Science

Barcodes contain a checksum – an ingenious use of mathematics that even lends itself to a fun way to surprise your friends, says Katie Steckles

In Shroud, Adrian Tchaikovsky's intriguing new novel, two women marooned on a strange moon encounter alien life – and struggle to recognise intelligence in other beings, finds Emily H. Wilson

Winning images from the 2025 Walk of Water photo competition showcase vanishing frozen landscapes, from sparkling ice caves to melting glaciers

A driven teenager up nights working on computer schemes. Could this be Bill Gates? Chris Stokel-Walker reads the much anticipated story of the billionaires's early years, as told by the man himself

Filippo Tommaso Marinetti coined the word futurism in 1909, going on to take an extreme rightward swerve into politics. This way of thinking about the future still influences us today, says Annalee Newitz

Feedback digs into the first peer-reviewed paper from the Game of Thrones author, and concludes that he may have picked the wrong fictional universe to analyse

Increasing numbers of people believe Earth has probably been visited by aliens. That’s a societal problem, says Tony Milligan

The Chinese firm threatens the dominance of Silicon Valley’s AI elite, and its innovations show the technology could be more affordable and less costly to the environment

Asteroid sampling missions are getting increasingly complex. Recent announcements about the existence of amino acids in the sample OSIRIS-REx returned from Bennu in 2023 will likely result in more interest in studying the small bodies strewn throughout our solar system. Engineering challenges abound when doing so, though, including one of the most important – how to collect a sample from the asteroid. A new paper from researchers at the China Academy of Space Technology looks at a gas-drive sample system they believe could hold the key to China’s future asteroid sample return mission.

There are three main categories of successful asteroid sampling missions – shooting, drilling, and puffing. The original Hayabusa mission in 2010 was an example of the first method – it fired a bullet into the asteroid’s surface after performing a “soft landing.” It used the force of the bullet’s impact to shoot fragments into a collection system. This has the advantage of not requiring the spacecraft to be anchored to the asteroid but isn’t very effective at breaking through hard surfaces.

The puffing method, which OSIRIS-REx used during its visit to Bennu, has the same advantages and disadvantages. Instead of a bullet, it puffed nitrogen at the surface as part of its Touch-and-Go Sample Acquisition Mechanism (TAGSAM). 

Fraser discusses the discovery of amino acids in the Bennu sample.

Rosetta took a shirt approach, though it did not successfully collect any sample from an asteroid due to problems with its lander, Philae. Philae had a drill called the SD2, intended to bore into the surface of comet 67P/Churyumov-Gerasimenko. It also included a sampling tube that extended through the drill to collect the material. This might have worked, but it required significant power and force on the lander.

In the new paper, the researchers took a hybrid approach to developing their regolith sampling system. It utilizes a pneumatic drill that punches a hole in the regolith rather than spinning to drill one directly. After the hole is punched, the system retracts the drill bit and pushes gas down into the hole to force some of the particles up in a sample collector.

According to the team’s simulations and experiments, this method works well in both microgravity and regular gravity environments. It also operated with various granular materials, ranging from hard marble to fine sand. More pressure (i.e., more gas) was needed to collect larger particles, but any future mission can estimate the necessary gas reserves well in advance.

Sampling system test setup.
Credit – Zhao et al.

There is a good chance that a future mission will use a sampling system like this. Much of the paper discusses how China is rapidly becoming a space scientific power and how the country’s interest in asteroid resources is growing. The research was funded by several governmental organizations in China, and the country has already shown an interest in asteroid sample return, with the Tianwen-2 mission planned for launch later this year. This hybrid sampling approach might someday be adopted, though it remains to be seen if it will stand the test of a rendezvous with an actual asteroid.

Learn More:
Zhao et al – Gas-Driven Regolith-Sampling Strategy for Exploring Micro-Gravity Asteroids
UT – The Building Blocks for Life Found in Asteroid Bennu Samples
UT – Asteroid Samples Returned to Earth Were Immediately Colonized by Bacteria
UT – OSIRIS-REx’s Final Haul: 121.6 Grams from Asteroid Bennu

Lead Image:
Image of the regolith sampling system under test.
Credit – Zhao et al.

The post Hybrid Gas/Drill Asteroid Sampler Could Improve Collection Amounts appeared first on Universe Today.

Although I’ve read quite a few books on quantum mechanics—popular books, not books intended for physicists—I still don’t understand it.  That is, I can understand the history, the controversies and some of the phenomena, as well as the various interpretations of quantum mechanics. But when it comes to stuff like entanglement, I’m baffled—not just by its existence, but what it really means physically and how it could be possible.

Sean Carroll (the physicist) has just published a paper in Nature that is about as clear an explanation of the weirdness of quantum mechanics as I can imagine.  I still don’t understand entanglement, but Carroll does point out why people like me have difficulty grasping some of the concepts and predictions.

Since, as Carroll notes, Heisenberg “first put forward a comprehensive version of quantum mechanics” in 1925, it is in one sense the 100th anniversary of quantum theory:

Click below to read for free:

I’ll give a few quotes under headings that I’ve made up:

Why quantum mechanics is qualitatively different from classical mechanics. 

The failure of the classical paradigm can be traced to a single, provocative concept: measurement. The importance of the idea and practice of measurement has been acknowledged by working scientists as long as there have been working scientists. But in pre-quantum theories, the basic concept was taken for granted. Whatever physically real quantities a theory postulated were assumed to have some specific values in any particular situation. If you wanted to, you could go and measure them. If you were a sloppy experimentalist, you might have significant measurement errors, or disturb the system while measuring it, but these weren’t ineluctable features of physics itself. By trying harder, you could measure things as delicately and precisely as you wished, at least as far as the laws of physics were concerned.

Quantum mechanics tells a very different story. Whereas in classical physics, a particle such as an electron has a real, objective position and momentum at any given moment, in quantum mechanics, those quantities don’t, in general, ‘exist’ in any objective way before that measurement. Position and momentum are things that can be observed, but they are not pre-existing facts. That is quite a distinction. The most vivid implication of this situation is Heisenberg’s uncertainty principle, introduced in 1927, which says that there is no state an electron can be in for which we can perfectly predict both its position and its momentum ahead of time.

On entanglement.

The appearance of indeterminism is often depicted as their [people like Einstein and Schrödinger’s] major objection to quantum theory — “God doesn’t play dice with the Universe”, in Einstein’s memorable phrase. But the real worries ran deeper. Einstein in particular cared about locality, the idea that the world consists of things existing at specific locations in space-time, interacting directly with nearby things. He was also concerned about realism, the idea that the concepts in physics map onto truly existing features of the world, rather than being mere calculational conveniences.

Einstein’s sharpest critique appeared in the famous EPR paper of 1935 — named after him and his co-authors Boris Podolsky and Nathan Rosen — with the title ‘can quantum-mechanical description of physical reality be considered complete?’. The authors answered this question in the negative, on the basis of a crucial quantum phenomenon they highlighted that became known as entanglement.

If we have a single particle, the wavefunction assigns a number to every possible position it might have. According to Born’s rule, the probability of observing that position is the square of the number. But if we have two particles, we don’t have two wavefunctions; quantum mechanics gives a single number to every possible simultaneous configuration of the two-particle system. As we consider larger and larger systems, they continue to be described by a single wavefunction, all the way up to the wavefunction of the entire Universe.

As a result, the probability of observing one particle to be somewhere can depend on where we observe another particle to be, and this remains true no matter how far apart they are. The EPR analysis shows that we could have one particle here on Earth and another on a planet light years away, and our prediction for what we would measure about the faraway particle could be ‘immediately’ affected by what we measure about the nearby particle.

The scare quotes serve to remind us that, according to the special theory of relativity, even the concept of ‘at the same time’ isn’t well defined for points far apart in space, as Einstein knew better than anyone. Entanglement seems to go against the precepts of special relativity by implying that information travels faster than light — how else can the distant particle ‘know’ that we have just performed a measurement?

Yes, I know that this cannot be understood in terms of everyday observation, but what I fail to understand—and perhaps some reader can explain this to me—is exactly what properties of a particle can be affected by ascertaining properties of another particle light years away.

I’ll leave you to read the various interpretations of quantum theory, the most trenchant involving whether it actually represents physical reality or is merely a theory meant to explain experimental results.  I’m not sure where Carroll fits on this spectrum, but I do see that while he describes another interpretation, the “Everttian or many-worlds interpretation,” I thought that Carroll used to favor this explanatin, which of course is  deeply, deeply, weird, creating a new but unobservable universe each time an observer measures something. His summary of the state of the field is this:

So, physicists don’t agree on what precisely a measurement is, whether wavefunctions represent physical reality, whether there are physical variables in addition to the wavefunction or whether the wavefunction always obeys the Schrödinger equation. Despite all this, modern quantum mechanics has given us some of the most precisely tested predictions in all of science, with agreement between theory and experiment stretching to many decimal places.

The big remaining problem. If you read even a bit about quantum physics, you’ll know this:

Then, there is the largest problem of all: the difficulty of constructing a fundamental quantum theory of gravity and curved space-time. Most researchers in the field imagine that quantum mechanics itself does not need any modification; we simply need to work out how to fit curved space-time into the story in a consistent way. But we seem to be far away from this goal.

What good is quantum mechanics? But of course quantum mechanics, even if not comprehensible by the standards of everyday experience, has been immensely useful, for we’ve long known that its predictions match observations about as closely as any theory can. Here are the benefits:

Meanwhile, the myriad manifestations of quantum theory continue to find application in an increasing number of relatively down-to-Earth technologies. Quantum chemistry is opening avenues in the design of advanced pharmaceuticals, exotic materials and energy storage. Quantum metrology and sensing are enabling measurements of physical quantities with unprecedented precision, up to and including the detection of the tiny rocking of a pendulum caused by a passing gravitational wave generated by black holes one billion light-years away. And of course, quantum computers hold out the promise of performing certain calculations at speeds that would be impossible if the world ran by classical principles.

And don’t ask me what “quantum chemistry” is, as I know it not.

These are just small excerpts. Go read about the theory in its centenary year.

Lawrence Krauss has edited a volume of essays and articles by 39 scientists writing about current threats to science, including censorship, ideological corruption, and so on. It also includes a revision of my paper with Luana Maroja on the ideological subversion of biology. The volume will be out this year, and that’s all I can say about it except that Richard Dawkins has published part of his contribution on his Substack “The Poetry of Reality”. You can read this part for free by clicking on the headline below.  You can guess what the answer to his title question is, and it’s correct.

The essay begins by recounting what prompted its publication online: the kerFFRFLE with the Freedom from Religion Foundation (FFRF) that led them to cancel my article on their website Freethought Now! discussing the binary nature of sex, an article that took issue with another piece on that site by an FFRF employee maintaining that “A woman is whoever she says she is.” (The original article is still there; my own critique was removed by the FFRF but you can read it here, here, here or here).  This act of censorship—I wasn’t even informed about it in advance—led me to resign from the FFRF’s Honorary Board, followed by the resignations of Richard and Steve Pinker, and then the dissolving of the entire Honorary Board by the FFRF. Freethought Now indeed!

As Richard notes at the outset:

It makes me particularly sad that [Annie Laurie Gaylor and Dan Barker, co-Presidents of the FFRF] have chosen to stray so far from their stated mission of promoting freedom from religion and the separation of church and state. They seem to think that opposition to militant trans ideology is necessarily associate with the religious Right. That is false. If it were true, it would be an indictment of the rest of us for neglecting our duty to uphold scientific truth. In fact there is strong opposition from feminists concerned for the welfare of women and girls.1 Also from within the gay and especially lesbian communities2, giving the lie to the myth of  a monolithic “LGBT.” “LGB” represents a coherent constituency within which “T” is regarded by many as an interloper. Most relevant here, cogent opposition comes from biological science – and that, after all, was the whole point of Professor Coyne’s censored article.

FFRF does not lack support. Indeed, among the secular / atheist / agnostic / sceptical / humanist communities of America, the  Center for Inquiry (CFI), with which is incorporated the Richard Dawkins Foundation for Reason and Science (RDFRS), is now the only major organization still standing unequivocally for scientific truth.

This lamentable affair is what has provoked me into posting the following critique on my Substack. It is an abbreviated extract from my article called Scientific Truth Sands Above Human Feelings and Politics, commissioned by Lawrence Krauss for a multi-authored volume on The War on Science, to be published in 2025 by Posthill Press3.  The full article makes a comparison with the debauching of science by TD Lysenko in Soviet Russia in the 1940s..

He then gives a long and very clear explanation, in classic Dawkinsian prose, of why biologists say that sex is binary and how the binary-ness evolved.I’ll give three short extracts, but do read the whole thing (for me, at least, it’s a pleasure to read anything Dawkins writes, not just for clarity but as a model of popular scientific writing). Below you can read about as clear an explanation that a human can produce. Sadly, clarity and truth do not lead to enlightenment among a certain ideologically recalcitrant moiety of Anglophones.  The piece also has sections on “transracialism” and “the theology of woke.”

How can I be so sure that there are only two sexes. Isn’t it just a matter of opinion? Sir Ed Davey, leader of the British Liberal Democrat party, said that women “quite clearly” can have a penis. Words are our servants not our masters. One might say, “I define a woman as anybody who self-identifies as a woman, therefore a woman can have a penis.6” That is logically unassailable in the same way as, “I define “flat” to mean what you call “round”, therefore the world is flat.” I think it’s clear that if we all descended to that level of sophistry, rational discourse would soon dig itself into the desert sand. I shall make the case that redefinition of woman as capable of having a penis, if not downright perverse, is close to that extreme. I shall advocate instead what I shall call the Universal Biological Definition (UBD), based on gamete size. Biologists use the UBD as the only definition that applies all the way across the animal and plant kingdoms, and all the way through evolutionary history.

. . . It is no idle whim, no mere personal preference, that leads biologists to define the sexes by the UBD. It is rooted deep in evolutionary history. The instability of isogamy, leading to extreme anisogamy, is what brought males and females into the world in the first place. Anisogamy has dominated reproduction, mating systems, social systems, for probably two billion years. All other ways to define the sexes fall afoul of numerous exceptions. Sex chromosomes come and go through evolutionary time. Profligate gamete-spewing into the sea gives over to paired-off copulation and vice versa. Sex organs grow and shrink and grow again as the aeons go by, or as we jump from phylum to phylum across the animal kingdom. Sometimes one sex exclusively cares for the young, seldom the other, often both, often neither. Harem systems change places with faithful monogamy or rampant promiscuity. Psychological concomitants of sexuality change like the wind. Amid a rainbow of sexual habits, parental practices, and role reversals, the one thing that remains steadfastly constant is anisogamy. One sex produces gametes that are much smaller, and much more numerous, than the other. That is all ye know of sex differences and all ye need to know, as Keats might have only slightly exaggerated if he’d been an evolutionary biologist.

. . . . Relative gamete size is the only way in which the male / female distinction is defined universally across all animal phyla. All other ways to define maleness versus femaleness are bedevilled by numerous exceptions. Especially those based on sex chromosomes, where you can’t even speak of a rule, let alone exceptions to it. In mammals, sex is determined by the XX XY chromosome system, the male sex having unequal sex chromosomes. Birds and Lepidoptera have the same system, but in the opposite direction and therefore presumably evolved independently. It’s the females who have unequal chromosomes. How do we know? Couldn’t you define males as the sex with unequal chromosomes? Well you could, but then you’d to have to say it’s the male bird that lays the eggs, the females that fight over males, etc. You’d lose every one of the 14 explanations I discussed earlier. Far better to stick with the UBD and say birds use sex chromosomes to determine sex, but it evolved independently of the mammal system. Birds are descended from dinosaur reptiles, and most modern reptiles don’t have sex chromosomes at all. Reptiles often determine sex by incubation temperature. In some cases higher temperatures favour males, in other cases, females. In yet other reptiles, extremes of temperature, high or low, favour females, males developing at intermediate temperatures. Many snakes, some lizards and a few terrapins use sex chromosomes, but they vary which sex has unequal sex chromosomes. Amidst all this variation, the only reliable discriminator is gamete size.

The way the sexes are defined (the UBD, universal and without exception) is, therefore, separate from the way an individual’s sex is determined during development (variable and far from universal). How we in practice recognize the sex of an individual is yet a third question, distinct from the other two. In humans, one look at a newborn baby is nearly always enough to clinch it. Even if it occasionally isn’t, the UBD remains unshaken.

And that is all ye need to know. You’ll have to wait for Richard’s full article, which I’ve read as I contributed to the book, as it has a nice section on censorship in biology as promoted by Lysenko and Stalin.

I still like my list of questions to ask people who claim that sex in humans (or other animals) is not binary but a spectrum. (The proportion of individuals who are exceptions to the gametic definition given above is minuscule, ranging from 1/5600 to 1/20,000):

1. How many sexes are there in nonhuman animals likes cats, horses, hyenas, ducks, or sharks?
2. If “two,” Is there a universal way to tell them apart? (the answer, of course, is “two” and “gamete type”)
3. Now how many sexes are there in humans?
4. If answer to #3 differs from that to question #1, Why is that the case, how many sexes are there in humans, then, and then how do you tell these more-than-two sexes apart?

Good luck getting an extreme gender ideologue to answer these questions!

A huge study of ancient DNA reveals the origins of the Yamna, who spread across Eurasia around 5000 years ago, showing they came from a mixing of populations north of the Black Sea

Mice have neurons that can be controlled to stop them eating - and people probably have them too

A newly analysed fossil skull settles a palaeontological debate over Vegavis iaai, confirming it as a relative of ducks and geese that lived 69 million years ago

Two-thirds of US cannabis is grown indoors, requiring lights and temperature control that produce a vast amounts of emissions

The odd superconductivity found in layered graphene may bring us closer to understanding room-temperature superconductors

Neuroscientist-turned-entrepreneur Emilė Radytė is using brain stimulation to explore how things like premenstrual syndrome and period pain impact the brain

A papyrus scroll carbonised by the eruption of Mount Vesuvius two millennia ago is slowly being read once again thanks to X-ray imaging and machine learning

Documentaries can be powerful. They can use the mature art-form of cinema in order to convey a specific narrative. The viewer can get drawn into that narrative, unaware they are being exposed to a very one-sided or limited take on a complex topic. I recently, for example, participated in a fun review of the Earthing Movie which was basically propaganda for the […]

The post The Telepathy Tapes – More FC Pseudoscience first appeared on Science-Based Medicine.

Hunting for meteorites can be a high-octane race as private collectors and scientists go head-to-head, reveals a new book by New Scientist features editor Joshua Howgego