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Ideas for popular science experiments

There are many science fair experiment ideas online. The following may be repetitions.
A windmill connected to an electric generator, which is connected to a lightbulb (small dimmable is best). Blow on the windmill to turn the light on. A separate generator similar to the one attached to the windmill, which can be cranked by hand to turn on the lightbulb. An electric fan that can blow on the windmill, with power consumption at the fan and power production at the windmill measured and displayed. This explains efficiency losses in power generation.
Pressure of light. A piece of paper attached vertically on a platform that can rotate at low friction. On one side of the rotation axis, the paper is painted black, on the other, it is white. Reversed on the opposite side of the paper. Transparent dome over the setup to prevent air currents interfering. Shining a light on the paper makes it rotate, because the pressure on one side is greater. The rotating platform can be a polystyrene disk floating in water.
Pulleys and gear ratios. A bicycle with gears, rear wheel removed, but axle in place. Rope attached to axle, weight to rope. Rotating the pedals lifts the weight. Different gears require different number of rotations to lift the weight to a given height, but the more rotations needed, the less force needed for the rotation. Explain why low gears on a bike should be used when starting and on uphills, but high gears on downhills.
Moving pulleys: the distance the rope has to be pulled becomes longer, but the force required to pull becomes smaller to lift a given weight a given distance.
Friction in braking. Several bicycle wheels with brakes attached. Some rims are dry, some wet, some oiled. Feel the braking force required to stop each. To provide the force that the brakes must counter, a weight can be attached to each wheel. Rotate the weight away from the lowest point of the wheel and try to use the brakes to prevent the weight from sinking to the bottom again.
Friction in accelerating. Old bicycle. Rotate the pedals to accelerate the rear wheel to a given speed (measured with a bicycle speedometer) when the chain is dry, or oiled, or sand is poured on the chain. Feel the different difficulty depending on the condition of the chain. Several bikes is better, so the chains in different condition can be compared.
Friction and heat: a fire drill. Rotate a sharp stick in a hole in a piece of wood – the hole blackens and starts to smoke.
Ball bearings. Stack two blocks, put weight on the top one, try to rotate the bottom one. Now the same blocks with two ball bearings, one between the ground and the bottom bearing and the other between the two blocks. Much easier to rotate the bottom block. Explain how rolling friction is smaller than dragging friction. Friction proportional to pressure. Friction related to surface area.
Tire pressure and friction. Bicycle wheels (preferably with identical rims, hubs and spokes) with different width tires on them. Measure the friction of the tires by the force required to rotate them at a given speed on some surface, with the tire bearing weight. A stationary bicycle trainer can be used. Which tire width gives the lowest friction? Research shows that 22-23 mm tires have the lowest friction under the weight of an adult cyclist. Deflate the tire, measure the friction. Inflate, measure the friction. Which inflation pressure gives the lowest friction? Research shows that it is not the maximal pressure, unless the surface on which the wheel rotates is very smooth.
Mining and ores. Different rock samples of various ores. Panning for “gold”: try to find a shiny grain hidden in a quantity of mud or sand.
Solvents. Pebbles or small toys mixed in sugar paste or syrup, which is then dried into blocks. Use water to dissolve the sugar and discover what is inside the blocks.
Leidenfrost effect. Air hockey table with air being pumped under the hockey puck. Compare to droplets of liquid nitrogen rolling on a warm surface. Compare to pancakes riding on the steam bubbles under them on a hot pan.
Bridge of spaghetti. Dry spaghetti can be attached to each other with small balls of dough (flour mixed with water). Then bake the spaghetti-and-dough construction to harden the dough. Check how much weight the bridge can carry. Compare the breaking weight for a bridge (triangularly connected spaghetti that look like high-voltage power line towers) to the breaking weight for a bunch of horizontal spaghetti. The bridge can also be made by glueing matches or toothpicks.
Detergents. Lightly grease some cloth that normally absorbs water. Put water on top of that cloth – droplets form and nothing leaks through. Put water in a cloth bag and show that it does not leak. Compare to ungreased cloth that lets water through. Add detergent to the water on the greasy cloth. With the right coarseness of cloth, amount of grease and detergent, the water should start leaking through.
A burner under a thin paper box filled with water. The paper does not burn and does not become soggy, so the water does not leak through.
Absorption and radiation. Heat lamp shining on a black and white rock. Which becomes warm first? Now heat the rocks by contact, e.g. in warm water. Which rock cools down first? Infrared laser thermometer may help confirm temperatures. Or an ordinary thermometer inserted in a hole drilled in the rock.
Hot air rises. A nonflammable parachute rises above a candle. The parachute could be of thin tinfoil. It should have a light weight attached below the canopy to keep it upright. A tinfoil pinwheel can be held above the candle – it starts to rotate in the updraft of hot air.
3D printing by hand. Mud dripped from a hand onto sand or another surface that lets water through easily. The water soaks out of the droplets of mud that hit the surface, leaving a series of solid bumps of mud. Drop another droplet of mud on top of the bumps – water soaks out again, the bumps are now higher. Use this technique to build walls, castles etc.
Internal combustion engine. A rotating shaft with two pistons attached (can be made of wood or some other cheap, light, strong enough material). A balloon under each piston. If two people rapidly inflate and let deflate the balloons in the right sequence, then the shaft starts to rotate. Also a great party game – which couple gets their motor running fastest? The balloons can also be inflated by a hand pump, but fast and well-timed deflation is then a problem. One end of a long snakelike balloon can be under the piston, the other end squeezed and released by hand. The right sequence of squeeze and release can make the shaft rotate. One person can hold two long balloons, so can rotate the engine alone. A single piston is enough to rotate a wheel if attached to the rim – this is the arrangement in some old steam locomotives and foot-pedalled Singer sewing machines.
Steam power. Electric kettle boiling water, with a small windmill above the spout. The steam rising from the kettle rotates the windmill. Measure the power generated by the windmill and compare to the electricity required to heat the kettle.
Electric motor. Hand generator produces electricity, which is led by wires to an electric motor, which starts to rotate. Or the electricity is led to a coil with a permanent magnet inside. The magnet starts to move when the hand generator is cranked. With the right speed of cranking, an alternating current can make the magnet rotate.
Water mill. Pour the water at the top of a halfpipe. A waterwheel in the halfpipe starts to rotate in the flow. The rotation can drive a small generator which lights up a tiny lightbulb.
Archimedes’ screw. A helix in a pipe that is slightly tilted from horizontal can be rotated to pump water up the pipe.
Connected vessels. Two cups of water at different heights linked by a bent drinking straw. Suck the bottom of the straw to get water over the hump in the straw. Then water will start to flow from the top cup to the bottom, initially going uphill in the straw.
A bit of charcoal dropped in a vial of pure oxygen spontaneously catches fire. The oxygen can be generated at the bottom of the vial using hydrogen peroxide and a drop of blood. Steel wire in a pure oxygen environment rusts rapidly enough to be observed in a single experiment.
Bimetal thermostat. Two strips of different metals glued, soldered or riveted together at the ends. Heat the joined strip with a hair dryer – it bends to one side. The bent strip can touch a contact and switch something on or off, for example the hair dryer. A feedback loop can be constructed: if the joined metal strip gets cold enough, then it switches on the hair dryer, which heats the strip, which then switches off the hair dryer.
Tracks vs wheels. Tracked and wheeled model vehicles driving in a sandbox and on a smooth surface. The vehicles are the same weight, have the same motor and battery. Compare performance going up a sandhill vs racing on a smooth surface.
A spinning top to illustrate gyroscopes and self-stabilising.
Degrees of freedom of movement. Mechanical devices that illustrate the 3 translation and 3 rotation possibilities by allowing some of them, but not others. For example the serial gimbal, 3-axis gimbal, origami for thick materials (Science 24 Jul 2015: Vol. 349, Issue 6246, pp. 396-400, DOI: 10.1126/science.aab2870), bicycle front fork with shock absorbers, shopping trolley wheel or office chair wheel. For fun, rotate a person on an office chair a few dozen turns, then ask them to walk in a straight line.
Origami: Miura fold, hexaflexagon. Cutting and gluing mathematical objects, e.g. a Mobius strip, a Klein bottle. Math drawing with compass and ruler, e.g. a flower made from 7 interlinked circles of the same diameter. Sierpinsky carpet. Inscribing circles in squares and vice versa.
Boil amaranth in a transparent vessel. The grains dance on the bottom, then form columns, then a goo with large breaking and splattering bubbles.
Water volcano. A small bottle of warm coloured water is dropped in a large transparent vessel containing clear cold water. The coloured water will rise to the top and spread out, like a volcanic ash plume rises in the atmosphere and spreads in a layer.
Twinkling stars and heat mirages. A transparent rectangular vessel of water with points of light behind it. Look through the water: the points do not move. Now heat the water from the bottom: the points of light start to wobble, because warm water currents are rising up and bending the light passing through them.
Refractive index measurement. Water and cooking oil in transparent vessels. One person puts a straight stick at an angle into the liquid – the stick seems to bend at the immersion point. The person points out where they perceive the bottom end of the stick to be. Another person at the side of the vessel measures the angle between the perceived and actual sticks. The difference in angles is different for water than for oil.
Muscles and joints. Ask a person to relax their hand on a table, palm up. Press on the inside forearm and pull it toward the elbow – the 3 smallest fingers bend. Pull the palm towards the wrist – the fingers bend. An excavator’s scoop is moved by pistons like human limbs are moved by muscles – by pulling on the joint on one side or another.
Centrifuge to separate liquids, or solids from a liquid. The low-cost whirligig centrifuge (paperfuge) is described in Nature Biomedical Engineering 1, Article number: 0009 (2017) doi:10.1038/s41551-016-0009 and http://www.nature.com/news/spinning-toy-reinvented-as-low-tech-centrifuge-1.21273 Animal blood or some mixture of liquids and solid flakes can be separated into component liquids and solids by spinning it.
Solar-powered distillation. The 1 square metre device made of polystyrene, paper and charcoal distils about 1 litre of water per hour, as described in http://www.sciencemag.org/news/2017/02/sunlight-powered-purifier-could-clean-water-impoverished Explain capillary action, evaporation and condensation, black material absorbing heat radiation faster.
Passive cooling. Glass beads 8 micrometres in diameter embedded in a polymethylpentene film backed with a thin silver film. The film conducts heat from the surface it sits on and radiates it away in in the other direction. http://www.sciencemag.org/news/2017/02/cheap-plastic-film-cools-whatever-it-touches-10-c
Oil- and water-repellent coating of glass. Cannot be prepared on the spot, but previously fabricated coatings can be demonstrated. Deposit candle soot on glass, then coat with a 25 nanometre silica film by putting the glass in a desiccator with open vessels of tetraethoxysilane and ammonia for 24 hours. Heat to 600C in air for 2 hours. Put in a desiccator with open beaker of semifluorinated silane for 3 hours. Xu Deng et al. “Candle Soot as a Template for a Transparent Robust Superamphiphobic Coating” http://science.sciencemag.org/content/sci/335/6064/67.full.pdf?sid=ca40c018-0715-4d3b-8e36-58c329dea347

Electricity and water analogy. Pouring water down an inclined halfpipe to rotate a water wheel under the bottom of the halfpipe. The water wheel is connected to a winch that can lift a small weight. The height or angle of the halfpipe and the quantity of water can be changed, which lifts the weight at different speeds or can lift a larger weight. The height of the halfpipe is analogous to the potential difference (voltage) and the quantity of water per second to the current (amperage, electrons per second). The water wheel can also be connected to a generator that powers a small dimmable lightbulb. The brightness of the bulb changes with the speed of the water wheel.
Plastic beads in water poured down a halfpipe can demonstrate the measurement of flow per unit of time: the number of beads passing a given point per ten seconds for example.
Ship shape. Make model boat hulls out of some easily worked material, e.g. putty, model clay (hull must be thin to float), cut styrofoam, cardboard taped together and covered with cling film. The styrofoam needs extra weight, for example a piece of sheetmetal pushed through it in the middle to make a keel. The cardboard boat can carry some gravel as ballast. Then each boat gets a motor of equal power, e.g. a propeller powered by a wind-up spring from some toy. Weigh the boats and add ballast as needed to equalise weights. Race the boats to see which hull shape is fastest. To keep the racing boats straight, put them in parallel halfpipes of water, or create swimming pool lanes in a large tub by parallel strings drawn taut on the surface of the water.

Camouflaged encryption

Many governments (US, Australia, all dictatorships) want to make end-to-end encryption illegal and prevent IT firms from providing it. The open-source community can create their own encryption software, but the creators and users of this could be punished as well. The reasoning of the governments for banning encryption is that criminals and terrorists use it. However, the same reasoning applies to knives, guns and cars, which are used much more directly to harm people and yet are strangely excluded from the ban. This contradiction makes me doubt the motives of these governments.
The obvious solution to a ban on some software is to camouflage it and its products. The code for the encryption software could be hidden in a seemingly nonexistent part of computer memory or blended in one log file among many, perhaps encrypted as well.
The encrypted messages passing through the internet should not look like encrypted messages, but would be embedded in innocuous-looking files. A simple way is to change the colour of some pixels in a self-made photo or video file, with the locations of the relevant pixels being known to the sender and receiver, but secret from others. The colours of the pixels can encode the data. Someone intercepting the picture or video would have to spend significant resources analysing it to find whether some pixels are of an unusual colour, especially if the starting image is riotously colourful and confusing. Publicly available images are not useful, because comparing the message-image with the original reveals the changed pixels.
A more sophisticated version of this idea has already been done by http://camouflage.unfiction.com/ A similar idea is to hide one’s browsing history in random websurfing (http://www.qqqtech.com/about.html), but this only hides the relative frequencies of websites visited, not the fact of visiting a site on a government watchlist that most people don’t visit.

Silly balconies

Everywhere in Australia, I have seen buildings with balconies that overlook busy roads. The view from the balcony often only includes other buildings. These balconies seem useless, because not many people want to sit in the street noise and car exhaust. I have rarely seen anyone on these balconies, and then only moving around for a practical purpose, not enjoying the air and view. Mostly the balconies are used for storing unwanted furniture and sports equipment, or growing potted plants. This makes sense, because even drying laundry over a busy road is problematic – everything gets covered in fine black soot. What does not make sense is adding these balconies to the buildings in the first place. A more practical use of the space would be to close the open parts of the balcony and thus add an extra room to the apartment. It is used as a storage room anyway.

In some cases, the building might have been constructed before the street became too busy or the views blocked by other buildings, but most of the buildings with balconies are new, so this explanation does not apply.

The reason the developers add balconies to their buildings is probably to market the apartments to impractical people. An included balcony makes the apartment sound more luxurious, and usually the view and relaxation opportunities of the balcony are touted in the advertisement. But people inspect the apartment before buying, so they should see the uselessness of the balcony for anything but storage. Inspections are usually scheduled on Saturdays when there is less traffic, and the inspecting buyers don’t sit on the balcony for long enough to become annoyed by the noise and the car exhaust.

There may be rules against the owner of an apartment closing up the balcony to create a room, because this makes the building facade uneven. Coordination problems between apartment owners may prevent them from closing up all the balconies of the building simultaneously.

Defence against bullying

Humans are social animals. For evolutionary reasons, they feel bad when their social group excludes, bullies or opposes them. Physical bullying and theft or vandalism of possessions have real consequences and cannot be countered purely in the mind. However, the real consequences are usually provable to the authorities, which makes it easier to punish the bullies and demand compensation. Psychological reasons may prevent the victim from asking the authorities to help. Verbal bullying has an effect only via psychology, because vibrations of air from the larynx or written symbols cannot hurt a human physically.

One psychological defense is diversification of group memberships. The goal is to prevent exclusion from most of one’s social network. If a person belongs to only one group in society, then losing the support of its members feels very significant. Being part of many circles means that exclusion from one group can be immediately compensated by spending more time in others.

Bullies instinctively understand that their victims can strengthen themselves by diversifying their connections, so bullies try to cut a victim’s other social ties. The beaters of family members forbid their family from having other friends or going to social events. School bullies mock a victim’s friends to drive them away and weaken the victim’s connection to them. Dictators create paranoia against foreigners, accusing them of spying and sabotage.

When a person has already been excluded from most of their social network, joining new groups or lobbying for readmission to old ones may be hard. People prefer to interact with those who display positive emotions. The negative emotions caused by a feeling of abandonment make it difficult to present a happy and fun image to others. Also, if the „admission committee” knows that a candidate to join their group has no other options, then they are likely to be more demanding, in terms of requiring favours or conformity to the group norms. Bargaining power depends on what each side gets when the negotiations break down – the better the outside option, the stronger the bargaining position. It is thus helpful to prepare for potential future exclusion in advance by joining many groups. Diversifying one’s memberships before the alternative groups become necessary is insurance. One should keep one’s options open, which argues for living in a bigger city, exploring different cultures both online and the real world, and not burning bridges with people who at some point excluded or otherwise acted against one.

There may be a case for forgiving bullies if they take enough nice actions to compensate. Apologetic words alone do not cancel actions, as discussed elsewhere (http://sanderheinsalu.com/ajaveeb/?p=556). Forgiving does not mean forgetting, because past behaviour is informative about future actions, and social interactions are a dynamic game. The entire sharing economy (carsharing, home-renting) is made possible by having people’s reputations follow them even if they try to escape the consequences of their past deeds. The difficulty of evading consequences motivates better behaviour. The same holds in social interactions. In the long run, it is better for everyone, except perhaps the worst people, if past deeds are rewarded or punished as they deserve. If bullying is not punished, then the perpetrators learn this and intensify their oppression in the future.

Of course, the bullies may try to punish those who reported them to the authorities. The threat to retaliate against whistleblowers shows fear of punishment, because people who do not care about the consequences would not bother threatening. The whistleblower can in turn threaten the bullies with reporting to the authorities if the bullies punish the original whistleblowing. The bullies can threaten to punish this second report, and the whistleblower threaten to punish the bullies’ second retaliation, etc. The bullying and reporting is a repeated interaction and has multiple equilibria. One equilibrium is that the bullies rule, therefore nobody dares to report them, and due to not being reported, they continue to rule. Another equilibrium is that any bullying is swiftly reported and punished, so the bullies do not even dare to start the bullying-reporting-retaliation cycle. The bullies rationally try to push the interaction towards the equilibrium where they rule. Victims and goodhearted bystanders should realise this and work towards the other equilibrium by immediately reporting any bullying against anyone, not just oneself.

To prevent insults from creating negative emotions, one should remember that the opinion of only a few other people at one point in time contains little information. Feedback is useful for improving oneself, and insults are a kind of feedback, but a more accurate measure of one’s capabilities is usually available. This takes the form of numerical performance indicators at work, studies, sports and various other tests in life. If people’s opinions are taken as feedback, then one should endeavour to survey a statistically meaningful sample of these opinions. The sample should be large and representative of society – the people surveyed should belong to many different groups.

If some people repeatedly insult one, then one should remember that the meaning of sounds or symbols that people produce (called language) is a social norm. If the society agrees on a different meaning for a given sound, then that sound starts to mean what the people agreed. Meaning is endogenous – it depends on how people choose to use language. On an individual level, if a person consistently mispronounces a word, then others learn what that unusual sound from that person means. Small groups can form their own slang, using words to denote meanings differently from the rest of society. Applying this insight to bullying, if others frequently use an insulting word to refer to a person, then that word starts to mean that person, not the negative thing that it originally meant. So one should not interpret an insulting word in a way that makes one feel bad. The actual meaning is neutral, just the „name” of a particular individual in the subgroup of bullies. Of course, in future interactions one should not forget the insulters’ attempt to make one feel bad.

To learn the real meaning of a word, as used by a specific person, one should Bayes update based on the connection of that person’s words and actions. This also helps in understanding politics. If transfers from the rich to the poor are called „help to the needy” by one party and „welfare” by another, then these phrases by the respective parties should be interpreted as „transfers from the rich to the poor”. If a politician frequently says the opposite of the truth, then his or her statements should be flipped (negation inserted) to derive their real meaning. Bayesian updating also explains why verbal apologies are usually nothing compared to actions.

Practicing acting in a drama club helps to understand that words often do not have content. Their effect is just in people’s minds. Mock confrontations in a play will train a person to handle real disputes.

Learning takes time and practice, including learning how to defend against bullying and ignore insults. Successfully resisting will train one to resist better. Dealing with adversity is sometimes called „building character”. To deliberately train oneself to ignore insults, one may organise an insult competition – if the insulted person reacts emotionally, then the insulter wins, otherwise the insulter loses. As with any training and competition, the difficulty level should be adjusted for ability and experience.

The current trend towards protecting children from even verbal bullying, and preventing undergraduate students from hearing statements that may distress them could backfire. If they are not trained to resist bullying and experience it at some point in their life, which seems likely, then they may be depressed for a long time or overreact to trivial insults. The analogy is living in an environment with too few microbes, which does not build immunity and causes allergy. „Safe spaces” and using only mild words are like disinfecting everything.

The bullies themselves are human, thus social animals, and feel negative emotions when excluded or ignored. If there are many victims and few bullies, then the victims should band together and exclude the bullies in turn. One force preventing this is that the victims see the bullies as the „cool kids” (attractive, rich, strong) and want their approval. The victims see other victims as „losers” or „outsiders” and help victimise them, and the other victims respond in kind. The outsiders do not understand that what counts as „cool” is often a social norm. If the majority thinks behaviour, clothing or slang A cool, then A is cool, but if the majority agrees on B, then B is preferred. The outsiders face a coordination game: if they could agree on a new social norm, then their number being larger than the number of insiders would spread the new norm. The outsiders would become the „cool kids” themselves, and the previously cool insiders would become the excluded outsiders.

Finding new friends helps increase the number who spread one’s preferred norms, as well as insuring against future exclusion by any subset of one’s acquaintances.

If there are many people to choose from when forming new connections, then the links should be chosen strategically. People imitate their peers, so choosing those with good habits as one’s friends helps one acquire these habits oneself. Having friends who exercise, study and have a good work ethic increases one’s future fitness, education and professional success. Criminal, smoking, racist friends nudge one towards similar behaviours and values. Choosing friends is thus a game with one’s future self. The goal is to direct the future self to a path preferred by the current self. The future self in turn directs its future selves. It takes time and effort to replace one’s friends, so there is a switching cost in one’s social network choice. A bad decision in the past may have an impact for a long time.

It may be difficult to determine who is a good person and who is not. Forming a social connection and subtly testing a person may be the only way to find out their true face. For example, telling them a fake secret and asking them not to tell anyone, then observing whether the information leaks. One should watch how one’s friends behave towards others, not just oneself. There is a tradeoff between learning about more people and interacting with only good people. The more connections one forms, the greater the likelihood that some are with bad people, but the more one learns. This is strategic experimentation in a dynamic environment.

Conferences and seminars as cargo cults

I wrote about the wastefulness of physically travelling to conferences or to give seminars, because one could give a presentation via a video call over the internet (http://sanderheinsalu.com/ajaveeb/?p=442). Other than habit or tradition, why would scientists organise conferences and seminars with physical attendance? One explanation I offered was that physical presence is a commitment device. Herding is another justification to any tradition. Irrationality is a third, which complements herding.

Holding conferences and seminars may be rational if top researchers are presenting and providing feedback, because there is much to learn from them. Such workshops may not be useful if the participants are not on the research frontier. Nonetheless, the low-achievers may organise such gatherings, because they want to publish like the high-achievers, and they perceive that the high-achievers benefit from the research meetings of large groups. A cargo cult means imitating someone’s behaviour to reach the same goals as them, but without understanding the reason why their actions lead to the results they do. The lack of comprehension of the underlying mechanism leads the imitation subtly astray, so it does not obtain the desired results. The conferences and seminars of low-achievers are a cargo cult if the following hold: only the participation of high-achievers makes research meetups useful, the high-achievers do not attend low-prestige meetups, and the low-achievers do not understand the above. It is difficult to test the usefulness of any action in research, because publication success is noisy, influenced by many factors and with long delays. Thus it is difficult to test whether there is a cargo cult in the less advanced levels of the research community.

Besides improving quality, the feedback of top researchers can increase publication chances by making the research of those lower in the scientific hierarchy conform to the tastes of the top. This is a horizontal differentiation effect – matching idiosyncratic tastes. It is not vertical differentiation (improving quality). If top people as referees and editors favour a certain field of research or ideology, then presenting work to them may uncover their biases and enable an author to pander to them.

Another way that presenting helps with publication is the familiarity effect. When the referee or editor has seen the paper presented before reading it, then the content is familiar and thus easier to understand. The reader may interpret the ease of comprehension as clarity of the paper, not familiarity of the material. Clear writing and well-structured ideas are a positive signal to the referee and increase the publication chances.

If the second-best people imitate the highest-achievers, then the third-best may imitate the second-best, etc. The cargo cults may be multilayered. Such imitation of imitators is called herding. It may sometimes be individually rational, but may lead to socially suboptimal ignoring of later information in favour of imitating the decisions of those who acted based on earlier info. Herding strengthens the effects of mistaken imitation, thus worsening cargo cult effects.

Cargo cults occur widely – any time there is a fad, fashion or bubble, some people jump on the bandwagon because their role models did, without asking why the role models did so. The personal situation of the trailbreakers may make it rational for them to act in a certain way, but the different circumstances of the followers may make imitation counterproductive for them. An example is creating a financial bubble to profit from it (pump-and-dump strategy). The starters profit from the amount invested by the followers. The last people to become followers lose their investment when the bubble bursts. I am not the first to compare the research community to a pyramid scheme – search „Profzi scheme” online.

Remembering the sacrifice

Many times and in many places I have seen a call to remember the sacrifice of the soldiers who died in some past conflict. Often, this call seems an attempt to direct attention away from the misguidedness of the particular conflict or the incompetence and selfish motives of the leadership who decided to enter the war. It tries to make people focus on the noble courage of the soldiers, not the sordid power-hunger of the rulers. The bravery of soldiers is discussed in another post (http://sanderheinsalu.com/ajaveeb/?p=595); here I would like to clarify this sacrifice business.

If the soldiers volunteered under reasonably accurate information about the reasons for the conflict and the chances of success, then indeed they chose to sacrifice themselves for the cause. Then we should remember their sacrifice. If, however, they were conscripted (dictatorships often call this volunteering) using the threat of punishment for them or their family, then they did not make the sacrifice any more than a sacrificial animal sacrifices itself. Others sacrificed the conscripts to further their own ends.

These ends are unlikely to prioritize defeating an evil regime and making the world a better place, although the propaganda claims this was the objective. Mostly the goal of leaders is to preserve and expand their power, whether by defending the country against takeover or conquering additional subjects and wealth. Even if this is acknowledged, current propaganda may point out some good side effect of sacrificing the soldiers, e.g. defeating an old enemy. This is again a distraction attempt. The world is complex and interconnected, so every event, including a mass death, has some beneficial side effects, just like every event has some negative side effects. One should consider the overall consequences of an event, not just one side effect.

If the soldiers genuinely volunteered, but due to being misled by propaganda, then they wanted to sacrifice themselves for one cause, but their leaders sacrificed them for another. Usually volunteers underestimate the length of the war and the probability of dying. Thus even when they know the true goal of the conflict, the sacrifice they are led to is larger than the one they intended to make.

The most clear and direct self-sacrifice is made by suicide bombers. They probably think that their bombing serves a good purpose, but such belief is almost always misguided. Religious indoctrination of the bombers manipulates them into believing in a noble cause, hiding the true goals of the leaders ordering the bombing.

I have not heard many calls to remember the sacrifice of present-day child soldiers. Rather there are calls to pity and save them. The situation of many soldiers in many wars has been similar to children forced to fight – ignorance and fear of punishment. Obeying the conscription order often offers a greater survival probability than refusal.

Instead of remembering the sacrifice of conscripts, we should remember them being sacrificed. Remember with pity. Remember to prevent.

Would a protest influence you?

Help, a politician I don’t like is in power! I should do something about it. But what? I know! I will join a protest – this is something. Now I can feel good about myself for having done something. And post on social media how I opposed evil so effectively. I am a socially conscious, altrustic person.

On a more serious note, one way to evaluate whether a given protest could change the situation is to put yourself in the position of the target audience. If your favourite politician was in power, would this protest change your support for said politician? If you were the politician in power, would you change your policy when many opponents use this protest against it?

Even if the answer is no, a protest may still have some effect, because it may change the preferences of the swing voters. The „no” may come from deeply ideological people, whereas more open-minded folks may conform to the herd. If they see many people opposed to something, they may start to oppose it too.

On the other hand, a protest may have the opposite effect to the one intended. It may harden ideological positions and increase polarisation. If the majority is weakly in favour of a policy, then protests against it may strengthen the support of the majority for it, leading to greater turnout and more yes-votes.

From an economic viewpoint, marching on the street with signs, chanting slogans or commenting on social media has no direct impact on politicians or most voters. The exception is those who are stuck in a traffic jam when a protest closes a street. Rational agents should not pay attention to protests which do not affect them (such activism is „cheap talk” in economic jargon, or at best „money burning”).

Real people may be swayed by the opinion of a large crowd. However, a form of protest that has an objective impact on people’s lives is likely to influence people more, because it affects them via both the opinion of the crowd and the direct impact. Both the belief shift and the hardening of the opposition are probably greater.

There are many illegal means of directly affecting the population, but also some legal forms of protest with objective impact. Economic protest is boycotting certain countries, firms or goods, refusing to work for the regime, and moving elsewhere („voting with one’s feet”), and is usually legal. The objective impact is that if enough intelligent and hardworking people shift their spending and taxpaying elsewhere, then the regime will be in fiscal trouble. If this does not change the policy of the leadership, then at least the lack of money will make the program harder to carry out.

There is a larger personal cost for economic protest than for cheap talk. One has to give up certain goods, or pay more, or experience the hassle of moving residence. This is why most people who threaten to boycott a firm or leave a country do not end up doing so. The threats are just another form of cheap talk, which can be posted on social media to impress other cheap talkers.

Incentivising refereeing

To shorten the refereeing lag and improve report quality in economics, the natural solution is to incentivise academics to do a better and quicker job. Economists respond to incentives, but currently no salary or promotion consequences arise from good or bad refereeing, as far as I know. In http://sanderheinsalu.com/ajaveeb/?p=503, I wrote about incentives for authors not to submit careless papers (in the hope that a refereeing mistake gets them accepted). One such incentive is requiring refereeing for a journal as a precondition for submitting to that journal. If a submitted paper gets n referee reports on average, then before submitting, an author should referee n papers in a timely manner, which should balance the supply and demand of refereeing. This forced refereeing may lead to quick, but sloppy reports.

An additional incentive is needed for quality. Rahman’s 2010 paper on the question „who watches the watchmen” suggests an answer. The editor can insert a deliberate mistake in every paper and see whether a referee finds it. If not, then the refereeing of that person is likely of low quality. The mistake is corrected before publication. Alternatively, the editor can ask each author to insert a mistake and tell the editor about it. The author is not penalised for this mistake and is asked to correct it if the paper is accepted. The referees are again judged on whether they find the mistake.

The above scheme derives refereeing incentives from publication incentives, requiring minimal change to the current system. However, it is somewhat indirect. A more straightforward incentive for refereeing is to reward it directly, either paying for it or basing promotion decisions partly on it. The speed of refereeing is already slightly monetarily incentivised in the American Economic Journal: Microeconomics. If the referee sends the report before a deadline, then she or he is paid 100 dollars. If a good referee report takes about 10 hours, then the amount is certainly not enough to motivate quality provision, but it is a step in one of the right directions. A simple improvement on the binary „before vs after deadline” reward scheme is to reduce the payment gradually as the delay of the referee report increases.

If refereeing is incentivised, then lower-ranked journals need larger incentives to compensate for the fact that refereeing for these has less inherent prestige and the paper one has to read is of lower quality. On the other hand, lower-ranked journals are less able to motivate refereeing with the threat of not accepting submissions from those who have not refereed. There are more lower-ranked journals, and it is less important to get accepted by any particular one of them. Some of the less prestigious journals would find no referees under the system proposed above. This is good, because it removes the „peer reviewed” status of some junk journals and may force them to close. If authors know that quality journals require refereeing before submission, then they draw the obvious conclusion about a journal that does not require it.

On military bravery

All countries and armed groups emphasize the bravery of their soldiers for propaganda purposes. Such claims are made regardless of whether there is any actual valour. Going to a dangerous situation or even certain death is not necessarily courageous, in particular if there is no knowledge of the danger or no choice. Are sheep going into a slaughterhouse brave? They are calmly walking to certain death, after all. But usually this is not ascribed to courage, but to ignorance. Analogously, soldiers used in early tests of the physiological effects of radiation exposure who were marched through an area of a recent nuclear explosion are not considered brave. They did not know the cancer risk.

If there is no choice, which usually means there are only perilous choices, then putting oneself in danger is not usually accounted brave. Jumping out of a burning building offers a higher probability of survival, so people do it despite the substantial risk of falling to death. When a sufferer of a painful terminal disease chooses euthanasia, this early death is commonly not considered brave. Some cultures even believe suicide to be a sign of cowardice. If a military has a well organized system for catching deserters and administering the death penalty to them (and their family in some regimes), then a soldier charging enemy machineguns is merely maximizing his survival probability. The enemy might miss, the firing squad rarely does.

The greater the probability of victory for one’s own side, the less attractive desertion becomes, because being caught is more likely. This explains the propaganda emphasis on own victories and the punishment of “defeatist talk” in wartime. The greater the military advantage of a party in an armed conflict, the less bravery its soldiers need.

Genuine bravery exists, but it is rare. Evolution favours cowardly bullies who attack the weaker (prey) and run from the stronger (predators). People who face no compulsion to fight in a war and know the dangers, yet still join, are brave. Freedom fighters (insurgents from the other side’s viewpoint) against a dictator qualify. With the caveat that only joining the fight initially requires bravery – after that, losing would mean being tortured to death by the dictator, so continuing the war is the safer option. Similarly, volunteering for the military requires some bravery (the more the greater the likelihood of being sent into danger), but once military law applies, desertion is usually more dangerous than the duty.

Military courage is proved for those who start the war as a weaker side against a stronger, if a continuing peace is not a slow death. Peasant revolts were often driven by hunger, meaning the participants may have perceived the probability of death from starvation as higher than the probability of being killed by the aristocrats.

People who have never faced an informed choice between a safe and a dangerous option may be “latently brave”, in the sense that given such a choice, they may exhibit courage. They are not proved brave, however, until they have made the choice. There are likely to be some latently brave people in the world’s militaries and armed groups. Probably a greater percentage than among the general population.

There are some proven brave folks even in the militaries of powerful countries, but the proof requires knowingly choosing a dangerous option when there is no future punishment for cowardice. For example, when nobody would know of the choice.

A topical question is whether suicide terrorists and other fighting religious fanatics are brave. Their behaviour may be driven by the fear of punishment either in the afterlife or by their fellow fanatics. It may also be due to ignorance – believing in an afterlife is like believing that one cannot really die and thus the danger is not real. In both cases, no courage is required for choosing death.

The belief in the impossibility of dying may even be literal – W.E.B. Griffin had a story of a witch doctor convincing the fighters of his tribe that his magic had made them immune to bullets. Great was the fighters’ surprise later… Their charge with spears against guns was not due to bravery, however.

On backpackers and low-spending tourists

Countries encourage tourism to make money. The same goes for local governments, tourism industry associations and tour firms. Some places provide options for low-spending tourists like backpackers, despite not making much money from them. These options may be cheap campsites, backpacker hostels, allowing hitchhiking and work-travel visas. At first sight, any positive revenue from poorer tourists would justify welcoming them. This simple revenue calculation, however, neglects the substitution effect and dynamic demand.

Substitution means that if cheaper travel options are available, then some tourists who would have spent more in the absence of these options now spend less. For example, a person who would stay in a hotel if there was no other accommodation, stays in a backpacker hostel instead. On the other hand, if all options are expensive, then the poorest tourists do not come at all. There is a tradeoff between the number of tourists and the average tourist’s spending. If introducing cheaper options leads to many tourists switching to these, but does not attract many additional low-spending people, then creating these cheaper options reduces total profit.

Dynamic demand means that a person who has toured a particular location once changes his or her likelihood of going there in the future. For example, having seen a tourist site, a person does not visit it again. Or someone going on vacation and liking the location starts going there year after year. If a region encourages young, low-income people to visit as backpackers, then it may increase or decrease future visits by these people when they are older and wealthier. In particular, if people do not tour the same location again (and spend more when older), then encouraging them to visit when young reduces the total profit from them over their lifetime.

The fact that some regions welcome backpackers has several possible explanations. There may not be much substitution, or a visit may increase future visits. The tourism industry may not have thought this through and may be reducing their own profit inadvertently. Or the government may have other objectives than taxes from the tourism industry. For example, allowing people from other countries to visit cheaply may make these people friendly to the host country, which may yield some nonmonetary benefit in international relations.