Archive for February, 2020

Feb 28 2020

Astronomers Detect Largest Explosion Ever

Published by under Astronomy

We can quibble about whether or not the Big Bang should be considered an explosion, or whether it happened “in the universe.” It was the expansion of spacetime that is the universe. In any case, astronomers have detected what they think is the biggest explosion (at least discovered so far) since the big bang –  in the Ophiuchus galaxy cluster, 390 million light years from us. The explosion is essentially a bubble with a diameter the size of 15 Milky Way galaxies – about 1.5 million light years across. That’s five time bigger than the previous record holder.

Astronomers first suspected something was going on when they discovered a big X-ray bubble. They report:

It was discovered in the Chandra X-ray image by Werner and collaborators, who considered a possibility of it being a boundary of an AGN-inflated bubble located outside the core, but discounted this possibility because it required much too powerful an AGN outburst.

An AGN is an active galactic nuclei – more on that below. So they initially discounted it because it was too big, but they then followed up with radio observation, and found an identical radio bubble, confirming that this was a real fossil of an ancient explosion, centered around an AGN. So what’s going on here?

Well, astronomers are not sure. The do not know exactly what may have caused some a massively energetic event. But let’s give some background on AGNs – these are supermassive black holes (SMBH) in the centers of galaxies. Most galaxies have them, including our own. But some supermassive black holes are more super massive than others – getting up to billions of solar masses. More importantly to their activity, some of the black holes are feeding, which means that gas and dust are actively swirling around the event horizon forming an accretion disc and then plunging into the incredible gravity well of the black hole. All that gravity represents an unimaginable amount of energy, and when that gas and dust falls in it swirls around at relativistic speeds – near the speed of light.

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Feb 27 2020

Anti-Intellectualism and Rejecting Science

“There is a cult of ignorance in the United States, and there has always been. The strain of anti-intellectualism has been a constant thread winding its way through our political and cultural life, nurtured by the false notion that democracy means that ‘my ignorance is just as good as your knowledge.”
― Issac Asimov

As science-communicators and skeptics we are trying to understand the phenomenon of rejection of evidence, logic, and the consensus of expert scientific opinion. There is, of course, no one explanation – complex psychological phenomena are likely to be multifactorial. Decades ago the blame was placed mostly on scientific illiteracy, a knowledge deficit problem, and the prescription was science education. Many studies over the last 20 years or so have found a host of factors – including moral purity, religious identity, ideology, political identity, intuitive (as opposed to analytical) thinking style, and a tendency toward conspiratorial thinking. And yes, knowledge deficit also plays a role. These many factors contribute to varying degrees on different issues and with different groups. They are also not independent variables, as they interact with each other.  Religious and political identity, for example, may be partially linked, and may contribute to a desire for moral purity.

Also, all this is just one layer, mostly focused on explaining the motivation for rejecting science. The process of rejection involves motivated reasoning, the Dunning-Kruger effect, and a host of self-reinforcing cognitive biases, such as confirmation bias. Shameless plug – for a full discussion of cognitive biases and related topics, see my book.

So let’s add one more concept into the mix: anti-intellectualism – the generalized mistrust of intellectuals and experts. This leads people to a contrarian position. They may consider themselves skeptics, but they do not primarily hold positions on scientific issues because of the evidence, but mainly because it is contrary to the mainstream or consensus opinion. If those elite experts claim it, then it must be wrong, so I will believe the opposite. This is distinct from conspiracy thinking, although there is a relationship. As an aside, what the evidence here shows is that some people believe in most or all conspiracies because they are conspiracy theorists. Others believe only in some conspiracies opportunistically, because it’s necessary to maintain a position they hold for other reasons. There is therefore bound to be a lot of overlap between anti-intellectualism and holding one or more conspiracies, but they are not the same thing.

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Feb 25 2020

Marsquakes and Magnetic Fields on Mars

Published by under Astronomy

The Mars InSight lander is yielding data, and the first slew of papers reporting early results. The two big stories so far is that Mars has more seismic and magnetic activity than previously thought.

One open question is how much tectonic activity there is on Mars. Earth has at least 15 tectonic plates, all moving with respect to each other. When two plates rub up against each other, building up and then releasing energy, this is the major source of Earthquakes. Both Mercury and the Moon, which are smaller and therefore cooled much faster than Earth, have single crust plates. That doesn’t mean they have no seismic activity, because they are also shrinking as their cores continue to cool.

Mars is still a bit of an open question in terms of tectonic activity. It appears likely that Mars does have a tectonic plate system, but much simpler than Earths with fewer plates, and they are moving much more slowly. But this still can allow for some seismic activity. There are other sources of activity as well, such as shrinking and settling. Information on seismic activity from InSight was anticipated to help better understand the geological activity on Mars.

What they have found so far is:

“We identify 174 marsquakes, comprising two distinct populations: 150 small-magnitude, high-frequency events with waves propagating at crustal depths and 24 low-frequency, subcrustal events of magnitude Mw 3–4 with waves propagating at various depths in the mantle.”

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Feb 24 2020

AI Antibiotic Drug Discovery

The use of artificial intelligence in the drug discovery process is not new, but it is advancing in significant ways. Several weeks ago the BBC announced the first AI developed drug to be taken to human trials. Now they are announcing the discovery of a new antibiotic using AI. Let’s talk about drug development to see how advances in AI are impacting this process.

Finding a drug that is useful medically is tricky, because it has to have a lot of properties simultaneously, and any one property can be a deal-breaker. A useful drug needs to get into the body, get to the target tissue, survive long enough to have the desired effect, it needs to have a desired effect at a dose that is lower than doses that cause significant side effects, and it needs to lack significant toxicity, such as liver or kidney damage. Will the compound be stable on the shelf? The same needs to be true, at least in lack of side effects and toxicity, for all the metabolites of the drug that may be created before everything is eliminated. On top of that we have to worry about drug-drug interactions, and even interactions with certain foods.

For this reason there is no perfect drug. Every pharmaceutical is a trade-off. Being “natural” is also not a magic wand that bypasses all these concerns. Substances that occur in nature did not evolve for our benefit. They generally evolved to be poisons to creatures that might eat them, including us. Drugs derived from plants are basically poisons that we have purified, usually altered, and then discovered a dose range that can be safely exploited.

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Feb 21 2020

Binaural Beats, Mood and Memory

Published by under Neuroscience

Binaural beats are an auditory illusion created by listening to two tones of slightly different frequency. This produces a type of feedback effect in the brain that produces a third illusory sound that has a pulsating quality, hence binaural beats. All perceptual illusions are fascinating, at least to neuroscientists, because they are clues to how the brain processes sensory information. What we ultimately perceive is the result of a complex constructive process (not passive recording) and understanding the process offers insight into the strengths and weaknesses of human perception.

But there is another angle to binaural beats about which I have always been, appropriately, skeptical. There is popular belief that listening to the binaural beat illusion is a method for “hacking” into the brain and affecting mood and cognition, improving memory and alertness. Most “brain hack” claims turn out to be false, or at least massively overstated, so initial skepticism is warranted. Such claims are often based on, “Look, something is happening in the brain, therefore…” types of evidence.  But the brain is a machine, albeit a biological one, and it is not impossible that outside stimulation can make the machine work more or less efficiently. So I filed this away as – a small effect is not impossible, but I would need to see convincing evidence before I believe this “one simple trick” claim.

There is a recent study of the effects of binaural beats which prompted this review, but this is just the latest in a couple of decades of research. Let’s first look at the most recent study – Binaural beats through the auditory pathway: from brainstem to connectivity patterns. The study looked at two things, the effect of binaural beats on the overall pattern of brain activity, and the effect on mood. What they found is discouraging for those who think binaural beats have some special effect on the brain. They found: Continue Reading »

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Feb 20 2020

Herbals Don’t Work for Weight Loss

One of the frustrating things I encounter as a practicing physician is listening to patients describe how they are motivated to improve their health, and then list all the things they are doing, none of which will improve their health. I am eating organic, taking probiotics, taking supplements, and “eating clean.” They may go into detail about their “paleo” diet, some specific megavitamin or superfood, or list the herbal supplements they think will supercharge some aspect of their health.

This is not their fault. They are motivated and taking action and responsibility for their health, but they have been failed by society. The regulatory infrastructure in place to protect the public from false or misleading health claims, from outright fraud, charlatans and snake oil peddlers has clearly failed. Further, the public largely assumed they are protected from fraud, when clearly they are not. People must protect themselves with information, often having to find on their own the glimmers of reliable information hiding in a sea of misinformation and slick marketing. So let me add one bit of helpful information – herbal supplements, according to a recent systematic review, do not work for weight loss.

To be more technically precise – there is currently insufficient evidence to conclude that any herbal product reviewed is effective for weight loss. Historically the most common reason for insufficient evidence of efficacy for a treatment that has been studied is that it simply does not work, or has only a clinically insignificant effect (which is functionally the same thing). You can hold out for larger and better studies to show a statistically and clinically significant effect, but don’t hold your breath, and in the meantime the most reasonable approach is to consider such treatments as ineffective until proven otherwise.

The authors reviewed and did meta-analysis on 54 placebo controlled trials. The herbs tested fell into one of several categories. Some straight up did not work. Others has small effects considered not clinically significant. Still others has few studies of poor methodological design, but also with clinically insignificant effects. No single treatment was shown to have both statistically and clinically significant effects in well-designed trials.

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Feb 18 2020

Bezos $10 Billion Earth Fund

Published by under Technology

Jeff Bezos, founder of Amazon, is the richest person in the world, with a net worth of around $115 billion. He recently announced that he is pledging 10 billion of those dollars to the Bezos Earth Fund, the primary objective of which is to fight climate change:

⁣⁣⁣”Climate change is the biggest threat to our planet. I want to work alongside others both to amplify known ways and to explore new ways of fighting the devastating impact of climate change on this planet we all share. This global initiative will fund scientists, activists, NGOs – any effort that offers a real possibility to help preserve and protect the natural world.”

Bezos reports that he will begin dolling out money this summer. Here is the big question – how will he spend this money? And how should he spend it? How would you spend it? This is a complex question. His statement suggests that he wants to primarily fund research, which I think is a good place to start – but research into what? I think this question is answered by simply looking at the sources of human CO2 release:

“87 percent of all human-produced carbon dioxide emissions come from the burning of fossil fuels like coal, natural gas and oil. The remainder results from the clearing of forests and other land use changes (9%), as well as some industrial processes such as cement manufacturing (4%).”

Clearly the largest culprit is the burning of fossil fuels. Land use is also a big chunk, and then 4% make up other industrial processes. Every bit helps, but let focus on these top two, starting with the smaller portion, land use. I think there are three significant efforts that could help reduce CO2 loss from improper land use. The first is to stop cutting and burning forests that represent major carbon sinks. I am not talking about logging for lumber, which can be done sustainably, but mostly the reduction of the Amazon rainforest and other old-growth forests. This will require regulations, but also we need to seek ways to reduce the incentive for farmers to clear forest to grow more crops.

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Feb 17 2020

Mainstreaming SETI

Published by under Astronomy

This weekend I was at the AAAS (American Association for the Advancement of Science) meeting in Seattle talking about science communication. The meeting often creates a pulse of science-news reporting, base on all the presentations and lectures there. One talk I didn’t get to see was by Dr. Anthony Beasley, director of the US National Radio Astronomy Observatory in Charlottesville, Virginia. He argued that the search for extraterrestrial intelligence (SETI) should “come in from the cold” and be incorporated into every aspect of astronomy. Let me go over the reasons why I completely agree.

First, doing so would be a great boost to SETI itself. For example, private funding has recently allowed a SETI project using the VLA (Very Large Array) which the project managers argue will increase the power of SETI by 10-100 fold. Taking SETI from an isolated project here and there to the mainstream of astronomy would certainly greatly magnify the power of SETI searches, and therefore increase the probability of achieving a positive result.

Further, as Seth Shostak has pointed out to us during interviews on the SGU, SETI research does a lot of non-SETI astronomy. Of you are scanning the skies with radio telescopes looking for signals that may be intelligent in origin, you are also gathering a lot of information that can be used for other purposes. So even if SETI never detects such a signal, the effort will not have been wasted. A lot of non-SETI astronomy will still have been done. The broader point is that, by combining SETI with other projects, astronomers are efficiently using equipment and data. What this means is that the question of SETI vs other projects is a false dichotomy. We can do both.

But the biggest question in all of this is – is SETI itself valuable? There are two criteria that are usually brought to bear in answering this question. Mostly people focus on the probability of detecting an ET signal, with critics of SETI arguing that it is probably too small to be worth the effort of searching. Defenders of SETI often focus on the other criterion – the value to humanity if we did detect a signal. In essence SETI is like playing the lottery – the probability of winning is low but the potential benefits are high. How do we balance these two things out?

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Feb 11 2020

Hyperexcitability in Migraines

Published by under Neuroscience

Migraines are a complex neurological phenomenon that offer a window into some general principles of brain function. A new study confirms previous findings and adds more details to the observation that the visual cortex in those who suffer from migraines is hyperexcitable – it has increased activity in response to stimuli. But this is also clearly only part of the picture.

Let’s start with some background on what migraines are. They are a clinical syndrome, which means they are defined entirely by how people present, not by any diagnostic tests. There is no imaging study, blood test, biopsy, or anything else helpful or used to make the diagnosis. Here are the specific criteria doctors use to make the diagnosis:

(1) At least five attacks fulfilling criteria (2)–(4)
(2) Headache attacks lasting 4–72 h (untreated or unsuccessfully treated)
(3) Headache has at least two of the following four characteristics:
(a) unilateral location
(b) pulsating quality
(c) moderate or severe pain intensity
(d) aggravation by or causing avoidance of routine physical activity (e.g. walking or climbing stairs)
(4) During headache at least one of the following:
(a) nausea and/or vomiting
(b) photophobia and phonophobia
(5) Not better accounted for by another ICHD-3 diagnosis.

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Feb 10 2020

Homeopathic X-rays

Homeopathy is pure pseudoscience. No reasonable review of the evidence can come to another conclusion. Most people who use homeopathic products don’t even know what it is – they generally think that the term refers to herbal or natural remedies. Nothing could be further from the truth. In fact, for most people, when I tell them what homeopathy actually is, their first reaction is disbelief. As silly as homeopathy is, it is good to give occasional reminders of how nonsensical the homeopathic industry is and how absurd their claims. This reminder is about homeopathic X-rays, which I will get to below.

The two core claims of homeopathy include the notion that like cures like – that a substance that causes symptoms will reduce those same symptoms in teeny tiny doses. There is no science to this claim, and no, it does not operate like allergy shots or vaccines. The substances and doses used generally do not provoke any immune response. They don’t provoke any response at all, because the doses are so tiny, they are usually non-existence. That is the second core foundation of homeopathy, extreme dilutions.

How extreme? A typical 30C dilution involves dissolving the starting ingredients 1:100 thirty times. That is a 10^60 dilution. There are about 10^50 atoms in the Earth, so you would need 10 billion Earths worth of homeopathic potion to have an even chance of getting a single molecule of “active” ingredient. But to the homeopath this is a feature not a bug, because they believe that the magical “essence” of the starting ingredient remains behind.

Homeopathy, in other words, is not medicine but magical potions, based on prescientific superstitions. That doesn’t stop corporations from pretending it is real medicine and selling it as such.

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