fund heritage through lotteries which are generally regressive right they don't offer fair odds poorer people by the tickets well so that does happen in this country should it well it's a good question I mean so the Heritage Lottery Fund actually I think it's now called the National Lottery Heritage Fund generates a significant some of money each year from the National Lottery which was set up in the 90s to fund various things including a lot of sport using a lot of community work so it's very broadly based and I would say that it's right to say that you have to be very alive to the demographics of those people who are buying lottery tickets I buy them myself so it's a broad community and the way that money is allocated by the Lottery Fund is acutely conscious of that and each project that you do and I've done a number of them where you receive money through the Lottery Fund you have to demonstrate how you are making a difference in the lives of the people who are buying the tickets but so much of the work that is done through that program is amazing grassroots work say for example in the town I live in Kingsland the local Fisher Folk Museum which documents the lives of the fishing people of that town through generations their livelihoods, their communities their way of life that wouldn't exist if it wasn't for the Lottery Heritage Fund and so that seems to me to be a wonderful thing and something that we should be really proud of which are the old buildings that we have too many of in Britain so there's a lot of Christopher Wren Churches I think there's over 20 what if they were 15 they're not all fantastic they're not all fantastic tell me one that isn't fantastic the Victorians knocked down St Mildreds I've seen pictures of it I don't miss it well you don't miss anything that's not there I think it would be pretty hard to convince me that any Christopher Wren Church would have done to but your point is right which is to say that not everything that was ever built is worth retaining and there are things which are clearly of much less interest are poorly built which are not serving a purpose anymore in a way that they need to so to me it's all about assessing what matters, what we care about but I think it's incredibly important to remember how you have to try and take the long view because if you let things go the decisions that were made in the past about things that we really care about that were demolished wonderful country houses we've mentioned it's fantastic for example Euston station one of the great stations of the world built in the middle of the 19th century demolished in the 60s regretted it forever since so I think one of the things you have to be really careful about is to make a distinction between fashion of the moment and things which we are going to regret for our children or our grandchildren are going to curse us for having not valued or thought about not considered which is why in this country we have this thing called the listing system where there's a kind of a process of identifying buildings which are important and what's called listing them putting them on a list which means that if you own them you can't change them without getting permission which is a way of ensuring that things which you as an owner treat with scorn that the kind of the interest of generations to come are represented in that why were so many big mistakes made in the middle part of the 20th century so St. Pancras almost was knocked down as I'm sure you know that would have been a huge blunder there was something about that time that people seemed to have become more interested in ugliness or what's your theory how do you explain the insanity that took all the Britain for what 30 years well I think this is this is such a good question because this is to me what the study of history is all about which is you have to think about what it was like for that generation you have to think of what it was like for people in the 1950s and 60s who had experienced either first hand or very close at hand not just one but two catastrophic world wars in which numbers had been killed places had been destroyed you know the whole human cost of that time was so colossal and the idea for that generation that something really fundamental had to change if we were going to be a society that wasn't going to be killing one another for all time and this is very this has a real kind of sort of mirror in the 17th century and during the Civil War in the 17th century there was a real feeling that something had to be done otherwise God was going to strike down this nation and I think for that generation in the 50s and 60s the sense that we simply have to do things differently because this pattern of life, this pattern of existence this way we've operated as a society has been so destructive so I have although I think that lots of things were done when it comes to urban planning and so on that we really regret now I think you had to be really careful not to diminish the seriousness of intent of those people who were trying to conceive of what that world might be more egalitarian, more democratic involving more space, more air, more light healthier, all these kind of things now we can see lots now that we say well that's ridiculous this is not how society works but I think that we didn't experience what they experienced so I actually have real respect for a lot of that and I think a lot of things that were done I'm going tomorrow to see a place in Batchworth, the world's first garden city which was planned and laid out north of London in the 1910s which was completely about saying we've got to design a new world so I think we've got to have a bit of humility in considering these decisions because people don't go around wantingly trying to destroy the environment they think that they're doing the right thing if we look at most of the western world it seems to me that after World War II there are very few really very few beautiful new neighborhoods created a lot of spectacular individual buildings but it's very hard to find neighborhoods that are as nice as what was built in the 1890s the 1910s or depends on the country the era what happened to neighborhood architecture why did it so radically decline in wealthier societies so such a good question I was talking about this for somebody at the end of the other day and I think there are clearly places where you do see it and you do see it work now but they're pretty few and far between and I think there's a lot of work going on with young architects in the field and really trying to crack this business about neighborhoods and the housing not least because in this country there's a real housing crisis because we're a small country with a lot of people and the challenges of building are very great but it is really stark I don't know the answer to it I think there are things that observations I would make one I would say is that the idea of the philanthropic neighborhood development scheme has really gone but there was a lot of that that happened in the late 19th, early 20th century to do with land owners and also company directors and so on doing things that were going to be beautiful there's a wonderful place up near Liverpool called Port Sunlight which was all laid out by a great industrialist absolutely the most beautiful place you could imagine for people who would be working for him and there's something about the kind of aspiration of beauty and a sense of responsibility for creating it that it feels like has really diminished in the world of either the state does it and they're trying to do it as cheaply as possible or developers do it and they have another reason for trying to do it as cheaply as possible so I agree I think it's something to really regret I think it's something we have to decide we care about or we're not going to make it any better if the House of Lords were abolished as Labour has proposed as you know would that make it harder for policy to protect heritage in Britain no I don't think so so you don't think they're a net force one way or the other because they do slow down legislation they slow down change I'm all for abolishing the House of Lords myself personally I think it's totally passed itself by date as an institution and the fact that we still have nearly 100 members of the House of Lords who are hereditary peers who are by definition all men I find extraordinary but they're being replaced right they're literally grandfathered in in some ways no but there's still 100 of them but they're going to die but they're not hereditary are they they're from a pool all of whom are hereditary so when the House of Lords reform happened in 1997 or they're about to kind of compromise instead of all the hereditary peers being able to sit in the House of Lords they said there'll only be 100 and they can nominate among themselves who they are but it seems to me absurd that there should be 100 I mean they're all men apart from anything else I mean it's not that they aren't great people they're wonderful people but it just is to me it's an utterly absurd basis on which to involve somebody in the process of legislation and when it comes to your point about heritage I think it's good to have a second chamber I think there's a debate to be had about what the basis of that is in terms of how you would come to have a seat in it but I believe that that a concern for our environment and the buildings and places in which we live and we're built by our ancestors is a really universal one and it doesn't require you to have a kind of particular sort of social slice of society in the House of Lords to ensure it's protected My British EMB friends claimed to me that the cost of living is too high here and we need to build at least two million new homes mostly in the south of England do you agree and would that threaten heritage? I definitely agree that we need a lot more places for people to live but my contention would be we have an incredible stock of buildings which are unoccupied you go into any British market town and you will see half the shops are empty and if you look above the shops these are generally speaking 19th and early buildings like the buildings are completely empty these could all provide wonderful places for people to live I live in a town centre in a market town myself with a bit of will to say let's use the things we have let's adapt them this is a part of many things apart from the interest and the beauty in my view these buildings are all embedded carbon the environmental cost of building them has already been incurred and then they bring people to live in towns near where other communities are not that I don't think there is a role for building new houses but I think it's an easy choice it's a developer very well thank you very much to build some houses on it and sell it off the task of saying how do we make sure our geography and our wonderful towns and villages are full of life and how do we use what we've got requires a bit more imagination but I think that the opportunity there is absolutely enormous and I long to see somebody really grasp that and what should policy do to enable that what has to happen well I don't know I'm not enough kind of wired into the way the system works but I think there needs to be a clear kind of national policy of exploring that and then there needs to be the will and the resources for local government to demonstrate that they have exhausted those possibilities before permissions given for new builds and new cases the aesthetic history of jewelry and the crown jewels the aesthetic history of architecture in England do they run on parallel tracks or are they very different stories well there's a kind of you know there's a through time ages have different kind of stylistic tastes if you like so we might think of we might think of the 1920s and 30s and kind of art deco architecture and if you look at jewelry and jewelry design you see that the kind of favor of the kind of square cut stones and very rectilinear things similarly if you look at the 70 late 17th century with Baroque buildings and then you look at the design for example of the crown jewels which were made most of them in the late 17th century the kind of you see common motifs in terms of decoration in terms of sort of floral devices in terms of massing of objects and the kind of relationship between different elements yeah I mean there's a kind of whether it's an age of ornament or an age of minimalism you see that across different artistic forms and jewelry and architecture like clothes and other things are all part of that will there be a new age of crown jewels that are designed today produced today viewed as important or do they somehow have to come from the 17th century and they have to be old but that wasn't the case in the 17th century right no one said back then they all have to be old well they produced new ones because the old ones have been melted down so it was a bit more it was a bit more of a necessity than a desire for novelty there wasn't any desire for novelty they could have had the old ones they would have had them and when the new ones were made in the 1660s which is the collection that we now have the instruction where these should be exact replicas of the things that were destroyed that's that said there has always alongside this idea that you should be using something very ancient that speaks of you know the your lineage and so on new pieces have in the past often been made to accompany the older sort of ancestral pieces quite often for queens for queens consort but I think I don't think that's where that's not the appetite of the age I think it would be very hard to imagine anyone feeling that it was a good use of money to you know spend a lot of money buying new diamonds and making a new crown at the moment not least because there are quite a lot in the collection so I'd be quite surprised if we see many more pieces made in my lifetime since they're not using the original jewel of Koh-i-noor anymore why not just give it back it was taken in wartime 1849 2nd Anglo-Sikh war East India Company India Pakistan they want it back why not just give it back well it's an interesting point the trouble is that well the Koh-i-noor diamond has been a stone that was taken in conquest through a whole series of conquests so as you say it came to Britain following the Anglo-Sikh wars in the middle of the 19th century and was a kind of you know it was given a kind of legal status but it clearly was a spoil of war but of course it had only been in what's now in Lahore which is where it was taken from for I can't remember how long now but you know decades and had been taken before then by Ranjit Singh who's the Maharaja from somebody that he had conquered who had previously taken it so it had been through Persia, it had been through the Moguls it had been through Pakistan so I mean you know how far back do you want where do you choose your moment I mean it could be given to Lahore give it back to Pakistan but then the Indians would say well hang on a second you should have given it back to us because Babua, the Indian Mogul emperors you have to well yeah you could do that I mean you could do that but I'm not sure where it gets you really I mean but then you start saying well what about all the other things do you go for a kind of massive repatriation you'd empty a lot of museums and I'm not sure you'd solve a lot of problems really I think there's you know it's been there for a long time and I think the I don't think there's an easy solution I don't think there's a kind of act that you could take in relation to that stone which would just involve kind of Britain saying well it's fine we don't need to have it anymore that would do anything other than cause infinitely more conflict and aggro because it would open up the whole question of all these other moments of conflict when the stone was taken and I don't know I just don't see that gets you very far I think it's bad it's not being used in the coronation which I think is very wise and it's an object which can be seen and viewed and discussed by all of us but I wouldn't start passing around the world myself here's a reader question and I quote why do houses in Britain have so little storage that's a very funny question I didn't know that they did do houses in the states have lots more storage I think they do well probably part of the reason is that houses in this country are on the whole very old houses I mean the vast majority of our building stock in this country was built before the Second World War in a time when you know the amount of garages and skis and snowboards and things that everybody needed to keep was considerably less and were built for people who were used to living less expanse of lives less well seen so it's probably a facet of that really as much as anything else but yeah it would make me look when I next go to the states looking some cupboards to see what the storage levels are now you live in Clifton House it's what an 800 year old house in Norfolk what's the hardest thing about living in a house that old keeping warm it's not always straight forward space heaters or that's what they did in New Zealand what do you do we light some fires that's nice light fires yeah we wear a lot of socks and jumpers and we also have a thing in this country I don't know if people go in for them in the states do you have an electric blanket sure of course again in New Zealand thing as well yeah so we love an electric blanket because you don't need to heat your bedroom because you don't need your bedroom to warm but it doesn't mean when you get into bed you're not freezing so keeping warm in the winter is a bit of a challenge but mostly it's the most wonderful delightful thing you could possibly imagine in a massive massive privilege to live in a very old and beautiful building and you have a dishwasher we did have a dishwasher we didn't for a long time we said that he thought we shouldn't but I said let's put the plumbing and he's pretty grateful now how practical are thatched roofs they're pretty practical I mean they're very if you see a thatched roof the thickness of the thatch is absolutely enormous so it has very good thermal properties it's very good for biodiversity lots of beetles live in but they're not cheap and you need a wonderful thatcher to replace the thatch on a cycle every generation or so they keep you very warm and they're very sustainable they're very low-carbon but they're not cheap what can you tell us about windows and alt-horms that maybe we wouldn't know well what I would say is that you must never underestimate just how much our ancestors cared about keeping warm you think we care about it the warming our hazards but if you had to chop every log that warmed your citigrame you'd pretty much be focused on it too but we often forget about the things that they did which we ought to do too to keep warm which is for example really thick curtains with lining which means that when you draw them really exclude all the heat not something very sort of flimsy a lot of old buildings have shutters which are also very very good so you use those in conjunction with the windows they are so those things are really really worth doing in your house and I think we've as far as making sure that old windows are doing their job in keeping you warm because I think there's a real real risk at the moment with the completely correct focus on insulation in buildings that all our beautiful old sash windows with their wonderful handmade glass get put in skips see windows get put in instead and so I think that is very important for all of us who care about this stuff to remind ourselves and remind each other about the things you can do that enable you to keep your beautiful windows but also to make sure that you're not wasting energy what makes the historical architecture of Norfolk so special so one of the things that's really interesting about Great Britain is if you ever have one of those maps that you can get which show the geology the place that you live, the country or the state you live in so it shows the kind of stripes or the bands of different kind of geology whether it's limestone or granite or chalk or whatever if you look at one for Britain it is amazing because there are so many different stripes of geology just to do with the way the world evolved geologically which means that places in Britain that are very close to each other have completely different geology and the reason that is interesting places are built overwhelmingly from the materials that you find locally when you have an old building stop like we do that's very vivid expensive to transport materials and so on so one of the great pleasures I would say of travelling around the UK is that places that are maybe only 15 miles apart can look completely different because of that so in the case of Norfolk what it means is that Norfolk has no building stone it has a lot of chalk which has seams of flint in it so what you get are buildings in our part of the world which are overwhelmingly brick very beautiful red brick that's been fired locally from local brick earth and then you get dressings of napped flint which is very beautiful black kind of knobbly sort of stone if you go 20 miles east from us to get to Northamptonshire beautiful limestone and everything is built of honeyed beautiful stone and it's such a lovely thing about your connection with your environment and I feel that in this country we are very lucky in this that you have this tremendous local distinctiveness you could open your eyes if you know about this stuff and you could just see by looking doing that which county of England you are in from and given all these places are very close together compared to the states and quite often which part of which county so Norfolk is very very strongly brick and has beautiful brick merchants houses and buildings of the 16th, 17th, 18th century and it has also some wonderful medieval churches because Norfolk was in a very very wealthy it's a sort of bulgy bit on the side of England if you look at the map of England on the right hand side and it's where it was the wealthiest part of England all the way through the middle ages because it was where all the sheep farming happened and all of England's wealth in the middle ages really came from wool came from the export of wool it had less of a 19th century also right in the sense of less of an industrial revolution yeah so it was its prosperity was in the middle ages and then it's essentially kind of you know disappeared from the sort of league table of affluence in the UK as the industrial towns of the north which is where you know big scale cotton production and so on really took off and and as a consequence as a part of the UK it's a very very beautiful it's not very wealthy at all and it's very unurbanised because it wasn't it essentially still has its kind of medieval and sort of early modern landscape both in terms of buildings and topography whereas if you go I mean equally interesting but it does very different somewhere like Manchester which is an amazing world's first industrial city you know had this extraordinary explosion in the 19th century the railways were invented there you know everything kind of was was was developing in a very different direction. Three final questions first which is your favourite John Fowles book and why? I think it is the French left-tenant woman I think it's just an amazing novel it really really bears really reading that it's less fashionable now than it was maybe 20 30 years ago but it is tremendous he wrote some pretty creepy other novels one called which I wouldn't particularly recommend amazing though it is but I think the French left-tenant woman as a kind of love story and as a kind of a dialogue with Victorian literature is peerless. Who's your favourite British composer and why? Oh I think Handel whose music I hope we will be hearing at the Coronation which is coming up next year and you count him as a British composer? I do yeah. Okay that's fine. Can you claim him? Can you claim Haydn? The shakier I would say and he compares that wonderful court music which I love that's great area that I've worked on. Before I ask you the last question just to repeat for our listeners and readers Anna's book which I'm a big fan of it's called The Restless Republic Britain Without a Crown if you type her name into Amazon it's pronounced Anna K but you spell it K-E-A-Y. Last and final question what is it you will do next? I'm trying to save an amazing building outside Edinburgh a house called Mavis Bank which was built in the 1720s for a man who was one of our great Renaissance figures, a great pioneer of the Scottish Enlightenment and it's the most beautiful beautiful house it's derelict just walls but the ceilings and the roofs have fallen in and it's clinging on to life by its fingernails so my great hope for what I'm doing next is being able to raise the money to save it from collapse. And are we doing enough to preserve the Scottish Enlightenment? No. What else should we do? Extra questions. Everything. Everything but what? What concretely? Well there are all sorts of things I think the Scottish Enlightenment is such a completely gripping extraordinary phenomenon that this tiny little country you know my birthplace but micro little place on any world view through the course of the early and into the later 18th century had such incredible influence around the world and I think the buildings of that period I think the political thought the poetry, all these things we should all know more about we should teach it more to our children and we should celebrate it. And if you're recommending one thing for people to read on the Scottish Enlightenment well there's a very good new book that your listeners might be interested in called Scotland a Global History written by someone called Murray Pittock that came out early this year and it is a wonderful account of how from the sort of mid 17th century Scotland as I say a tiny little country with a miniscule population came to have such incredible global reach in terms of science, technology thought, politics music so much so yeah, that's a good place to start Anna has numerous other books all of which I've enjoyed Anna, thank you very much