You need to determine three things toreverse-engineer a mix:

When you’re creating your final product, you need to addthings in the right order. Otherwise, your mixture might not mix well, things might precipitate out, you might have a runaway reaction, or any number ofother happenings. A chemical analysis might help you with the first two requirements, butthat last requirement is something that’d rely on knowledge and wisdom.

Unfortunately, unlike the movies, you can’t just plop yoursample onto a scanner and have the computer instantly spit out a perfectanalysis of what and how much. Instrumental analysis is not that straightforward:

Does that sound like a lot of work? It is.

Going back to your question: what equipment you will needdepends on what samples you’re analyzing. In the example of hair dye, I wouldexpect you need to have some common organic solvents, filtration setups, flashchromatography columns, and the glassware required to do some basic workups to separatethe organic dyes from the everything-else. You will also need volumetric equipment to dilute your samples with acceptable precision.

Ideally you’d have a fully functioning HPLC (high pressureliquid chromatography) that you can feed the appropriately-dilutedsample and it’d separate and analyze all the dyes in the sample for you (I knowAgilent has a column that can do this). The silicones common in hair products could probably be identified via GCMS (gas chromatography-mass spectrometry) or FTIR (Fourier transform infrared). Some of the inorganic stuff could probably be identified via ion chromatography. These instruments would need to be set up, supplied with appropriate gases, and calibrated with calibration standards. The samples would need to be prepped, with stabilizing solutions, correct solvents, and internal standards.

Seeing that instrumentation works when the instrument is appropriately chosen and calibrated, suchquantitative analysis really only works when you have some idea of what you’relooking for. If you have a blob of red gel and no idea what it is, this maytake you a while.

As for what would be difficult to source after the apocalypse…this is really hard for me to answer. It’s reasonable to assume that many chemicals, especially laboratory-grade chemicals (which are graded for high purity), would be hard to source after the apocalypse. However, if you’re at the point where you are able to set up chemical laboratories, then perhaps enough time has passed for industry to sufficiently recover. As a reader, I would accept that you can source the ingredients for hair dye if you’re at the point where you can set up a lab to analyze hair dye; the latter has higher standards of purity.

Now, my question to you: do you have to reproduce thissample of hair dye exactly?

Assuming there’s nothing amazing about this particularsample of hair dye, I don’t think it’s worth the effort to exactlyreverse-engineer this sample. Hair dye is also pretty low on thelist of priorities after an apocalypse. If we are at the point post-apocalypsewhere we can think about dyeing our hair, and we have the resources to set upchemistry laboratories correctly and interpret their results, I’m assuming someknowledge from the pre-apocalyptic days survived the apocalypse. Even if theexact formula of your favourite L’Oreal dye didn’t survive, maybe something fromGarnier did, and you can simply reproduce whatever you do have and tweak as yougo along. Or you might just mix the dyes you do have on hand, add in a bit of antimicrobial agent, and call it a day, even if it doesn’t smell as nice or work as well.

Desperate times, desperate measures and all that.

~Z

Disclaimer

Sorry anon, this is a writing advice blog. You could try to conduct informational interviews or use a school career centre if you have access to one.

This is a followup to this earlier question.

In real life we don’t have any super soldiers, so anything involving super soldiers is tripping into Aunt Scripty’s “you break it, you bought it” policy. Hopefully you’ll find the below helpful, but ultimately this is up to you as the writer.

Drugs are supposed to induce a change in your body via biochemical pathways. That’s the point. Modafinil promotes wakefulness through unknown mechanisms (we know it inhibits dopamine transporters and elevates histamine, among other things, but those don’t seem to be responsible for its wakefulness-promoting behaviour), ibuprofen inhibits the cyclooxygenase enzymes, which inhibits synthesis of the prostagladins that mediate pain and the inflammatory response, so on so forth.

But in general, drugs are not supposed to induce a permanent change in your body. If you want enduring effects from your drug you have to keep taking it. There are plenty of drugs we take on a limited duration or as-needed basis, but that’s because the root cause has been addressed or because the drug was only temporarily addressing the symptoms. You stop taking antibiotics because the ones you’ve taken have eradicated your infection. Anti-inflammatories can be stopped when healing–from your body, not from the drug–has progressed sufficiently. Et cetera.

However, inducing Wolverine healing powers or bulletproof skin or whatever is taking a human well beyond their natural capabilities, or adding brand new capabilities altogether. What you’re asking to do is genetic modification via drugs because you want to permanently and dramatically change how this particular human body works. You may not be manually inserting or removing genes from this organism, but you are manipulating (mutating) their genes all the same.

Even if your fictional world is one where scientists know the human body inside and out and understand everything that goes on within it, you would need an astounding number of scientific and medical professionals for the super soldier project. You’d need the biochemists, geneticists, and all their subdivisions, because they would be the ones who know how the human body is supposed to work in its vanilla form. You’d need the medicinal chemists and pharmacologists, because they’d be synthesizing and devising the drug that makes this happen. You’d need the genetic engineers too, as they would be the ones familiar with manipulating genes and genomes. You’d need medical professionals galore: doctors and nurses and pharmacists, technicians and radiologists, to study, stabilize, and treat the subjects whether they succeed for fail. You would probably need a panel of consultants from every area of medical specialty that exists, to help determine whether Drug Trial #652 actually induced observable or meaningful change in any area of the human body. Mutagens often induce cancer so you’d probably need some oncologists to determine the type of cancer, its progression, and its treatment, for documentation’s sake if nothing else (but honestly, you would likely have a lot more failed subjects than successful ones, and from an ethical standpoint they should try to keep their subjects alive to the best of their abilities). Pathologists would perform autopsies to discover any new information in death that the doctors couldn’t obtain in life, with samples from the cadavers sent off for lab analysis. I’m probably forgetting a whole bunch of people too. There are also many people who would never have direct contact with the super soldier subjects but are nevertheless integral to everything running smoothly: the clerks with the paperwork, the janitors keeping everything clean, the facilities staff who make sure the lights stay on and orders the supplies, the maintenance crew who keep the instruments running, the analysts who analyze the samples at their labs, the grant writers obtaining the research grants/cash flow, the IT folks maintaining the databases and computers, et cetera ad nauseum…

For the record, you’d need almost the exact same array of experts for all iterations of the super soldier project. You may have slight variations to the extended team depending on which vector you choose to introduce your new genes. For example, you may swap in virologists for the medicinal chemists and pharmacologists if you decide to use a retrovirus to introduce the new genes. But most of the scientists, medical personnel, and support staff would stay.

And after all that…well, even for fiction, some powers are probably more believable than others. As the writer, you’ll need to decide what kind of super soldier you’re trying to make. What do you want this person to be capable of?

In our current reality we have therapies and drugs that can accelerate healing via growth factors and boosting stem cell production and whatnot. So in a far off future with all the advantages and caveats above, I might be able to believe they’ve enhanced healing capabilities significantly (I mean, I can suspend my disbelief for Wolverine and the Hulk for the sake of enjoying the story, and Marvel doesn’t even try to explain their abilities in the present day). But if you’re trying to make your super soldier breathe fire, then that would involve dramatically changing the human body not just on a genetic/cellular level, but on a physiological level as well, and that’s harder to explain away with any modicum of scientific plausibility.

~Z

Disclaimer

It’s not a bad or stupid ask, anon. Don’t worry about it!

There’s a connection between the three in that the principles of chemistry underlies why things happen the way they do (caveat: there are still many, many things we don’t know about the human body). But if you’re asking whether a character can be an expert in chemistry, biochemistry, and genetic engineering, my answer to that is “probably not.”

Chemistry encompasses the study of the properties, structure, composition, and changes in matter. Since there is a lot of matter, chemistry is divided into many sub-disciplines, which vary in the subject and the scale. A chemist’s specialty can range from the subatomic to the macromolecular. If your character is good at chemistry, you need to ask yourself: “what type?” Being “good at chemistry” doesn’t tell me much (unless you want your character to be a subject matter expert for all of chemistry, which stretches my suspension of disbelief quite a bit).

Biochemistry focuses on the structures, functions, and interactions of biological macromolecules, such as proteins, nucleic acids, carbohydrates, and lipids.  Loosely speaking, biochemistry would be studying the processes that are already there (and we’re still constantly discovering new things, so we’ve hardly exhausted all that biochemistry has to offer)–metabolism, tissue repair, signalling, and much more can all be considered under the (already very broad!) biochemistry umbrella. Biotechnology and genetic engineering, on the other hand, would be manipulating genes and an organism’s genome to do something specific–in this case, create a super soldier with super abilities. Those are two related, but different, focuses.

I suppose if you want to make a super soldier with Wolverine’s healing powers, Jean Grey’s telepathy, and the speed of the Flash you need to know what’s already there before you mess around with improvements. That said, I wouldn’t expect any one person to have all that knowledge, especially with something as complex as a human being (producing super abilities would likely involve manipulating many, many genes at a time, which increases the complexity considerably). It’s far more likely for the super soldier project to be a collaboration between many, many people. Some might be responsible for actually inserting/removing genes, some might be responsible for figuring out what gene X + Y + Z does in a vanilla human, some might study the aftereffects of replacing X + Y + Z with A + B + C and how that translates to actual, observable differences in the human physiology, some might be the ones cleaning up after failed test subjects. There are lots of roles connected to a super solder project. You can decide whether your character is a knowledge expert in what’s already there, if your character will be doing the experimenting, or something else.

~Z

Disclaimer

If you’re trying to come up with somewhat plausible pharmacological action for your drug, you’re better off asking @scriptpharmacist.

Forensics is rather out of our wheelhouse, anon. The excellent @fantasticallyfactualforensics will be far more helpful than us.

Unfortunately for your protagonist, household chemistry is not on her side in this battle. I’m assuming the idea is to spray the reanimated skeletons with the substance (let’s call it Skel-O-Solve™) to either degrade them to the point where they’re no longer mobile, or to weaken them in a way that would make other forms of attack more effective. To do this Skel-O-Solve needs to check a number of different boxes, some of which are almost mutually exclusive:

Finding something that checks the first box requires a basic understanding of the complex biominerals comprising your reanimated skeletons. Bone is best described as a composite material in which hydroxylapatite, an inorganic calcium phosphate mineral with the formula Ca5(PO4)3(OH), is embedded in a matrix of elastic collagen fibers made of the protein ossein. This is a simplified view that ignores most of the components necessary for full biological function, but hydroxylapatite and collagen are primarily responsible for the structure and strength of bone and are therefore the most important targets for Skel-O-Solve.

Starting with the hydroxylapatite, an acidic solution is probably the best way to dissolve it, though the process isn’t entirely straightforward – this review evaluates eight different models of the mechanism and still points out where certain phenomena aren’t fully understood. While pure crystals can be dissolved fairly quickly in concentrated acids, the composite nature of bone hampers the process greatly, as the acid must slowly diffuse through the protein matrix in order to reach most of the hydroxylapatite. A fairly common home science experiment is to place a chicken bone in a jar of vinegar (dilute acetic acid) for at least three days, at which point enough of the hydroxylapatite has been dissolved to render the bone very flexible, owing to the collagen matrix still holding it together. Maybe your protagonist can organize a skeleton swimming league in a pool of vinegar? Though I suppose that would only leave you with bendy skeletons who were less susceptible to blunt-force attacks.

On the other hand, dissolving the collagen matrix is most efficiently done with a strongly basic solution, as strong bases are effective at hydrolyzing the amide bonds holding the protein together. If you can completely degrade these bonds, bones will become very brittle and the remaining hydroxylapatite will crumble into dust. Unfortunately this takes rather a long time and usually requires a significant amount of heat as well – in the process of alkaline hydrolysis (an alternative to traditional cremation or burial), it takes about three hours at 160 °C in a pressurized vessel to complete the process with a concentrated solution of sodium hydroxide. However, if your protagonist can convince the skeletons to climb into confined spaces, I would recommend tricking them into a trash-compactor or a wood-chipper instead – it would be faster.

While strong acids and bases both check box number one for effectiveness, they fall short on box number two for efficiency. I’m loath to leave your protagonist without any solutions to her problem, but anything that could possibly work in this type of situation would be extremely difficult/dangerous to acquire and would almost certainly kill your character faster than the skeletons could. Unfortunately, Skel-O-Solve just isn’t a thing at this point in time.

~J

Disclaimer

The answer to this question will depend on your exact definition of “powerful” and whether or not you need something that is commercially available. There is actually a numerically defined Strongest Base™, but you’re going to need to be writing about some fairly advanced chemical research before any of your characters might encounter it, though I suppose it could be useful as a tidbit of trivia.

Before we get to the actual Strongest Base™, it would be prudent to briefly review the defining characteristics of a chemical base and to discuss how basicity is measured. Here I will be using Brønsted-Lowry acid-base theory to define a base as a substance that can accept a proton from an acid, which in turn is anything that can donate a proton to a base. Upon accepting a proton a base becomes a conjugate acid (because now it has a proton that it could in theory give to something else), and acids that give up protons become conjugate bases.  It may seem recursive, but it works – the generalized reaction looks like HA + B ⇌ A- + HB+. As an example, dissolving large quantities of ammonia (NH3) in H2O can be described as NH3 (aq) + H2O (l) ⇌ NH4+ (aq) + OH- (aq). In this case NH3 is a base that becomes its conjugate acid NH4+ by accepting a proton, while H2O is an acid that becomes its conjugate base OH- by giving up a proton. The strength of a base can be measured a few different ways, but we’ll focus on the pKa of the conjugate acid, and when that fails us we’ll look at the absolute proton affinity.

In the generalized equation above for a Brønsted acid, the equilibrium constant (a measure of how far the reaction proceeds to one side or the other) is referred to as the acid dissociation constant, Ka. This is a decent quantitative measure of the strength of an acid or base in a solution – an acid that dissociates completely has a very large Ka, while the conjugate acid of a base that dissociates a negligible amount and has a very small Ka. These constants theoretically vary over more than 130 orders of magnitude, and to avoid writing a ridiculous amount of zeros chemists have defined the negative logarithm of the constant (i.e. -log10Ka) as pKa, reducing the span of numbers we have to deal with down to a range from around -60 to +70. Lower pKa values denote stronger acids, while higher values denote weaker acids (meaning the conjugates are stronger bases). The NH4+ cation has a pKa of 9.25 which makes NH3 a weak base in water, while the pKa for HCl (a strong acid) is somewhere around -6, though it is very hard to measure accurately. In aqueous solutions there is something known as a leveling effect – any acid stronger than water will simply donate a proton to create the hydronium ion (H3O+), and any base stronger than water will abstract a proton and generate the hydroxide ion (OH-). As such, H3O+ (pKa = -1.7) and OH- (pKa of H2O = 14) are respectively the strongest acid and base that can exist in water. A pKa lower than -1.7 is a strong acid (like HCl), while a pKa higher than 14 indicates a strong base. These substances can’t be measured experimentally in water, but through the use of other solvents or theoretical calculations there are ways to measure or estimate the pKa of very strong acids or bases.

The strongest acid known to modern science (which may or may not be what you know as the most powerful acid) is the helium hydride ion, HeH+. It forms during the radioactive decay of tritium, and it has an estimated pKa of -63. Recall that the pKa scale is logarithmic, so that makes it roughly 1057 times more acidic than HCl. On the other end of the spectrum you have things like the isobutane anion (C4H9-), where the estimated pKa of its conjugate acid isobutane (C4H10) is 71, making it approximately 1057 times more basic than OH-. Unfortunately for chemists who would like to rip hydrogen atoms off of pesky organic molecules like benzene, you can’t actually use the isobutane anion by itself under bulk synthetic conditions – the closest you can really get is taking isobutane and replacing one of the hydrogens with lithium, creating your suggested strong base t-butyllithium, or t-BuLi for short.

Despite t-BuLi having a partially ionic bond between the lithium and the alkyl group, it doesn’t behave in quite the same fashion as just the isobutane cation and the effective pKa is estimated to be ~53. This is plenty strong enough to grab a proton off of most organic molecules, but it still won’t work for benzene. There is a more active mixture called the Lochmann-Schlosser base, which is made from n-BuLi (the straight-chain version of t-BuLi) and potassium t-butoxide (t-BuOK). This base will deprotonate benzene, but there aren’t any good estimates of its pKa because the actual reactive species in the mixture is not fully understood.

As a brief departure from the wonders of acid-base chemistry, I must point out that the compounds included in this casual discussion are extremely dangerous to work with. For most chemists in need of a strong base, a trip to the reagent cabinet to grab the bottle of sodium hydroxide (NaOH) is all that is required. It comes as solid pellets and other than being caustic there aren’t too many safety considerations -- it’s even available to the general public as lye, usually to be used as a drain cleaner. If an inexperienced chemist were to pry the sure-seal septum cap off a bottle of t-BuLi and pour some out, the contents of said bottle would immediately erupt into a catastrophic fireball and the unfortunate individual would be lucky to survive the event. All work done with these reagents is performed under some kind of inert atmosphere, usually nitrogen or argon, in order to prevent violent reactions with oxygen and moisture in normal air. While a full description of proper air-free technique is way beyond the scope of this ask, be aware that any handling mistakes (dropping a bottle, pressurizing the wrong cannula, pulling the plunger out of a syringe, etc.) could put your characters and anyone nearby in a hospital (or worse) and potentially burn down the fume hood, lab, or building. These materials are not to be taken lightly, and tragic accidents have caused numerous injuries and claimed lives in the real world.

Now back to our search for the Strongest Base™ -- in terms of practical use in a laboratory, t-BuLi and the Lochmann-Schlosser mixture are the strongest bases you can get, but they are not the strongest bases known. To go even stronger one has to abandon solution chemistry and go straight to the gas phase, where some very unstable compounds can be trapped and analyzed. In these cases the pKa doesn’t really apply, so instead chemists will calculate the absolute proton affinity (PA), or the amount of energy released when a base accepts a proton in the gas phase, with higher values denoting stronger bases. As a point of reference the weakest base known is helium (He + H+ ⇌ HeH+) with a PA of 178 kJ/mol, and the value for water is 690 kJ/mol. The isobutane cation has a PA of ~1730 kJ/mol, and there are very few things that can top it. For a long time the most basic substance known was the methanide anion (CH3-) with a PA of 1742 kJ/mol, until it was displaced in 2008 by the lithium monoxide anion (LiO-) with a PA of 1782 kJ/mol. This too was beaten just last year by the ortho-diethynylbenzene dianion (o-DEB2-), which has a PA of 1843 kJ/mol.

So there you have it – if you want the Strongest Base™ and you don’t care if it can only exist in the ion trap of a mass spectrometer, the answer is the ortho-diethynylbenzene dianion. Your research did in fact lead you to the strongest base you can buy (t-BuLi), though mixing n-BuLi and t-BuOK to get the Lochmann-Schlosser base is slightly more potent.

~J

Disclaimer

Henbane belongs to the Solanaceae family and many of its members have a type of compound called tropane alkaloids. Henbane in particular contains the tropane alkaloids atropine, hyoscyamine, and scopolamine, all of which areanticholinergic agents (inhibit the neurotransmitter acetylcholine), thus affecting the parasympathetic nervous system.

These alkaloids can be incapacitating in doses as small as 10 mg, though as with all drugs, the effect is dependent on the size of the person ingesting it. As these chemicals affect the parasympathetic nervous system, overdoses can affect the heart, salivary glands, sweat glands, GI tract, and others. The list of symptoms is quite long, and depending on the severity of overdose, (a non-exhaustive list of) symptoms can include dry mouth, fever, urine retention, hallucinations, seizures, tachycardia (rapid heartbeat), and finally death.

All of the above-mentioned alkaloids are also prescription drugs marketed under a variety of names. @scriptpharmacist may have further information on the pharmaceutical uses and dosages of these alkaloids. 

~Z

Disclaimer

Molten lava is quite hot, usually in the range of 700 - 1200 °C, but it’s not actually very difficult to find a material that will withstand this temperature. For instance, I set the Dynamic Periodic Table to display melting points with the temperature set to 1200 °C (1473 K).

All of the elements that aren’t blue will still be solid at 1200 °C, though I’ve highlighted tungsten because its melting point of 3422 °C is the highest for any pure metal. Platinum (1768 °C) and tantalum (3017 °C) are easier to work with and are used for high-temperature crucibles more often than tungsten, but you could also use just about any type of steel (~1300 - 1500 °C) and still not have to worry about melting.

There is one other thing you might want to consider – radiant heat. Molten rock radiates a huge amount of thermal energy, which in turn heats up anything nearby. Volcanologists have to wear heavy-duty protective garments when working near active lava flows, and even then the intense heat limits how close they can get. The following video demonstrates (on beef steaks) just how much heat you can get from a relatively small amount of lava.

The lava never touches the steaks, but it very quickly cooks them all the way through. The flames are actually from the fat cooked out of the steak, burning vigorously as it runs down onto the lava.

I will assume that your transformable character won’t have any issue with this, being able to turn to metal and all, but the other character will want to get away from the lava as quickly as possible to avoid being cooked.

~J

(Edit: New link to the lava-steak video -- the old one was taken down.)

Disclaimer

As per the oft-quoted fire triangle, a fire requires oxygen, heat, and fuel. Assuming the air in your world is anything like the stuff we’re used to, the atmosphere will be about 78% nitrogen and 21% oxygen, so that takes care of the oxygen. Your sorcerers have somehow tricked the laws of physics into letting them heat things up at will, so that gets heat out of the way too. There might be a few ways to provide the necessary fuel, and these range from “downright practical” to “fraught with danger” to “inescapable doom.” Let’s consider each in turn, and then you can pick what you like best for your story.

Before we begin, there are a few world-building things we’ll need to take into consideration, specifically regarding the mechanics of how sorcery works in your story. I’m going to assume that sorcerers are not immune to fire/heat, and engage in otherwise normal behaviors like breathing oxygen in order to survive. If this is correct, then you’ll need to keep in mind that creating a large amount of fire around them could consume all available oxygen and cause them to suffocate. If the sorcerers can happily dance a jig in a bonfire without a care, then asbestos/fiberglass/nomex clothing + oil = scary flaming fire mage.

Some other questions you will need to answer for yourself might include:

Now, onward to the burning!

For the downright practical route we can look to stage magic and theatrical flame effects, as there are many illusions that require a performer to produce fire out of nowhere. While propane is usually used for impressive plumes of flame, the storage and delivery systems are generally large, heavy, and not very portable. When a magician only needs a small amount of fire, the fuel of choice is nitrocellulose.

Cellulose is a sugar polymer (polysaccharide) made by chaining together glucose molecules, and it is the primary component of cell walls in green plants. As it is the main component of things like wood pulp and cotton, it is used to make things like paper and cloth, and with a little bit of chemistry it can be turned into something that burns with great enthusiasm. Any source of cellulose (tissue paper, cotton, string, etc.) can be nitrated by exposing it to concentrated nitric acid, converting it from (C6H10O5)n to (C6H7(NO2)3O5)n. The process itself is extremely dangerous and should not be attempted in an uncontrolled setting, and the resulting nitrocellulose, while moderately stable, is also known as gun cotton for a reason. It is used in stage magic because it is easy to ignite with a small flint-wheel mounted on a ring, it burns very quickly with a highly visible flame, and it produces a relatively small amount of heat, allowing performers to ignite it in their hands without suffering from thermal burns. Your sorcerers could carry around a supply of nitrocellulose and then heat it up to the ignition temperature whenever they needed some fire, but they would need to be fairly careful to avoid accidentally igniting the rest of it.

Moving on to fuels that are potentially fraught with danger, we can perhaps make better use of your sorcerers’ ability to magically heat objects at will. While I definitely would not recommend the use of liquid fuels like oil – they spread far too easily and the fires would very quickly get out of control – something like paraffin candle wax might work nicely. It should be readily available and easy to carry, and it could be cut into small chunks that your sorcerers could throw wherever they needed fire. The auto-ignition temperature is somewhere between 200-350 °C and the boiling point is slightly above 370 °C, and if magical heating can reach these temperatures then it wouldn’t be too much of a stretch to toss a wax cube into the air and have it explode into a large ball of flame. You might run into trouble if you used too large a chunk of wax, as fast heating could cause molten/flaming wax to fly in all directions and start collateral fires or cause nasty burns to anyone in the vicinity.

Finally, we must discuss one option that can only lead to inescapable doom – using the air itself to achieve similar effects. Neither nitrogen nor oxygen will burn under normal circumstances, but if you’re willing to go to extremes and your magical heating doesn’t have an upper limit, there’s some weird chemistry and physics that starts to happen at ridiculously high temperatures. Let’s consider what would happen if your sorcerers started heating the air around them (and for a loosely related and more thorough treatment, see Randall Munroe’s Hair Dryer What If?). Once the air reaches about 525 °C it will become incandescent and glow a dull red, though it won’t be very visible until much higher temperatures. Between 1000-1500 °C it will be yellow- or white-hot, and the nitrogen will actually start reacting with oxygen to give various NOx species. This was the basis for an obsolete method to produce nitric acid, and the toxic fumes would not be great for anyone nearby. If you were to continue upwards to 30,000 °C you would start dissociating nitrogen molecules into individual atoms, and by 60,000 °C chemical bonds essentially cease to exist. Up over 100,000 °C you can start to ionize the atoms into a plasma by sheer thermal energy alone, but by that point (or significantly sooner) your sorcerers would have been well and truly cooked; furthermore, releasing that kind of energy into the environment would look a lot more like an explosion than a fire, assuming anyone survived to see it.

Given those options I might suggest carrying around a few extra candles, but if your sorcerers are in need of flames and must decide between the clothes on their backs and the air around them, setting fire to themselves is probably the more survivable option.  You could also have them magic up some phlogiston, but I’ll leave the use of superseded scientific theories up to you.

~J

Disclaimer

This is really more of a physics ask, but what the hell. Let’s talk about pressure.

Pressure is defined as force per unit area. We are talking here about air pressure, which can basically be thought of as air molecules bouncing around, exerting force onto the things–you, buildings, other objects–around them. Air pressure is affected by

Let’s call the area of interest the system and everything else the surroundings.

When you change the pressure of a system in relation to its surroundings, you create a pressure differential. If you have an airtight, closed system in which matter may not enter or exit, you maintain this pressure differential until the closed system is opened (whether that is by your choosing or by failure of the vessel). Gases (air) are highly mobile and will rush from an area of higher pressure to an area of lower pressure. Dramatic effects, if any, occur as the pressure equilibriates between your system and its surroundings; the degree of drama is dependent on how large the pressure differential is and how quickly the system and surroundings equilibrate. (If the vessel containing your system remains closed and impervious to the surroundings, and does not fail in any way even after you increase or decrease its pressure, then nothing really happens. Carry on.)

So what happens when you rapidly decrease the pressure in a system? Consider the following options:

1) You have increased the pressure of your system, then opened the system to equilibrate with its surroundings. This can be subdivided up into the change from 1a) normal atmospheric pressure (1 atm) to something below that, or 1b) from very high pressure (many atm) to atmospheric pressure (1 atm). In both cases the pressurized air from your system will vent outwards to the lower-pressure surroundings, and the air pressure of your system will decrease until the system and its surroundings reach equilibrium.

1a) A change from 1 atm to something below. The most extreme example in this category is the change from atmospheric pressure to a vacuum (pressure difference: 1 atm), which is encountered in space; less extreme examples include depressurized airplane cabins in mid-flight. Aside from the outward rush of air from your system (space shuttle, plane cabin, etc) to the surroundings, there will be some adverse effects to humans from the decompression of dissolved gases in our bodies. Effects range from swelling of tissue, hypoxia, unconsciousness, and lung barotrauma. But human skin is fairly stretchy and humans will not explode from a change of even 1 atm, never mind less than that.

1b) A change from many atm to something approaching 1 atm. This usually doesn’t occur except in very specialized environments. The most notable example of this is the Byford Dolphin incident where there was a dramatic change in the system’s pressure from 9 atm to 1 atm (pressure difference: 8 atm) in a fraction of a second (note: DO NOT google this if you are squeamish. There are pictures). Such a drastic decompression will result in an explosive blast of air outwards toward the surroundings; unsecured objects (including human bodies) become projectiles, gases (including gases within the body) rapidly expand, leading to boiling blood, ruptured organs, violent dismemberment (when forced through too-small spaces), and death.

2) You have decreased the pressure of your system, then opened the system to equilibriate with its surroundings. The higher-pressure air from your surroundings will rush into your system, and the pressure of your system will increase–essentially, the reverse of the previous scenario. You will get something resembling an implosion.

The severity of the implosion will depend on the pressure differential between your system and surroundings. On Earth, the air pressure at sea level is one atm, and thus the worst you can do is drop your system’s pressure to 0 atm, i.e. a vacuum (pressure difference: 1 atm). At a pressure differential of 1 atm or less, humans in the lower-pressure system are unlikely to be strongly harmed by the incoming rush of air, absent physical trauma or other projectiles (though the same cannot be said of structures; even with a small pressure differential, you’ll very likely shatter some windows at least). However, even at equilibrium with the system, humans will suffer adverse effects from decreased atmospheric pressure. An example of this is found in high-altitude mountaineering: 0.5 atm (5000 m above sea level) is about the lowest air pressure humans can tolerate without supplementation, and you begin to run into various symptoms of altitude sickness. The risk of pulmonary or cerebral edema rises as surrounding pressure drops. At 0.35 atm (8000 m above sea level), the amount of oxygen dissolving into the blood is insufficient to sustain life. At 0.03 atm (0.38 psi), water will boil at room temperature, though nobody will be alive to appreciate it.

It also goes without saying that if your story is not set on Earth and the atmospheric pressure of the surroundings is much higher, you could have a much more dramatic implosion, in addition to the effects of low atmospheric pressure on humans.

Final thought: you need to consider how you are going to create and maintain a pressure differential in your system (in this case, your building) in order to have a dramatic effect.

Recall that gas (air) pressure is typically changed by manipulating temperature, volume, or number of molecules. Those are what you have to work with if you simply want to manipulate the air pressure on its own, without introducing a chemical explosive (which provides an explosive effect on its own), magic, or other external factor.

Your regular building isn’t going to be airtight and is not designed to be able to build a significant pressure differential. Air flow is a good thing within buildings, and the movement of air is inevitable, what with air gaps, void spaces, hollow partitions, service chases, fans, ducts, AC systems, and the like. There is also a large volume of air within a building. The air pressure won’t be perfectly uniform; you will have slight variations (this is why your Fitbit’s altimeter can detect when you climb a flight of stairs). But overall, whether you choose to dramatically crank up the heat (increase temperature), pump a lot of compressed gas into your building (increase the number of molecules), or fire Mr Freeze’s freeze gun around (decrease temperature), you will be hard pressed to produce a significant pressure differential over so large an area.

Also, most buildings are not built to withstand large overpressures. Since your average building can’t build up that kind of pressure differential the point is moot, but should you decide to handwave the pressure differential into your story anyway, you will expect a lot of structural damage when the pressure differential is high. Per J’s recent post, at an overpressure of 20 psi concrete buildings are severely demolished; if you did handwave the 8 atm (117.6 psi) pressure differential into a building in a fraction of a second with the resulting pressure wave, I have no hope of your average building remaining standing afterward.

~Z

Disclaimer

Edited to correct my typo: the pressure at which water boils at room temperature is about 0.03 atm, not 0.06 atm. Sorry!

A disclaimer up front – this post is going to deal with the topic of an individual being killed in an explosion-type accident. I’m definitely not going to show you any pictures of that kind of injury, and I won’t even be giving detailed descriptions (that’s @ScriptMedic’s gig, and the topic has already been covered), but I wanted to give everyone a fair warning before proceeding.

This is quite an interesting ask because the scenario you’re aiming for is actually fairly difficult to produce; you need enough oomph™ to get a person in motion, but it needs to be a controlled and directed oomph™ because I’m assuming that after the character is thrown you’d like there to be a body, a building, and potentially even some witnesses left to tell the tale. First we should take a moment to discuss what an explosion is, and the different sorts of explosions you can get from chemical reactions; then we’ll move on to how they might affect the surroundings and an unfortunate individual who happened to be nearby. Finally, I may be able to offer some advice as to how to throw your character and still have them be recognizable at the end of the scene, though it’s going to take some careful planning to do it in a realistic fashion.  

Just so we’re all on the same page, an explosion is a very fast release of stored potential energy, with most of it being released as heat, light, sound, and pressure. Chemical explosives are usually compounds that decompose to release a lot of heat (energy from chemical bonds) and large volumes of gaseous products like nitrogen; the rate of this decomposition plays a large part in how useful a material is as an explosive. So-called ‘low explosive’ compounds decompose by deflagration, meaning that the reaction travels through the material slower than the speed of sound; low explosives include things like gunpowder, pyrotechnics, propellants (propane/gasoline), and many other mixtures of fuels and oxidizers. If the reaction propagates faster than the speed of sound, you have a ‘high explosive’ material that decomposes by detonation. As an example, let’s take a look at something called detonation cord (det. cord), a thin flexible line filled with the high explosive pentaerythritol tetranitrate (PETN). Below is a setup where a bullet is fired from right to left, activating an electronic trigger connected to the end of 16 feet of det. cord. (FullMag’s full video can also be found here.)

PETN detonates at 24-28,000 ft/s, so in the time it takes the bullet to travel the remaining 2.25 feet to the target (moving around 2800 ft/s), the reaction front of the explosive travels 16 feet to catch up with it. If you look closely, you can also see the blast wave from the newly formed gases expanding outward after the explosion – look for the ripple in the air at the top of the frame, or for the wave of dust knocked off the right-hand cinder block as the concussive force of the shock wave moves past it. This high-pressure, high-velocity wave of compressed gas is what causes most of the damage associated with an explosion, but unfortunately we’re going to run into a slight problem if we try to use an explosive to throw a person – humans are relatively small and squishy, which makes them extremely resilient to pressure waves and able to survive much more than you might expect. Here’s one more explosion gif to demonstrate how this works (and this time it’s a splodey-melon):

There are a few things to take note of here, besides the complete lack of eye protection – if the chunk of watermelon rind that struck his head was two inches lower down, that eye may very well have been lost. First and foremost, the individual pictured was completely unharmed by the pressure wave, and the melon shrapnel luckily only caused a welt; you can see the full clip here. However, if you watch the edge of the table you can see it flex down with the pressure of the explosion, and if you look really carefully you can see chunks of debris knocked off the bottom side of the table at very high speed (through a process called spallation). When a pressure wave encounters a solid object, it deposits some of its momentum as kinetic energy and is then reflected off the surface; that energy must either be absorbed or dissipated by the solid, and if the solid is rigid it will crack and crumble. If the solid is squishy and flexible (like a person), it can deform slightly to both absorb and dissipate energy without shattering and falling apart. This table compares damage to structures and humans at various peak blast overpressures in the frame of mining explosions; at peak overpressures of 5 psi, only 1% of humans exposed will even rupture an eardrum, but at this pressure most buildings will collapse. Real-world mining explosions that reach 5 psi overpressures do in fact cause many injuries and fatalities, but it isn’t the pressure that kills – it’s the shrapnel and the blast wind that accompanies large-scale explosions. The other factor protecting a person is the fact that humans have a relatively small surface area when compared to things like tables or walls or buildings, so only a fraction of the explosive energy from a pressure wave can even be absorbed by a person to begin with. In order for enough energy to be transferred to a person to throw them across a room, the explosion needs to be massive.

So what does this mean for your character and their exploding potion? If you want the actual explosion to throw them, you’re going to need something huge; it’s going to take out the room, probably the floors above and below it, and maybe even the entire building/wing of the dungeon. An explosion of this scale involves forces far greater than those holding the body together, so if the character is near the center of it then there isn’t going to be much left at the end; to get this effect from something the size of a potion would also require military-grade high explosives, and they’re not the sort of thing you make accidentally.

There is perhaps another way to achieve the same effect, but with a much smaller explosion – it’s even a plausible accident that could occur in the real world. Consider that fact that the amount of energy in a small firework, which can turn a watermelon into a vapormelon without injuring a person sitting a few feet away, is more than an order of magnitude larger than the energy required to fire a bullet from a gun. The difference here is how the explosion is contained; with the melon it expands in a spherical wavefront and can bounce around and reflect off of things, but with the bullet the explosion is funneled down the barrel, propelling a single piece of shrapnel to a very high velocity. If you can contain the explosive energy of your potion and channel it into a heavy, solid object, it could easily strike your character and carry them across a room, killing them in the process through blunt force trauma.

Perhaps your character was preparing something in an iron cauldron over a small open fire, and instead of grabbing that vial of Horklump juice they accidentally grabbed the hydrochloric acid. Iron (and a number of other metals) will react with hydrochloric acid to produce iron chloride and hydrogen gas; the reaction isn’t particularly fast or violent, and the gentle bubbling and yellow color of the solution might not even be noticed in the bottom of a black cauldron. If your character were to put a heavy iron lid on top and let it simmer for half an hour, quite a lot of very flammable gas would build up, but as long as the lid remained in place it wouldn’t be able to come into contact with an ignition source.  Your character returns and grabs the next ingredient, but as they start to lift the lid off, hydrogen can escape into the room and oxygen from the air can diffuse into the cauldron. The escaped hydrogen is ignited by the small open fire, and it quickly flashes back towards the cauldron, snaking down under the lid where it meets an ideal mixture of hydrogen and oxygen. This results in a powerful explosion with almost all of the force being directed straight up into the iron lid; it takes off towards the ceiling and strikes your character’s head or torso on the way, causing them to fly back and collapse in a heap.

This is just one way to spin this unfortunate tale, but it would give you a plausible potion accident with a readily available material, and it could cause an explosion that (indirectly) kills your character and sends them flying across the room. You could even have any number of people standing around with ringing ears who are otherwise uninjured, and besides that dent in the ceiling you haven’t done much structural damage.

Of course it goes without saying that you are always free to exclaim “MAGIC” at any point to either augment or supplant chemistry and physics, but going that route is entirely beyond the purview of my expertise.

~J

Disclaimer

First, let’s just get this out of the way – heroin is bad. Making it is bad. Please don’t.

Now more to the point, whether or not it is reasonable for your characters to be making their own heroin will mostly depend on the acquisition of two things: the necessary raw materials/equipment, and the knowledge of what to do with them.

As for the raw materials and equipment, your characters will most likely run into one of two hurdles, depending on which synthetic methodology they are pursuing. The first route, and where most of the heroin in the world actually comes from, is deriving it from the opium poppy. If your characters are somehow in a position to be receiving shipments of this illicit substance, they’re also likely to be able to come across the knowledge of what to do with it – see below. The other route is to take commercially available pharmaceuticals with related active ingredients, like morphine or codeine, and add or remove functional groups (small pieces of the molecule) to end up with heroin; all three compounds have the same general structure, with the only difference being the functional groups bonded to two oxygen atoms. In morphine they both bond to hydrogen to make hydroxide (-OH) groups, while in codeine they bond to one hydrogen and one methyl (-CH3) group; heroin has two acetyl (-C(=O)CH3) groups. As you might be aware, almost everything containing morphine or codeine (both narcotics) either requires a prescription or is otherwise strictly controlled, and a group of young adults without prescriptions are going to need to befriend a morally bankrupt doctor or steal the heavier-duty pharmaceuticals (talk about a fast-track to jail). Some countries allow the sale of over-the-counter products that contain narcotics in low concentrations; most will keep the products locked up behind the counter and require purchasers to provide identification and sign a log-book, and even still they restrict the number of purchases in a given period of time. Trying to get these products in large quantities is not only going to be extremely expensive, it is also quite likely to get them blacklisted or outright earn them a visit from local police asking why someone would need five gallons of cough syrup every other week.

As for materials, let me just say that people are very good at repurposing everyday items to do what they need. The Federal Criminal Police Office of Germany once had the opportunity to send two forensic chemists and a police officer to observe an authentic heroin manufacturing process in Afghanistan; the full report is available online, but suffice it to say that there wasn’t any fancy or specialized equipment available. That didn’t stop two self-described ‘illiterate farmers’ from making 4 Kg of white heroin hydrochloride (at a higher purity than most drugs seized by police elsewhere in the world) from 70 Kg of raw poppies over the course of two days. If your characters try to go the pharmaceutical route they will likely be able to improvise the equipment, but getting their hands on several of the necessary reagents will be difficult. It just so happens that most governments know what people use to make heroin, and place the ‘key ingredients’ under strict regulations. Your characters would also need gather some strong acids and bases, and potentially one or more materials that are toxic, flammable, and water-reactive.

This brings us to the second part of what your characters need – the knowledge of what to do with the raw materials in order to get heroin out of them. I’d like to point out that this doesn’t necessarily have to be knowledge of the chemistry involved in the process; as mentioned above, the two individuals making heroin on a commercial scale described themselves as illiterate, and had absolutely no scientific training whatsoever. What they did have was someone to give them a recipe and teach them how to follow it. When your average baker successfully makes a lemon meringue pie, they have no idea what kind of chemistry is going on underneath (and to be honest I have relatively little idea myself, being an inorganic chemist), but that doesn’t stop them from making a delicious pie.

So if your characters have access to raw materials, simple equipment, and someone to teach them what to do, they might be able to pull it off. They might also end up in a hospital with horrifying chemical burns. If they do succeed, the final product will probably be toxic and definitely be illegal, but that isn’t always enough of a deterrent.

One final thing to consider – if anyone happens to observe your characters in any part of the process, you’re going to need to contend with either evading the authorities or having your characters get caught and dealing with the consequences. The manufacture of illicit substances isn’t taken lightly, and in most places the legal penalties for even being associated with this kind of activity are extremely harsh.

~J

Disclaimer

This is more of a general physics question than a specific ask. Are you asking about decompression effects for humans? Are you talking about depressurization of an airplane cabin? Are you talking about a faulty gas cylinder? Depending on the subject, the answer can range from clinical and scientific to incredibly morbid (and we’re not authorities on the latter).

Please clarify your ask! If it’s chemistry-related, we’ll answer as best we can, otherwise we can redirect you to another ScriptX blog if need be.