 So let's take a look at an important issue which is helping coal workers. This is a serious problem because over the past 30 years over 100,000 jobs have been lost in the coal mining industry. The obvious question on the minds of all those who live in coal country, can we bring those jobs back? In order to answer that question we have to understand why those jobs have disappeared, and the decline of the coal industry has been blamed on a number of things. Equal regulations, cheap oil, expensive safety equipment, but here's an inconvenient truth. While the number of workers in the coal mining industry has steadily declined over the past 30 years, US coal production over the past 30 years has remained more or less the same. The reason that mining jobs are disappearing is that a miner in the year 2015 can produce three times as much coal as his father did in 1985. Technology and the desire of the major companies for more profitability means that the coal industry does want to produce more coal, but wants to do so using fewer workers. And this trend is likely to continue. So even if coal production does come back, the mining jobs will not. And so this raises the question, what shall we do with these unemployed coal workers? The traditional response when workers have been displaced by technological or economic shifts is to allow them to suffer, and when desperate people take desperate actions to deploy the full force of the government in order to protect property and profits. But there's a better solution, which is to retrain displaced workers to find employment in new fields. And one of those new fields is the solar industry, which over the past few years has undergone an enormous increase in the total number of jobs available. The Bureau of Labor Statistics predicts that the solar industry will add more than 200,000 jobs between the year 2014 and the year 2024. And that's great news, but the question remains, how difficult will it be to retrain coal workers to become solar workers? One way we can answer this question is by using the mathematics of vectors. A vector is an ordered set of numbers, and they appear in many contexts. For example, if you go in for routine medical examination, several vital pieces of information are going to be recorded, your age, your weight, your height, blood pressure, and so on. This information can be converted into a vector, an ordered sequence of numbers. We can find these ordered sequences of numbers in many, many different locations. The Department of Labor maintains a site known as ONET, which includes detailed information about almost every career available to workers in the United States. And given any occupation, we can find detailed information about the knowledge, skills, and abilities required for success at the job. For example, an important job in the coal industry is a roof bolter. And so one question we might ask is, can we train a roof bolter to become a solar fault of a platic installer? To answer this question, let's take a look at the ONET data. So if you're a successful roof bolter, one of the skills that you have is quality control analysis. And based on interviews with job holders and job analysts, a roof bolter needs this skill at a level of 36 out of a possible 100. A PV installer, on the other hand, requires this skill at a level of 45, which means that some training is necessary. Roof bolters also need mechanical knowledge at a level of 57, while photovoltaic installers need it at a level of 67. Now, skills and knowledge are relatively easy to acquire through training and education, but abilities are harder to acquire. They're things like arm-hand steadiness and manual dexterity. If you're a roof bolter, arm-hand steadiness is important. A successful roof bolter has it at a level of 45 or more, which exceeds the 39 needed for a successful solar photovoltaic installer. And we can take all the information that we have about the knowledge, skills, and abilities required for success in both jobs and put it into a vector, and we can then compare the vectors to see if a successful roof bolter who has a certain level of each of these can be retrained to become a successful PV installer. In some cases, what they have exceeds what is required and so little to know retraining is necessary. On the other hand, in other cases, there may be some retraining and education needed in order to be qualified for a job in the photovoltaic industry. The smaller the gap, the easier it will be to retrain someone in one industry to work in another industry. And easy means faster and cheaper. In 2016, Edward P. Lewy of Oregon State University and Joshua M. Pierce of Michigan Technical University performed a similar analysis to see how easily we could retrain coal workers to work in the photovoltaic industry. Pierce and Lewy found that this would be relatively easy to do. Much of the knowledge and many of the skills and abilities transfer over very easily or could be acquired through very little additional retraining or education. Moreover, a switch from the coal industry to the solar industry would actually result in an increase in the average wages of the coal workers because jobs in the solar industry tend to pay higher. Lewy and Pierce ran several scenarios assuming the entire coal industry shut down. In the best case scenario, all non-coal specific workers found jobs in other industries. So the coal industry employs a number of janitors, a number of secretaries, a number of accountants, and the assumption is that these people could find equivalent jobs in other industries and not require any retraining. Under this scenario, only the coal specific workers would have to be retrained and this could cost as little as $180 million. Under the worst case scenario, everybody in the coal industry had to be retrained to work some job in the solar industry. And even in this worst case scenario with massive amounts of retraining, this would cost no more than about $1.9 billion. And again, these numbers assume the entire coal industry vanishes, but the industry won't vanish anytime soon. The actual cost will be significantly less. And this is one of those unusual situations where everybody wins. The coal workers win because they now have new employment opportunities at higher wages. The environment wins because we've replaced a finite resource with an infinite one. And the people of the country win because the growth industry means that we have a larger tax base. Retraining the entire coal industry to work in the solar industry would cost far less than $2 billion. So if you have a couple of billion dollars to throw around on something, why not spend it on something that benefits everyone? Workers, the environment, the country. Side effects of knowledge include greater understanding of the world around you and an increased demand of evidence from elected officials. Difficulty swallowing lies has been reported by some users, as well as reduced tolerance for flawed arguments, personal effects, anecdotal evidence, and false equivalences. Other users report becoming addicted to learning. A small percentage of users also exhibit behavior changes, such as fact checking, rejection of internet memes, and political activism. Educational videos slow, but do not stop the spread of misinformation, propaganda, and alternative facts. 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