Introducing the Artificial History of Science Now this is just plain kind of a weird idea, but it seems to me it would be a hell of a lot of fun and possibly enlightening a little bit as well. I think it's best to just jump in with how it would work. So, you select a modern scientific theory of interest, and demonstrate it from scratch. What does that mean? I mean you go naked into a field with absolutely nothing and do it all from that start. That's not to say you go in ignorant or without plans. No, the idea is to put a lot of effort ahead of time to work out the best and fastest possible way to get from sticks and rocks to the equipment you need. The goal is never to recreate any sort of historical era or to do anything they way any historical character did it, but to bring the history to a new life by confronting the same set of difficulties yourself in a situation unique to your experience. How hard is this? The first time it will take many years to get anywhere to be sure, but the idea is that it should be done again and again, each generation improving on the efficiency of previous attempts by studying them in detail. I got into the idea initially reading an eccentric but fascinating intro chemistry text called Caveman Chemistry by Kevin Dunn. Eventually I happened onto the idea of making a paper excercise of getting quantitative bulk chemistry off the ground without Avogadro's number. This turns out to be a possible but difficult sort of chemical crossword puzzle. You can easily see how it took eighty years between the first published chemical formula for water HO and the first correct formula H2O. Having worked out what I thought was a minimal starting solution (it's relatively easy to add new elements once you have a few determined for sure), I eventually decided to work out a plan to measure the true mass of the neutral hydrogen atom suitable for an imagined early-modern chemistry lab, having run across a clever idea for measuring Boltzmann's constant. The early history of modern chemistry seems to be especially rich in missed opportunities to make major breakthroughs, and on studying this I got in the habit of making up experiments that could have been conducted long ago so as to prove some point centuries before it was understood. That's not obviously useful or anything, but I wondered how you would go about re-experiencing the mental environment in which these questions are genuinely difficult, having experienced a little of that myself in doing the chemistry on paper. And the obvious answer is to take it back technologically, but also theoretically, as far as you could and face all of the difficulties, but in you own scenario. The work you do in this isn't itself of any evident value, but I think the experience would be. It's not easy to set up an environment where you can practice making mental syntheses of such scale and difficulty. Here's my outline of a plan to do this for what I described above, measuring the mass of the neutral hydrogen atom from scratch. 1. From sticks and stones to carpentry AKA the hard one. Re-invent the mesolithic. A lot of expertise with the properties of different rock surfaces is required, and also how to take apart animals to get leather, bones, antlers, sinew, etc. It goes without saying that you need a deep and abiding knowledge of the properties of a vast array of woods in different stages of drying and curing. You're not circular-sawing pine 2x4s here, rather more like steam-twisting vines in fire pits lined with wet leaves. Making charcoal in mounds in large quantities happens here also. The goal is to be able to produce and reproduce small dimensionally accurate objects and large modestly precise constructions using time-efficient means. 2. From carpentry to iron age AKA the long one. Re-invent pottery, copper/lead/tin, iron, glass. Prepare to make them into proper instruments. This stuff is much better known but there's an enormous amount of work involved. I haven't started trying to make any sort of minimal path through this yet, as there's so much involved it's hard to know at first how much you could cut out or simplify. The goal is the same as the last one, but with a better range of materials and better precision. Early practical chemistry is all done at this stage, as you also want mortar, plaster, rubber, sulfur, etc. A quick word about what's not involved. First of all, you're not supposed to live the life of the distant past in any real sense. Accelerating the progress of the central activity is very much the idea, and every complication that's not necessary to the philosophical purpose is to be avoided. Second, the finding of materials is not part of the process, or rather is anterior to it. You assemble all of the materials you're supposed to need during the planning stage, without concern as to whether they would be available at one place on earth in the actual past. What's important is that all materials be in (as close as possible to) the state you would find them in nature, as the difficulty of processing natural materials certainly is part of the purpose. Really searching for everything would just make it take far too long. 3. From iron age to science lab This is really the first stage at which it feels like you're doing science. The key thing here is to establish a system of measurement. Yo don't want SI, that's for sure. My own True Decimal units would just happen to work quite well for this. Those units can be much more easily recreated by taking an idea with you instead of artifacts. A. Make a water clock, and make measurements of local noon, and using these subdivide the day into 1 million units. Then make graduated beakers to establish a system of time measurement. B. Recapitulate Galileo's rolling ball experiments, except in this case you don't determine the value of the acceleration of gravity in an existing system of units, but rather determine the distance unit which makes its value unity together with the established time unit. C. Make a set of scales, a carefully measured cube, and a beaker to sit on the sacles full of water while the cube is dunked in so that water overflows a spout. You dunk the cube (with an edge or corner pointing up, not a face to give a more accurate endpoint) to remove an exact volume of water, then remove it and make a weight to restore the balance. That's your mass measure. The theoretical development is to be a part of the "inside" effort, although in some sense guided by plans (evidently made by other people). In this case, that is supposed to go sort of like: I. Develop a simple version of the kinetic theory of gasses. II. In combination with results from the experiments which I call the "3 furnaces" (described below), develop the concepts of atomic weight, molecules and molecular weight, and quantity of substance together with Avogadro's number. III. Develop the thought experiment known as the canonical ensemble, and from it the concepts of temperature, entropy, and Boltzmann's constant. Now that you have a science lab and some theory, you can get directly at the problem. 4. Absolute temperature Using piston-and-thermometer type expeiments, estimate absolute zero, establish an absolute temperature scale, and measure the ideal gas constant R. You can define the mole based on your mass unit not knowing NA, up to the unknown factor of relative molecular weights, determined in the next setp. 5. Chemistry A simplified and streamlined version of the Laviosier-Dalton experiments to determine molecular formulas, reaction coefficients, and relative atomic weights. I'll go into more depth on this below. 6. Boltzmann's constant Determine Boltzmann's constant by an experiment in which a thin collimated beam of monochromatic light is passed through two glass vials side by side and projected onto a screen. The two vials contain a suspension of slightly bouyant uniform tiny shperes (pollen grains e.g.) in a solution of known and just-heavier density. One vial is heated a small and measured amount, and mounted in a holder which has a screw adjustment of its height, precisely measurable. When one vial is heated by a known amount, its band of light will widen because of the increase in pollen grains at the depth where the beam of light intersects it near the top of the liquid. The height is raised by the measuring screw until the band of light on the screen returns to its original width - the same as the other vial. The change in height with temperature can be turned into a measure of k. Young's optical method of measuring the size of red blood cells could be applicable here for measuring the size of the spheres in the first place. N(h) = exp((d_fluid * V_sphere - m_sphere) g h / k T) / constant Finally, the real masses of the atoms can be determined by R = k N_A (derived in 4). The experiment of the 3 furnaces is as follows. Each furnace is an iron box with sealable lid and with inlet and outlet tubes, of say roughly one liter volume. It is designed to contain a substance and be heated externally by a charcoal fire while a gas is passed through the inlet to the outlet after reacting with the contents, or sometimes with the inlet sealed and the contents generating gas by thermal decomposition. The standard combination of three furnaces is an important conceptual experiment that was never conducted historically during the time when its results would have been highly revealing (as late as 1810 at least). The first furnace has its inlet closed and contains limestome to be thermaly decomposed to generate pure CO2. The second furnace takes this input and contains charcoal, producing nearly pure CO by external heat. The third furnace contains an oxide of one of: copper, tin, lead, or silver. Taking in CO, it produces CO2 by reduction to metal of the oxide. Another important aspect is that each furnace can be weighed before and after the experiment to determine its change. A second component of this experiment is a device for measuring the ratio of densities of a pair of gasses contained in two chambers mounted side-by-side and separated by a partition of thin metal mounted so as to be slightly flexible - to maintain both samples at the same temperature and pressure. The measurement of densities is made by a pair of tubes forming a right-angle L shape, also mounted side-by-side in the two chambers. The first tube, the propulsion tube, contains a piston connected to a lever extending outside the chamber, with both levers connected to a common handle to operate both pistons simultaneously. The pistons blow gas across the top of the second or resonating tube which acts as a flute. The opposite end of the resonating tube extends outside the chamber and is terminated with a flexible membrane onto which is fixed a whisker. Stealing a great idea from a 19th-century linguist, the two whiskers side-by-side scrape a smoked-glass plate drawn by a mechanism at constant speed to produce an oscilloscope trace. The ratio of wavelengths of the two traces provides the measurement. This method differs from the usual in providing a rapid measurement, which can be important when working with chemically active substances (e.g. Zn or Li or Ca vapor). A third component of this complex of experiments is the chemical analysis of air. A measured amount of air is caused to flow out of a chamber by filling it with water under gravity. The air is first passed through what are described above as furncaes 2 and 3 - the first to combust oxygen to a mixture of carbon oxides, and the second to convert those to CO2. Next it is bubbled through lime water to absorb the CO2, and then it is passed through a cartridge containing powdered quicklime to absorb water vapor. All four of the stages mentioned can, as above, be weighed for difference to determine the amounts of the various constituents. The output is a mixture of N2 and argon. It turns out even these can be separated at this technology level! In short, if iron filings are put into molten NaOH sodium metal may be produced (Na floats and hematite - which it would react with - sinks). This may be used to produce lithium metal, and Li reacts with N2 to produce Li3N (which makes ammonia + LiOH when put in water), leaving a "chemical argon" produced at atmospheric pressure and moderate temperature. The water bubbler and quicklime absorber can also be made into an instrument to measure the molarity of solutions via Raoult's law. If a measured amount of air is bubbled through distilled water and then put through the quicklime absorber, the change in weight of the absorber is a proxy for vapor pressure. If the same amount of air (at the same temperature and pressure - assured by doing the second measurement immediately) is passed through a solution, the ratio (change in mass of absorber with water) / (change with solution) gives the mole fraction of water in the solution. The simplest way to get quantitative chemistry off the ground would be to start with the three elements H O Li and three reactions producing three compounds (H2O Li2O LiOH) and six distinct oxidation states (Li Li+ O O2- H H+). i. 2 H2 (g) + O2 (g) -> 2 H2O (g) ii. 4 Li (g) + O2 (g) -> 2 Li2O (s) iii. Li2O (s) + H2O (g) -> 2 LiOH (s) The masses of reactants and products are measured for all three reactions, and also the densities of vapors of H2, O2, H2O, Li, as well as the non-reaction of the compounds H2O Li2O and LiOH with the elements H2 O2 Li. Together with the assumption that the oxidation states do not change in reaction iii, this produces a unique and correct solution that can easily be extended to other elements and compounds. However the difficulty of handling lithium vapor, the explosiveness of reaction i, etc. may make this a less than ideal choice. An alternative involves five elements: Ca H C O Cl and 14 reactions involving 13 compounds (CO2 CO CaO H2O Ca(OH)2 CaCO3 HCl CaCl2 C2H5OH C2H4 CCl4 CaH2 CH4) with 14 oxidation states (Ca2+ Ca O O2- Cl Cl- H+ H H- C4+ C2+ C C2- C4-). i. C (s) + O2 (g,xs) -> CO2 (g) (using a metal oxide to convert CO and subtracting) ii. CO2 (g) + C (s,xs) -> 2 CO (g) iii. CaO (s) + H2O (l) -> Ca(OH)2 (s) iv. Ca(OH)2 (aq,xs) + CO2 (g) -> CaCO3 (s) + H2O (l) v. CaO (s) + CO (g,xs) -> Ca (g) + CO2 (g) vi. CaO (s) + 2 HCl (g) -> H2O (g) + CaCl2 (s) vii. Ca (s) + Cl2 (g,xs) -> CaCl2 (s) (Cl2 from HCl + MnO2 or PbO2) viii. Ca (s) + 2 HCl (aq,xs) -> H2 (g) + CaCl2 (s) ix. C2H5OH (g) + 3 O2 (g,xs) -> 2 CO2 (g) + 3 H2O (g) x. C2H5OH (l) -> H2O (H2SO4) + C2H4 (g) (in hot conc. H2SO4, condensing off EtOEt) xi. C (s) + 2 Cl2 (g,xs) -> CCl4 (l) (w/ S catalyst) xii. Ca (l) + H2 (g,xs) -> CaH2 (s) xiii. CaH2 (s) + 3 H2O (l,xs) -> Ca(OH)2 (aq) + 2 H2 (g) xiv. 2 CaH2 (s) + CCl4 (l,xs) -> 2 CaCl2 (s) + CH4 (g) Measuring the masses of reactants and products, the vapor densities of H2 O2 H2O CO2 CO HCl Cl2 Ca CCl4 C2H4 CH4 and C2H5OH, and finally doing Raoult's law measurements of Ca(OH)2 CaCl2 HCl and C2H5OH to establish ions. Despite the overall milder experimental conditions, the necessary assumptions regarding the oxidation states are more complicated. The assumptions are necessary eventually anyway, and the reward of more difficult reasoning in closing the loop initially is the revelation of a broader array of phenomena. OK, enough about that particular experiment. What is this really all about? I feel there's a certain disconnect in science education. You go into a lab to learn things by taking measurements, but those are all on displays of instruments you could never build with your own hands in a million years. Major discoveries require million dollar machines that no individual understands. Successful scientists understand how to work in this mode and rightly don't consider this problem to be a big deal. But as it happens trust in science among the general public is low and getting lower. I think science education needs to be supplemented with things that counter this tendency. This artificial history excercise is about trying to show what is knowledge in the most basic sense and where does it come from? If you're bored with your scientific life, look around you and think: how would you do that from scratch?