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Infertility affects an estimated 186 million people worldwide, with fallopian tube obstruction contributing to 11%-67% of female infertility cases. Researchers have developed an innovative solution using a magnetically driven robotic microscrew to treat fallopian tube blockages. The microrobot is made from nonmagnetic photosensitive resin, coated with a thin iron layer to give it magnetic properties. By applying an external magnetic field, the robot rotates, generating translational motion that enables it to navigate through a glass channel simulating a fallopian tube.

Infertility affects an estimated 186 million people worldwide, with fallopian tube obstruction contributing to 11%-67% of female infertility cases. Researchers have developed an innovative solution using a magnetically driven robotic microscrew to treat fallopian tube blockages. The microrobot is made from nonmagnetic photosensitive resin, coated with a thin iron layer to give it magnetic properties. By applying an external magnetic field, the robot rotates, generating translational motion that enables it to navigate through a glass channel simulating a fallopian tube.

I wanted to like this paper because its thesis—that the prevalence and dogmatism of religion impedes scientific progress—is one on which I’ve written a book. This paper purports to demonstrate such an incompatibility between science and religion using data, but the data are correlative without any indication of causation, and the data have some problems.  To be sure, the data are provocative, and author Matías Cabello may be on to something, but right now the paper is at SSRN (Social Science Research Network) and doesn’t appear to have been published or peer-reviewed. You can see it by clicking the title below or download paper here. If you’re interested, read it and form your own opinion.

For a long time historians of science, the most prominent of which was the late Ronald Numbers, maintained that the “conflict hypothesis”—that religion and science were in historical conflict—was dead wrong. I never found their arguments convincing, one reason being that they would weasel and wiggle around clear cases of conflict, like that of Galileo versus the Catholic Church. Sure, there were other things beyond a Bible/science conflict involved in that dispute, but you’d have to be blind not to see that the heliocentric solar system, and Galileo’s writings promoting it, deeply irked the Catholic Church. One philosopher who also sided with these “no-conflict” folks was the late Michael Ruse, who, though an atheist, devoted a lot of time and writings to showing the science and religion are compatible. I found him tendentious and unedifying. Finally, Francis Collins, former head of the NIH and of the Human Genome Project, has come out with a new book, The Road to Wisdom, which goes to great lengths to show that one can be a scientist and a believer, too (he’s an Evangelical Christian).

My book Faith Versus Fact makes a case that in fact the two areas are incompatible, since they both involve empirical assertions about the universe, but only science has a way to test and verify them. (Read the book.) And in the beginning I dispel the idea that there is no conflict between science and religion, supporting the “conflict” hypothesis. But I won’t go on, as you can read it for yourself.

At any rate, Cabello’s manuscript uses historical and present-day data to make two points:

a.) The conflict between religion and science can be seen because science began to grow up until 1520, but then stagnated between 1520 and 1720.  This 200-year period, says Cabello, coincided with a growing religious dogmatism, imposed largely by the Catholic Church. At the same time, science itself stagnated. After 1720, when the Counter-Reformation ended and Catholic dogma waned, science began to grow rapidly again. This correlation, says Cabello, is some evidence that religious (mainly Catholic) dogma was repressing the growth of science.

b.) Analysing Wikidata on nearly 125,000 scientists, Cabello found (and equations are involved) that scientists who were less religious over the entire period (yes, he controls for some extraneous variables)—scientists including deists, pantheists, agnostics, and atheists— tended to be more accomplished than scientists who were clearly religious. (Quakers, who are in the middle, tended to be more scientifically accomplished than religious people but not as much as freethinkers.)

Now readers who scrutinize the paper will probably find a lot to beef about, and since I read it only twice, and not very carefully, I’m not going to come out in strong support of its results. But I do want to call attention to it because it’s one of the few papers to support the “conflict” hypothesis with data.

a.) The temporal correlations.

Here are some plots showing the change in religiosity over time and the change in science activity over time. The first plot gauges religiosity by looking at the frequency of “God-referring words”—”God”, “Jesus,” and “Christ”—in Google books published in five different European languages.

You can see that religion increased around 1520, and stayed fairly constant (in terms of word density) until about 1720, when it began a more rapid decline that seems to have asymptoted at a low level around 1900.

(From paper): (a) shows that God-referring words (God, Jesus, and Christ, in vernacular and Latin) appear with greater frequency in the period 1520–1720 than before and after, suggesting a rise-and-fall pattern of religiosity Source: Own work based on Google’s ngram service (https://books.google.com/ngrams/, accessed in August, 2024).

Here is the corresponding temporal change in science activity, using as a proxy the density of words in books associated with science or protoscience (see caption for words counted). The stagnation between 1520 and 1720 is clearer here, followed by a rise in science word density up to the present time. One sees an inverse correlation between the lines in (a) and (b), a mirroring that Caballo considers evidence for his thesis.

(from paper) (b) shows that the post-1720 decline of God-referring words coincides with the increased use of words that were strongly associated with (proto)science already in the 1500s (medicine, astronomy, mathematics, geometry, philosophy, hypothesis, logic, and experiment, in vernacular and Latin). Source: Own work based on Google’s ngramservice (https://books.google.com/ngrams/, accessed in August, 2024).

Further evidence is adduced in the following two graphs of the “pace of science,” based on word counts of scientists and discoverers per capita during different periods (top graph) compared to per capita words in Wikipedia about scientists and discoverers. Both graphs show the same stagnation during the 200 years after 1520, with, in this case, an increase before 1520 and again after 1720. The notes on the graphs are indented below both:

Notes: (a) shows that the per capita number of famous scientists and discoverers aged 20 to40 stagnated between 1520 and 1720, while it had been growing before and grew thereafter; (b) shows that the impact of these scientists, proxied by the number of words written in their biographies, declined during that same period, while it had been growing before and thereafter. Overall, these figures suggest that Europe’s scientific output per capita stagnated during the age of religious fever that spans roughly between 1520 and 1720. Source: Wikipedia’s scientists and discoverers are from Laouenan et al. (2022). Population data is from the Maddison Project Database 2020 (Bolt and Van Zanden, 2020), Prados de la Escosura, ÅLAlvarez-Nogal, and Santiago-Caballero (2021), Malanima (2011).

Finally, here’s a graph of the degree of “secularization” of science, taken as “the percentage of all scientists who were clergy.  This is not so convincing to me because before the 18th century only clergy had the luxury of doing science, as it was an avocation. And the proportion of clergy doing science isn’t, to me, a strong index of how much science itself was impeded by the beliefs of clergymen. After 1720, one could begin to make a living doing science, and thus didn’t need a clergyman’s stipend to do science. Nevertheless, one can’t dismiss these data completely.

From paper: Notes: The figure depicts the share of famous scientists and proto-scientists who were part of the clergy according to Wikidata’s person description or occupation. It shows that the share remained stable at around 20% during the religious revival of 1520–1700, while it had been declining before and continued to decline thereafter, with 1720 marking the sharp beginning of a quick secularization of science.

And one thing is for sure: scientists began losing their religion after the turn of the 18th century, to the point now that, in America and Britain, scientists are far less religious than the average person. The proportion of believers in America’s National Academy of Sciences, for instance, is about 8%—just about exactly the proportion of atheists among the general population! As I point out in my book, as one rises higher in science, going from employment at a university to employment in an elite university to membership in the National Academy, the proportion of believers drop steadily, something that’s also true in the UK. This could mean that the more atheistic you are, the higher you’re likely to rise in science, OR that the better scientist you become, the more you lose your faith. OR, it could reflect both factors.

b. The religiosity versus the achievements of scientists.

Finally, the author did a multivariate calculation on the “fame” of scientists related to their religiosity, dividing scientists into three classes: least dogmatic (atheists, deists, agnostics, and pantheists), “moderately dogmatic” (Unitarians and Quakers), and “strictly dogmatic” (Puritans and Jesuits, religious groups who did the most science). He found that accomplishment, as reflected in words in Wikipedia, was highly, significantly, and positively associated with membership in the “least dogmatic” group, and not nearly as correlated with membership in the other two groups (Quakers born after the 17th century are an exception; they are scientifically accomplished.) Cabello thinks that freedom from religious belief “opened up a whole path of ideas disconnected from the prevailing thought system”, allowing scientists to become more accomplished.

Again, one could pick nits with these data, and I’m not going to answer potential criticisms, as the author deals with some of them. I’ll just give his conclusion:

This article presents quantitative evidence—from the continental level down to the personal one—suggesting that religious dogmatism has been indeed detrimental to science on balance. Beginning with Europe as a whole, it shows that the religious revival and zeal associated with the Reformations coincides with scientific deceleration, while the secularization of science during the Enlightenment coincides with scientific re-acceleration. It then discusses how regional- and city-level dynamics further support a causal interpretation running from religious dogmatism to diminished science. Finally, it presents person-level statistical evidence suggesting that—throughout modern Western history, and within a given city and time period—scientists who doubted God and the scriptures have been considerably more productive than those with dogmatic beliefs.

There are two further points. First, as the author notes, we don’t know why lack of religiosity is correlated with  greater scientific accomplishment, something that I discuss above. He says this:

All these results are silent about the direction of causality. Did high-impact thinking lead to abandon dogmas? Or did less dogmatic minds produce high-impact science? Or both? The correlation can be interpreted either way. Charles Darwin, for example, became agnostic late in life, what suggests that science may have eroded his beliefs. Newton, by contrast, was young (“very early in life”) when he “abandoned orthodox belief in the Trinity” (Keynes, 2010); this suggests that his unorthodox beliefs may have opened the way for his science. Such bidirectional causality is consistent with the aggregate and regional trends and propositions discussed in previous sections.

Finally, Caballo ponders why opposition to the “conflict hypothesis” (which, by the way, is embraced by a majority of Americans) is so strong among academics.  His theory is that academics see a lot of religious scientists, and from that conclude that there can be no conflict. To that I’d respond, “those people demonstrate compartmentalization, not compatibility.”

Instead, I’d say that people like Numbers and Ruse adopt the “no conflict” hypothesis because it is more or less a “woke” point of view: it goes along with the virtue-flaunting idea that you can have your Jesus and Darwin, too.  You don’t get popular by touting a conflict, as I’ve learned, but people love to hear that you can be religious and also embrace modern science. Even if those people are atheists, they can be “atheist butters” or promoters of the “little people” hypothesis that society needs religion to act as a social glue. If you tell people that it’s a form of cognitive dissonance to be both religious and a supporter of science, one might think that the glue would dissolve. (It won’t.) And, of course, “sophisticated” believers don’t like to hear that their faith is at odds with science.

But it is.

h/t: Bruce

Biological nanopore technology revolutionised DNA sequencing – now it has been adapted for analysing alcoholic drinks, providing a quick test for quality and safety

The biodiversity, climate, health, water and food crises need to be addressed together rather than regarded as separate issues, urges a major report

An asteroid orbiting near our planet that temporarily became our second moon seems to have come from the actual moon, hinting that a hidden population of lunar rocks is drifting in space

Well, gosh… what nice news as 2024 comes to a close… My book has received a ringing endorsement from Ethan Siegel, the science writer and Ph.D. astrophysicist who hosts the well-known, award-winning blog “Starts with a Bang“. Siegel’s one of the most reliable and prolific science writers around — he writes for BigThink and has published in Forbes, among others — and it’s a real honor to read what he’s written about Waves in an Impossible Sea.

His brief review serves as an introduction to an interview that he conducted with me recently, which I think many of you will enjoy. We discussed science — the nature of particles/wavicles, the Higgs force, the fabric (if there is one) of the universe, and the staying power of the idea of supersymmetry among many theoretical physicists — and science writing, including novel approaches to science communication that I used in the book.

If you’re a fan of this blog or of the book, please consider sharing his review on social media (as well as the Wall Street Journal’s opinion.) The book has sold well this year, but I am hoping that in 2025 it will reach an even broader range of people who seek a better understanding of the cosmos, both in the large and in the small.

Send in your photos, folks!

Today we have some arthropod photos from regular Mark Sturtevant, whose IDs and captions are indented. You can enlarge the photos by clicking on them.

Hello again from Eastern Michigan. Here are various insects and spiders that I had photographed in my area from two summers ago. My last post left us at a very productive park near where I work, and this post starts with some things that I’d found during that same outing.

We start with a boldly marked Stink Bug called the Anchor Stink Bug (Stiretrus anchorago).

The field in this park always has numerous Chinese Mantids (Tenodera sinensis). This being early August, they had not yet reached adult-hood so here is a nymph. By early fall I can expect to see many huge adults in the field. It seems guaranteed. I suspect that some years ago, someone had set out many of their oothecae (egg pods), and this thriving population remains the result.

Overlooking the field was a hardwood forest, and I was quite pleased that many interesting kinds of critters were in it. Among these were weird planthoppers from the family Derbidae, which are one of the many good things found under tree leaves. These lack common names, so I gave them my own. First, here is what I call the Flat Derbid (Anotia uhleri) because when fully at rest they spread their wings out flat, making them resemble a small translucent moth. This one was slightly disturbed by my attentions so it had gone into a more alert posture. Although Derbids can jump and fly like other planthoppers, they are rather placid in nature so they are easy to photograph when handled with care. The prominent thingies on the head are its antennae:

The next one is what I call the Red Derbid (Apache degeeri). This is my favorite Derbid, and I found several of these that day. Its antennae are long and squiggly, making it look like it has some kind of weird face. There is a third species that I call the White Derbid. It is nearly the twin of the Red Derbid, but it’s mostly white. These are found under tree leaves that are farther to the south:

The woods were full of orb webs, and most of those belonged to an odd but quite common spider called the Spined Micrathena (Micrathena gracilis). These pea-sized spiders are pretty helpless when displaced outside of their web, but they are quite skillful when in their web and of course they swiftly build their large orb webs at night when they are basically blind:

Among these spiny weirdos I was amazed to find a striking color variant, as shown in the next picture. I had to take this one home for staged pictures! That is one spider that belongs on a heavy metal music album cover!:

The remaining pictures came from other area parks. As I am still feeling spidery after that last one, here is our largest spider, the Fishing Spider (Dolomedes scriptus). The linked picture gives you an idea of their size. Fishing Spiders hunt near and on water, and this one was found along a river bank. This lady had carried her egg sac to the top of a plant, and she is guarding her recently hatched spiderlings in a web nursery. You can see the mass of babies in the background. Fishing Spiders can be irritable at this time, but she was not at all aggressive so I had no trouble taking a wide-angle macro picture. Although the composition does not suggest it, the lens had to pretty much touch the spider since the working distance for wide-angle macro is extremely short:

I have some odds-and-ends remaining, but I will finish with an interesting one.

Next up is an Ailanthus Webworm Moth (Atteva aurea). These small moths have expanded their range northward since they have accepted the invasive Ailanthus or Tree of Heaven as a host plant. If one plays with the lighting, as I have done here, one can get a bit of iridescent blue out of the black markings on the wings:

Next up is a Scaly Bee Fly (Lepidophora lepidocera). Adult Bee Flies feed on nectar, and the larvae are either parasitic or predatory on other insects, depending on the species:

Here are some of our local wasps. First is our native Northern Paper Wasp, Polistes fuscatus, followed by an Eastern Yellowjacket, Vespula maculifrons. These are of course social wasps:

Next up is a White-banded Potter Wasp, Ancistrocerus albophaleratus. Potter wasps are solitary, and they build a mud-pot nest which they will provision with paralyzed arthropods like caterpillars or spiders, depending on the species:

The above wasps all belong to the family Vespidae, which can be immediately recognized because their front wings are folded lengthwise into a V in cross-section (V is for Vespidae).

The next insect looks like a lovely green-eyed bee, but I soon realized it lacked certain bee characters and so it had to be a wasp. It took a while, but I finally identified it as belonging to the family Crabronidae, and the genus Tachytes – that is all I know. These solitary wasps raise their young in burrows, provisioning them with paralyzed grasshoppers or katydids:

The last insect is rather comical and I don’t understand what it wants. This is a Pixie Robber Fly (Beameromyia sp.). Robber Flies are of course predatory. I occasionally see this species drawn to the porch light at night, as this one was, and for some reason they really want to stand on their head. I managed to coax this one onto a stick for pictures, and while I would tip and turn the stick to get it into frame, it would immediately adjust its stance so that it remained as you see it here. I have no idea why:

Renewable energy continued to grow in 2024, and there were other hopeful developments in technologies aiming to reverse the rise in greenhouse gas emissions

Some narratives are simply ubiquitous in our culture (every culture has its universal narratives). Sometimes these narratives emerge out of shared values, like liberty and freedom. Sometimes they emerge out of foundational beliefs (the US still has a puritanical bent). And sometimes they are the product of decades of marketing. Marketing-based narratives deserve incredible scrutiny because they are crafted to alter the commercial decision-making of people in society, not for the benefit of society or the public, but for the benefit of an industry. For example, I have tried to expose the fallacy of the “natural is always good, and chemicals are always bad” narrative. Nature, actually, is quite indifferent to humanity, and everything is made of chemicals.

Another narrative that is based entirely on propaganda meant to favor one industry and demonize its competition is the notion that organic farming is better for health and better for the environment. Actually, there is no evidence of any nutritional or health advantage from consuming organic produce. Further – and most people I talk to find this claim shocking – organic farming is worse for the environment than conventional or even “factory” farming. Stick with me and I will explain why this is the case.

A recent article in the NYT by Michael Grunwald nicely summarizes what I have been saying for years. First let me explain why I think there is such a disconnect between reality and public perception. This gets back to the narrative idea – people tend to view especially complex situations through simplistic narratives that give them a sense of understanding. We all do this because the world is complicated and we have to break it down. There is nothing inherently wrong with this – we use schematic, categories, and diagrams to simplify complex reality and chunk it into digestible bits. But we have to understand this is what we are doing, and how this may distort our understanding of reality. There are also better and worse ways to do this.

One principle I like to use as a guide is the Moneyball approach. This refers to Paul DePodesta who devised a new method of statistical analysis to find undervalued baseball players. Prior to DePodesta talent scouts would find high value players to recruit, players who had impressive classic statistics, like batting average. They would then pay high sums for these star players. DePodesta, however, realized that players without star-quality stats still might be solid players, and for their price could have a disproportionate positive effect on a team’s performance. If, therefore, you have a finite amount of funds to spread out over a team’s players, you might be better off shoring up your players at the low end rather than paying huge sums for star players. Famously this approach worked extremely well (first applied to the Oakland Athletics).

So let’s “Moneyball” farming. We can start with the premise that we have to produce a certain amount of calories in order to feed the world. Even if we consider population control as a long term solution – that’s a really long term solution for any ethically acceptable methods. I will add as a premise that it is not morally or politically feasible to reduce the human population through deliberate starvation. Right now there are 8.2 billion humans on Earth. Estimates are this will rise to about 10 billion before the population starts to come down again through ethical methods like poverty mitigation and better human rights. So for the next hundred years or so we will have to feed 8+ billion people.

If our goal is to feed humanity while minimizing any negative effect on the environment, then we have to consider what all the negative effects are of farming. As Grunwald points out – they are huge. Right now we are using about 38% of the land on Earth for farming. We are already using just about all of the arable land – arable land is actually a continuum, so it is more accurate to say we are using the most arable land. Any expansion of farmland will therefore expand into less and less arable land, at greater and greater cost and lower efficiency. Converting a natural ecosystem, whether a prairie, forest, meadow, or whatever, into farmland is what has, by far, the greatest negative effect on the ecosystem. This is what causes habitat loss,  isolates populations, reduces biodiversity, and uses up water. The difference between different kinds of farming is tiny compared to the difference between farming and natural ecosystems.

This all means that the most important factor, by far, in determining the net effect of calorie production for humans on the environment is the amount of land dedicated to all the various kinds of farming. Organic farming simply uses more land than conventional farming, 20-40% more land on average. This fact overwhelms any other alleged advantage of organic farming. I say alleged because organic farms can and many do use pesticides – they just use natural pesticides, which are often less effective requiring more applications. Sometimes they also rely on tilling, which releases carbon from the soil.

But even if we compare maximally productive farming to the most science-based regenerative farming techniques, designed to minimize pesticide use and optimize soil health – maximally efficient farming wins the Moneyball game. It’s no contest. Also, the advantage of efficient factory farming will only get greater as agricultural science and technology improves. GMOs, for example, have the potential for massive improvements in crop efficiency, leaving organic farming progressively in the dust.

But all this does not fit the cultural narrative. We have been fed this constant image of the gentle farm, using regenerative practices, protecting the soil, with local mom and pop farmers producing food for local consumption. It’s a nice romantic image, and I have no problem with having some small local farms growing heirloom produce for local consumption. But this should be viewed as a niche luxury – not the primary source of our calories. Eating locally grown food from such farms is, in a way, a selfish act of privilege. It is condemning the environment so you can feel good about yourself. Again, it’s fine in moderation. But we need to get 95% of our calories from factory farms that are brutally efficient. This also does not mean that factory farms should not endeavor to be environmentally friendly, as long as it does not come at the cost of efficiency.

At this point many people will point out that we can improve farming efficiency by eliminating meat. It is true that overproducing meat for calories is hugely inefficient. But so is underproducing meat. What the evidence shows is that maximal efficiency comes from using each parcel of land for it’s optimal use. Grazing land for animals in many cases is the optimal use. Cattle, for example, can convert a lot of non-edible calories into edible calories. And finishing lots can also use low grade feed not fit for humans to pack on high-grade calories for humans. Yes – many industrialized nations consume too much meat. Part of optimizing efficiency is also optimizing the ratio of which kinds of calories we consume. But zero meat is not maximally efficient. Also – half our fertilizer comes from manure, and we can’t just eliminate the source of half our fertilizer without creating a disaster.

It’s a complicated system. We no longer, however, have the luxury of just letting everyone do what they want to do and what they think is in their best interest. Optimally there would be some voluntary coordination for the world’s agricultural system to maximize efficiency and minimize land use. This can come through science-based standards, and funding to help poorer countries have access to more modern farming techniques, rather than just converting more land for inefficient farming.

But first we have to dispense with the comforting but ultimately fictional narrative that the old gentle methods of farming are the best. We need science-based maximal efficiency.

 

The post Factory Farming is Better Than Organic Farming first appeared on NeuroLogica Blog.

One of the biggest uncertainties in the ongoing AI revolution is whether these systems can legally be trained on copyrighted data. Now, the UK says it plans to clarify the matter with a change to the law

Reality. Doesn't care what you think.

The post Reality first appeared on Science-Based Medicine.

The fossilised remains of an ancient carnivore provide intriguing hints about how early relatives of mammals began regulating their own body temperature

Cryonics promises an opportunity for you to be frozen and revived at some distant point in the future — though with plenty of controversy.

A long-envisioned futuristic world of humanoid robots doing all the work has yet to arrive, but these startling images reveal some of the surprising ways that advanced robotics is becoming more ubiquitous in people's lives

Eating disorders have increased - and many are pointing the finger at sites like Instagram and TikTok

A novel nanobody-based immunosensor, designed to function stably in undiluted biological fluids and harsh conditions, has been developed. Their innovative design leverages BRET -- bioluminescence resonance energy transfer -- and exhibits great potential for point-of-care testing, therapeutic drug monitoring, and environmental applications using paper-based devices.

When it comes to our modern society and the many crises we face, there is little doubt that fusion power is the way of the future. The technology not only offers abundant power that could solve the energy crisis, it does so in a clean and sustainable way. At least as long as our supplies of deuterium (H2) and helium-3 hold up. In a recent study, a team of researchers considered how evidence of deuterium-deuterium (DD) fusion could be used as a potential technosignature in the Search for Extraterrestrial Intelligence (SETI).

The study was conducted by David C. Catling and Joshua Krissansen-Totton of the Department of Earth & Space Sciences and the Virtual Planetary Laboratory (VPL) at the University of Washington (respectively) and Tyler D. Robinson of the VPL and the Lunar & Planetary Laboratory (LPL) at the University of Arizona. In their paper, which is set to appear in the Astrophysical Journal, the team considered how long-lived extraterrestrial civilizations may deplete their supplies of deuterium – something that would be detectable by space telescopes.

At the heart of SETI lies the foregone conclusion that advanced civilizations have existed in our galaxy long before humanity. Another conclusion extends from this: if humanity can conceive of something (and the physics are sound), a more advanced civilization is likely to have already built it. In fact, it has been suggested by many SETI researchers and scientists that advanced civilizations will adopt fusion power to meet their growing energy needs as they continue to grow and ascend the Kardashev Scale.

The spherical tokamak MAST at the Culham Centre for Fusion Energy (UK). Photo: CCFE

This is understandable, considering how other forms of energy (fossil fuels, solar, wind, nuclear, hydroelectric, etc.) are either finite or inefficient. Space-based solar power is a viable option since it can provide a steady supply of energy that is not subject to intermittency or weather patterns. Nevertheless, nuclear fusion is considered a major contender for future energy needs because of its efficiency and energy density. It is estimated that one gram of hydrogen fuel could generate as much as 90,000 kilowatt-hours of energy – the equivalent of 11 metric tons (12 U.S. tons) of coal.

In addition, deuterium has a natural abundance in Earth’s oceans of about one atom of deuterium in every 6,420 atoms of hydrogen. This deuterium interacts with water molecules and will replace one or both hydrogen atoms to create “semi-heavy water” (HOD or DOH) and sometimes “heavy water” (D2O). This works out to 4.85×1013 or 48.5 billion metric tons (5.346×1013 U.S. tons) of deuterium. As they argue in their paper, extracting deuterium from an ocean would decrease its ratio of deuterium-to-hydrogen (D/H), which would be detectable in atmospheric water vapor. Meanwhile, the helium produced in the nuclear reactions would escape to space.

In recent years, it has been suggested that excess carbon dioxide and radioactive isotopes in an exoplanet’s atmosphere could be used to infer the presence of an industrial civilization. In the same vein, low values of D/H in an exoplanet’s atmosphere (along with helium) could be used to detect a highly advanced and long-lived civilization. As Catling explained in a recent interview with phys.org, this possibility is one he began pondering years ago.

“I didn’t do much with this germ of idea until I was co-organizing an astrobiology meeting last year at Green Bank Observatory in West Virginia,” he said. “Measuring the D/H ratio in water vapor on exoplanets is certainly not a piece of cake. But it’s not a pipe dream either.”

A model JWST transmission spectrum for an Earth-like planet, showing the wavelengths of sunlight that molecules like ozone (O3), water (H2O), carbon dioxide (CO2), and methane (CH4) absorb. Credit: NASA, ESA, Leah Hustak (STScI)

To model what an advanced civilization dependent on DD fusion would look like, Catling and his colleagues considered projections for what Earth will look like by 2100. At this point, the global population is expected to reach 10.4 billion, and fusion power is projected to provide 100 Terawatts (TW). They then multiplied that by a factor of ten (1,000 TW) for a more advanced civilization and found that they would reduce the D/H value of an Earth-like ocean to that of the interstellar medium (ISM) in about 170 million years.

The beauty of this approach is that the low D/H values in an exoplanet’s atmosphere would persist long after a civilization went extinct, migrated off-world, or became even more advanced and “transcended.” In terms of search strategies, the team used the Spectral Mapping Atmospheric Radiative Transfer (SMART) model to identify the specific wavelengths and emission lines for HDO and H2O. These findings will be useful for future surveys involving the James Webb Space Telescope (JWST), NASA’s proposed Habitable Worlds Observatory (HWO), and the Large Interferometer For Exoplanets (LIFE).

“It’s up to the engineers and scientists designing [HWO] and [LIFE] to see if measuring D/H on exoplanets might be an achievable goal. What we can say, so far, is that looking for D/H from LIFE appears to be feasible for exoplanets with plenty of atmospheric water vapor in a region of the spectrum around 8 microns wavelength.”

Further Reading: phys.org, arXiv

The post A New Study Suggests How we Could Find Advanced Civilizations that Ran Out of Fusion Fuel appeared first on Universe Today.

Researchers have developed microchips using field-effect transistors that can detect multiple diseases from a single air sample with high sensitivity. The technology enables rapid testing and could lead to portable diagnostic devices for home and medical use.

Researchers have developed microchips using field-effect transistors that can detect multiple diseases from a single air sample with high sensitivity. The technology enables rapid testing and could lead to portable diagnostic devices for home and medical use.