Courts don’t determine scientific facts

Most people have probably seen the recent news that Monsanto has been ordered to pay $289 million following the ruling by a California jury that Monsanto’s glyphosate (a.k.a. Roundup) is dangerous and likely contributed to Dewayne Johnson’s cancer. I could write many lengthy posts about why that ruling is wrong. I could talk about the numerous scientific studies that failed to find evidence that glyphosate causes cancer (e.g., this large, long-term cohort study with over 50,000 participants that wasn’t funded by Monsanto and failed to find an association between glyphosate use and cancer among farmers [Andreotti et al. 2017]). I could talk about the well-established fact that the toxicity of glyphosate is quite low. I could talk about the fact that multiple well-respected scientific bodies have examined the evidence and concluded that it does not suggest that glyphosate causes cancer. I could also talk about how the one dissenting scientific report (i.e., WHO’s IARC report) cherry-picked their evidence and reached a conclusion that has been widely criticized by the scientific community. Plenty of other pages have, however, already done all of those things, so I won’t spend more time on them here. Rather, I want to discuss why trials like this one are inherently problematic. Citing court rulings is an extremely common tactic among science deniers (anti-vaccers do it all the time), but it is not a logically valid tactic because courts don’t determine what is and is not a scientific fact.

The first major problem is simply that juries don’t consist of experts in the relevant scientific field. As I’ve talked about before, science is complicated. It takes years of carefully training, study, and hands-on experience to learn everything that you need to know to be able to properly evaluate scientific evidence. The notion that an untrained jury is going to master that over the course of a trail is absurd. Further, it is especially ridiculous when you consider that courtroom conditions inherently involve two opposing sides arguing as if they have equivalent merit. To put that another way, it is extremely easy to cherry-pick evidence to make it look like the science isn’t settled on an issue or, worse yet, like the scientific consensus is the opposite of what it actually is, and in a courtroom, a lawyer will do precisely that. They are obligated to argue in favor of a given position, regardless of whether that position is actually supported by the evidence.

Let me try an example. Imagine that there is some issue with your heart that you want diagnosed, and someone suggested to you that it might be because a particular aspect of your diet (i.e., you eat X, and they think X is bad for your heart). So, you take two approaches to figuring out whether your diet is the cause. In the first approach, you get multiple respected scientific organizations to examine the scientific evidence that X can lead to heart problems. These bodies of highly trained and experienced experts spend months or even years systematically examining the studies on this topic. The look at all the evidence that they can get and, ultimately, they conclude that there is no compelling evidence for X contributing to heart problems.

For the second approach, you construct a jury using the same criteria as in a court, then you get two lawyers to debate the issue as in a courtroom. One of them tries to convince the jury that X does cause heart problems, and the other tries to convince the jury that X does not cause heart problems. Rather than systematically examining all of the evidence, both lawyers cherry-pick evidence that supports their position, attempt to play on the jury’s emotions, bring in cherry-picked “expert” witnesses, etc. At the end of the trial, the jury concludes that X does cause heart problems (which is the opposite of what the scientific committees found).

Which conclusion seems more reliable to you? The one that was arrived at by experts spending months carefully and systematically examining all of the available evidence, or the one that was arrived at by non-experts basing a decision on a comparison of two extremely biased representations of the evidence? I think that the answer to that is pretty obvious.

To be clear here, I’m not saying that scientists are infallible or that the conclusions of scientific organizations are definitive statements of reality. That would be an appeal to authority fallacy. Rather, my point is that the courtroom system is fundamentally flawed and unreliable for determining scientific facts. The fact that a jury decided that X causes Y is completely and 100% irrelevant in any scientific debate. It has no bearing on reality, and you would be crazy to trust it instead of relying on numerous high-quality studies and reviews and meta-analyses of those studies that were systematically assembled by teams of experts. Whether or not something is a scientific fact has to be determined by actual research, and a jury’s opinion about that research is irrelevant.

Posted in Nature of Science, Rules of Logic | Tagged , , , | 54 Comments

Scientism: Is it a straw man or a legitimate critique?

If you browse through the comments on this blog/Facebook page, or the pages of just about any other pro-science page, you will quickly find accusations of “scientism.” Indeed, among those who like to disagree with scientific results, this seems to have become a get-out-of-jail-free response that they use to dismiss any evidence or arguments that conflict with their preconceptions. People seem to think that accusing their opponent of scientism is a valid substitute for presenting actual evidence to back up their position. Further, at least in instances that I have personally observed, this accusation is often a straw man fallacy that either misrepresents scientism or misrepresents the science-advocates’ claims. Nevertheless, it is very easy to get sloppy with how we phrase things and inadvertently make a statement that has the appearance of scientism, even if that was not the intent. Therefore, I want to briefly talk about what is and is not scientism.

Scientism is a philosophical position that emphasizes science above all else. Unfortunately, like many philosophical views, it is a bit amorphous, and there is no one universally accepted definition, and it’s really probably more of a spectrum than one discrete view. Nevertheless, here are a few common themes that you generally see in definitions of scientism. First, scientism often overstates our confidence in the results of science. Second, it often tries to apply science to topics that are outside of the scope of science, and third, it often states that science is the only source of knowledge. I’m going to talk about each of these and give some examples.

Let’s start by talking about our confidence in scientific results. I frequently get angry comments on my blog/Facebook page about how other skeptics and I are clueless idiots who worship scientists like gods and think that science is infallible. If we actually worshiped scientists or thought that science gave absolute and infallible answers, then we would, in fact, be guilty of scientism. However, I have yet to see anyone actually do either of those things, and this argument is usually a straw man. Science doesn’t give definitive answers. Rather, it is an inherently probabilistic process that simply tells us what is most likely true given the current evidence. That probability can change, however, when new evidence arises. In other words, all that we are saying is that we have to accept the results science gives us until such time as scientific evidence arises showing that those results are wrong.

The problem here is that people often jump from, “science doesn’t give definitive answers” to “science is unreliable, and I don’t have to accept its answers.” That’s illogical (in fact it is the very definition of science denial). That fact that science doesn’t give 100% proofs doesn’t mean that we can’t be very certain of the results that it gives, and it certainly doesn’t mean that you can reject it whenever you want. When dozens, hundreds, or even thousands of studies have all converged on a result, then it is very unlikely that the result is false, and it would be foolish to reject that result. That’s not a statement of scientism, rather it is simply a rational, evidence-based view of reality.

To put it simply, saying, “numerous studies have found that X is true, therefore X is absolutely true and there is no chance that it is wrong” would be scientism. However, saying, “numerous studies have found that X is true, therefore it is most likely true and we should act as if it is true until we have evidence to the contrary” is not scientism (at least not by any reasonable definition I’ve read).

This comment was left on my page a while ago, and it is very typical of the type of straw man fallacy I am describing. Challenging the accepted wisdom because you have new studies that show that it might be wrong is fine. Challenging it because you don’t like it or because it conflicts with your preconceptions is not. (note: I forget the exact topic that this comment was left on, but I recall it being something for which a very strong consensus of studies existed)

To state that another way, any scientific result can be overturned, and scientists should consider new evidence as it arises, but, importantly, there is no reason to doubt a well-established scientific result until solid new evidence arises. In other words, many people want scientists to question well-established results based on anecdotes, speculation, and other forms of shoddy evidence, and when scientists refuse to do that, they accuse them of scientism (see the comment to the right that someone left on my Facebook page, for example). Being open-minded means being willing to accept new evidence, not being willing to accept something despite a lack of evidence (that’s being gullible). Further, it is worth clarifying that asking questions is good, even encouraged, but you have to be willing to accept the answers to your questions. It is fine to ask a question like, “is this treatment safe?” but if the answer is that there are multiple high-quality studies saying that it is and no compelling evidence that it isn’t, then refusing to accept the results of those studies is, by definition, science denial.

Moving on, scientism can occur when you try to use science to argue about a topic that is outside of the realm of science. Science, by its very definition, is limited to the physical universe. If we can’t observe and quantify it (or at least observe and quantify its results), then we can’t study it using science. Thus, philosophy and theology are outside of the scope of science, and science cannot answer questions like, “is there a god?” or “does life have meaning?” or “is this morally right?” To put that another way, science can show us how to clone a human being, but it can’t show us whether or not it is morally right to clone a human being.

Usually, religion is where people get into trouble with this more than in philosophy (again, in my observations at least). Anytime you hear someone make a statement like, “science has disproved the existence of god,” you are hearing scientism. The concept of god is inherently one of a metaphysical being who exists outside of the laws of science. Therefore, science cannot address his or her existence.

The flip-side of that is that religious people will often use accusations of scientism to attack scientific results that conflict with claims that their religion makes about the physical universe. Creationism is the most obvious example of this. Science can’t tell us if god exists, but it can tell us (with an extremely high degree of certainty) that life on earth has evolved for billions of years, Noah’s flood didn’t happen, etc., and none of that is scientism. You see, anytime that religion makes a claim about the physical universe, it has entered into the realm of science, and we can use physical evidence to evaluate the claim.

This leads to the final category I want to talk about: claims that science is the only source of knowledge. This is tricky to talk about, because the concept of knowledge has been debated by philosophers for millennia. So rather than getting bogged down in the definition of knowledge, I’m just going to explain why I don’t agree with the notion that science is the only source of knowledge, as well as discussing how confusion arises with accusations of scientism (note: I am assuming that I am real and in a real physical universe, but if you want to get philosophical, I agree that I cannot “know” that in the strongest sense of the word; again, I’m trying to avoid getting derailed by debates like that).

There are plenty of things that we “know” without science. First, relating back to the previous point, I would argue that for many philosophical/moral topics, we can arrive at pretty good conclusions by logic and reasoning. So, I don’t agree that philosophy is worthless; rather, it simply answers different questions than science does.

Even in the physical world, we can know plenty of things without science. I know, for example, that I am sitting at a computer right now. Did I acquire that knowledge by doing a systematic experiment and running some statistics? Obviously not, and I don’t think anyone would argue that we need to do that to know that I am sitting at a computer. Indeed, our lives are full of this type of knowledge that is acquired by simple observation, rather than systematic research. The problem is that at times our observations are very unreliable and conflict with scientific results.

Let me give a trivial example. On countless occasions, I have had people in the US insist that rattlesnakes hybridize with non-venomous snakes like garter snakes and rat snakes. They claim to know this because they’ve seen hybrids. As a herpetologist, however, I know that the notion of those species hybridizing is patently absurd. Those snakes are in totally different families. Their reproductive structures are different, their genetics are different, their mode of reproduction is different, etc. I hesitate to use the word “impossible” after the above discussion of probabilities, but something like this is so unlikely that for all intents and purposes, it might as well be called “impossible.” We would have to be fundamentally wrong about so many things for those snakes to be able to hybridize that it is extraordinarily unlikely that it is possible. Thus, I can state with a very, very high degree of confidence that the aforementioned people’s knowledge on this topic is wrong and the scientific results are correct. Again, that’s not scientism, that’s just accepting evidence, but you will notice that the evidence disagrees with people’s casual observations. In other words, casual observation is a way of knowing, and often a useful way of knowing, but it does not confer the same degree of confidence as systematic research (i.e., science).

Perhaps the most common way that this plays out is with anecdotes about medicine (or the various “treatments” that masquerade as medicine). People love anecdotes, and they frequently claim to know things based on anecdotes. The problem is that, as I have previously explained, anecdotes cannot establish causation. Forget science for a minute and let’s just talk about logic. Saying, “X happened before Y, therefore X caused Y” is a logical fallacy known as post hoc ergo propter hoc. It is an invalid line of reasoning. Nevertheless, people frequently insist that a given treatment works or a given medicine is dangerous because they’ve “seen it themselves.” This is where false accusations of scientism tend to start flying.

What I usually see happen is the following.

  • Person 1: Here are multiple studies showing that X does not cause Y.
  • Person 2: Those studies must be wrong because I know that X causes Y. I’ve seen it happen myself, so I know that it is true.
  • Person 1: Personal anecdotes aren’t good evidence of causation. There are lots of things that could make it appear that X causes Y, even if it doesn’t. You need carefully controlled studies for your position to be valid, and in lieu of those studies, ignoring the evidence against a causal relationship is science denial.
  • Person 2: That’s scientism! Science isn’t infallible, and science isn’t the only form of knowledge! How dare you say that my personal experiences are less valid than your science? Questioning the accepted wisdom isn’t science denial. Scientists are supposed to be open-minded.

Do you see what is going on there? Person 2 is committing a straw man fallacy and is using the accusation of scientism as an excuse for science denial. In other words, they don’t want to admit to denying scientific evidence, so instead they try to shift the blame by saying that they aren’t denying the evidence, the other person is just exhibiting scientism.

That line of reasoning is specious. The fact that science isn’t infallible doesn’t mean you can ignore its results anytime that you want, and the fact that science isn’t the only source of knowledge doesn’t automatically mean that other sources of knowledge are equal in all contexts. When it comes to establishing causation in the physical universe, science is the best and most reliable method, and you can’t reject it anytime that you want. Further, I’ll reiterate my previous point that asking questions in the absence of evidence is fine, but refusing to accept the results of numerous studies is not.

This all comes back to a concept that I discuss frequently on this blog: the burden of proof. The person making the claim bears the burden to back up that claim, and extraordinary claims require extraordinary evidence. To put that another way, science is not infallible, but it is really good, and if you want to say that numerous studies are wrong, then you are going to need some extraordinary evidence, and logically invalid personal anecdotes won’t cut it.

Indeed, all of this can be summed up with the simple statement that scientific topics require scientific evidence. That’s not scientism, that’s just how science works.

In short, scientism is a philosophical position that over-values science and argues that it is the only source of knowledge and/or that it applies to all topics. Although people do sometimes make arguments along those lines, accusations of scientism are often straw men that are used simply to deflect from the weakness of one’s own position. In other words, rather than admit that their view is incompatible with scientific evidence, many people simply accuse their opponent of scientism in an invalid attempt to delegitimize their opponent’s position. Science isn’t infallible, but you must have good evidence before you challenge the results it produces.

Note 1: Although observation is an important part of science, it is not in and of itself science. Science requires a systematic collection of observations.

Note 2: To be clear, I’m not suggesting that no skeptics are ever guilty of scientism. It does happen. My point is simply that in many cases, accusations of scientism are straw men.

Posted in Uncategorized | 40 Comments

Replacing science-based cancer treatments with “alternative treatments” increases your risk of dying from cancer (new study)

Cancer is a truly terrible disease, and although our ability to treat and even cure many types of cancer has greatly improved, our current methods for dealing with it are admittedly imperfect and often have serious side-effects. It is, therefore, hardly surprising that many people who are diagnosed with cancer would forgo science-based treatments for “alternative” or “complimentary” treatments (aka CAM). After all, who wouldn’t be tempted by the promise of a miracle cure? The problem is that these “natural” treatments are unproven and unregulated, and choosing them over science-based medicine actually increases your risk of dying from cancer. This was demonstrated by a paper published earlier this year (Johnson et al. 2018a) that compared people who took only alternative cancer treatments to those who took conventional treatments. It found that those who relied on alternative treatments had a significantly lower survivorship. A second study (by some of the same authors as the first study) was just published and further supports that conclusion, so I want to talk about it for a minute.

This study (Johnson et al. 2018b) differed from the previous study in that all of the patients used at least one round of conventional treatment, but some of them also used alternative treatments. To compare these groups, authors used a design known as a retrospective cohort study. I discussed this design at length here, but in brief, this means that the researchers took the medical records for a large group of people who had cancer, and the went through the records and split them up into a group that only reported using conventional treatments and a group that used at least some alternative treatments. Because this study design is entirely observational and these groups weren’t assigned beforehand, there were potential confounding factors. Therefore, the authors matched patients such that for every one person who used alternative treatments, there were four people who were similar in age, ethnicity, cancer type, cancer stage, etc. but used only conventional treatments. This resulted in the groups being as similar as possible for all confounding factors so that causation could be assigned.

They used a couple of different methods to analyze the data, but the core analyses were hazard ratios. The simplest way to think about this is that it is the hazard associated with one group divided by the hazard associated with the other group. Thus, a hazard ratio of 2 means that one group has twice the hazard as the other. In other words, if the outcome of interest is death, then all else being equal, you’d expect one group to have twice the rate of mortalities as the other at any given time point during the study. The actual math there gets a bit complicated because you need to use models that take into account confounding factors, but that’s the idea in a nutshell (note that this is not a measure of absolute risk).

So, what did this study find? There are several interesting results. First, people who used alternative treatments were less likely to use the full rounds of conventional treatments. In other words, many people were choosing alternatives instead of using the recommended schedule of conventional treatments.

Figure 1 from Johnson et al. 2018b showing the difference in survivorship between those who did and did not use alternative cancer treatments.

The second key result was that the mortality rates were higher for people who used alternative treatments. The hazard ratio was 2.08 with a 95% confidence interval of 1.50–2.90. That result was based on a test that did not account for differences in the levels of conventional treatments that were used, and the authors followed up on it by doing a test that incorporated the history of conventional treatments. That second model showed no statistically significant difference between the two groups. This suggests that the increased mortality for people who used alternative treatments was driven by skipping conventional treatments rather than by the alternative treatments themselves. Thus, using the full course of conventional treatments was the key factor for maximizing survival.

So, does this mean that it is fine to take alternative treatments as long as you also take the full line of conventional treatments? Not necessarily. For one thing, there is no proven benefit from those alternatives. Further, out of necessity, this study lumped all alternative treatments together. As a result dangers of particular treatments may have been masked by a large number of benign treatments. Some alternatives are clearly dangerous (like drinking bleach and paint thinner), and others may be harmful on their own or have negative interactions with science-based treatments. We simply don’t know.

Risk assessment always has to weigh the benefits against the risks, and given that there are no known benefits of these alternative treatments, in my opinion, the risk and wasted money is not worth it. Having said that, as long as you are following the convention treatment schedule it is entirely possible that taking alternatives won’t do any harm (other than to your wallet), but at the very least tell your doctor exactly what you are taking and make sure that they don’t have reason to think that your chosen complementary “medicine” isn’t dangerous.

Finally, I want to talk about an important weakness of this study. Namely, the fact that, as I just stated, they lumped all alternative treatments together. This was out of necessity because there are a mind-boggling number of alternative treatments out there, and they only had 258 people in the alternative treatment group. Thus, there simply wasn’t enough power to test any particular alternative remedy. Further, beyond the dizzying array of alternatives available, for a study, you’d also need information about doses, schedules of administration, etc. In other words, the data simply aren’t there to do a comparison based on specific treatments. As a result, you could try to argue that your specific preferred alternative works, and it just couldn’t be detected because of all the statistical noise from the treatments that don’t work. It is technically possible that there were a few effective treatments in there, but that’s a dice-roll. It’s exactly the same as what I described earlier for risks. There may be a few good treatments in the mix, there may be some very harmful ones, there’s probably lots of neutral ones, and without properly controlled studies, you have no way of knowing which treatment is which. They all have anecdotes “supporting” them, and for any one of them you can find countless blogs, forums, etc. singing their praises, and you have no objective way of which ones (if any) are actually safe and beneficial. That’s why we have to rely on science, and why I don’t recommend that anyone take these untested treatments.

In short, replacing science-based cancer treatments with alternative or complementary treatments reduces your chance of survival, and you should not rely on them.

Related posts

Literature cited

  • Johnson et al. 2018a. Use of Alternative Medicine for Cancer and Its Impact on Survival. Journal of the National Cancer Institute 110:121–124.
  • Johnson et al. 2018b. Complementary Medicine, Refusal of Conventional Cancer Therapy, and Survival Among Patients With Curable Cancers. JAMA
Posted in Vaccines/Alternative Medicine | Tagged , , | 2 Comments

6 major problems with a flat earth

I’m going to do something I thought I never would and hoped I’d never have to. I’m going to talk about the concept of a flat earth and explain a few of the many lines of evidence that clearly indicate that the earth is not flat. There are several reasons why I am doing this. First, I want to use the flat earth movement as a case-study in the types of flawed reasoning employed by science-deniers. As I have previously explained, most (if not all) forms of science-denial rely on the same logically-flawed tactics. Climate change deniers, anti-vaccers, flat earthers, etc. all commit the same suite of logical fallacies. Therefore, even if you think that the flat earth movement is ridiculous, hopefully you will benefit from this post by gaining a better understanding of the flawed lines of reasoning that lead to such positions.

The second reason for writing this is that I fear that the skeptic community has not done a good job of dealing with the apparent increase in the flat earth movement. With some noteworthy exceptions, we have tended to either ignore it or simply mock and deride those who believe in a flat earth, and I do not think that those are particularly helpful approaches. People are easily influenced by those around them, and in the modern technology age, finding misinformation is absurdly easy. Indeed, the internet is full of articles, videos, etc. claiming to have “proof” that the earth is flat. In such an environment, it should hardly be surprising that flat earthers seem to be growing in numbers, and I think it is important to make it as easy as possible for people to find explanations for why the flat earth arguments fail. To that end, this post will not contain any mocking, name-calling, etc. I have attempted to write it as a dispassionate explanation of the facts and logic, and although I occasionally deviated from that for dramatic effect, I want to make it clear that I am calling particular arguments stupid, rather than making any judgements about the people who use those arguments (even an intelligent person can use really insane arguments).

I’ve grouped this post into six major problems with a flat earth, but most of those groups actually include multiple different lines of evidence that preclude a flat earth (in one case, I broke the category up into sub problems, but each one builds on the others).


Ad hoc fallacies and the nature of science

Before I begin going over arguments about the shape of the earth, I need to spend a few minutes explaining an extremely common logical fallacy among flat earthers (and creationists, anti-vaccers, etc.). This is what is known as an ad hoc fallacy. Unlike most fallacies, this does not occur as part of an argument, but rather as part of a counterargument. It arises when someone is faced with evidence that contradicts their view, and they respond by inventing a solution for which there is no evidence. In other words, they invent a response that you would never accept unless you were already convinced of their view. It also often has the property of being unfalsifiable. In other words, it is something that cannot actually be tested and must be accepted on faith.

Let me give you an example. Imagine that I was talking to a self-proclaimed psychic, and I presented them with a test of their powers which they failed. Then, rather than accepting that I had exposed them as a fraud, they simply retorted with, “my powers don’t work in the presence of skeptics.” That would be an ad hoc fallacy. There is absolutely no evidence for that statement, and, indeed, I would never accept that response unless I was already convinced that they were a psychic. Further, it is not a falsifiable claim. If their magical powers conveniently stop working any time that they are tested, then there would, by definition, be no way to test that claim. I’d have to take it on faith.

Because they rely on self-reinforcing assumptions rather than evidence, ad hoc fallacies are not allowed in rational discussions, and they are diametrically opposed to how science works. Science, by its very nature, requires evidence. If you test a hypothesis and the test does not support it, you can’t simply make up some nonsensical “solution” and insist that your solution is correct. You’d have to accept that your hypothesis has been discredited (at least for the time being). To be clear, if you think that there may be something else occurring, you can propose that as a possible answer and subsequently test it, but your answer has to be falsifiable, and you cannot state it as a fact or even as a high probability until you have actually tested it.

All of this comes back to two important concepts of logical thought: Occam’s razor and the burden of proof. Occam’s razor is often incorrectly stated as “the simplest solution is usually the correct one,” but it actually has nothing to do with simplicity. It actually states that the solution with the fewest assumptions is more likely to be correct, and it dictates that we should not make any more assumptions than are strictly necessary to explain our observations. The burden of proof is simply the concept that the person making a claim is responsible for providing evidence to support it. In other words, it is not acceptable to make a claim like, “my powers don’t work in the presence of skeptics” unless you can provide actual evidence to support that claim. Further, the other party is not required to discredit the claim until that evidence has been provided (i.e., I am under no obligation to disprove the “psychic’s” claim).

With those concepts in mind, let’s take a look at some evidence.

Note: There is no one set of universally held views for flat earthers, so I have done my best throughout this to discuss the views that seem to dominate flat earther conversations and are endorsed on pages such as the flat earth wiki. Also, in situations where no one view seemed to dominate, I have tried to discuss all of the most common views I found.


1). The sun and the moon

This is a typical flat earth map, with the sun and moon circling overhead.

Many of the most obvious problems with flat earth views revolve around the sun and the moon, so let’s start there. For a flat earth to work, the earth clearly cannot be orbiting the sun, nor can the moon be orbiting the earth, and neither of them can be very far from the earth. To solve this problem, flat earthers argue that the sun and the moon are actually very small (only about 32 miles in diameter), they are very close to the earth (2,000–3,000 miles depending on which flat earther you ask), and they simply move in a giant circle over the earth, rather than orbiting anything.

1.1 Assumptions

There’s a lot to unpack there, but let’s begin with a simple question, “how did they get those numbers?” Quite simply, they got them by assuming that the earth was flat, then working out the math to try to make it possible to have a sun and moon on a flat earth. They even admit that to get those numbers you have to start with the assumption that the earth is flat. To put that another way, I would never think that those numbers are correct unless I was already convinced that the earth was flat. This is, already, an ad hoc fallacy. There is no evidence to support the claim that the sun is only 3,000 miles from the earth or that the sun is impossibly small. Rather, it is a cop-out that requires you to first believe that the earth is flat (thus it fails to meet the burden of proof). Further, we can use things like radar and lasers to calculate the distance of the moon, planets, etc. Flat earthers, of course, simply ignore all of those measurements and claim that they are part of a vast conspiracy (more on that later).

1.2 Impossible movements

Next, we have the problem of how the sun and moon are running around in circles above the earth. According to flat earthers, this is because all of the celestial bodies we see are moving around like a giant binary star system on steroids with the center of gravity conveniently above the north pole of the earth. This is, once again, ad hoc. It’s also mathematically absurd, but the math is too complex to take the time to explain, so instead, I will simply point out a huge inconsistency in flat earther’ views. This view requires gravity. That is the only way for such a system to even be hypothetically possible, but, as I’ll explain more later, flat earthers reject gravity and say it isn’t real (they have to do this, because otherwise, the earth’s gravity would pull the sun and moon crashing down into it).

This diagram (viewing a flat earth from the side) illustrates the absurdity of flat earther’s “spotlight” argument. Panel A shows how things would need to be for their model to be correct, but that is clearly not how light works. As panel B illustrates, if the sun acted as a spotlight, then no light would reach the moon. Panel C shows how light actually works. It radiates out from all points of a sphere. In reality, it would continue radiating out well past the moon, but for this figure I stopped it at the moon to illustrate that for light from the sun to reach the moon, it also has to, at the very least, constantly reach essentially the entire northern hemisphere (in reality it would constantly reach the entire earth).

1.3 Why can’t we see the sun all the time?

The next problem comes from the sun illuminating planet earth. If the sun is a mere 3,000 miles above the earth and is constantly hovering above the earth, we should see it all the time. There should never be a point in the day during which we cannot see it way off in the distance. To “solve” this, flat earthers propose that the sun acts like a spotlight that magically directs its light downward, rather than allowing the light to radiate outward. Thus, you only see it when it is close to overhead. This, of course, is pure madness (it’s also another ad hoc fallacy). That’s not how light works. A ball of light (such as a sun) radiates light in all directions, not just down. Further, if the sun was a spotlight, then it shouldn’t be able to illuminate the moon. I have sometimes seen flat earthers try to explain this away by proposing that the atmosphere (which they amusingly call the “atmoplane”) is so dense that the sun can’t pass through it at a shallow angle (i.e., when the sun is distant on the horizon, it has more atmosphere to pass through). That is, however, just more ad hoc speculation. Further, if it was true that our atmosphere was that thick and that good at blocking light, then how is it possible for us to see the stars? Surely their exceedingly dim light wouldn’t penetrate that atmosphere. Or, at the very least, they should only be visible from directly above, and we shouldn’t be able to see them on the horizon. The fact that we can see stars on the horizon, but not the sun clearly indicates that the thickness of the atmosphere is not the issue here.

This diagram (viewing a flat earth from the side) illustrates the fact that, on a flat earth, people in the northern hemisphere would see a different side of the moon than people in the southern hemisphere (the pink and blue triangles show the angle of view form a person in each hemisphere. Panels A and B show the same problem, but they demonstrate that the problem becomes worse as you move away from the equator. The size of the sun and the moon is not to scale with the earth based on flat earther views (but that is irrelevant since we are talking about spheres, and making them large was necessary or else they wouldn’t be visible), but their position above the earth is approximately correct for flat earth views, and even if the scale was way, way off from their claims, the same problem would remain.

1.4 Why do both hemispheres see the same surface of the moon?

There are other issues with this view of the sun as well, but let’s move on to the moon, because it creates a whole new set of problems for flat earthers. First, if the moon was circling 3,000 miles above us, then people in the northern hemisphere and people in the southern hemisphere should see very different faces of the moon. In reality, however, everyone sees them same face, it is just flipped upside down in one hemisphere. That alone clearly demonstrates that the moon is not circling overhead, but wait, there’s more.

This diagram (viewing a flat earth from the side) illustrates the fact that, on a flat earth, people in the northern hemisphere and southern hemisphere would experience different lunar cycles. For simplicity, I showed the sun casting a single beam, but it obviously actually radiates out in all directions. The dotted triangles show the points of view from people in the northern and southern hemispheres. Panels A and B show the same problem, but they demonstrate that the problem becomes worse as you move away from the equator, with people in the far south rarely seeing more than a sliver of lit moon. Panel C shows that even if we drastically alter the altitudes of the sun and the moon (as some flat earthers propose) the problem still remains. The size of the sun and the moon is not to scale with the earth based on flat earther views (but that is irrelevant since we are talking about spheres, and making them large was necessary or else they wouldn’t be visible). Their position above the earth is approximately correct for flat earth views, and even the scale was way off from their claims, the same problem would remain.

1.5 Why does everyone experience the same lunar cycles at the same time?

The lunar cycles also present a huge problem for flat earthers. They generally explain them by saying that the moon circles at a different rate than the sun, thus the cycles are caused by the sun’s light hitting the moon at different angles. That’s highly problematic though. First, as stated above, it conflicts with their “the sun is a spotlight” claim. Further, if that were true, then the entire earth wouldn’t experience the same lunar cycles simultaneously. In fact, it’s worse than that. According to this model, people in the southern hemisphere should never have a full moon, or, at best, a full moon should only occur in the middle of the day. Some flat earthers have tried to get around this by saying that the moon is sometimes at a higher altitude than the sun, but this still would not let someone in New Zealand (for example) see a full moon, and people in New Zealand do see full moons. Ergo, this position must be bogus. Just to prove that I am not making things up, here is a video by flat earthers showing what the lunar phases would look like on a flat earth. Notice that according to this video, different parts of the world should experience different lunar cycles (in reality we all experience the same cycles) and the southern hemisphere only gets a full moon in the middle of the day (again, that’s not what we actually see).

1.6 Flat earther responses to moon problems

Flat earthers have some imaginative ways to try to solve these problems with the moon. One popular view is that the moon is actually a flat disk, like a Frisbee. This is, once again, an ad hoc fallacy. They are just making things up to solve problems with their world view. Also, we know the moon isn’t a disk, because if it was, it would start to look like an oval as it descended over the horizon, ultimately looking like a sliver before disappearing on the horizon. The type of circular moonrise and moonset we observe is simply not possible with a Frisbee (it would have to turn so that it was facing us, rather than being a disk that is parallel to us). Additionally, if you look at the moon with a telescope or high-powered camera, you’ll notice that its craters are round in the middle, and gradually become ovals towards the edges. That makes perfect sense if we are looking at a sphere, but makes no sense whatsoever if it is a disk.

Another popular view is that the moon is actually self-luminous. In other words, it produces its own light (I wish I was making this up, but I’m not). Can you spot the logical fallacy there? Now, how or why it lights up is a mystery that flat earthers can’t explain. Similarly, the phases of the moon are hard to explain with this view, but that doesn’t stop flat earthers from trying. I have seen some propose that it is bioluminescent (so there is life on the moon apparently), and for unknown reasons these organisms light themselves up in massive groups that vary on a predictable pattern thus creating the illusion of lunar phases. Others propose that parts of the moon are simply “turned off” at various times (one wonders by whom, how, and for what purpose). Regardless of the mechanism, a self-illuminous moon still doesn’t solve the problem that people in the north and south should see different faces of the moon. Also, we know that the moon is illuminated by the sun, not itself, because its craters cast shadows, and those shadows are always consistent with the position of the sun.

1. 7 Lunar eclipses are impossible on a flat earth

One final problem that I want to talk about is the lunar eclipse. This happens when the earth passes between the moon and the sun, thus blocking the sun’s light. This is 100% impossible in a flat earth model (they even admit that). Therefore, they have invented what they call the “shadow object.” This is an object that orbits the sun, and is usually so close to the sun that you can’t see it, but occasionally it passes between the sun and the moon causing the eclipse. That’s right, they just completely invented a celestial object for which we have 0 evidence, and the only reason to ever think that such an object exists is because doing so is necessary for a flat earth view. That is a textbook ad hoc fallacy. You can’t simply invent celestial objects to save your pet view. That violates fundamental principles of logical reasoning and maintaining an evidence-based view of reality.

1.8 Other forms of science denial commit the same logical blunders

Now, at this point, it would be easy to laugh at flat earthers for constantly inventing solutions that they have no evidence for, but the reality is that most (if not all) groups of science-deniers do this. Creationists, for example, do this all the time. Just to give two quick examples, they arbitrarily claim that the radiometric decay was faster in the past, and they invent magical mechanisms for sorting fossils during Noah’s flood. Similarly, when faced with the fact that we have carefully tested the natural drivers of climate change and found that they cannot explain the current warming, climate change deniers often insist that there must be some other driver that we don’t know about. That response is, however, ad hoc. Inventing and unknown driver of climate change is no different from a flat earther inventing a shadow object. Anti-vaccers and the anti-GMO crowd are no better. They invent fanciful mechanisms through which vaccines and GMOs supposedly cause harm and they invent conspiracies and conflicts of interest anytime that a paper disagrees with them. All of these groups (and many others) commit the exact same logical flaw: they make massive assumptions to solve problems in their views, and that is not logically valid. You must have evidence to support your claim. It’s that simple.


2). Gravity

Gravity is another huge thorn in the side of flat earthers. You see, gravity should preclude a flat earth, because gravity would pull the earth into a sphere (you know, like it actually does). Further, even if the earth was solid adamantium and could resist gravity’s pull, a big problem would still remain. Namely, anytime that you weren’t on the North Pole, gravity would pull you sideways as well as down, because there would be more mass to one side of you. This would become exaggerated the further you moved from the North Pole. Most flat earthers admit this and acknowledge that gravity is fatal to their view, but don’t worry, they have a solution.

According to flat earthers, gravity is an illusion, and actually the earth is accelerating upwards at a rate of 9.8m/s^2, thus creating the appearance of gravity. So, when you drop an object, it doesn’t fall, rather the earth accelerates up towards it. This is, of course, yet another ad hoc fallacy. Also, there is no explanation for why the earth is accelerating. Flat earthers usually just cop out with, “dark energy is causing it,” or some other claim for which there is clearly no evidence or logical reasoning.

Additionally, it is clearly not enough for the earth to be accelerating, because if it was just the earth, then we would crash into the sun and the moon and shoot past the stars. Therefore, according to flat earthers, the entire universe is accelerating via unknown mechanisms (because reasons). Somehow, though, the earth shields the objects close to it (thus they can still fall) but doesn’t shield the sun and the moon, even though they are only a few thousand miles directly above the earth. How this happens is anyone’s guess.

Having the universe accelerate at a constant rate of acceleration raises the obvious problem that the earth would soon be going faster than the speed of light, which is impossible. To get out of this one, flat earthers invoke special relativity and claim that it allows an object to accelerate infinitely at a constant rate of acceleration without ever reaching the speed of light because of differences in reference frames. Invoking special relativity and other complex physics concepts is a common and irritating tactic by science-deniers. It is irritating because these concepts are so complicated that it takes an immense level of knowledge before you can even assess them. Thus, someone with no real knowledge of relativity can invoke it, and even if they are dead wrong, their opponent can’t explain why they are wrong without first earning a PhD in theoretical physics (which I don’t have).  The one thing I am sure of is that as you approach the speed of light, the energy needed for further acceleration increases to the point of infinity. So, they not only need a mechanism to explain the acceleration, but they need to explain how it is consistently infinitely increasing its energy output (good luck).

Note: originally I explained why I thought they might be wrong about relativity, but based on the comments, it seems that they may actually be correct that it can accelerate infinitely at a constant rate; it’s still hopelessly ad hoc though.

One final note about gravity is that their views on it are self-contradictory. As explained earlier, they invoke it to explain the movements of the sun and moon. They also need it for their mythical shadow object to orbit the sun. Further, we can very clearly see that celestial bodies move according to the laws of gravity, and we have used gravity to predict the existence of objects before they were directly observed (e.g., Neptune). Flat earthers seem to accept all of this. Thus, they have to argue that gravity is true, except for planet earth. Everything else produces gravity and acts according to the laws of gravity, but not earth (makes perfect sense, right?).


3). Coriolis effect

Flat earthers also struggle to explain the movement patterns of storm systems in the northern hemisphere vs the southern. You see, the spinning of the earth results in a phenomenon known as the Coriolis effect, and that causes storm systems in the northern hemisphere to spin counter-clockwise, while storm systems in the southern hemisphere spin clockwise (this video illustrates and explains why this happens). This is a huge problem for flat earthers, because they have no way to explain why storm systems spin in opposite directions in the north compared to the south.

I have yet to see a flat earther give a well-reasoned response to this problem, but here are the three responses that I have encountered on various videos, forums, and blogs. The first is to simply cop out by saying, “because of wind patterns.” That is clearly a non-answer, however. What causes the wind patterns? Yes, the storms circulate because of the wind patterns, but those wind patterns only move that way because the earth is spinning. There is no reason for them to move that way on a flat earth, that’s the point.

The second response is to attribute it to gravitational pull from the “celestial gears.” This is another baffling concept that flat earthers have invented. It proposes that different star systems form “celestial gears” and their rotation somehow has an impact on earth. This is, once again, ad hoc, but it is also inconsistent with their other views. Remember again that flat earthers reject gravity, yet here they are invoking it. Further, how could the stars (which according to them are tiny) create that type of gravitational pull? It just doesn’t make sense.

The final option is to simply claim that the Coriolis effect isn’t a real thing. On several forums, I have seen flat earthers assert that the differential movement of storm systems is just a myth invented as part of the “round earth conspiracy.” Thus, all those photos of storm systems are fake, and all the people (like me) who have experience both hurricanes in the northern hemisphere and cyclones in the southern hemisphere are liars. That is, of course, patently absurd, but the there is an entire section is on conspiracy theories, so I’ll simply direct you there.

Note: it is a myth that toilets in the southern hemisphere flush in a different direction than ones in the north. The Coriolis effect is not powerful enough to act on such a small scale. The direction of flush for toilets is determined by their plumbing, not the Coriolis effect.


4). Impossible flights

Flat earthers also struggle to explain many airline flights. You see, if you look at a flat earth map, continents in the southern hemisphere are very far apart, whereas ones in the northern hemisphere are quite close. This should cause impossibly long flights in the southern hemisphere, but very short flights in the northern hemisphere. Reality, however, is quite different.

This is the path that Flight 28 would have to take on a flat earth. It is impossibly long. There is no way to make this flight with a 747 on a flat earth.

Let’s take Qantas Flight 28 that goes between Sydney Australia and Santiago Chile as an example (there are multiple others that could be used, and you can find plenty of other websites that have worked out this math for other flights). This is a non-stop flight that travels over 11,000 km and takes 14 hours and 20 minutes. That is all well and good on a round earth, but if you look at a flat earth map, the distance becomes substantially larger. In fact, it should be around 25,000 km. This is a huge problem because 747s simply cannot fly fast enough to make that flight in that time. In fact, given that 747s fly at 920 km per hour, it would take over 27 hours to make the flight!

As you might expect, flat earthers have some entertaining ways to “solve” this problem. My favorite is probably the argument that people on the plane get drunk or fall asleep and lose track of time (yes, they do make this claim). I have seen others claim that airlines drug their passengers. These are clearly absurd suggestions. Obviously not everyone on the plane is drunk. Further, many people watch movies the whole time, and they’d notice if their flight took 10 hours longer than advertised. Further, many people (including me) don’t reset their watches until they land. So even if I got waisted, I’d know something was up when I looked at my watch and it was 10 hours off of what it should be, not to mention that most people coordinate pick up times at their destination, which will be seriously off if the airline lied by a full 10 hours.

Others, perhaps slightly more logically, propose that airlines have simply upgraded the engines on the planes so they go much faster than the airlines report. This is also insane. For one thing, why wouldn’t they use these fast engines on all their planes. Why keep it a secret? Further, the planes would have to go ludicrously faster than their reported speeds to make flights like this. A 747 would need to go over 1,700 km per hour to make that flight. That’s nearly twice its actual speed, and is 1.4 times the speed of sound. A 747 is not a supersonic plane. I shouldn’t have to say that.

Oh, and one other thing I failed to mention, 747s only have a range of 13,450 km. So, on a 25,000 km flight, they’d make it about half way before running out of fuel and crashing.

Given all these problems, many (possibly most) flat earthers take yet another route: they deny the existence of these flights. According to them, these flights only show up on the websites to further the “round earth illusion,” but they can’t actually be booked and no one has ever actually flown on one. Everyone who claims to have been on one of these flights is either lying or (according to some flat earthers) actually got off in a different country than the one advertised (you’d think they would have noticed that when going through immigrations).

Regardless of which answer you choose, the end result is that you have to believe in ludicrously impossible physics and a vast conspiracy involving every airline in the world. There is absolutely no way that commercial airline pilots wouldn’t know if the earth was flat. Their routes would make no sense if they were flying round earth routes on a flat earth. Further, although I used a long-distance flight as an illustration, these problems exist on a smaller scale for shorter flights as well, and pilots would notice the discrepancies. This conspiracy would be on an utterly absurd scale. Tons of people at Boeing would have to know about it, every airline company would know about, numerous officials at every airport would know about, every airline pilot would know about it, military pilots would know about it, etc. Also, the same problems would occur for sea travel. So, we have to add cruise companies, international shipping companies, every navy in the world, etc. to that list. It is a completely ludicrous conspiracy.

Note 1: Some flat earthers try to get out of problems like this by arguing that the actual flat earth map is unknown, thus the miles reported by the airlines (and seen on real maps) may actually be correct. The problem is that constructing a flat map where those miles are correct is utterly impossible. The geometry simply doesn’t work on a flat map. To put that another way, no flat earth map can explain these discrepancies in airline times/routes.

Note 2: Some flat earthers try to counter this by presenting multi-flight trips that seem unintuitive for a round earth (for example, a flight from Africa landing in Europe before going to South America). These flights are, however, completely possible on a round earth, they just aren’t the straightest routes (as opposed to the flight I presented which is impossible on a flat earth). Further, the reason for these non-direct routes is pretty obvious: demand. If airlines have very little demand for flights from A to C but plenty of demand for A to B and B to C, then they simply won’t run a direct flight from A to C and will route passengers through B instead.

A screen shot of Flight 28 on a booking site.


5). Impossible coordinates

GPS coordinates provide another proof that we are not on a flat earth. I’ll use the decimal degree system to illustrate, but you can do the same thing with any coordinate system. This system splits the earth up into a grid with 360 degrees running east-west (longitude) and 360 degrees running north-south (latitude). The system can seem a bit confusing at first, because longitude is scored as 0 to +/- 180 degrees, whereas latitude is scored from 0 to +/- 90 degrees, but if you look at the figures below, it should make sense. You’ll notice on the lower image (which is a projection of a globe onto 2-dimensional space) that the distance between the longitude lines (i.e., the lines running north and south) decreases as you move away from the equator, but the decrease is consistent both north and south of the equator. In other words, the distance covered by 1 degree of longitude changes as you move away from the equator (i.e., change in latitude). This should make sense if you think about a ball. Any line around a ball can be broken into 360 degrees, with each degree comprising the same distance along that line. Where you draw the line determines what that distance is, however. If you draw it around the center of the ball, it will be a long line that runs along the circumference with each degree measuring 1/360th of the circumference; whereas, if you draw the circle near the top of the ball, the line will be small, as will the distance contained in each degree.

This is really important because it indicates two things. First, a formula to calculate distances between two points on this coordinate system must take the curvature of the earth into account, or else the distance will be wrong. Second, for each degree of change in latitude, the change in the distance covered by a degree of longitude must be consistent when moving north or south from the equator. In other words, 1 degree of longitude (i.e., distance east to west) at a latitude of 15 (i.e., 15 degrees north of the equator) must cover the same distance as 1 degree of longitude at a latitude of -15 (i.e., 15 degrees south of the equator).

A flat earth model inherently requires a different relationship. The distance covered by a degree of longitude has to decrease above the equator and increase below it. In other words, on a flat earth, 1 degree of longitude at a latitude of 15 would cover far less distance than 1 degree of longitude at a latitude of -15.

As you can see, our coordinates systems shouldn’t work on a flat earth. On a flat earth, the distance between two points of longitude would decrease as you moved away from the equator heading north, and increase as you moved south. In reality, they decrease both north and south of the equator. That can only happen on a round earth (see the text for details).

You can clearly see how this plays out if you look at the dots on the maps I drew. The purple dots are at the following positions: lat 30 long 15, lat 30 long 30, lat -30 long 15, lat -30, long 30. The red dots are at: lat 75 long -60, lat 75 long -75, lat -75 long -60, lat -75 long -75. Now, we have a simple test of the shape of the earth. If it is round, then when we calculate the distances (east to west) of those points, we should find that both sets of purple dots have the same distance, and both sets of red dots have the same distance, but the distance between the red dots is smaller than the distance between the purple dots, even though all four sets of dots are separated by 15 degrees of longitude. In contrast, on a flat earth, that distance must be different for each set of points, with the distance decreasing as you move north.

So, which prediction is correct? You guessed it, we’re on a globe. At both 30 and -30 degrees latitude, 15 degrees longitude equals 1,442 km, and at both 75 and -75 degrees latitude, 15 degrees of longitude is only 430 km. That result is 100% impossible on a flat earth.

Think about it. These coordinate positions really are where things are. There’s no way to fake it. Every map, every GPS, every smart phone, etc. agrees. Further, we know that the distances between those points are correct. Just watch your odometer as you drive on a straight line and you can easily test this. In other words, we know that the calculations work. They have been ground-tested countless thousands of times, and you can easily test them yourself. Field biologists like me use them constantly, and if they didn’t work, we’d constantly be getting lost in the field, because nothing would be where we had calculated that it should be. The fact that the trigonometry accounts for the earth’s curvature and produces accurate results is proof that the earth is round. The math simply could not work on a flat earth.

If you are tempted by the flat earth position, then really think about this. Think about degrees around a circle, then try explain how it is possible that degrees of longitude have matching distances in the northern and southern hemispheres (as I have illustrated). Coordinates and distances that we know are correct simply cannot fit on a flat earth map. It is not mathematically possible. The math that people like me use daily cannot work on a flat earth.


6). We’ve been to space/everything is a conspiracy

I’ve talked briefly about the insane conspiracy theory that must accompany flat earth views at several points in this post, but I want to really focus on it here, because it is far more ridiculous than I had previously stated. You see, we have been to space. We have seen that the earth is round. Astronauts are orbiting it right now. We have countless hours of video and tens of thousands of photos. According to flat earthers, however, those are all fake. Every last one of them. According to them, we have never been to space (according to some of them, space doesn’t even exist). Thus, every single space agency in the world is conspiring together to fake space programs and create the illusion of a round earth. Also, the International Space Station doesn’t exist (even though you can see it with a telescope and photograph it with about $2,000 worth of camera gear). Additionally, satellites aren’t real either. Every company that claims to be using them is actually using a complex series of weather balloons. If all of this sounds insane, good, because it is. NASA alone employs thousands of people every year. That’s an awful lot of people to be keeping quiet, not to mention everyone who works with satellites, other countries’ space agencies, etc.

Now, you may be wondering why so many countries would do this. What benefit do they get from fooling all of us? Why, for example, during the Cold War would the Soviet Union and the USA both conspire together while simultaneously competing with each other? These are good questions, and flat earthers don’t have good answers.

Often, they make some claim about how these programs actually just exist for the militarization of space, and so they just fake their own accomplishments as propaganda to keep the public interested and keep the money flowing in. That explanation makes no sense though. For one thing, how are they militarizing space if we have never even been to space!? Further, why would all of today’s space agencies conspire together. Do you honestly expect me to believe the US and Russia are in a joint conspiracy to help each other build their militaries?

Additionally, the military argument makes utterly no sense when you start looking at the numbers. NASA gets around 20 billion dollars annually. In contrast, the US military gets around 600 billion a year. Further, funding for the US military is one thing that is never in question. Why on earth does the military need to invent this utterly insane conspiracy theory just to get an extra 20 billion!? That’s only 3.3% of their annual budget. It’s nothing for them. Further, by the time that you buy off everyone involved (thousands of NASA employees, thousands of airline pilots, thousands of ship captains, etc.), launch rockets into the ocean (which is where flat earthers think the rockets go), and fake all the videos and photos (which would involve hiring actors, building sets, special effects, tons of computer animation, etc.), there is hardly going to be anything left. Honestly, 20 billion a year is probably not enough to even attempt a conspiracy like this. Nothing about this makes any sense.

Nevertheless, regardless of the sheer lunacy of this conspiracy theory, it presents a more fundamental problem. Namely, conspiratorial thinking like this is inherently irrational because it makes it possible to explain away any evidence against the conspiracy theory. In other words, no matter what evidence anyone presents that the earth is round, flat earthers will simply write it off as part of the conspiracy. The airline situation is a perfect example of this. Rather than accepting that these long-distance flights discredit their view, flat earthers simply write them off as part of the conspiracy. That type of reasoning is inherently illogical, and if you care about rational thought, then that alone should be enough to make you reject the flat earth movement (to be clear, that isn’t a fallacy fallacy, because the flat earth position requires this conspiracy, but the conspiracy itself has no evidence to support it and is irrational).

Here again, I want to pause and point out that lots of people are quick to laugh at flat earthers for this type of thing, then immediately make identical arguments themselves. Anti-vaccers, for example, propose that there is a vast conspiracy involving all of the world’s medical agencies, governments, and the vast majority of the world’s scientists and doctors. Similarly, both anti-GMO activists and climate change deniers imagine a conspiracy involving numerous governments, every major scientific body, and thousands of scientists. All of these conspiracies theories are irrational for the same reasons. Namely, they don’t have any solid evidence to support them (i.e., they are ad hoc assumptions), and are used to blindly write off any contrary evidence.


In short, to believe in a flat earth, you have to believe that the sun and moon both defy physics to run in continuous circles overhead, and you have to overlook the fact that this would prevent people in the southern hemisphere from ever seeing a full moon, and you have to overlook the fact that this would result in people in different hemispheres seeing different faces of the moon, and you have to ignore the fact that this would result in different lunar cycles in different parts of the world. You also have to believe that the sun somehow acts as a spotlight (which makes no sense). You also have to either believe that this spotlight somehow also illuminates the moon even though the moon should not be in the direction of the spotlight or you have to believe that the moon is self-illuminating. You also have to believe in a “shadow object” for which there is zero evidence, but the existence of which is required to explain a lunar eclipse on a flat earth. Further, you have to ignore the fact that a flat earth model can’t explain the fact that storm systems spin in different directions in different hemispheres. You also have to believe that gravity is a myth and via unknown means, the entire universe is accelerating upward at a constant rate of acceleration of 9.8m/s^2, but the earth somehow shields objects on it from the force causing this acceleration, yet somehow the sun and moon aren’t shielded. Also, you have to simultaneously believe that gravity does exist for every celestial body other than earth. Additionally, you have to either believe that certain airline flights don’t exist and everyone who claims to have been on them is lying, or you have to invent fictional technology that lets 747s fly faster than the speed of sound and greatly exceed their fuel limitations. On top of all of this, you have to ignore the fact that it is impossible to consistently plot known geographic coordinates onto a flat earth map. The math simply doesn’t work. Finally, you have to invent an insanely massive conspiracy involving every government, every space agency, every airline company (and their pilots), every international shipping company (and their ships’ crews), every company that is involved with satellites, etc. None of this makes any sense whatsoever.

As absurd as all of this may seem (and, indeed, as absurd as it actually is), flat-earthers are not alone in constructing this type of lunacy. The logical fallacies, conspiracy theories, etc. that pervade the flat earth movement are also prevalent among anti-vaccers, climate change deniers, etc. Indeed, essentially all forms of science denial suffer the same suite of logical blunders. So, before you mock flat earthers, take a good look at your own views, and make sure that you aren’t suffering the same errors in reasoning.

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No one is hiding a cure for cancer

A cure for cancer is something of a holy grail in medicine, and many people would have you believe that we’ve already found it, but it’s existence is being hidden and suppressed by greedy companies who only care about profit. These people are, however, wrong, and a cure for cancer is just as mythical as the holy grail itself. Indeed, as I will explain, this conspiracy theory fails at every level. It has no supporting evidence, it is entirely an assumption, and it makes no sense scientifically, logically, or economically.

A single cure is scientifically implausible

First, it is absolutely crucial to realize the cancer is not a single disease. Rather, there are many different types of cancer, each of which behaves differently, and each of which will require a unique treatment/cure. Once you actually understand what cancer is and how it behaves, it quickly becomes clear that the very notion of a single cure for cancer is absurd. It is highly unlikely that there will ever be a single solution to all cancers. Rather, there will be different solutions for the different types of cancer. So, right off the bat, we can see that this conspiracy theory is bunk, because it completely ignores the complexity of cancer and proposes the existence of an implausible solution.

Why wouldn’t a cure be profitable?

This conspiracy theory postulates that companies are hiding a cure for cancer because a cure isn’t profitable. That premise has, however, never made the slightest bit of sense to me. How on earth would a cure not be immensely profitable? Purveyors of “natural remedies” already make a fortune off of “cures” that don’t even work, so why wouldn’t pharmaceutical companies be able to profit from an actual cure?

Some people try to counter this by claiming that companies make more from treating cancer than they would from curing it, but couldn’t a company simply charge the same amount for a cure that they currently charge for a full course of treatment? This argument seems to assume that cures would be sold for reasonable prices, but given that pharmaceutical companies have a long history of charging exorbitant prices for products that are relatively cheap for them to make, that assumption is clearly ridiculous. Further, never forget that there are multiple pharmaceutical companies that compete with each other. So, if one of them came out with a cure, they would have a monopoly on the market. How could that possibly be anything other than immensely profitable? Additionally, even beyond the direct profits from the monopoly on the cure, just think about how much good publicity that company would get, and think about investors. Who wouldn’t want to invest in a company that just announced a cure for cancer?

At this point, I usually find that people invoke planned obsolescence and the concept that a cure would be such a great product, that it would quickly put the company out of business. The idea of planned obsolescence is basically this, if you make a product that is really good and lasts forever, you’ll quickly saturate the market and have no one left to sell to. If, for example, you make a microwave that lasts forever, then once everyone has one, you have no one left to sell to. Thus, some companies design their products to eventually fail, that way there are always people who need the product.

I don’t deny that planned obsolescence is a real thing that companies do, but it has absolutely no bearing on the topic of cancer cures, because there will always be new cases of cancer. In other words, this isn’t a situation where once you’ve cured everyone’s cancer, there will never be more cases of cancer. Rather, there will always be new cancer cases. Indeed, over 1.7 million people are diagnosed with cancer annually in the US alone. Worldwide, that number is closer to 15 million. That’s a pretty steady income stream if you have a cure. Further, having a cure gives you repeat customers, not only for cancer, but also for countless other medicines that pharmaceutical companies produce. After all, who are you going to sell Viagra to if everyone is dying of cancer before they need it?

Cures and preventions already exist for many conditions

The next critical flaw in this conspiracy theory is the fact that many cures already exist for various conditions. Take antibiotics, for example. According to the argument that a treatment is worth more than a cure, a prolonged hospital stay from an out-of-control infection is surely worth more to pharmaceutical companies than a simple course of antibiotics, so why do they sell antibiotics? Similarly, the HPV vaccine actually prevents some types of cancer and costs only a tiny fraction of the cost of treating cancer! So if this conspiracy was true, then why on earth do pharmaceutical companies produce that vaccine?

Why do companies invest in cancer research?

In my opinion, this is one of the best pieces of evidence against this conspiracy. Pharmaceutical companies invest billions of dollars in studying cancer. Why would they do that if they already have a cure that they have no intention of ever using? How is it profitable to spend billions of dollars looking for something that you already have and will never use?

I’ve yet to have someone give me a reasonable answer to this, but I want to briefly talk about a response that I’ve heard that always amuses me. This response suggests that companies do this to keep their competitors from getting the cure, but if you think about that for five seconds, an obvious problem emerges. Keeping your competitor from having the cure only makes sense if your competitor can profit from it, so if they can profit from it, why can’t you? In other words, this response acknowledges that a cure would actually be profitable.

There are lots of independent scientists studying cancer

I don’t understand why conspiracy theorists never seem to realize that there are thousands of independent scientists who aren’t beholden to companies and who have absolutely no reason not to go public with a discovery like a cure for cancer. Do these people know about the cure? If so, why aren’t they telling anyone? Further, if the cure is as simple and obvious as most proponents of this conspiracy theory seem to think, then if these scientists don’t know of the existence of the cure, why haven’t they discovered it themselves?

Cancer affects everyone

Nearly 40% of people will develop cancer at some point in their lives, and almost everyone has lost a friend or relative to cancer. This is important, because it means that everyone involved in this conspiracy would not only have to be willing to let millions of people die annually from cancer, but they would also have to be willing to let their loved ones or even themselves die rather than letting the cure become public knowledge. That’s not likely. It’s easy to forget that big corporations are run by people, and they may be greedy, but when their spouse, child, etc. is dying of cancer, they are going to want that cure just as badly as anyone else, and they’d pay anything for it. Further, keep in mind that if a cure existed, tons of people would know about it. An entire research team consisting of numerous scientists, lab techs, interns, etc. would be aware of it. Countless people involved in budgeting and finances would be aware of it, numerous CEOs would know about it, etc. All it takes is for one of them to grow a conscience and the whole thing is shot. Yes, there would be consequences for breaching a contract, but history is full of people who sacrificed far more for far less than a cure for cancer.

Fortune and glory

indiana jones fortune and glory kidAnother thing that people often overlook is that fact that if a team of scientists found a true cure for cancer, they would win immeasurable fortune and glory. A cure for cancer is a guaranteed Nobel prize. It would give you a spot on any talk show you wanted to be a guest on, multiple book deals, your face on the cover of Time Magazine, etc. Further, beyond the public fame, you would be known professionally as one of the best in your field, and every university in the world would be begging for you to give guest lectures, be the head of a department, etc. Indeed, you would go down in medical history alongside the greats like Jonas Salk and Louis Pasteur. Your name would be taught to elementary school children for generations to come. Who in their right mind would turn that down? No scientist would sit on a discovery like that.

Now, you may try to counter this by saying that these scientists are under contractual obligation with the companies not to make their results public. I would respond to that by directing you to the previous sections on independent scientists and the fact that cancer affects everyone. Further, given the immense rewards for this discovery, I have a hard time accepting that most scientists wouldn’t be willing to face the consequences of breaching their contract.

Cancer treatments have been improving

In addition to everything else I’ve said, I want to point out that all of those billions of dollars we’ve spent on cancer research haven’t been wasted. Our knowledge of cancer and our ability to treat it has increased greatly. Indeed, over the past 30 years, the survival rate for cancer has increased 20–23% (depending on which ethnic group we are talking about)! That’s a huge increase. It has been particularly pronounced for certain cancers like lymphocytic leukemia, for which the survival rate went from 41% to 70%. Similarly, chronic myeloid leukemia went from a 31% survival rate to a 63% survival rate. Why are the survival rates for cancer going up? Because scientists are doing real research, and companies are marketing the results of that research. Also, let’s be clear here that many of these people were cured of their cancer. Most of them aren’t receiving life-long treatments. In other words, we already cure many cases of cancer. So if Big Pharma had no interest in curing people, then why are the rates of cancer survival going up? (stats are from the American Cancer Society’s 2016 Cancer Statistics report)

Look, science is a slow, steady process of accumulating knowledge, and the idea that it is even possible to suddenly find a magical cure for all cancer is naïve and childish. It completely ignores the incredible complexity of cancer. Remember, there are lots of different types of cancer, each of which has to be treated differently. Further, cancer is more challenging than many diseases because we have to fight our own cells. Making a cure for something like a bacterial infection is comparatively simple, because bacterial cells are chemically quite different from our cells, so we just need a drug that targets bacterial chemistry, but doesn’t interact with our cells. Cancer is more complicated because the differences between a cancer cell and a healthy cell are far more subtle. Healthy cells and cancerous cells share the vast majority of their chemistry. So figuring out a way to target cancer cells without affecting healthy cells is extraordinarily difficult. As a result, scientists have never expected to find a single simple solution. No one writes a grant application that says, “I’m going to cure cancer.” Rather, we chip away at the puzzle one little piece at a time, with each piece of evidence building on the last. We gradually accumulate knowledge and improved treatments. That is how research actually works, and that is what has been taking place.

There’s no evidence of a conspiracy

Finally, and perhaps most importantly, there is absolutely no evidence that a cure exists and is being hidden, and you have to have that evidence before you can claim otherwise. In other words, even if everything that I had said thus far was incorrect, even if a single cure for cancer was scientifically plausible, and even if it really wouldn’t be worth butt-loads of money, and even if scientists would be willing to pass up a Nobel Prize, and even if companies weren’t already making cures for various conditions, and even if companies were willing to waste billions on irrelevant research, and even if every single person involved with cancer research was a greedy SOB, that still wouldn’t make it rational to conclude that a cure exists. In other words, even if you came up with a compelling argument that demonstrated that a cure would be suppressed if it was ever found, that wouldn’t automatically mean that one has been found. This entire conspiracy is 100% an assumption. It is a belief that is based on people’s gut feelings, rather than evidence. It is no different than believing in alien abductions, Big Foot, or the Loch Ness Monster, and just like all of those things, it is a belief that is not rational unless you can provide compelling evidence that the object of your belief is real. You have to have evidence. That is how the burden of proof works.

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Occam’s razor is about assumptions, not simplicity

occam's razor meme peope complex answers simple

Image via The Questionist

Occam’s razor is an important tool for critical thinking, and it is employed constantly in science. Nevertheless, it is often misunderstood and is frequently (and erroneously) stated as, “the simplest solution is usually the correct one.” This is an unfortunate and misleading way to phrase the razor, because it leads people to conclude that conceptually simpler hypotheses are more likely to be correct, and that isn’t actually true. I have, for example, shared images like the one above multiple times on my blog’s Facebook page, and almost without fail, someone responds to them with something to the effect of, “Occam would have something to say about this.” The reality is, however, that Occam’s razor is actually about making assumptions, not conceptual simplicity. In other words, a “simple” hypothesis is one that doesn’t make unnecessary assumptions, not one that is conceptually simple.

I will elaborate on what I mean by unnecessary assumptions in a moment, but first I want to talk a bit more about conceptual simplicity. If you have ever really studied science, then it should be obvious to you that reality isn’t simple. Indeed, the history of science is largely the history of replacing a conceptually simple understanding of nature with an increasingly complicated understanding. In the pre-science era, many people had a very simple understanding of nature. There were only four elements, the earth was the center of the universe, etc. Those ideas were all replaced with far more complex scientific explanations, but those complex explanations are correct.

This accumulation of complexity also happens within science. Gravity provides a good example of this. Newton’s understanding of gravity was far simpler than the more complicated general relativity model proposed by Einstein, but that doesn’t make Einstein wrong nor does it mean that he violated any guidelines of logical thought by proposing it. Indeed, science has repeatedly confirmed that Einstein was right, and we need his conceptually complex model to account for how nature works. Biology has gone through similar revisions. Our modern understanding of evolution, for example, is far more complicated and nuanced than what Darwin proposed. There are many additional (and very correct) layers of complexity that have been added to our understanding over the years (e.g., neutral evolution, punctuated equilibrium, etc.). Indeed, most, if not all, branches of science have experienced similar increases in complexity, and that’s fine. It doesn’t violate Occam’s razor.

Note: In the examples above (and many examples for core scientific topics), the original idea was not wrong so much as incomplete. Darwin and Newton were mostly right, there were just some special circumstances that they weren’t aware of.

Having said that, you should never make a model, hypothesis, etc. more complicated than it needs to be, but simply saying, “hypothesis X is complex and hypothesis Y is simple” doesn’t really tell you much about which one is more likely to be correct. Assumptions, in contrast, tell you a great deal about which hypothesis is more likely to be correct.

Assumptions are the heart of what Occam’s razor is actually about, and the correct way to state the razor is that you should never make more assumptions than are strictly necessary. This concept, sometimes referred to as parsimony, is a guiding principle of science. Everything should be based on evidence and known facts, and the further outside of the known you have to step, the more likely you are to be wrong.

If you think about this for a second, it should make good, intuitive sense. Assumptions are, by definition, things that may or may not be true. Thus, the more potentially untrue components your hypothesis has, the higher the probability that it will be wrong. We can describe this mathematically. Let’s say, for sake of example, that you have a hypothesis that makes one assumption and there is a 90% chance that your assumption is correct (pretend we know that somehow). Watson also has a hypothesis, but his hypothesis makes three assumptions, each of which has a 90% chance of being correct. Your hypothesis only has a 10% chance that its assumption is wrong; whereas for Watson’s hypothesis, there is a 27% chance that at least one of the assumptions is wrong. Thus, it is obvious that his hypothesis is less likely to be correct (see this post for probability calculations).

In case math isn’t your thing, we can use some every-day examples to illustrate this as well. Imagine that you get in your car and try to start it, but when you turn the key, the engine won’t start. It won’t even turn over. Now, there are several possible hypotheses. The most obvious three are that it is the battery, starter, or alternator, but let’s say that you have an additional piece of information. Let’s say that yesterday you had your alternator and battery tested, and they both checked out as fine. Now, which of those three hypotheses is more likely to be correct based on the information you have? It’s obviously the starter, right? You just had the other two tested, so it’s reasonable to conclude that they likely aren’t the problem. This is a perfectly rational and intuitive conclusion, but when we break it down, it’s really just an application of Occam’s razor. Consider, the starter hypothesis proposes only one unknown: there is something wrong with the starter. In contrast, both the battery and alternator hypotheses require additional assumptions, because not only must there be something wrong with one of those car parts, but you also have to assume that the test equipment you used yesterday was faulty, or that a problem happened to develop right after being tested, etc. You have to make an assumption that is not required for the starter hypothesis.

To further illustrate this, we can construct hypotheses with additional assumptions. I could, for example, propose that the starter, battery, and alternator all died simultaneously. Now I have multiple assumptions running, and I trust that it is clear that it is unlikely for all of those things to have gone bad at the same time. We can make it even more ridiculous though by also assuming that in addition to those three parts, the ignition coil, spark plugs, and spark plug wires are also dead (see note). Do you see my point? Every time that we add another unnecessary assumption, the odds of the hypothesis being correct go down. We don’t need to be making assumptions about spark plugs, ignition coils, etc., and therefore we shouldn’t. We should work with what we know and add other assumptions only if they become strictly necessary.

Note: Yes, I know that bad spark plugs, spark plug wires, and the ignition coil(s) would not prevent the engine from turning over, but that only further illustrates the absurdity of assuming that they also stopped working. 

I want to segue here briefly into a related topic: ad hoc fallacies. These fallacies are prevalent in anti-science arguments, and they are fundamentally failures to apply Occam’s razor. They occur when, after being faced with evidence that defeats your position, you invent a solution (i.e., make an assumption) that serves no function other than attempting to patch the hole in your argument.

Let me give an example. Suppose that a friend is with you when your car won’t start, and suppose that you have bragged to him repeatedly about how your car is impervious to faults and can’t break-down. Thus, upon seeing your car’s failure to start, he snidely says, “so much for your car never breaking down.” You are, however, unwilling to acknowledge that your car is capable of having flaws, so instead, you claim that someone must have sabotaged it. That is an hoc fallacy. You arbitrarily assumed that someone sabotaged your car even though you have no evidence to support that claim and even though it breaks Occam’s razor by making unnecessary assumptions.

That example may seem absurd and obviously silly, but people do this all the time. For example, anytime that you see someone in an internet debate blindly accuse their opponent of being a “shill,” they are committing this fallacy. They are assuming that their opponent has a conflict of interest rather than accepting contrary evidence. Similarly, when people blindly reject scientific studies based on assumptions that the studies were funded by major companies, they are committing this fallacy. Indeed, anytime that someone resorts to a conspiracy theory to dismiss a contrary piece of evidence, they are committing this fallacy and are being irrational.

This brings me to my final point. Namely, the quality of the assumptions matters as well as the quantity. In other words, some assumptions are more justified than others. Someone could, for example be pedantic about my car example and argue that saying that the starter died and saying that the starter and spark plugs died both make the same number of assumptions because the first one implicitly assumes that the spark plugs did not die. It should be obvious, however, that (unless you have been having perpetual problems with your car) the default position should be to assume that things work. Every time that you get in your car, you’re implicitly assuming that all of its necessary parts work. Technically, you could argue that the opposite hypothesis (i.e., that none of the parts work) makes the same number of assumptions, but one set of assumptions is clearly more justified than the other (the reasons behind that get into inductive logic and the burden of proof and other concepts that I don’t have time to go into here). The same is true in science and debates. It is not valid to, for example, assume that the entire scientific community is involved in a massive conspiracy, and you can’t try to validate that assumption by saying that everyone else is assuming that the conspiracy doesn’t exist. Those two assumptions are not equal, and you need some concrete evidence before you can claim that there is a conspiracy.

In short, Occam’s razor does not state that the simplest solution is more likely to be correct. Rather, it says that the solution that makes the fewest assumptions is more likely to be correct; therefore, you should restrict your assumptions to only the ones that are absolutely necessary to explain the phenomena in question. A solution can be very complicated and still likely be correct if it is based on facts, not assumptions. Indeed, the answers science produces tend to be conceptually complex, and the history of science is a graveyard of simple ideas that were replaced with more complex ones.

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Vaccines are “unavoidably unsafe,” but that doesn’t mean they are dangerous

vaccineI have increasingly seen anti-vaccers citing the fact that vaccines are considered “unavoidably unsafe,” as proof that vaccines are dangerous and should be avoided. In reality, however, the term “unavoidably unsafe” is just legal jargon that does not mean what anti-vaccers think it means. So let’s talk about what it actually means

The first thing to realize is that this is a legal term, not a scientific one. This is not a term that scientists use when doing risk assessments or testing the safety of drugs. So right off the bat, we have a huge problem because this argument is conflating legal terms with scientific ones (I’ll return to that at the end). So what does this legal term actually mean?

Basically, it means that there is nothing that can be done to make the product safer without compromising the function of the product. The term comes from the legal document, “Restatement (Second) of Torts, Section 402A,” and it is about protecting manufacturers from frivolous law suits, not about providing consumers with health information. The basic idea is simply that companies cannot be held accountable for an injury that arises from unavoidably unsafe products because there was nothing that the company could have done to prevent that injury (inherent in this term is the requirement that the product was manufactured correctly, labelled correctly with adequate instructions for how to administer it, etc.).

Let me give you an example of what that means. The term is generally not applied to food, but if it was, peanut butter could be considered unavoidably unsafe, because some people have allergic reactions to peanut butter, and there is nothing that a peanut butter company can do to prevent that. In other words, there is no way to manufacture peanut butter without that risk being present. Thus (assuming that the product was manufactured and labelled correctly), a peanut butter company would not be liable if someone had an allergic reaction to the peanut butter, because that reaction was not the result of manufacture negligence. Now, does that mean that peanut butter is dangerous? No, obviously not. For the majority of us it is perfectly fine. “Unavoidably unsafe” does not mean that a product is dangerous and should be avoided. Rather, it simply means that are risks that cannot be removed.

When we apply that to vaccines, we see the same thing. Vaccines have side effects. No one has ever denied that, but serious side effects are rare, and the benefits far outweigh the risks. Indeed, Section 402A specified that “unavoidably unsafe” products should have benefits that outweigh their risks. So labeling vaccines as unavoidably unsafe absolutely does not mean that they are dangerous and should be avoided. It simply means that there are risks that are not manufacture’s fault. Also, just to be 100% clear here, everything has risks, including the decision not to vaccinate. People often focus on the risk of taking an action and ignore the risk from not taking that action, but a correct risk assessment has to consider both, and for vaccines, the risk from not vaccinating is much higher than the risk from vaccinating.

Finally, I want to return to me previous comment about this being a legal term not a scientific term. Those who deny science frequently like to cite courts, legal documents, etc. as evidence of their position, but that is simply not how science works. Even if a legal body like the Supreme Court had said that vaccines are dangerous, that would not be evidence that vaccines are dangerous. Lawyers and judges are not scientists. When they make a statement about science, they are stepping outside of their area of expertise. Further, even if they were scientists, that wouldn’t turn what they say into a fact. In other words, when they say something it doesn’t automatically become true. Whether or not something is a fact has to be determined by conducting studies. That is where scientific evidence comes from, and scientific studies overwhelmingly support the safety and effectiveness of vaccines. Trying to use a legal ruling as evidence against scientific studies is foolhardy. It is also pretty ironic and hypocritical for anti-vaccers (a group that is notorious for distrusting the government) to cite a government ruling as if it gives them a checkmate.

In short, “unavoidably unsafe” is simply a legal term that means the manufacture is not liable because they cannot do anything to make the product safer. It does not mean that the product is dangerous and should be avoided.

Note: Some pedants may take issue with the way that I have been using the term “dangerous” and, admittedly, even some documents about “unavoidably unsafe” products use it in a way that is inconsistent with how we usually use the term. So, when I say “dangerous” I mean a product or activity with a high enough chance of causing harm and low enough benefits that it should be avoided. That does not mean, however, that there is no chance of something “safe” causing harm. Swimming, for example, is not something that I would usually consider “dangerous” even though death is possible. Swimming during a thunder storm, however, I would consider dangerous. See the difference?

Recommended further reading

Schwartz. 1985. Unavoidably unsafe products: Clarifying the meaning and policy behind comment K. Washington and Lee Law Review 42: 1139–1148.

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Posted in Vaccines/Alternative Medicine | Tagged , , | 8 Comments