I guess I can't rule it out. I do remember a lot of my dreams, but probably not all of them. I can't remember what I dreamed last night, for instance. Still, it seems odd that lucid dreams - specifically, the ones that don't wake me up, because I remember other dreams that also didn't wake me - would always be forgotten by the next morning.
The hypothesis is a dark force, which does not affect normal matter, but only dark matter (at low energies). It is supposed to be a part of the electroweak force at high energies, so its effects might be observed with particle collider experiments. They claim to have a model that explains a certain experiment better than the standard model does. If they could successfully apply this model to other experiments as well, this would be a huge discovery.
IN CERTAIN FAIRY tales, when treasure is hidden from prying eyes and thieves in secret vaults, access is granted by the magic words: “Open sesame!” But it isn’t magic, of course, that unlocks the golden bounty of sesame seeds themselves so that you can enjoy them on your bagel; it’s physics.
Sesame seeds are produced by the plant of the same name, formally Sesamum indicum . It’s a plant with a very flexible growing season, but now, in the early fall, some of the world’s major producers—Sudan, India, Nigeria and others—are harvesting their crop. A sesame plant is a robust stalk, 3 to 5 feet tall, with leaves coming directly from the stalk and sporting white, purple or blue flowers. The fruits are vertical green capsules a couple of inches long; each one is made of four long hollow compartments, giving it a reasonably square cross-section. The sesame seeds are neatly lined up inside each compartment, protected from the world as they grow.
We generally have the idea that plants can’t move, but that’s not exactly the case. They can’t walk away, but they can change shape. The way plants usually do it is by exploiting the fact that even though their tissues have a fixed structure, the water inside them can come and go. If the plant cells have either a water-balloon structure that can inflate and deflate, or a type of material that is a different shape when wet than dry, there’s potential for movement that the plant can control. In the case of sesame, the plant needs to disperse the fully grown seeds by opening each capsule in a way that will let the seeds blow away on the wind. So the structure of the capsule has a very specific pattern. Each of its four compartments is made up of a long C-shaped trough, with the seeds on the inside. A compartment wall has three layers: The first two are made of stiff cells full of cellulose microfibrils, but the outer one is quite different, made from a much more open and disorganized collection of soft cells with no stiff microfibrils.
The two inner layers hardly change when they dry out or get wet, but the outer layer is like a soft but strong sponge. When the capsule is growing, that layer is thick and plump because it’s full of water, but as the seeds ripen it starts to dry out. It loses so much water that it shrinks to 30% of its original thickness; it also shrinks asymmetrically. This leaves the whole outer layer in tension, a bowstring primed to fire. When the tension gets too much— pop!—each compartment pulls away from the others by breaking at the line of weakness where the compartments join, snapping back and outward, away from the center. At the same time, the C-shapes open up, flattening the compartment walls. Seeds can come flying out at this point, or they can wait until the wind picks them up and carries them off. It’s thought that this sudden reveal is the origin of the phrase “Open sesame,” made famous in the story of Ali Baba in “One Thousand and One Nights.”
TOMASZ WALENTA
Ironically, there’s lots of research going on now into how to prevent this natural propulsion, so that the seeds can be harvested mechanically in a more orderly fashion. But if you have a bagel for breakfast, spend a moment considering the nutty treasure stuck to the outside and how it gets there, at least for now. Each seed will have had its dramatic moment of being revealed to the world, proving that physical principles are even more magical than a genie in a lamp.
I am sure I posted about a pre-print of this paper, because I recognise the image, but the search is failing me. It seems the publication has brought some criticism:
If the impresario P T Barnum was right to say that there’s no such thing as bad publicity, then the paper just published in Nature by Sara Walker of Arizona State University, Lee Cronin of the University of Glasgow, and their coworkers has been a runaway success.
The paper claims that an idea called assembly theory (AT) ‘explains selection and evolution’. This has drawn a clamour of responses from scientists on social media – many of them offended, some baffled – and prompted unusually vigorous debate in the online ‘comments’ section of the Nature site. Evolutionary biologists in particular have expressed outrage – denouncing the paper as nonsense, and even a Trojan horse for creationism.
It’s not hard to see why. From the first sentence of the abstract, the paper seems to imply that the authors have cracked a foundational problem for biology: ‘Scientists have grappled with reconciling biological evolution with the immutable laws of the Universe defined by physics.’ No we haven’t, biologists respond – we have never found the slightest contradiction between them, and to suggest otherwise opens the door to intelligent design.
Some of the responses are also vituperative, often directed at Cronin himself, who has rarely held back from expressing bold and controversial views. Others see this as evidence that Nature is no longer a serious journal. That’s all unfortunate, both because AT might contain some fertile ideas, and because there are some useful lessons here for cross-disciplinary science.
It’s evolution, maybe
The potential virtue of AT is that it offers a quantitative framework for understanding how complexity arises – which is not, in general, by chance but as a hierarchical process of assembly from less complex building blocks. At first glance, your genome sequence looks like a random string of bases, but the same sequence appears with barely any deviation in each of your trillions of cells. This very high ’copy number’ is possible only because the sequence was selected, in this case by being templated on existing DNA and carefully proofread by enzymes. What’s more, that selection is deeply historically embedded: as molecular phylogeny shows, your DNA is a record of your evolutionary past.
On the one hand, that’s all Genetics 101. On the other hand, articulating this view in AT might point to new directions in understanding molecular complexity. One of the problems for origin-of-life theories is that there seems to be a gap between the raw ingredients of the prebiotic Earth and the complexity of even the most primitive molecular systems capable of Darwinian evolution. Walker and Cronin believe that some kind of selectivity – perhaps due to chemical kinetics and catalysis, or the thermodynamics of self-organisation – must have helped to restrict the combinatorial explosion of prebiotic molecules and bridge that gap. By the same token, they have argued that there is a molecular complexity threshold, above which only life-like processes can generate high copy numbers. If so, the experimentally measurable “assembly index” of molecules could act as a biosignature for astrobiological searches that is agnostic about the chemical basis of alien life. In short, AT might help us decide, when we encounter apparent complexity, how surprised we should be by it.
Selective thinking
So why the fuss? Part of the friction comes from terminology. When Walker and Cronin talk about selection and evolution, they mean something that overlaps but does not coincide with Darwinian evolution by natural selection. That could have been made more explicit – far from ‘explaining’ selection, their paper seems barely even to discuss it in a way evolutionary biologists recognise.
And partly the paper does appear to contain a fair amount of hubris. However, I believe that provocative first sentence was not meant to suggest Darwinian evolution ever seemed to violate physics, but rather that physics itself struggles to accommodate the kind of historical contingency and path-dependence that is the hallmark of biology. At every step of the way, Darwinian evolution depends on what precedes it. You simply can’t calculate outcomes a priori: no Theory of Everything can predict the existence of bananas. Could physical laws predict Darwinian evolution itself, though? Could they predict life? Biologists mostly don’t care; for them, life is just what we have. But it shouldn’t count against AT that it raises the question.
The uproar is also an expression of a longstanding tension. There is an inglorious history of other scientists (physicists in particular) barging into biology only to contribute very little because they haven’t done their homework. On the other hand, sometimes these intrusions have made all the difference: ex-physicists Francis Crick, Max Delbrück and Seymour Benzer loomed large in molecular biology from the mid-20th century. Conflicts arise not so much because the intruders claim to have all the answers, but because they often insist on asking questions that don’t mean anything to biologists; as the late science historian and philosopher Evelyn Fox Keller put it, it is a matter of what counts as an explanation of phenomena. 3 While it’s possible for outsiders to ask important but overlooked questions, more often the truth is that they make the greatest scientific contributions when they are able to formulate their ideas in a way that is meaningful to the daily practice of those in the field. Perhaps that is now the challenge for advocates of assembly theory.
SpoilerPaper abstract :
Assembly theory explains and quantifies selection and evolution
Scientists have grappled with reconciling biological evolution [1,2] with the immutable laws of the Universe defined by physics. These laws underpin life’s origin, evolution and the development of human culture and technology, yet they do not predict the emergence of these phenomena. Evolutionary theory explains why some things exist and others do not through the lens of selection. To comprehend how diverse, open-ended forms can emerge from physics without an inherent design blueprint, a new approach to understanding and quantifying selection is necessary3,4,5. We present assembly theory (AT) as a framework that does not alter the laws of physics, but redefines the concept of an ‘object’ on which these laws act. AT conceptualizes objects not as point particles, but as entities defined by their possible formation histories. This allows objects to show evidence of selection, within well-defined boundaries of individuals or selected units. We introduce a measure called assembly (A), capturing the degree of causation required to produce a given ensemble of objects. This approach enables us to incorporate novelty generation and selection into the physics of complex objects. It explains how these objects can be characterized through a forward dynamical process considering their assembly. By reimagining the concept of matter within assembly spaces, AT provides a powerful interface between physics and biology. It discloses a new aspect of physics emerging at the chemical scale, whereby history and causal contingency influence what exists.
SpoilerSummary image? :
SpoilerLegend :
a, Assembly processes with and without selection. The selection process is defined by a transition from undirected to directed exploration. The parameter � represents the selectivity of the assembly process (�=1: undirected/random expansion, �<1: directed expansion). Undirected exploration leads to the fast homogeneous expansion of discovered objects in the assembly space, whereas directed exploration leads to a process that is more like a depth-first search. Here, �d is the characteristic timescale of discovery, determining the growth of the expansion front, and �p is the characteristic timescale of production that determines the rate of formation of objects (increasing copy number). b, Rate of discovery of unique objects at assembly �+1 versus number of objects at assembly �. The transition of �=1 to �<1 represents the emergence of selectivity limiting the discovery of new objects. c, Phase space defined by the production (�p) and discovery (�d) timescales. The figure shows three different regimes: (1) �d≪�p, (2) �d≫�p, and (3) �d≈�p. Selection is unlikely to emerge in regimes 1 and 2, and is possible in regime 3.
I am sure I posted about a pre-print of this paper, because I recognise the image, but the search is failing me. It seems the publication has brought some criticism:
If the impresario P T Barnum was right to say that there’s no such thing as bad publicity, then the paper just published in Nature by Sara Walker of Arizona State University, Lee Cronin of the University of Glasgow, and their coworkers has been a runaway success.
I wasn't too impressed by it back then either. Certainly every time it tries to talk about biology (or for that matter chemistry), it goes into grandiose sounding waffle that seems to flat out misrepresent the current state of understanding when it comes to evolution. The opening two sentences of the abstract are straight up crap.
There are two references to support the opening statement "Scientists have grappled with reconciling biological evolution [1,2] with the immutable laws of the Universe defined by physics". One is a book, so I cannot go there, the other is a paper laying out really basic misconceptions of evolution. I am really surprised that got through peer review.
The citation issues don't get much better further down the line. Next up at [3] we have Darwin's Origin of Species - apparently in it's entirety since they don't give a chapter or page number - as a citation for the statement "a new approach to understanding and quantifying selection is necessary". Maybe should stick to references that are at least from this century for assessing the current state of understanding .
The claim about generation of "novelty" (i.e. any increase in complexity) "not fitting cleanly into the frameworks of biology or physics" is cited to what appears to be a random paper on modelling ecological diversity, and of all things Newton's Principia (again, in it's entirety). I'm left wondering if the peer reviewers even looked at the bibliography. I've seen better blagging from undergraduates.
Songbird Farm may be the first in Maine to serve as a model for farmers to sell PFAS-contaminated land to the state in the future.
www.bangordailynews.com
Someone had this bright idea to reduce sewage to something clean enough to use as fertilizer. And then do so on farms. But what they missed is that sewage contains a lot of persistent chemicals. These chemicals are often toxic, and as they have extremely long periods of remaining stable, once you've spread enough fertilizer on a farm, you've contaminated it, all the food grown on it, for at least decades.
I think this study could be significant, if we really care about animals. We treat chickens REALLY badly, the conditions in intensive production of both eggs and meat really is about the worst. I personally have worried less about it than pig farming, as I have considered chickens far less intelligent/sentient than pigs. It seems that may have been a bias of mine (and much of the world I would posit), based in the closeness of biological relation.
The ability to recognise yourself in the mirror has been held as a "higher" intellectual function, and used as a way get humans to have empathy for animals like elephants and dolphins. Now it seems they have demonstrated this is chickens.
I wonder what the odds are of this changing husbandry practices anywhere?
Touching a mark on the own body when seeing this mark in a mirror is regarded as a correlate of self-awareness and seems confined to great apes and a few further species. However, this paradigm often produces false-negative results and possibly dichotomizes a gradual evolutionary transition of self-recognition. We hypothesized that this ability is more widespread if ecologically tested and developed such a procedure for a most unlikely candidate: chickens (Gallus gallus domesticus). Roosters warn conspecifics when seeing an aerial predator, but not when alone. Exploiting this natural behavior, we tested individual roosters alone, with another male, or with a mirror while a hawk’s silhouette flew above them. Roosters mainly emitted alarm calls in the presence of another individual but not when alone or seeing themselves in the mirror. In contrast, our birds failed the classic mirror test. Thus, chickens possibly recognize their reflection as their own, strikingly showing how much cognition is ecologically embedded.
SpoilerGraphical representation of the four conditions of the mirror-audience test and its outcome :
The focus rooster stood in a longitudinal compartment with transparent acrylic glass (control for reflections) and wire mesh partition. Occasionally, the moving shadow of a passing bird of prey was projected onto the ceiling. The focus rooster did not emit alarm calls in conditions A (focus bird is alone), B (focus bird with its own mirror reflection), and D (focus bird with its own mirror reflection while another rooster is obstructed from view but located in the adjacent compartment). The alarm calls only occurred in condition C (focus bird with another rooster in the adjacent compartment).
Songbird Farm may be the first in Maine to serve as a model for farmers to sell PFAS-contaminated land to the state in the future.
www.bangordailynews.com
Someone had this bright idea to reduce sewage to something clean enough to use as fertilizer. And then do so on farms. But what they missed is that sewage contains a lot of persistent chemicals. These chemicals are often toxic, and as they have extremely long periods of remaining stable, once you've spread enough fertilizer on a farm, you've contaminated it, all the food grown on it, for at least decades.
The European Commission is poised to break a promise to outlaw all but the most essential of Europe’s hazardous chemicals, leaked documents show.
The pledge to “ban the most harmful chemicals in consumer products, allowing their use only where essential” was a flagship component of the European green deal when it was launched in 2020.
It was expected that between 7,000 and 12,000 hazardous substances would be prohibited from use in all saleable products in an update to the EU’s Reach regulation, including many “forever chemicals” – or per- and polyfluoroalkyl substances (PFAS) – which accumulate in nature and human bodies, and have been linked to various hormonal, reproductive and carcinogenic illnesses.
But the Guardian has learned that the EU’s executive is on the brink of a climbdown under heavy pressure from Europe’s chemical industry and rightwing political parties.
The industry-led backlash is causing internal disquiet over the threat to public health and policymaking. One EU official said: “We are being pushed to be less strict on industry all the time.”
A leaked legislative document seen by the Guardian proposes three options that would restrict 1%, 10% or 50% of products containing hazardous chemicals currently on the market. The EU typically selects the middle option.
The draft analysis estimates that health savings from chemical bans would outweigh costs to the industry by a factor of 10. Reduced payments for treating illnesses such as cancer and obesity would amount to €11bn-€31bn (£9.4bn-£26.5bn) a year, while adjustment costs to businesses would be in the range of €0.9bn-€2.7bn a year.
As well as PFAS, EU regulators found that 17% of European children were at risk from combined exposure to mixtures of phthalates – linked to developmental and reproductive illnesses – in a survey of 13,000 EU citizens’ blood and urine last year. Traces of the reprotoxic endocrine disruptor bisphenol A were found in 92% of adults.
The study’s coordinator, Dr Marike Kolossa-Gehring, said that more than 34m tonnes of carcinogenic, mutagenic and reprotoxic substances were consumed in Europe in 2020.
I just heard a radio program about a company using artificially-produced enzymes to break down textile dyes in Mumbai. It sounded like it was still in its early phase, and they didn't say anything about how expensive or scalable it is, or whether the same technology could be used for other contaminants. (I guess clothing dyes are a big problem there. They mentioned a famous incident of stray dogs that had turned bright blue from exposure to dyes used in denim manufacturing.)
Somewhat related anecdote - I just filled a form required by the county where I was explaining how I'll deal with my biowaste from now on or at latest April 1st next year. The type of all-year compost etc - seems stupid atm but there's a fair idea of sorting everything before we ran into the situation above.
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Egon as fast as lightning came in the middle - I was refering to Cutlass' post.
The draft analysis estimates that health savings from chemical bans would outweigh costs to the industry by a factor of 10. Reduced payments for treating illnesses such as cancer and obesity would amount to €11bn-€31bn (£9.4bn-£26.5bn) a year, while adjustment costs to businesses would be in the range of €0.9bn-€2.7bn a year.
I wonder what the draft in "draft analysis" means. That it has not been peer reviewed?
Way I see it, all that is an aggregate.
One should look at each suspect chemical already in use one by one. Consider carefully what its adverse impact is. Consider whether there are functional
safer alternatives are, and if there are, how much safer are those alternatives. Assign costs for health damage and for moving to alternatives, substitutes.
So for each chemical: a cost of use, and a cost of not using it can be determined and a ratio established.
Has that been thoroughly undertaken for each of those 7,000 to 12,000 substances. I suspect not.
Then one might look to ban those chemicals with the highest cost of use/cost of not use (e.g. using alternatives) ratio first.
And one needs to be a little careful, with things like obesity. Afterall sugar makes one fat, so let us ban all sugar.
And genetics has a role. What is dangerous for a minority (e.g. the allergen in peanuts) may be nutricious for the majority.
One doesn't tend to think of hurricanes & typhoons as sneaky. They're usually kaiju monsters that you can see coming a week away. Hurricane Otis went from being a tropical storm to a Category-5 hurricane in 12 hours, less than 24 hours before hitting Acapulco.
It's what keeps hurricane forecasters and emergency managers up at night. Here's what happened with historic Hurricane Otis. - Articles from The Weather Channel | weather.com
Hurricane Otis’s burst of strength as it bore down on the Mexican resort city of Acapulco was so extreme that forecasters called it a nightmare scenario — one that’s becoming all too common.
Otis’ stunning transformation into a monster hurricane killed at least 27 people as it devastated Acapulco, officials say. President Andrés Manuel López Obrador says at least four people remain missing.
One should look at each suspect chemical already in use one by one. Consider carefully what its adverse impact is. Consider whether there are functional
safer alternatives are, and if there are, how much safer are those alternatives. Assign costs for health damage and for moving to alternatives, substitutes.
So for each chemical: a cost of use, and a cost of not using it can be determined and a ratio established.
Has that been thoroughly undertaken for each of those 7,000 to 12,000 substances. I suspect not.
The snag with considering each specific chemical in isolation is you incentivize making very minor modifications to the structure to get something that is technically not the banned chemical, but which is functionally indistinguishable. Both in terms of industrial applications and negative health effects. It's already a common trick in the field of patent busting, along with a few other areas. It's much simpler and cheaper to stick an irrelevant substituent onto the structure somewhere than to shift to a completely new class of compounds (e.g. removing fluorine entirely). If a ban is going to be meaningful, in practice it does mean banning broad classes of fluorinated compounds.
Smart Chickens! As a long time owner of chickens I applaud that study and have already been convinced that chickens are much smarter than most believe.
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