Pro-science skeptical activist blogger, musician, and polymath promoting science education, and smashing pseudoscience and denialism

Glyphosate and the Gut Microbiome: Another Bad Argument Annihilated

Introduction:

Glyphosate is a broad spectrum herbicide that was first introduced by the Monsanto company in the 1970s under the brand name Roundup. The already popular product grew even more popular among farmers upon the introduction of various commodity crops which were genetically engineered to resist the herbicide while it killed the surrounding weeds with which the crops would otherwise compete for water and nutrients. Glyphosate went off patent back in the year 2000, and since then many manufacturers have cashed in on its popularity [1]. Although it is of unusually low toxicity, glyphosate receives a level of scrutiny and vehemence of criticism that is disproportionate to its actual established risks [2],[3],[4]. This is attributable in part to its ubiquity in modern conventional farming, but it’s likely even more attributable to its association with Monsanto, against which a large and well-organized counter-movement has emerged [5]. (more…)

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By Credible Hulk, ago

Genetically Engineering Foods Involves Greater Precision and Lower Risk of Unintentional Changes Than Traditional Breeding Methods

Introduction

There exists an international scientific consensus that existing genetically engineered foods are at least as safe as their closest corresponding non-GMO counterparts [1]. This consensus is drawn on decades of research and thousands of studies. Despite this fact, there still exists a broad gap between the science and public perception of the topic. According to PEW reports, this gap is wider than on any other topic for which a strong scientific consensus exists [2].

This is significant because we know several other scientific topics have remained highly controversial in the court of public opinion for decades after having achieved mainstream acceptance among experts. Young Earth Creationists have been trying out various strategies for roughly a century to undermine the teaching of evolution in public schools in the US [3]. Rejection of Anthropogenic Climate change is ubiquitous in the US, and even extends to the POTUS himself, despite the weight of the evidence and resulting scientific consensus to the contrary [4],[5],[6],[7]. Although its prevalence has waxed and waned over time, vaccine opposition has been a near constant presence ever since the discovery of the cowpox vaccine [8],[9]. So, for there to exist an even bigger gap between science and public perception on GE foods than for any of these other topics, is no trivial matter.

One of the most common reasons given for trepidation with respect to GE foods is the idea that it’s a more radical way of altering our foods than more traditional methods of artificial selection, and that we therefore can’t know whether or not GE foods are bad until they’ve been around for several more human generations. This view relies on an argument from ignorance logical fallacy, and presents a double standard with no biologically plausible justification. One fact that proponents of this view rarely acknowledge is that it also leads to the generation of testable hypotheses, the results of which actually suggest the exact opposite. Allow me to explain. (more…)

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By Credible Hulk, ago

Scientific Consensus isn’t a “Part” of the Scientific Method: it’s a Consequence of it

Although conceptually simple, the term “scientific consensus” is often misused and misunderstood. It can get confused with appeals to popular opinion or erroneously conflated with “consensus” in the colloquial sense of the word. These misunderstandings can lead to things like opinion polls, often predominated by unqualified individuals, being misconstrued as evidence that no scientific consensus exists on some topic for which it clearly does, or that it leans towards a different conclusion than it actually does. In some cases, the very concept itself invokes resentment or even retaliatory commentary from people whose views are threatened by its implications. The purpose of this article is to clarify the concept that the term scientific consensus is meant to refer to and address some of the arguments commonly leveled against it.

Defining Scientific Consensus

Just as the term “theory” has a different meaning in science than its colloquial usage, the term scientific consensus means something different than “consensus” in the usual colloquial sense. The latter typically refers to a popular opinion, and needn’t necessarily be based on knowledge or evidence. On the other hand, a scientific consensus is, by definition, an evidence-based consensus. A convergence of the weight of existing evidence is a prerequisite which distinguishes a knowledge-based scientific consensus from mere agreement. This is critical, because the scientific enterprise is essentially a meritocracy. As a result, it doesn’t matter if a few contrarians on the fringe disagree with the conclusions unless they can marshal up evidential justification of comparable weight or explain the existing data better. The weight of the evidence is paramount. (more…)

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By Credible Hulk, ago

Why The Asbestos Gambit Fails

People who oppose one or more areas of mainstream science have developed a wide variety of creative ways of rationalizing their rejection of scientific evidence and scientific consensus. Realizing that they cannot rebut a particular scientific idea on the basis of the evidence, some of them will instead resort to attacking the reliability of scientific knowledge more generally. A popular method of doing so is the Asbestos Gambit. The argument is that the story of asbestos implies that areas of strong scientific consensus can’t be trusted. The purpose of this article is to examine the history of asbestos use and the evolution of our knowledge of the health dangers it presents, and to explain why the Asbestos Gambit is a terrible argument on multiple levels. (more…)

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By Credible Hulk, ago

The One True Argument™

Anyone who has spent much time addressing a lot of myths, misconceptions, and anti-science arguments has probably had the experience of some contrarian taking issue with his or her rebuttal to some common talking point on the grounds that it’s not the “real” issue people have with the topic at hand. It does occasionally happen that some skeptic spends an inordinate amount of time refuting an argument that literally nobody has put forward for a position, but I’m specifically referring to situations in which the rebuttal addresses claims or arguments that some people have actually made, but that the contrarian is implying either haven’t been made or shouldn’t be addressed, because they claim that it’s not the “real” argument. This is a form of No True Scotsman logical fallacy, and is a common tactic of people who reject well-supported scientific ideas for one reason or another. In some cases this may be due to the individual’s lack of exposure to the argument being addressed rather than an act of subterfuge, but it is problematic regardless of whether or not the interlocutor is sincere. (more…)

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By Credible Hulk, ago

No, Solar Variations Can’t Account for the Current Global Warming Trend. Here’s Why:

In part I of this series on the sun and Earth’s climate, I covered the characteristics of the sun’s 11 and 22 year cycles, the observed laws which describe the behavior of the sunspot cycle, how proxy data is used to reconstruct a record of solar cycles of the past, Grand Solar Maxima and Minima, the relationship between Total Solar Irradiance (TSI) and the sunspot cycle, and the relevance of these factors to earth’s climate system. In part II, I went over the structure of the sun, and some of the characteristics of each layer, which laid the groundwork for part III, in which I explained the solar dynamo: the physical mechanism underlying solar cycles, which I expanded upon in part IV, in which I talked about some common approaches to solar dynamo modeling, including Mean Field Theory. This installment covers how all of that relates to climate change and the current warming trend. (more…)

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By Credible Hulk, ago

Mean Field Theory and Solar Dynamo Modeling

In a recent post, I talked about the characteristics of the sun’s 11 and 22 year cycles, the observed laws which describe the behavior of the sunspot cycle, how proxy data is used to reconstruct a record of solar cycles of the past, Grand Solar Maxima and Minima, the relationship between Total Solar Irradiance (TSI) and the sunspot cycle, and the relevance of these factors to earth’s climate system. In a follow up post, I went over the structure of the sun, and some of the characteristics of each layer, which laid the groundwork for my last post, in which I explained the solar dynamo: the physical mechanism underlying solar cycles.

Before elaborating on the sun’s role in climate change in the installment following this one, I’ll be going over an approach called “Mean Field Theory” in this installment, which dynamo theorists and other scientists sometimes use to make the modelling of certain systems more manageable. As was the case with part III, this may be a bit more technical than most of my subscribers are accustomed to, but I think the small subset of readers with the tools to digest it will appreciate it. And to be perfectly blunt, writing this was not just about my subscribers. I wanted to do it. It was an excuse for me to dig more deeply into something that has been going on in modern stellar astrophysics that I thought was interesting. The fact that it happened to be tangentially related to my series on climate science was a mere convenience. Anyone wanting to avoid the math and/or to cut to the chase with respect to the effects of solar cycles on climate change might want to skip ahead to part V, or perhaps just read only the text portions of this post. However, for those who don’t mind a little bit of math, I present to you the following: (more…)

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By Credible Hulk, ago

The Solar Dynamo: The Physical Basis of the Solar Cycle and the Sun’s Magnetic Field

In my previous article, I laid out some basics about the sun’s structure and physical characteristics in order to set up the groundwork upon which I could then explain the physical mechanism which underlies the solar cycles I talked about in the article prior to that one. I understand that this is a bit more technical than most readers may be accustomed to, which is why I’ve included a simplified “tl; dr” version before delving deeper.

Solar Dynamo Theory

The leading scientific explanation for the mechanism by which these solar cycles emerge is the solar dynamo theory. It arises from an area of physics called magnetohydrodynamics, which is the field which studies the magnetic properties of electrically conducting fluids, and is covered in most university textbooks on plasma physics. So how does it work?

The tl; dr version is as follows: (more…)

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By Credible Hulk, ago

The Structure and Properties of the Sun

In my most recent post, I discussed the characteristics of the sun’s 11 and 22 year cycles, the observed laws which describe the behavior of the sunspot cycle, how proxy data is used to reconstruct a record of solar cycles of the past, Grand Solar Maxima and Minima, the relationship between Total Solar Irradiance (TSI) and the sunspot cycle, and the relevance of these factors to earth’s climate system. Before elaborating on the sun’s role in climate change, I’d like to take a look at the mechanism in terms of which the magnetic cycles underlying these solar cycles actually arises, but in order to do that, it’s necessary to first go over some basics:

The Structure of the Sun

The Core: The core of the sun is where pressures and temperatures are high enough to facilitate the nuclear fusion reactions which power the sun (Eddington 1920). The sun is so hot that there are few (if any) actual atoms of hydrogen and helium gas (Bethe 1939). They exist in a plasma state; the gases are ionized and cohabit with free electrons. So protons are being collided and fused into helium nuclei in what’s known as the proton-proton chain (PPO Chain), which is the dominant fusion process in stars of masses comparable to (or less than) the sun. In the PPO chain, two protons fuse and release a neutrino. The resulting diproton either decays back into hydrogen via proton emission, or undergoes beta decay (emitting a positron), which turns one of the protons into a neutron, thus yielding deuterium. The deuterium then reacts with another proton, producing 3He and a gamma ray. Two 3He from two separate implementations of this process then fuse to produce 4He plus two protons (Salpeter 1952).  (more…)

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By Credible Hulk, ago

The Sun and Earth’s Climate: The Solar Cycle and the Maunder Minimum

The Solar Cycle

The Sun goes through an approximately 11 year periodic solar cycle (Gnevyshev 1967). This cycle includes variations in solar irradiation, the amount of ejected materials, solar flares and sunspot activity. Total Solar Irradiance (TSI) is measured in power per unit area (energy per unit time per unit area), and is of particular importance in that it represents the total incoming energy driving the climate system.

Since we’ve only had direct satellite measurements of TSI since the mid-late 1970s, estimates of solar output for earlier times were (and are) based on one or more proxies. Sunspot observations are one such proxy. Sunspot abundance correlates strongly with TSI, so they can thus be used as a proxy for solar maxima and minima. Astronomers have recorded telescopic sunspot observations since the early 1600s, and there is evidence of naked eye observations dating much further back (Stephenson 1990). In addition to noticing that the number of sunspots oscillated in 11 year cycles, astronomers also noticed that sunspots would first appear in pairs or groups at about 30 – 35 degrees both North and South of the solar equator, and the mean latitudes of subsequently appearing spots would tend to migrate towards the solar equator as the cycle progressed, a phenomenon referred to as Spörer’s Law (Carrington 1858, Carrington 1863, Spörer 1879). (more…)

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By Credible Hulk, ago