Science

Over time, batteries break down. Studying this process in-depth with imaging techniques may help us improve the lifespan of batteries.

Asteroids that orbit close to the Earth inevitably cause us some anxiety due to the even remote possibility of a collision. But their proximity also offers ample opportunities to learn more about the universe. Ryugu, a 900-meter diameter asteroid in the Apollo belt, has recently proven useful in our search for signs of life's precursors elsewhere in our Solar System. A team of researchers has found evidence of salt minerals in samples recovered from Ryugu during the initial phase of Japan's Hayabusa2 mission.

A unique dataset of Type Ia Supernovae being released today could change how cosmologists measure the expansion history of the Universe.

A survey of adults found most had low trust in their health care system to use artificial intelligence responsibly or to make sure an AI tool would not harm them.

As more satellites, telescopes, and other spacecraft are built to be repairable, it will take reliable trajectories for service spacecraft to reach them safely. Researchers are developing a methodology that will allow multiple CubeSats to act as servicing agents to assemble or repair a space telescope. Their method minimizes fuel consumption, guarantees that servicing agents never come closer to each other than 5 meters, and can be used to solve pathway guidance problems that aren't space related.

A remarkable discovery appeared in the journal Science in 2010.  Felisa Wolfe-Simon and her colleagues reported finding, in California’s salty Mono Lake, a bacterium that could substitute arsenic for phosphorus in its metabolism.  This was stunning, as phosphorus was thought to be an essential constituent of many biological macromolecules, including proteins and DNA—the latter using phosphorus as part of its backbone.  (The bacterium was, by the way, named GFAJ-1, standing for “Give Felisa a job,” as she was apparently looking for a permanent academic position.)

At any rate, this was huge news, and implied, to many, including hype-promoting journalists, that if life could thrive on arsenic, perhaps the chances of life on other planets was higher than we thought. Wolfe-Simon herself implied that perhaps there was a “shadow biosphere,” on Earth, including organisms that we didn’t know of because their biochemistry was so different from that of life we knew.

The publicity attending this discovery was huge: NASA held a press conference in which Simon was the only one of the dozen authors to appear. Simon also gave a TED talk on this subject, and in 2011 Time Magazine named her one of “Time’s 100 people,” supposedly the most influential group in the world.

The problem, which emerged pretty rapidly, is that this discovery was wrong. The research was sloppy, the reviewers apparently didn’t have the proper expertise to review the paper, and researchers who did have the expertise began pointing out the discovery’s flaws, first online and then in a series of eight critiques published in Science. As Wikipedia notes,

 If correct, this would be the only known organism to be capable of replacing phosphorus in its DNA and other vital biochemical functions.[14][15][16] The Science publication and an hour-long December 2, 2010 NASA news conference were publicized and led to “wild speculations on the Web about extraterrestrial life”.[17] Wolfe-Simon was the only one of the paper’s authors at that news conference.[18] The news conference was promptly met with criticism by scientists and journalists.[19] In the following month, Wolfe-Simon (and her co-authors and NASA) responded to criticisms through an online FAQ and an exclusive interview with a Science reporter, but also announced they would not respond further outside scientific peer-review.[20][21] In April 2011 Time magazine named Wolfe-Simon one of that year’s Time 100 people.[22][23]

The Science article “A Bacterium That Can Grow by Using Arsenic Instead of Phosphorus” appeared in the June 3, 2011 print version of Science;[1] it had remained on the “Publication ahead of print” ScienceXpress page for six months after acceptance for publication. However, Rosemary Redfield and other researchers from the University of British Columbia and Princeton University performed studies in which they used a variety of different techniques to investigate the presence of arsenic in the DNA of GFAJ-1 and published their results in early 2012. The group found no detectable arsenic in the DNA of the bacterium. In addition, they found that arsenate did not help the strain grow when phosphate was limited, further suggesting that arsenate does not replace the role of phosphate.[24][25]

Following the publication of the articles challenging the conclusions of the original Science article first describing GFAJ-1, the website Retraction Watch argued that the original article should be retracted because of misrepresentation of critical data.[26][27] In October 2024, Science editor Holden Thorp notified the article’s authors of its intention to retract, arguing that, whereas formerly only misconduct justified retraction, current practice allows it for unreliablity.[22]

I wrote about the controversy at the time; see my several posts here.  Simon et al. apparently were dead wrong.  This was first revealed byblog posts by Rosie Redfield (who later published a critique in the literature) and followed by eight critiques in Science about the Wolfe-Simon et al, paper, and two failed attempts to replicate their results, both of which failed. Wolfe-Simon did not get her coveted job and, as the new NYT article below reports, she now spends her time making music on the oboe, and working part-time on bacteria that apparently can use the Earth’s magnetic field to navigate.

Now the NYT has revisited the controversy on its 15th anniversary, and has published a long and remarkable article that does its best to exculpate Wolfe-Simon and demonize her critic. As the headline below implies, she further “changed science forever.”  That’s wrong. Why do they do this? Greg Mayer has two theories, which are his, and I’ll mention them below.

Click below to read the NYT article by Sarah Scoles, which is also archived here.

The article is remarkably soft on Wolfe-Simon, downplaying the scientific sloppiness of her theme and making her into kind of heroine who was unfairly attacked by a social-media mob They don’t mention microbiologist Rosie Redfield, a prime critic responsible for pointing out the errors of Wolfe-Simon et al., though one link goes to her.  The article implies, as I said, that “her discovery” (it was a group of people!) nevertheless changed science forever, for it was critiqued on social media (something that the NYT implies is bad), and from then on science has been vetted, even before papers are formally published, by non-scientists or scientists who publish their criticisms on social media, including blogs. This, claims author Scoles, has affected science so it’s never been the same.

Scoles is wrong and grossly exaggerates the situation.  Papers were criticized on social media long before Wolfe-Simon’s, but hers received special attention solely because not only was it a remarkable phenomenon, one hard to believe, but also because the authors gave it huge hype, helped along by the press. Remarkable results deserve remarkable attention. And, in the end, the problems with the Wolfe-Simon paper and the failure to replicate it found their way into the scientific literature, so that nobody now believes that there was an arsenic-using bacterium.  This is the way science is supposed to work, and in this case it did work. A sloppy and incorrect report was corrected.

Now others, including Science‘s editor Holden Thorp, as well as David Sanders in the Retraction Watch article below from 2020, feel that Wolfe-Simon et al. paper should be retracted.  I disagree. Retraction, if it’s used for anything, should be reserved for papers that were duplicitous, containing fake data or false assertions.  Wolfe-Simon et al. simply produced an incorrect and poorly reviewed paper, but there was no cheating. The paper should stay, and its simply met the fate of many papers that were wrong (remember, at least two Nobel Prizes have been given for sloppy and incorrect science). It is an object lesson on how wonky results get fixed.

Click below to read this Retraction Watch article from 2021, or see the more recent article here.

The question remains: why did the NYT paint a misleading picture of Felisa Wolfe-Simon, of her detractors, and of the scientific process? Why did they go so easy on her, making her into a heroine who was unfairly mobbed—to the point where she could not find an academic job.  Greg Mayer suggested two theories:

1.) Greg notes that because the article “makes her out as a victim”, it plays into the “victim narrative” of scientists who were treated unfairly (she was a woman, too, which feeds into that narrative).  And newspapers love victim narratives.

2.) Greg also wrote,  “The article seems in line with the Times’s embrace of woo: another example of credulous reporting of outlandish claims, a la their recent UFO coverage.”

I’m going to let Greg dilate on these theories, which are his, below, so come back to this post later on today to see what he says. I agree with him in the main, and we both agree that Wolfe-Simon’s paper should NOT be retracted.

Addendum by Greg Mayer.

My first suggestion is actually the “scientist as hero” narrative, which portrays the lone scientist as struggling against an entrenched orthodoxy that tries to suppress their discoveries. For some discussion of the narrative, its faults, but also its upside, see this post by Andrew Gelman and the links within it. The media love this narrative– sometimes it’s even true! That the “hero scientist” becomes a “victim” is even better– now you’re Galileo! It doesn’t hurt if the victim seems to be opposed by heartless male editors like Holden Thorpe; it helps if you neglect to mention that some of the most incisive criticisms were by another female scientist. But as someone once said, you can’t wrap yourself in the cloak of Galileo merely because orthodoxy opposes you: you must also be right. Getting a sympathetic reassessment in the Times also fits well with the initial strategy of maximum media attention (NASA press conference, TED talk, Glamour, Time, Wall Street Journal, etc.) as a way to advance one’s career, and with the general approach to science of the media, including the Times.

The second suggestion, which is not mutually exclusive, is that the article follows the Times recent attraction to woo, like astrology and UFOs. A lot of elite media have gotten in on the latter– see Andrew Gelman again, especially here. He points out that the media seem to think they are being skeptical of elites and authority when purveying this stuff, but while doubting authority, they gullibly accept anything else they’re told. (There’s a very similar strain in RFK Jr.’s approach to science.) But, as Gelman notes, extreme skepticism bleeds into credulity.

My friend Phil Ward at UC Davis found this reference and called it to my attention. It’s from the Philosophical Transactions of the Royal Society (B), and access is free (click on title below).  The pdf with the numbered references is here.

The paper is about how the evolution of two different types of gametes (“anisogamy”: a requirement for the origin of biological sexes) can originate from isogamy (same-sized gametes) under certain conditions. It is a theoretical paper, and I haven’t read it closely as I’m math-averse. However, what’s of interest is the first paragraph of the paper, which reviews the literature on anisogamy.  That paragraph states that anisogamy (ergo biological sex) has originated independently in many groups of eukaryotes (organisms with true cells).  I’ve put that first paragraph below and have bolded the relevant part. I’ve also linked to each group so you can see what they are.  The numbers lead to the references, which I have not checked.

Multicellular organisms typically produce gametes of two distinct size classes: larger eggs and smaller sperm. This dimorphism—known as ‘anisogamy’—is a remarkable case of convergent evolution. It has arisen independently in multiple distantly related eukaryotic lineages, including in animals [1]; dikaryotic fungi [2]; various groups of green algae, including the ancestors of land plants [3,4]; red algae [5]; brown algae [6,7]; yellow-green algae (Xanthophyceae: Vaucheria) [8]; diatoms [9]; oomycetes [10]; dinoflagellates [11]; apicomplexans [12]; and parabasalids (Trichonympha) [13]. By contrast, the gametes of most unicellular and some multicellular eukaryotes are isogamous, with a unimodal distribution of gamete sizes. Anisogamy is often taken as the defining difference between ‘male’ and ‘female’ sexual strategies: males produce only sperm; females produce only eggs; and hermaphrodites have the potential to produce both gamete types, either simultaneously or at different life stages. Isogamous species lack sexes by this definition. However, their gametes can often be classified into two, or occasionally more, ‘mating types’, such that fertilization only occurs between gametes of unlike types [2,14–16].

If you add up these groups, you get at least 11 evolutionarily independent origins of anisogamy: the production of “larger eggs and smaller sperm.”  The independence is probably inferred via a “cladistic” method by looking at the family trees of these groups, seeing that the ancestors were either asexual or isogamous, and noting that anisogamy appeared on a later-appearing derived branch.

If the authors are indeed correct, then what we have here is a remarkable example of evolutionary convergence: eleven separate groups independently evolving binary sex with large eggs and small sperm.  There are of course evolutionary theories showing why an ancestral condition of sex with equal-size gametes would split into a derived condition with two sizes of gametes, but that is a theoretical result.  Here we see that this has actually happened in nature nearly a dozen times, so the theories may hold some water.

I’ll add one thing. Not only has anisogamous sex apparently evolved eleven times independently, but, even in the one group of animals the determinants of sex—the features that trigger the development of two types of animals producing different-sized gametes—have also evolved independently. Luana and I pointed this out in our paper, “The ideological subversion of biology” (bolding is mine):

We can see the stability of the two-sex condition by realizing that what triggers the development of males versus females varies widely across species (Bachtrog et al. 2014). Different sexes can be based on different chromosomes and their genes (e.g., XX vs. XY in humans, ZW vs. ZZ in birds, individuals with like chromosomes being female in mammals and male in birds); different rearing temperatures (crocodiles and turtles); whether you have a full or half set of chromosomes (bees); whether you encounter a female (marine worms); and a host of other social, genetic, and environmental factors. Natural selection has independently produced diverse pathways to generate the sexes, but at the end there are just two destinations: males and females. And so we have an evolved and objectively recognized dichotomy—not an arbitrary spectrum of sexes.

Now I’m not smart or diligent enough to figure out why once there are two sexes—which is the case in animals, and must thus have been true in our common ancestor)—how you can evolutionarily traverse from one determinant of sex (say a gene on a chromosome) to something like temperature-dependent sex determination or social sex determination (e.g. the famous clownfish, used by miscreants to claim that there are more than two sexes).  It’s a mystery waiting to be solved.  But so even here, in one group, we have convergent evolution—of the factors that cause the two sexes to diverge.

I find all this fascinating, and it shows the power of Orgel’s Second Rule: “evolution is cleverer than you are.”

Crops don't generally thrive in desert-like ground, but 1000 years ago farmers in Israel utilised refuse such as ash and bones to turn sand into fertile land

Please send in your wildlife photos! Do I have to beg? Very well, then, I’m begging.

Today we have some photos by ecologist Susan Harrison: mostly birds but two mammals and one astronomy picture. Her captions are indented, and you can enlarge the photos by clicking on them.

More miscellany of early 2025

It’s been a turbulent time at work and a slow time for birdwatching, so it’s challenging to come up any wildlife photos, let alone ones with a theme.   But here are a few more random sights from around Davis, California in January – early February 2025.

Overwintering Snow Geese (Anser caerulescens):

American Beaver (Castor canadensis) in the local stream:

Mountain Bluebird (Sialis curricucoides), an uncommon overwintering bird around here, hunting crickets in a plowed field:

Merlin (Falco columbarius), distinguished from the similar-sized American Kestrel by having a white eyebrow instead of a black mustache (as birders call the vertical facial stripe):

American Kestrel (Falco sparverius) for comparison:

Miniature goats (Capra hircus), seemingly puzzled that the human is looking up into trees rather than bringing them carrots:

Horned Larks (Eremophila alpestris), which always look to me like they’re searching for someone’s lost keys:

American Avocets (Recurvirostra americana), in which females have more upcurved bills than males, possibly giving them different feeding niches:

Killdeer (Charadrius vociferus), inexorably drawn to stony surfaces like gravel roads and railroad beds:

Cinnamon Teal (Spatula cyanoptera) pairing up, Northern Shoveler (Spatula clypeata), and a rear-end view of a Northern Pintail (Anas acuta):

Mixed ducks flying away, as they are—sadly but for good reason—very shy of humans:

Savannah Sparrow (Passerculus sandwichensis), a drab little bird with not much to fear from a human:

And finally, though I’m no celestial photographer, the Moon being approached by Mars:

A new look at fossils from the Cambrian Period around 500 million years ago has revealed that some of the earliest animals spent time on mudflats that were sometimes exposed to the air – a find that could rewrite the story of when life first left the oceans

It’s a familiar sight to see astronauts on board ISS on exercise equipment to minimise muscle and bone loss from weightlessness. A new study suggests that jumping workouts could help astronauts prevent cartilage damage during long missions to the Moon and Mars. They found that the knee cartilage in mice seems to grow stronger after jumping exercises, potentially counteracting the effects of low gravity on joint health. If effective in humans, this approach could be included in pre-flight routines or adapted for space missions.

In space, astronauts experience significant loss of bone and muscle mass due to microgravity. Without Earth’s gravitational pull, bones lose density, increasing fracture risk, while muscles, especially in the lower body and spine, weaken from reduced use. This deterioration can impair mobility when back on Earth and effect overall health. To combat this, astronauts follow rigorous exercise routines, including resistance and cardiovascular training, to maintain strength and bone integrity. 

ESA astronaut Alexander Gerst gets a workout on the Advanced Resistive Exercise Device (ARED). Credit: NASA

The next obvious step as we reach out into the Solar System is the red planet Mars. Heading that far out into space will demand long periods of time in space since its a 9 month journey there. Permanent bases on the Moon too will test our physiology to its limits so managing the slow degradation is a big challenge to space agencies. A paper published by lead author Marco Chiaberge from the John Hopkins University has explored the knee joints of mice and how their cartilage grows thicker if they jump! They suggest astronauts should embed jumping activities into their exercise regiment. 

Mars seen before, left, and during, right, a global dust storm in 2001. Credit: NASA/JPL/MSSS

Cartilage cushions the joints between bones and decreases friction allowing for pain free movement. Unlike many other tissues in the body, cartilage does not regenerate as quickly so it is important to protect it. Prolonged periods of inactivity, even from bed rest but especially long duration space flight can accelerate the degradation. It’s also been shown that radiation from space can accelerate the effect too. 

To maintain a strong healthy body, astronauts spend a lot of time, up to 2 hours a day running on treadmills. This has previously shown to slow the breakdown of cartilage but the new study has shown that jumping based movements is particularly effective. T

The team of researchers found that, over a nine week program of reduced movement, mice experienced a 14% reduction in cartilage thickness in joints. Other mice performed jumping movements three times a week and their cartilage was found to be show a 26% increase compared to a control group of mice. Compared to the group that had restricted movement, the jumping mice had 110% thicker cartilage. The study also showed that jumping activities increased bone strength too with the jumping mice having a 15% higher density than the control.

An interesting piece of research but further work is needed to see whether jumping would herald in the same benefits to humans but the study is promising. If so, then jumping exercises are likely to be a part of pre-flight and inflight exercise programs for astronauts. It is likely that for this to be a reality in the micro-gravitational environment, astronauts will be attached to strong elasticated material to simulate the pull of gravity. 

Source : Jumping Workouts Could Help Astronauts on the Moon and Mars, Study in Mice Suggests.

The post Should Astronauts Add Jumping to their Workout Routine? appeared first on Universe Today.

One of the basic principles of cosmology is the Cosmological Principle. It states that, no matter where you go in the Universe, it will always be broadly the same. Given that we have only explored our own Solar System there is currently no empirical way to measure this. A new study proposes that we can test the Cosmological Principle using weak gravitational lensing. The team suggests that measuring tiny distortions in light as it passes through the lenses, it may just be possible to find out  if there are differences in density far away. 

The Cosmological Principle is a fundamental assumption stating that the universe is homogeneous on a large scale. In other words regardless of location or direction, the universe appears uniform and it underpins many cosmological models, including the Big Bang theory. Taking the assumption that physical laws apply consistently everywhere makes calculations and predictions about the universe’s structure and evolution far simpler, but research has been testing its validity by searching for potential anomalies.

This illustration shows the “arrow of time” from the Big Bang to the present cosmological epoch. Credit: NASA

A paper has been published by a team of astrophysicists, led by James Adam from the University of Western Cape in South Africa and explains that the Standard Model of Cosmology predicts the Universe has no centre and has no preferred directions (isotropy.) The paper, which was published in the Journal of Cosmology and Astroparticle Physics, articulates a new way to test the isotropy of the Universe using the Euclid space telescope.

The Euclid telescope is a European Space Agency mission to explore dark matter and dark energy. It was launched in 2023 and maps the positions and movements of billions of galaxies. It’s using this instrument that the team hope to search for variations in the structure of the Universe that might challenge the Cosmological Principle. 

Artist impression of the Euclid mission in space. Credit: ESA

Previous studies have found such anomalies before but there are conflicting measurements of the expansion rate of the Universe, in the microwave background radiation and in various cosmological data. Further independent observations are required though, providing more data to see if the observations were the result of measurement errors. 

The team explore using weak gravitational lenses, which occur when matter sits between us and a distant galaxy, slightly bending the galaxies light. Analysis of this distortion can be separated into two components; E-mode shear (caused by the distribution of matter in an isotropic and homogenous Universe) and B-mode shear which is weak and would not appear in an isotropic Universe at large scale. 

If the team can detect large scale B-modes this in itself wouldn’t be enough to confirm the anisotropies since the measurements are tiny and prone to measurement errors. To confirm, and finally test the Cosmological Principles, E-mode shear needs to be detected as well. Such discovery and correlation of E-mode and B-mode shear would suggest the expansion of the Universe is anisotropic. 

Ahead of the Euclid observations, the team simulated the effects of an anisotropic universe expansion on a computer. They were able to use the model to describe the effect of the weak gravitational force and predict that Euclid data would be sufficient to complete the study. 

Source : Does the universe behave the same way everywhere? Gravitational lenses could help us find out

The post Do We Live in a Special Part of the Universe? Here’s How to Find Out appeared first on Universe Today.

For more than 40 years, Jonathan McDowell has tirelessly catalogued the space industry. Now he is planning to retire, and looking to pass on his extensive collection of knowledge

A UK start-up is producing dyes made by bacteria and yeast rather than fossil fuel-derived chemicals, which could help clothes manufacturers cut energy use and pollution

$160 million is a lot of money, especially when you consider its not just money. It's lost dreams, careers, and discoveries.

The post Open Letter II: President Levin, There Are Now 160 Million Reasons Why You Shouldn’t Have Censored We Want Them Infected Doctors first appeared on Science-Based Medicine.

Fossil teeth of extinct megalodon sharks have grooves made by other megalodon teeth, hinting at violent encounters between these giant predators

The Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) and NTT Research, Inc., a division of NTT, announced the publication of research showing an application of machine-learning directed optimization (ML-DO) that efficiently searches for high-performance design configurations in the context of biohybrid robots. Applying a machine learning approach, the researchers created mini biohybrid rays made of cardiomyocytes (heart muscle cells) and rubber with a wingspan of about 10 mm that are approximately two times more efficient at swimming than those recently developed under a conventional biomimetic approach.

The Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) and NTT Research, Inc., a division of NTT, announced the publication of research showing an application of machine-learning directed optimization (ML-DO) that efficiently searches for high-performance design configurations in the context of biohybrid robots. Applying a machine learning approach, the researchers created mini biohybrid rays made of cardiomyocytes (heart muscle cells) and rubber with a wingspan of about 10 mm that are approximately two times more efficient at swimming than those recently developed under a conventional biomimetic approach.

Researchers demonstrated the first fully 3D-printed, droplet-emitting electrospray engine. The low-cost device can be fabricated more quickly than traditional thrusters, potentially from on board a spacecraft, and could enable CubeSats to perform precise, in-orbit maneuvers, aiding space research projects.

Researchers demonstrated the first fully 3D-printed, droplet-emitting electrospray engine. The low-cost device can be fabricated more quickly than traditional thrusters, potentially from on board a spacecraft, and could enable CubeSats to perform precise, in-orbit maneuvers, aiding space research projects.