Archive for June, 2018

Jun 21 2018

Iceman Update

Published by under General Science

In 1991 the mummified remains of a 5,300 year old man were found in the Alps on the border of Italy and Austria. The Iceman, also referred to by the nickname, Ötzi (because he was found in the Ötzal mountains) has been the subject of endless study ever since. He represents our best single window into copper-age society.

Scientists continue to learn more and more about Ötzi, what he ate, how he died, what he was doing in the hours before his death, and about the tools he had with him. Recently scientists have published a detailed report looking at the lifecycle of Ötzi’s tools, providing yet more insight.

Before we get to the new info – here is a quick summary of some basic facts about Ötzi. We know that he was shot in the back by an arrow. The arrowhead remains, in fact, in his back as smoking-gun evidence of the cause of death. Amazingly, the presence of the arrowhead was missed on X-rays of Ötzi for years – a great example of inattentional blindness.

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Jun 19 2018

New York Times and the Return of Astrology

A recent opinion piece in the New York Times by Krista Burton is perhaps one sign of recent social trends – increasing belief in things like astrology, especially among millennials. Burton provides some insight into this phenomenon, but then also makes some horrible justifications for it.

Belief in astrology, the notion that the relative positions of planets and start affect our personality and perhaps our destiny, has been measured at about 25% in the UK, Canada and US in recent decades. However, as researchers, Nicholas Campion, points out, the number depends greatly on what exactly you ask:

In one of my groups – of mostly male students aged 18 to 21 – I found that 70% read a horoscope column once a month and 51% valued its advice. Other questions produced a huge variation: 98% knew their sun sign, 45% thought it described their personalities, 25% said it can make accurate forecasts, and 20% think the stars influence life on Earth. The higher figures are close to previous research which showed that 73% of British adults believe in astrology, while the lowest figures are similar to those found by Gallup’s polls.

It’s difficult to know how to parse all of that, but it seems like about half of people take astrology seriously to some extent, and 20-25% very seriously. That is a significant percentage of the population to believe in something which is 100% superstitious nonsense. Let’s get this out of the way now – there is no plausible mechanism by which astrology could work, there is no evidence that any form of astrology does work, and it is structured and functions like a classic pseudoscience. A moderate amount of scientific literacy, and a trace of critical thinking skills, should be enough to purge any belief in astrology.

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Jun 18 2018

Gut Microbiome and Anxiety

Humans are a symbiotic creature, like pretty much all other animals. It is estimated that there are as many bacteria in your body as there are human cells. Bacterial cells are much smaller, so this amounts to 1-3% of body weight.

Bacterial cells line all mucous membranes, where they serve critical functions. They are a critical part of our immune system, crowding out other bacteria and organisms that can potentially cause infection. Many of our bacteria live in the gastrointestinal system, our “gut microbiome” , “microbiota”, or “flora”, where they also aid in digestion.

As is often the case, scientists have been discovering that our relationship with our friendly bacteria is more complex than we thought. The microbiome is not a collection of random bacteria, but a stable ecosystem. There is also evidence that there are only a few distinct types of bacterial ecosystems in people. We have an “enterotype” which may affect our health.

There is also growing evidence that our gut microbiota not only have local effects within our GI system, but may have remote effects on the brain and nervous system. This suggests that some bacteria produce neurotransmitters, hormones, or some chemical signal that can get into the blood and then travel to other parts of the body and have an effect.

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Jun 15 2018

More Evidence of Water on the Moon

Published by under Technology

As we contemplate not only more Moon missions, but establishing a long term base on the moon (Moonbase Alpha, of course) the question of how much water on the moon becomes pragmatic, and not just theoretical. It seems paradoxical – the Moon’s surface is the very image of a dry wasteland. How much water can there be?

Well, a new study supports prior evidence that there may be more water than you think trapped in the lunar soil, and in perpetually shaded craters at the poles. It is indirect evidence, but not unreasonable.

Japanese researchers have found moganite in lunar meteorites. They report:

Silica micrograins occur as nanocrystalline aggregates of mostly moganite and occasionally coesite and stishovite in the KREEP (high potassium, rare-earth element, and phosphorus)–like gabbroic-basaltic breccia NWA 2727, although these grains are seemingly absent in other lunar meteorites.

Basically moganite in a mineral of silicon dioxide. What is special about this particular crystal formation is that it only forms in the presence of water and high pressure. So if there is moganite in a lunar meteorite, that implies the moganite formed under the surface of the Moon, which means there may be significant water there.

The article makes specific mention that other examined lunar meteorites did not have moganite, but this actually supports the conclusion that the moganite was formed in the Moon. This is because an alternative hypothesis is that the moganite formed on the meteorite after it landed on Earth. But if this were true, then you would expect to find moganite on many or all of the meteorites found in the same location (meaning in the same Earth condition). The absence of moganite on the other meteorites means that the mineral probably did not form on Earth, which means it likely formed on the Moon.

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Jun 14 2018

New Review of Antarctic Ice

Published by under General Science

A new review of the past few decades of satellite data published in the most recent edition of Nature tells the story of what is happening to ice on Antarctica. The result is probably exactly what you think – the ice is melting, at an accelerating rate. But the details are interesting.

First, we should note that Antarctica is a continent. There is land under all that ice, unlike the Arctic which is floating ice without any land. This makes a huge difference. While Arctic ice melts, the water fits exactly into the space previously displaced by the ice, so does not result in any sea-level rise. There are other effects to be concerned about, such as the effect on ecosystems and the effects of all that fresh water melting into the North Atlantic.

When ice sitting on top of land melts, however, that is new water finding its way to the sea, resulting in direct sea-level rise. As water gets warmer, it also expands, which further causes sea level rise. Also, the weight of all that ice pushes down the land, and when the mass of that ice decreases the land actually lifts up a bit.

The Antarctic ice system is also more complex than the Arctic. There are different glacier systems, which terminate at the ocean, and then there is the surrounding sea ice. There are several ways to estimate the extent of ice also, not just land coverage. Scientists need to also measure the thickness of the ice, the relationship between land and sea ice, the weight of the ice (the gravity it produces), and look at the under side of the glaciers that can erode away from warm sea water.

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Jun 12 2018

Anti-GMO Lying

Published by under Pseudoscience

The anti-GMO site, Independent Science News, declares in a June 3rd headline: “GMO Golden Rice Offers No Nutritional Benefits Says FDA.” The problem with that headline is that it’s a lie. The FDA was forced to write a response stating that the claim is “misleading.”

Yeah – it’s deliberately misleading by distorting the facts and presenting them out of context so that they lead to a conclusion which is untrue. That is a form of lying.

Often I am asked how to sort science from fiction when there are many sides all loudly proclaiming opposing claims and citing their own evidence. (Gratuitous plug – for a thorough answer to this question, you can preorder my upcoming book.) One good way is to take any specific argument and follow the evidence as far as you can. Try to get back to primary sources, and see what they actually say. Follow the arguments back and forth, and see which side tends to have the final word.

Typically the side with the weaker position, or the one that is more ideological and less science-based, will display common characteristic behaviors. They will misrepresent primary sources – say, by citing a study to support a claim, when it doesn’t, or blatantly misrepresenting what the study shows. They will also cherry pick evidence, ignoring solid evidence that seems to contradict their position. When firmly challenged on one point, they may simply shift over to a separate point, without ever responding to or acknowledging the challenge. And – they will lie.

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Jun 11 2018

The State of Carbon Capture

Published by under Technology

The basic idea of carbon capture is fairly simple – in order to counteract industries that release CO2 into the atmosphere, we develop technologies that remove CO2 from the atmosphere. If these industries exist in near balance, then there will be no net increase in CO2.

When you think about it, we do have to eventually get there – to the point that human activity does not result in a net increase in CO2 in the atmosphere. Any significant amount will build up over time and have an effect. We need to get down to negligible amounts, compatible with homeostasis and indefinite sustainability.

Clearly we are not there now. Currently the world emits about 9.8 gigatonnes (billion tonnes) of carbon per year. That carbon winds up in the air (44%), ocean (26%) and land (30%). Ninety-one percent of these emissions come from fossil fuels: “coal (42%), oil (33%), gas (19%), cement (6%) and gas flaring (1%).”

One obvious way to reduce global carbon emissions, therefore, is to use carbon neutral sources of energy to replace fossil fuels. But no energy source is completely carbon neutral – you still have to build the wind turbines and solar panels, or farm the biofuels. Also, until we find a replacement for cement, that industry will still release massive amounts of carbon. So there is certainly a lot of room to reduce our carbon emissions, but it does not seem that we will reduce them to globally negligible anytime soon.

Carbon capture, therefore, is an attractive idea. However much carbon we remove from the environment (air, water, and soil) gives us a budget of carbon we can afford to release into the environment with other industries. The consensus, however, is that carbon capture technology is no where near being a magic solution to climate change and carbon. At best it will be one of many technologies that inch us toward a carbon-neutral future.

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Jun 08 2018

Séralini Fails Replication

Published by under General Science

Gilles-Éric Séralini is a French researcher who came to fame from publishing a study in 2012 claiming that herbicide-tolerant GMO corn, with or without combination with glyphosate herbicide, increased tumor risk in rats. He used this study to call into question the safety of GMOs generally, and to call for long term feeding studies. His results were embraced by the anti-GMO crowd, and to this day are cited as evidence GMOs are not safe.

One small problem, however, is that Séralini’s study was terrible. It immediately came under intense criticism. Specifically, the study had small sample size, and used a strain of rats known to have a high background rate of tumors. The data, therefore, was full of noise and was essentially uninterpretable. This is probably the reason for the lack of statistical analysis – because there were no significant findings. For these reasons in 2013 the study was retracted. In 2014 the paper was republished in a new open-access journal,  Environmental Sciences Europe, without additional peer-review.

It is pretty clear that Séralini is anti-GMO, and this likely biased his research. But regardless, the study methodology is terrible and the results worthless. But it did serve its (what I believe to be its true) purpose – to stoke fears about GMOs and to provide published “scientific” evidence to support the claims of anti-GMO activists.

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Jun 07 2018

Homeopathy Loses NHS Case

The National Health Service (NHS) in England decided in November 2017 to stop funding homeopathic treatments. That was an excellent decision, made for the right reasons – “lack of robust evidence of clinical effectiveness”. While I think that is an understatement, it is true enough, and is sufficient justification for any modern health care system to abandon homeopathy.

Now a High Court Judge has affirmed that decision by the NHS. Why was a judge even involved? Because the British Homeopathic Association (BHA) sued the NHS over that decision.

Legally, this case was fairly straight forward. The judge was  clear to point out that it was not his job to review the scientific evidence regarding homeopathy. The BHA argued in court that there is “plain evidence that homeopathic treatment does work in particular cases”. That is complete nonsense – homeopathy is nothing but magic potions, with no scientific plausibility, and the scientific evidence clearly shows that it does not work for anything.

But the judge did not have to get into that in court, which is appropriate. It should not be for a judge to make scientific decisions like that. His job was to answer the BHA complaint that the NHS was being unfair in their decision. The judge ruled, however, that the NHS process was “fair and balanced” and that “there was no evidence of ‘bias or predetermination'”.

I do worry when such issues come up before courts or regulatory bodies. It is easy to make the claim of bias against those who are simply following the evidence. It would, for example, be easy to make the case that I am “biased” against homeopathy. After all, I have been regularly trashing the pseudoscience for years. But in reality I am just following logic and evidence. Correctly stating that something is pseudoscience is not a bias when it is the logical conclusion of a fair process.

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Jun 05 2018

Powering Implanted Devices

One of the cutting edge medical technologies that promises to be a game-changer in terms of our ability to affect biological function is the interaction between machines and biology. Of course we already have many medical devices, from cardiac pacemakers to artificial joints. Increasingly sick and aging humans are becoming cyborgs, as we augment and replace broken body parts with machines.

We have only scratched the surface of this potential, however, and the technology is advancing quickly. There are definitely technological hurdles that limit such technology, however, and perhaps chief among them is the need for power.

MIT researchers have recently presented a new method for powering implanted devices that may open the door to a further proliferation of implantable medical devices. They use radio waves as an external power source, which eliminated the need for cumbersome batteries.

Right now power is a major limiting factor for implantable medical devices. We can make small batteries, but they still become the largest part of many devices. Especially as solid state digital technology improves, we can make very tiny electronic devices, and then we attach a relatively large battery to them. Even these “large” batteries also have a limited life span.

There are several possible approaches to this problem. One is to make better batteries, ones that can hold more energy for longer in a smaller package. This is happening, incrementally, but is still a major limiting factor.

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