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Global experts help nanomedicines deliver on healthcare promise

Matter and energy from Science Daily Feed - Fri, 09/06/2024 - 11:16am
New findings from a global team of expert scientists in academia and industry has generated new research quality standards that will help slash costs and reduce the time it takes to develop advanced nanomedicine treatments and make them available for patients.
Categories: Science

Shining light on how solar power and farming can coexist

Matter and energy from Science Daily Feed - Fri, 09/06/2024 - 11:16am
Scientists have developed a new tool to help identify optimal photovoltaic (PV) materials capable of maximizing crop growth while generating solar power.
Categories: Science

Massive merger: Study reveals evidence for origin of supermassive black hole at galaxy's center

Space and time from Science Daily Feed - Fri, 09/06/2024 - 11:13am
Researchers have discovered compelling evidence suggesting that the supermassive black hole at the center of our Milky Way galaxy, known as Sagittarius A* (Sgr A*), is likely the result of a past cosmic merger. The study builds on recent observations from the Event Horizon Telescope (EHT), which captured the first direct image of Sgr A* in 2022.
Categories: Science

Sharks leap out of the water more often than you might think

New Scientist Feed - Fri, 09/06/2024 - 10:00am
Breaching is a common behaviour in a wide range of sharks and rays, and it is thought to have functions related to courtship, birthing and hygiene
Categories: Science

Michael Shermer — Pseudohistory Makes a Comeback on Tucker Carlson’s Show

Skeptic.com feed - Fri, 09/06/2024 - 10:00am
https://traffic.libsyn.com/secure/sciencesalon/mss465_Michael_Shermer_2024_09_06.mp3 Download MP3

During a two-hour interview with Tucker Carlson, Darryl Cooper made sensational claims about the Holocaust and World War II, with Carlson calling him “the best and most honest popular historian in the United States.” In this solo episode, Michael Shermer takes a critical look at the pseudohistory and historical revisionism presented by Cooper on Carlson’s show.

Categories: Critical Thinking, Skeptic

JWST Reveals Star Formation at Cosmic Noon

Universe Today Feed - Fri, 09/06/2024 - 9:28am

Understanding the star formation rate (SFR) in a galaxy is critical to understanding the galaxy itself. Some galaxies are starburst galaxies with extremely high SFRs, some are quenched or quiescent galaxies with very low SFRs, and some are in the middle. Researchers used the JWST to observe a pair of galaxies at Cosmic Noon that are just beginning to merge to see how SFRs vary in different regions of both galaxies.

A rare alignment of massive objects in space allowed astronomers using the James Webb Space Telescope to observe a pair of distant, ancient galaxies that are just beginning to interact and merge. The JWST sees the galaxies as they were about seven billion years ago, near the end of the Universe’s Cosmic Noon. The Cosmic Noon was when star formation was at its peak.

One of the galaxies is a blue, face-on galaxy, and the other is a dusty red, edge-on galaxy. The JWST can only see them because of an intervening galaxy cluster named MACS-J0417.5-1154. It’s a gravitational lens that magnifies the light from the galaxy pair and smears the galaxies’ light into an arc.

Astronomers have found many gravitational lenses and regularly use them to observe objects that are otherwise nearly impossible to see. But this lens is different. It’s a hyperbolic umbilic gravitational lens and produces multiple images of the same objects, where each one has a different magnification and brightness.

“We know of only three or four occurrences of similar gravitational lens configurations in the observable universe, which makes this find exciting, as it demonstrates the power of Webb and suggests maybe now we will find more of these,” said astronomer Guillaume Desprez of Saint Mary’s University in Halifax, Nova Scotia. Desprez works with the CAnadian NIRISS Unbiased Cluster Survey (CANUCS), the team presenting the Webb results.

Not only does the cluster magnify the distant background galaxies, but it also warps their appearance and produces multiple copies. Together with an unrelated one, the galaxies combine to look like a question mark. They’ve been dubbed the Question Mark Galaxy Pair.

False colour images of the Question Mark Pair and MACS J0417.5?1154 (right-hand panel). The left two panels are zoom-in images of four of the multiply lensed images of the Question Mark Pair taken with HST and JWST. By comparing the JWST and HST images, we see how dusty the red edge-on galaxy is as it is barely visible in the HST/ACS imaging. Image Credit: Estrada-Carpenter et al. 2024.

This isn’t the first time astronomers have observed these galaxies. The Hubble observed it previously. But the Hubble and the JWST see things differently. The JWST can see longer wavelengths of infrared light that pass through cosmic dust, while the Hubble only sees the wavelengths of light that get trapped in the dust. So, the Hubble couldn’t detect the question mark shape, whereas the JWST could.

“This is just cool looking. Amazing images like this are why I got into astronomy when I was young,” said astronomer Marcin Sawicki of Saint Mary’s University, one of the lead researchers on the team.

But the question mark shape is just an interesting visual curiosity. The research is about star formation, and these results highlight the JWST’s ability to identify star formation regions in distant galaxies.

“Knowing when, where, and how star formation occurs within galaxies is crucial to understanding how galaxies have evolved over the history of the universe,” said astronomer Vicente Estrada-Carpenter of Saint Mary’s University. Estrada-Carpenter used both Hubble’s ultraviolet and Webb’s infrared data to show where new stars are forming in the galaxies.

The researchers developed a new method to probe SFRs on different timescales of about ten million years and one hundred million years. The ten-million-year timescale relied on H-alpha emission line maps, and the one-hundred-million-year timescale relied on UV observations. H-alpha is sensitive to ten-million-year timescales because it stems from gas around massive, short-lived stars. UV is sensitive to one-hundred-million-year timescales because it originates from longer-lived stars.

Together, the ratio between the two can spatially resolve star formation burstiness.

They found that SFRs decrease at longer distances from the galactic center. That’s not surprising since star-forming gas tends to accumulate near galactic nuclei. However, they also found that overall, the SFR has increased by a factor of 1.6 over the last ~100 Myr, an indication that the galaxies are beginning to merge.

To better understand the merger aspect, the researchers broke the QMP down into segments: blue galaxy bulge and disc, red bulge and disc, and three types of clumps: bursting, equilibrium, and quenching.

This figure from the study shows how the researchers broke the QMP into segments to better understand it. Image Credit: Estrada-Carpenter et al. 2024.

“Both galaxies in the Question Mark Pair show active star formation in several compact regions, likely a result of gas from the two galaxies colliding,” said Estrada-Carpenter. “However, neither galaxy’s shape appears too disrupted, so we are probably seeing the beginning of their interaction with each other.”

They identified twenty star-forming clumps in the galaxy pair, highlighting the JWST’s ability to spatially resolve star formation in distant galaxies. Of those 20, seven were experiencing bursty star formation, 10 were quenching, and three were in equilibrium. The blue face-on galaxy, especially its disk, is mostly in a quenching phase, which makes sense since the JWST is seeing the galaxy pair as they were near the end of Cosmic Noon.

Galaxies grow massive by merging, and one of the JWST’s science goals is to better understand mergers and how they affect star formation. The QMP could be beginning to merge which only increases its value as an observational target.

“What makes the QMP so interesting is that these galaxies are possibly at the beginning of an interaction (as their morphologies do not seem to be disturbed). An interaction between the galaxy pair could lead to a burst of star formation, and this may be the reason why the blue face-on galaxy contains so many clumpy star-forming regions,” the authors write in their paper.

These results are also giving us a look at what our own galaxy was like during Cosmic Noon.

“These galaxies, seen billions of years ago when star formation was at its peak, are similar to the mass that the Milky Way galaxy would have been at that time. Webb is allowing us to study what the teenage years of our own galaxy would have been like,” said Sawicki.

The post JWST Reveals Star Formation at Cosmic Noon appeared first on Universe Today.

Categories: Science

The mathematical theory that made the internet possible

New Scientist Feed - Fri, 09/06/2024 - 9:00am
Information theory tells us the limits of what can and cannot be communicated – and without it, the digital revolution could never have happened
Categories: Science

Why criticize the Left?

Why Evolution is True Feed - Fri, 09/06/2024 - 9:00am

If you read here, you’ll know that I spend more of my time calling out the excesses of the Left than of the Right. I’ve explained why, and it’s not because I’m a right-winger or am unaware of their program and, especially, of their deranged candidate for President.

But this time I’ll let Bari Weiss answer for me, in an extract below from a recent piece she wrote for The Free Press.  I’m not interested much in the fracas about Tucker Carlson, for too much else is happening in the world, but below is an extract from Weiss’s piece that mirrors my own sentiments. You can read the whole piece, if you wish, by clicking on the headline.

An excerpt:

If there is a criticism I’ve gotten over the past several years it’s that I pay too much attention—and apply too much scrutiny—to the excesses of the illiberal left at the expense of the illiberal right. Wasn’t I ignoring the elephant and allowing myself to get distracted by the gnat?

My response to that is twofold.

The first is that there is no shortage of writers, reporters, and outlets focusing on the dangers of the far right. I saw the far left as conspicuously overlooked by people who otherwise take a great interest in political extremism. And I understand why they were averting their gaze: The social cost of noticing this subject is very high. Given that the job description of a journalist is to observe the world, uncover things in the public interest, and then tell the plain truth about it, choosing topics where others fall silent seems wise to me. It still does.

The second is that I have been concerned for years now that the illiberal ideology that has become increasingly mainstream on the political left—one that makes war on our common history, our common identity as Americans, and fundamentally, on the goodness of the American project—would inspire the mirror ideology on the right.

And that is exactly where we find ourselves, with an illiberal left that defaces Churchill statues—and an illiberal right that defaces Churchill’s legacy. With a left that insists 1619 was the year of the true founding of America—and a right that suggests the Greatest Generation was something closer to genociders. With a left that sympathizes with modern-day Nazis in the form of Hamas—and a right that sympathizes with the original ones.

Categories: Science

Greenland voyage sheds light on little-known ancient Arctic culture

New Scientist Feed - Fri, 09/06/2024 - 8:00am
On a recent expedition, researchers braved summer storms in northern Greenland to learn the secrets of the ancient peoples who lived there 4500 years ago
Categories: Science

Smart speakers at crime scenes could provide valuable clues to police

New Scientist Feed - Fri, 09/06/2024 - 7:25am
Information on faces recognised, voice commands and internet searches can be extracted from an Amazon Echo smart assistant without help from the user or manufacturer
Categories: Science

A Māori defends indigenous “ways of knowing” against my critique

Why Evolution is True Feed - Fri, 09/06/2024 - 7:00am

The other day I put up a post about an indigenous “science initiative” in New Zealand with a wonky aim: to cure the country’s iconic kauri trees of a fungal blight by, yes, playing whale songs to sick trees and rubbing them with whale oil and pulverized whale bones. This endeavor, I asserted, had no empirical basis to justify its funding—by New Zealand taxpayers, of course.

Indeed, the project came from a Māori legend that whales once roamed the land and were BFFs with kauri trees, but then got separated. The project was based on the supposition that bringing tree and whale back together again could not only revive their erstwhile friendship but also save the sick trees.  (I can guarantee you here that they’re not talking about evolution of the trees and whales from a common ancestor, nor about terrestrial ancestors of whales.)

A quote from the initiative:

Māori whakapapa  [genealogy] describes how the kauri and tohorā (sperm whale) are brothers, but they were separated when the tohorā chose the ocean over the forest. In this research area we looked at how this connection could possibly help save the kauri from kauri dieback disease.

The team was led by Matua Tohe Ashby and investigated rongoā (traditional medicine) solutions for kauri dieback. This involved tohorā, karakia and mōteatea, and tied into the second Oranga research project: Te reo o te waonui a Tāne. The team also traind kauri communities in rongoā solutions to help save their rākau (trees).

Here’s the video linked to Ashby’s name:

I called this project “mishegass”, a transliteration of the Yiddish word for “silliness” or “craziness”, and also used the English “nonsense”.  How could I not mock such an endeavor, for doesn’t basing a funded project on a ludicrous myth fully deserve mockery? That is, unless you are a taxpaying New Zealander, in which case it should make you mad.

But my criticism also irritated a Māori journalist, who wrote me an email yesterday:

Hello Jerry

I am a journalist in New Zealand for the Southern Cross News I have recently read your article on Mātauranga Māori and would like to ask you a few questions

Have you ever been to New Zealand ?

Have you experienced Mātauranga Māori or was your research online?

Are you aware of the Pre-Polynesian Civilisation conspiracy theory and have you commented on this topic?

Do you have a bias towards Western Science and dismiss indigenous science?

Was colonisation an overwhelmingly positive event for Māori ?

Do you believe non-Māori should control the destiny of Mātauranga Māori

Joe Trinder | Editor

I hadn’t heard of the Southern Cross News (SCN), but it appears to be.a Māori-centric New Zealand website, and Joe Trinder is clearly of Māori ancestry, describing himself on “X” as “Woke Elite Maori of the highest order.”

As you can see, Trinder’s questions are loaded ones, and though I was tempted to respond, I saw no point, for there was already an article in the SCN, written by one Dr. Rawiri Waretini-Karena, criticizing my own critique and defending indigenous ways of knowing and the usefulness of whale songs, bones, and oil at curing kauri blight.  Waretini-Karena himself is described at IGI Global as

. . . a current Post Doc Research Fellow Recipient lecturer and researcher at Te Whare Waananga o Awanuiaarangi Indigenous University in Whakatane. His qualifications include a PhD Indigenous Philosophy, 2014 Te Whare Wananga o Awanuiarangi, a Master of Arts Commercial Music 2010 WINTEC, and a Bachelor of Applied Social Science- Maaori Counselling 2004 WINTEC. He has spent the last 20 years in the education field.

He also has a TedX talk which he notes not only that he was a convicted murderer, but that (according to the caption), he

. . . .  graduated in 2014 with a PhD Doctorate of Philosophy in Indigenous Studies and was the recipient of three prestigious doctoral scholarship awards for his research into transforming Māori experiences of historical intergenerational trauma.

Waretini-Karena doesn’t appear to have any formal scientific training.  I won’t dismiss his critique because of that, but it does give us some understanding of his failure to understand modern science and how it differs from indigenous “ways of knowing”.

I got the link to Waretini-Karena’s article in SC from a Kiwi colleague, but the bizarre thing is that the article kept appearing and disappearing on the SC website for reasons unknown. (It wasn’t my browser, for the vanishing post also vanished in New Zealand.) The second time this happened, my colleague made a pdf of the article so it couldn’t be permanently removed. Below a screenshot of the article, and if it appears again I’ll put up a working link to the piece.

I checked this morning and the link is still dead and the critique is gone.  But I’ve put the entire article below from the pdf saved by a colleague.

Here’s the short article; the text is indented and my comments are flush left. There was no link to my original piece nor even my name given as the author.  From Waretini-Karina

Introduction:

The recent article critiquing the “Whale Song” project, a government-funded initiative aimed at revitalizing kauri trees using Māori knowledge, exemplifies a persistent problem in Western engagement with Mātauranga Māori: a fundamental misunderstanding of its core principles and its historical context.

The article is titled:

The author’s dismissal of the project as “ludicrous” and “nonsense” is not only disrespectful but also indicative of a narrow, reductionist view of knowledge. This dismissal stems from a Western perspective that prioritizes empirical evidence and scientific methodology as the sole measures of validity, failing to acknowledge the inherent limitations of such approaches in understanding and appreciating the complexities of Māori knowledge.

Mātauranga Māori  [MM] is not simply a collection of “legends and anecdotes,” as the author suggests. It is a dynamic, evolving system of knowledge, practices, and beliefs that have been developed and refined over generations through observation, experimentation, and deep connection to the natural world. It operates on a holistic and interconnected understanding of the universe, where all things are intrinsically linked and interdependent.

This is of course a distortion of what I’ve written. I’ve noted that there is some empirical trial-and-error knowledge in MM (but also a passel of legend, myth, religion, and instruction about how to live), though I’m not aware of any explicit experimentation, at least not how modern science conceives of an “experiment”. The defense continues:

The article’s assertion that “there is no underlying ‘wisdom’ or scientific data suggesting that sounds played to ailing trees could cure them” reveals a lack of understanding of the potential benefits of sound therapy, a field of study that has shown promising results in various areas, including plant growth and stress reduction.

Yes, sound waves have been shown to affect plant growth in some studies, but this conclusion is controversial (see here).

I don’t doubt that some stressed humans can be soothed by music, but the issue at hand is not that: it’s whether reuniting infected kauri trees with the oil, bones, and songs of their ancient buddies can cure the blight. Beyond the author’s anecdotal claim, I argue that it’s not worth spending the money investigating this theory, which, in the end, is based on a palpably false legend: that whales once roamed the earth (as whales, not their ancestors), became friends with kauri trees, and then they lost touch.  This experiment is designed fix the legend by playing whale songs to the trees and dousing them with whale oil and whale bones. Experimenting based on an unsubstantiated legend, and using taxpayer money to do so, is not something that seems propitious. In contrast to the author’s claim, this research is indeed based on a legend, and one that we know to be false.

Furthermore, the article’s focus on “double-blind control tests” as the sole measure of validity ignores the inherent limitations of Western scientific methodology in understanding and appreciating the complexities of Māori knowledge. Mātauranga Māori operates on a different epistemology, one that values lived experience, intergenerational knowledge transmission, and the interconnectedness of all things.

Here the author is blowing smoke.  How do you establish that a treatment of any sort works unless you compare the effects of the treatment with a group not given it, and blinding the experimenters as far as possible (i.e., those who measure the effects wouldn’t know if the trees had had whale songs played to them or whether they were doused with whale oil and bones).

The “different epistemology” of MM appears to be based not on rigorous experimentation, but on wish-thinking.  Don’t forget, too, that modern science is also based on “intergenerational knowledge transmission”. As for the “interconnectedness of all things,” I don’t see how that claim is of value in this study.  My boss Dick Lewontin once countered an “interconnectedness” claim by saying something like “Yes, but this doesn’t mean that the emissions of a supernova has any effect on my gardening.” The defense continues:

The article’s dismissal of the project as “science-dissing” also reveals a lack of understanding of the historical context of Māori knowledge. The colonization of Aotearoa (New Zealand) has led to the suppression and marginalization of Māori knowledge systems. The “Whale Song” project represents a significant step towards reclaiming and revitalizing this knowledge, and should be viewed not as a rejection of science, but as acomplementary approach to addressing the challenges facing our environment.

The article’s reliance on anecdotal evidence to support its claims, such as the anonymous scientist’s “concerns,” further undermines its credibility. It is essential to approach discussions about Māori knowledge with respect, humility, and a willingness to engage in meaningful dialogue rather than resorting to prejudiced and discriminatory language.

The “Whale Song” project, while perhaps unconventional, represents a valuable opportunity to explore the potential of Māori knowledge in addressing environmental challenges. It is crucial to approach such initiatives with an open mind and a genuine desire to learn from different ways of knowing.

Science is based on dispute, attempts to falsify, and constant criticism. Here the author argues that indigenous knowledge should be immune to that type of criticism, as it’s is seen as “disrespectful.” (The implication is that it’s also bigoted.)  The very motivation for this project—a claim that walking whales were friends with kauri trees—is so ludicrous that the project should be dismissed unless there are preliminary modern scientific tests showing there’s even a hope that it would work.  Modern science is indeed at work on kauri blight, and has even identified the organism causing it. To me, that gives more hope of a cure than does this project.

Conclusion:

This article serves as a reminder that genuine engagement with Mātauranga Māori requires a willingness to move beyond Western-centric perspectives and embrace the richness and complexity of indigenous knowledge systems. Only through respectful dialogue and a commitment to understanding can we truly appreciate the value

Once again, the author tries to render indigenous science immune from criticism because it’s “rich and complex”.  That alone is not sufficient to sacralize indigenous knowledge. If we’re to move forward with real knowledge about the world, projects like this one should be subject to exactly the same kind of criticism as is modern science.

Once again I quote former pastor Mike Aus. Bolding is mine.

When I was working as a pastor I would often gloss over the clash between the scientific world view and the perspective of religion. I would say that the insights of science were no threat to faith because science and religion are “different ways of knowing” and are not in conflict because they are trying to answer different questions. Science focuses on “how” the world came to be, and religion addresses the question of “why” we are here. I was dead wrong. There are not different ways of knowing. There is knowing and not knowing, and those are the only two options in this world.

If you want to know if whale songs and whale oil and bone cure kauri blight in nature, there is no option save the experimental tools of modern science.

I’ve wasted a lot of time on this post, for there are many initiatives like it that need criticism, and time is limited. But then again, the taxpayers of New Zealand need to know that they’re wasting their money on projects like this one.

And, I wonder, why did the site take down the post—twice? Was it too embarrassing to publish? Your guess is as good as mine.

Categories: Science

Friday: Hili dialogue

Why Evolution is True Feed - Fri, 09/06/2024 - 1:49am

Meanwhile, in Dobrzyn, Hili is being demanding, as cats are:

Hili: We have to have a serious talk.
A: What about?
Hili: About your duties.

Hili: Musimy poważnie porozmawiać.
Ja: O czym?
Hili: O twoich obowiązkach.

Categories: Science

Biosafety Now: Releasing The Virus Was Mass Murder. Intentionally Spreading It Was Forgivable.

Science-based Medicine Feed - Fri, 09/06/2024 - 12:15am

I suppose it's my turn to be called a fraudster, liar, perjurer, felon, grifter, stooge, imbecile, and maybe even murderer. What I won't get is a reasonable explanation as to why supposedly releasing a deadly virus was mass murder, but intentionally spreading it was a forgivable "policy position".

The post Biosafety Now: Releasing The Virus Was Mass Murder. Intentionally Spreading It Was Forgivable. first appeared on Science-Based Medicine.
Categories: Science

What Type of Social Justice Do We Want?

Skeptic.com feed - Fri, 09/06/2024 - 12:00am

We are three college professors who wish to call attention to a growing problem, namely the erosion of the foundational values of a college education: free inquiry and free speech, rationality and empiricism, civil discussion and debate, and openness to new ideas.

The Rise of Critical Theories

Critical theory is a school of thought that has its roots in Marxist theories of human nature and society. It originally developed in Germany in the 1920s among a group of scholars at the Institute for Social Research. They were attempting to salvage some of the failed ideas of Marxism by extending theory to embrace non-economic forms of inequality and oppression.

Critical theorists believe that mainstream knowledge is used to promote the interests of the powerful. Unlike traditional social science, which aims to objectively describe human nature and society by carrying out scientific research, critical theory promotes ideological narratives as self-evidently true. Based on their theories about human nature and social justice, critical theorists promote political activism (or “praxis”), and at times even violent revolution, to achieve their goals.

The predecessor to critical theory, Marxism, simplistically divided people into groups labeled as oppressors or oppressed. Marxism’s original group division was economic—the groups were the oppressive Bourgeois (those who controlled the means of production) and the oppressed Proletariat (the workers). It tried to explain the systemic causes of these group divisions (capitalism) and it developed a set of proposed solutions, including violent revolution, that it presumed would lead to a utopian communist society. These steps, which we will call “Marxist methodology, subsequently became part of critical theories that then focused on additional ways of dividing people into categories of oppressors and oppressed. The Marxist methodology follows the steps shown in Table 1.

Click table to enlarge

  1. Divide people into two (or more) groups.
  2. Label one group as the oppressed (“the good”), the other as the oppressors (“the bad”).
  3. Develop a theory that purports to explain the systemic causes of this division. The theory is often conspiratorial in nature—oppressors are seen as scheming to keep the oppressed in their place.
  4. Identify and implement solutions. Encourage group solidarity among the oppressed group, promote an “us-versus-them” mentality, groupthink, and adherence to the party line, invent insulting labels to brand members of the out-group, and engage in activism and/or revolution that will purportedly end those social injustices.

Many social movements based on critical theories have used this Marxist methodology, as noted in Table 1.

All these ideological movements have restricted free speech, encouraged an “us” versus “them” political tribalism, employed personal ad hominem attacks against opponents, and promoted cancellation campaigns. While it is important to respect diversity and historical injustices, we should keep in mind that truly liberal worldviews emphasize our common humanity—which is far less divisive.

What Does “Social Justice” Mean?

The new higher education mantra, “social justice” sounds good, but it in fact can refer to either of two often mutually exclusive philosophies: liberal social justice or critical social justice. Though few acknowledge it, increasingly social justice is sold as the former, but practiced as the latter. Consider how they compare in the Table 2.

Click table to enlarge

As is evident, liberal social justice and critical social justice employ two very different methods in determining what constitutes social justice.

Language Revisionism

Critical social justice activists often use the “Motte and Bailey strategy” (see Table 3) to make extreme proposals appear moderate. In this gambit a highly defensible “Motte” position is promoted, while successively working toward a more radical “Bailey” position. This gambit is used often in postmodernist discourses. For example, by asserting that morality is socially constructed, the Motte is that our beliefs are socially influenced, and the Bailey is that there is no such thing as morality or truth. Another example:

  • A (non-controversial) Motte position: “We want social justice.” This statement is difficult to argue against, as just about everyone believes in fairness (though they may differ in how they define the term or how to achieve it).
  • A (controversial) Bailey position: “We need to re-define social justice as critical social justice and we need to make fundamental (sometimes radical) changes to our society including ending the rule of law, free speech, property rights, and merit systems.” This statement is much more controversial than the Motte, as it suggests that the current social order is inherently unjust and so needs to be overthrown.

Here are more examples of the Motte and Bailey strategies with respect to the re-definition of some commonly used words.

Click table to enlarge

What is social justice when re-interpreted from a critical social justice lens?1

Again, the term “social justice” in common language refers to the liberal social justice conceptions of individual rights and responsibilities, equal opportunity, blind justice, equality before the law, etc., as noted above. These ideas evolved from historic common law, the Enlightenment (particularly the Scottish Enlightenment), and U.S. constitutionalism.

However, over recent decades the term social justice has come to be redefined in terms of critical, not liberal, social justice. This re-definition was accomplished surreptitiously through the Motte and Bailey gambit, and it also allowed the more radical philosophy of critical theory itself to be covertly introduced into college campuses while flying under the academic radar. By analogy, the term “social justice” has been used as a terminological Trojan horse to insert critical social justice and critical theory into the academy under the guise of liberal social justice.

Restrictions on Freedom of Speech and Open Inquiry

This sort of critical social justice activism and indoctrination (as opposed to exposing students to these perspectives in the context of discussing and debating the respective strengths and weaknesses of a range of perspectives) is the opposite of free expression and open inquiry, and thus it is the antithesis of the foundational values of traditional higher education.

Often mere attempts to question how, why, or whether X-injustice is happening leads to accusations that the questioner must be a bigoted “X-ist” or “X-phobe.” Questioning is often dismissed by critical theorists as defensive rhetoric employed to defend one’s privilege and power. The questioner needs thus be silenced, ostracized, and/or canceled. As documented by the Foundation for Individual Rights and Expression (FIRE), this has in fact happened thousands of times.

Some Examples of Restriction of Speech and Open Inquiry

A series of large-scale empirical studies beginning in the year 2000 found that both students and professors report fearing to express or explore political and ideological viewpoints that are critical of critical theory.2 Further, campuses have little ideological diversity among faculty and administrators, with typically a 12:1 ratio of liberal/progressive to conservative/libertarian, and many departments and some whole fields lacking any conservative or libertarian faculty members. Studies document that many professors freely admit to discriminating against colleagues and students who support liberal, rather than critical, conceptions of social justice. Here are some recent representative examples:

  • Bret Weinstein, a former professor of biology at Evergreen State College in Olympia, WA, was deplatformed and forced to resign after he was accused of racism and white privilege for refusing to participate in a “Day of Absence,” which asked white faculty to stay off campus for the day to celebrate people of color.
  • Lindsay Shepherd, a teaching assistant at Wilfrid Laurier University in Canada, was suspended after she showed her class a video of a debate about gender pronouns. She was accused of violating the university’s policy on discrimination and harassment.
  • Dorian Abbot, an associate professor of geophysics at the University of Chicago, was disinvited from giving a prestigious lecture at the Massachusetts Institute of Technology (MIT) after he wrote an opinion piece criticizing diversity initiatives and instead supporting meritbased college admissions, hiring, and promotions.
  • Nicholas Christakis, a professor of sociology at Yale University, was placed on administrative leave after he sent an email to students urging them to be civil to those with whom they disagree.
  • Ayaan Hirsi Ali, a former Dutch politician and women’s rights activist who herself suffered female genital mutilation as a child in a traditional Islamic society, was disinvited from speaking at the University of California, Berkeley, after students protested her views on Islam.
Critical Pedagogy: Political Activism in the Classroom

Critical pedagogy is an ideological approach to teaching that attempts to impose political views and activism in the classroom that are consistent with critical theory. It was founded by the Brazilian philosopher and educator Paulo Freire, who promoted it through his 1968 book Pedagogy of the Oppressed. It pressures students to adopt a specific political ideology and rejects dissenting views. Doing so takes time away from developing core academic skills, including critical thinking skills.

At its worst, critical pedagogy can produce an environment where some professors and administrators try to tell students not how to think, but what to think. Professors should not be using the lectern as an activist bully pulpit to push their personal ideological or political beliefs. Since professors are in positions of power relative to their students, such activism in the classroom is unethical and constitutes professional misconduct. Students should not be expected to conform to ideologies or dogmas in the classroom.

It is unfortunate that students will very likely be subject to activism on the part of some of their professors and even some fellow students. If they disagree with them, they may at times feel that they should keep their thoughts to themselves. But do not. Speak up!

Spotting Education v. Indoctrination

To be clear, although we do not subscribe to critical theory because of the difficulties with it that we (and many others) have identified, we do not object to a professor teaching or discussing critical theory and critical social justice and presenting his or her opinions about matters based on those perspectives. College is all about exposing students to a range of ideas and opinions. However, professors should not attempt to indoctrinate their students with critical theory or anything else, and they should expose students to a range of perspectives on various issues. Below are a few pointers to help students to identify whether a course or a professor is promoting critical theory through indoctrination rather than education.

Courses that educate tend to have:

  • A Balance of Perspectives: Look for courses that present multiple viewpoints and encourage open discussion. A balanced education should expose students to various ideas, even those that challenge the prevailing consensus.
  • Freedom of Thought: If a course or professor discourages questioning or presents information as absolute truth without room for debate, it might be indoctrination. In contrast to a fundamentalist religion, education encourages students to question, analyze, and form their own conclusions.
  • An Evidence-Based Approach: Knowledge should be grounded in research, evidence, and historical context. If a course lacks substantial evidence to support its claims or relies primarily on emotional appeals, it is less education than indoctrination.
  • Engagement with Opposing Views: A healthy educational environment should encourage engaging with opposing viewpoints. If a course dismisses or demonizes dissenting perspectives, it could be leaning towards indoctrination.

Whereas courses that indoctrinate tend to:

  • Discourage Disagreement: The professor discourages students from challenging their favored concepts and ideals.
  • Rely on Emotional Appeals and Ad Hominem Attacks: The professor uses emotional appeals and personal attacks to silence dissent.
  • Campus activism can be covert rather than overt, with the professor communicating to students what is acceptable or not based on their reactions to student comments, the topics they select to discuss and to omit, their grading practices and feedback, how they interact with and treat students having different opinions, or even their body language when talking about various topics.

    A 2007 American Association of University Professors (AAUP) subcommittee report stated such activist professors present their favored worldview “dogmatically, without allowing students to challenge their validity or advance alternative understandings” and such instructors “insist that students accept as truth propositions that are in fact professionally contestable.” Given that professors are in a position of power over their students, this type of behavior is especially inappropriate. And, as far back as 1915, the AAUP advised that professors “should, in dealing with [controversial] subjects, set forth justly, without suppression or innuendo, the divergent opinions” on the issue. This 1915 advisory is still in effect. Indeed, any failure to do so may constitute an ethical breach. Professors should teach students about different sides of an issue and do so fairly, rather than pretending there is just one permitted viewpoint, as in a Marxist or authoritarian organization or system.

    What Should Be Done?

    First, if students encounter a professor that they believe is using the classroom to engage in ideological or political activism, students should speak up. That may be less risky than students think. Remember, education should empower students to engage in critical thinking and constructive dialogue. If students encounter concerning situations, approach professors for respectful discussions. If needed, seek guidance from department chairs or administrators who value open inquiry. There usually are some.

    This article appeared in Skeptic magazine 29.2
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    Often, students cannot rely on their institution’s hierarchy alone—indeed they may be part of the problem. Moreover, there is safety in numbers. Enlist parents and outside organizations to lobby college or university to ensure that it is promoting intellectual diversity, open inquiry, and free thought. (A very simple change is to ask that course evaluations include questions on whether students felt free to voice their opinions in class, whether the professor dealt fairly with students having divergent views, and whether different sides of controversial issues were presented or discussed.)

    Today, there are numerous organizations to help students. Currently, the most prominent bipartisan protectors and promoters of free thought are the Foundation for Individual Rights and Expression (FIRE) and Speech First. The important thing to remember is that you are not alone. Aside from those organizations, it is certain that many others at their institution will be rooting for students, even if they feel that they can only do so privately.

    Second, know that when confronted with transparency (sometimes supplemented with attorneys), bullies tend to back down.

    Third, know that the trials students are facing now can make them stronger, and further, are nothing like those faced by Alexander Solzhenitsyn, Vaclav Havel, Martin Luther King, Jr., Jackie Robinson, James Meredith, and thousands of others who faced suppression for their beliefs or their identity. The worst fate awaiting students would be having to transfer from a school which does not value free thought to one that does. Students have choices. Make them wisely.

    About the Author

    Michael Mills is an evolutionary psychologist at Loyola Marymount University (LMU). He earned his B.A. from UC Santa Cruz and his Ph.D. from UC Santa Barbara. He has served as Chair, and as the Director of the Graduate Program, at the LMU Psychology Department. He serves on the editorial boards of several academic journals and on the executive board of the Society for Open Inquiry in the Behavioral Sciences (SOIBS).

    Robert Maranto is the 21st Century Chair in Leadership in the Department of Education Reform at the University of Arkansas, where he studies bureaucratic reform and edits the Journal of School Choice. He has served on the Fayetteville School Board (2015-20) and currently serves on the executive board of the Society for Open Inquiry in the Behavioral Sciences (SOIBS). With others, he has produced about 100 refereed publications and 17 scholarly books so boring his own mother refused to read them, including President Obama and Education Reform (Palgrave/Macmillan, 2012), Educating Believers: Religion and School Choice (Routledge, 2021), and The Free Inquiry Papers (AEI, 2024). He can be reached at rmaranto@uark.edu.

    Richard E. Redding is the Ronald D. Rotunda Distinguished Professor of Jurisprudence and Associate Dean, and Professor of Psychology and Education at Chapman University. He has written extensively on the importance of viewpoint and sociopolitical diversity in teaching, research, and professional practice. Notable publications include Ideological and Political Bias in Psychology: Nature, Scope, and Solutions (Springer, 2023); Sociopolitical Values at the Deep Culture in Culturally-Competent Psychotherapy (Clinical Psychological Science, 2023); and, Sociopolitical Diversity in Psychology: The Case for Pluralism (American Psychologist, 2001). He is the founding President of the Society for Open Inquiry in the Behavioral Sciences (soibs.com).

    Organizations
    Additional Resources
    References
    1. This section relies heavily on three works. For the best conceptual analyses of various branches of critical theory, see Helen Pluckrose and James Lindsay, Cynical Theories: How Activist Scholarship Made Everything About Race, Gender, and Identity. (Pitchstone Publishing). For a sound journalistic account about how critical theory spread across institutions, see Christopher F. Rufo, America’s Cultural Revolution: How the Radical Left Conquered Everything (Broadside Books). Though Rufo has become a political activist, we can attest that his journalistic work is sound, as least as regards those areas with which we are familiar. Finally, the best single work about how critical theory and other moral panics spread, particularly in higher education, remains Greg Lukianoff and Jonathan Haidt’s The Coddling of the American Mind (Penguin). Also see Kenny Xu’s School of Woke: How Critical Race Theory Infiltrated American Schools and Why We Must Reclaim Them. (Center Street) and Isaac Gottesman’s The Critical Turn in Education (Routledge)
    2. Coddling of the American Mind; Eric Kaufmann, https://cspicenter.org/reports/academicfreedom/. Analyzing largescale surveys, political scientist Eric Kaufmann found over a third of conservative professors and doctoral students facing threats of discipline for their views. So have one in ten liberals, often censored by those farther left. Also see Richard E. Redding, “Psychologists’ Politics,” in Craig Frisby, Richard Redding, William O’Donohue, and Scott Lilienfeld, Ideological and Political Bias in Psychology: Nature, Scope, and Solutions (Springer), comprehensively reviewing all historical and current studies on the political views of professors and university administrators.
    Categories: Critical Thinking, Skeptic

    Stunningly preserved pterosaur fossils reveal how they soared

    New Scientist Feed - Thu, 09/05/2024 - 10:01pm
    The largest pterosaurs, ancient reptiles that were the first vertebrates to master flight, may have mostly soared while smaller ones flapped their wings, a pattern that persists in today's birds
    Categories: Science

    The Final Vega Rocket Blasts Off

    Universe Today Feed - Thu, 09/05/2024 - 6:17pm

    The European Space Agency (ESA) launched its final Vega rocket this week, lofting a Sentinel-2C Earth observation satellite into orbit. This wraps up 12 years of service and 20 successful flights for the venerable Vega. The rocket launched several well-known missions, including LISA Pathfinder (2015), the Earth-observing satellites Proba-V (2013), and Aeolus (2018). ESA will now launch these types of payloads on the new Vega-C rocket, capable of launching heavier payloads at a lower price.

    Vega’s final launch was on September 5, 2024 from Europe’s Spaceport in French Guiana, and ESA said that it was fitting the rocket boosted to orbit one of the Sentinel satellites, as Vega had previously launched Sentinel-2A in 2015 and Sentinel-2B in 2017.

    Vega was a smaller but powerful rocket launcher designed to loft smaller science and Earth observation satellites, specializing in launching of satellites into polar orbit. At 30 meters (98 ft) tall the rocket weighs 137 tons on the launch pad. Vega consisted of three solid-propellant powered stages with the a liquid-propellant fourth stage.  before the fourth liquid-propellant stage took over to bring satellites to their required orbit. Vega could reach space in just six minutes.

    On 13 February 2012, the first Vega lifted off on its maiden flight from Europe’s South American Spaceport in French Guiana and deployed 9 science satellites. Credits: ESA – S. Corvaja

    Vega’s first launch took place in February 2012, conducting a perfectly executed qualification flight to deploy 9 science cubesats into Earth orbit.

    On Vega’s second flight in 2013, a secondary payload adapter called Vespa was added. This provided different options for payload ride-sharing where multiple satellites could be launched on one rocket. This flight brought three satellites to orbit — Earth observation satellites, ESA’s Proba-V, Vietnam’s VNREDSat-1A and Estonia’s first satellite, the ESTCube-1 technology demonstrator. All three were released into different orbits and the complex mission required five upper-stage boosts, with the flight lasting about twice as long as its first launch.

    Countdown and launch of Vega’s final flight.

    The most satellites Vega ever launched to orbit was in 2020 when a variant of Vespa was used — called the Small Spacecraft Mission Service — and brought over 50 satellites at once to orbit.

    2015 was Vega’s’ busiest year, launching three ESA missions including a reentry demonstrator called IXV that prove the technology to launch a vehicle to space and return it safely to Earth. According to ESA, in less than two hours Vega accelerated IXV to speeds of 27,000 km/h (16,777 mph) at a height of 412 km (250 miles) before the reentry vehicle splashed down in the Atlantic Ocean.

    But now ESA is building on Vega’s heritage, and the era of Vega-C has already begun. This new rocket completed its inaugural flight in July of 2022, putting the main payload LARES-2 – a scientific mission of the Italian Space Agency ASI – into orbit as well as six research CubeSats from France, Italy and Slovenia. ESA said Vega-C will provide better performance and greater payload capability as it has two new solid propulsion stages, an uprated fourth stage, a newly designed fairing, and new ground infrastructure.

    Lift-off of a Vega-C rocket, with the Lares-2 mission plus rideshares. Credit: ESA

    The post The Final Vega Rocket Blasts Off appeared first on Universe Today.

    Categories: Science

    Ouch! A Monster Asteroid Crashed Into Ganymede 4 Billion Years Ago, Rolling it Over

    Universe Today Feed - Thu, 09/05/2024 - 6:01pm

    Jupiter’s moon, Ganymede, is a fascinating celestial body. Measuring 2,634 km (1,636 mi) in diameter, it is also the largest satellite in the Solar System and even larger than Mercury, which measures 2,440 km (1,516 mi) in diameter. Like Europa, it has an interior ocean and is one of the few bodies in the Solar System (other than the gas giants) with an intrinsic magnetic field. The presence of this field also means Ganymede experiences aurorae circling the regions around its northern and southern poles due to interaction with Jupiter’s magnetic field.

    In addition, based on its surface craters, scientists believe that Ganymede experienced a powerful impact with an asteroid about 4 billion years ago. This asteroid was about 20 times larger than the Chicxulub asteroid that caused the extinction of the dinosaurs, or the Cretaceous–Paleogene extinction event (ca. 66 million years ago). According to a recent study by Naoyuki Hirata of Kobe University, this impact occurred almost precisely on the meridian farthest away from Jupiter. This caused a reorientation of Ganymede’s rotational axis and allowed Hirata to determine exactly what type of impact took place.

    Naoyuki Hirata is an assistant professor with the Department of Planetology at Kobe University’s Graduate School of Science. His paper, “Giant impact on early Ganymede and its subsequent reorientation,” recently appeared in Science Reports. Since the Pioneer 10 and 11 and the Voyager 1 and 2 probes flew through the Jupiter system in the 1970s, scientists have known that large parts of Ganymede’s surface are covered by furrows that form concentric circles around a single spot. This led researchers in the 1980s to conclude that these were the result of a major impact event.

    On large parts of its surface, Ganymede is covered by furrows (right) that form concentric circles around one specific spot (left, red cross). © HIRATA Naoyuki

    The exact nature of this impact and its effects on Ganymede has been the subject of debate ever since. As Hirata said in a Kobe University press release:

    “The Jupiter moons Io, Europa, Ganymede, and Callisto all have interesting individual characteristics, but the one that caught my attention was these furrows on Ganymede. We know that this feature was created by an asteroid impact about 4 billion years ago, but we were unsure how big this impact was and what effect it had on the moon.”

    Using data obtained by the New Horizons mission of Pluto, Hirata drew on similarities with an impact event on Pluto that caused a shift in the (dwarf) planet’s rotational axis. As a specialist who simulates impact events on moons and asteroids, Hirata was able to calculate what kind of impact would have caused Ganymede’s orientation to shift. According to his estimates, the asteroid had a diameter of around 300 km (~186.5 mi) that created a crater measuring between 1,400 and 1,600 km (870 and 995 mi) in diameter before the debris resettled on the surface.

    Evidence of this impact is visible today in the center of the furrow system on the anti-Jovian side of Ganymede (the hemisphere facing away from Jupiter) and currently measures roughly 1,000 km (662 mi) in diameter. Looking ahead, Hirata hopes to learn how this impact could have affected the moon’s evolution, particularly where its internal ocean is involved:

    “I want to understand the origin and evolution of Ganymede and other Jupiter moons. The giant impact must have had a significant impact on the early evolution of Ganymede, but the thermal and structural effects of the impact on the interior of Ganymede have not yet been investigated at all. I believe that further research applying the internal evolution of ice moons could be carried out next.”

    Distribution of furrows and the location of the center of the furrow system shown in the hemisphere that always faces away from Jupiter (top) and the cylindrical projection map of Ganymede (bottom). © HIRATA Naoyuki.

    The ESA’s JUpiter ICy moons Explorer (JUICE) mission is currently en route to Jupiter and will establish orbit around Ganymede by 2034. The observations it makes over the next six months will help shed light on these and other questions regarding Ganymede and its sibling satellites, Europa and Callisto – not the least of which is whether or not these “Ocean Worlds” can support life.

    Further Reading: Kobe University, Scientific Reports

    The post Ouch! A Monster Asteroid Crashed Into Ganymede 4 Billion Years Ago, Rolling it Over appeared first on Universe Today.

    Categories: Science

    NASA’s Putting its Solar Sail Through its Paces

    Universe Today Feed - Thu, 09/05/2024 - 4:01pm

    Those of you following the Advanced Composite Solar Sail System may have heard that its booms and sail are now deployed. It is receiving light pressure from the Sun to propel it through the Solar System. Like a test pilot in a new aircraft, NASA are now testing out just how it handles. Before deployment, the spacecraft was slowly tumbling and now the controllers will see if they can get it under control and under sail power. The reflectivity of the sail means its an easy spot in the night sky, just fire up the NASA app to find out where to look.

    Solar sails are an ingenious propulsion technique that employs pressure from sunlight to generate low levels of thrust. As the photons of light strike the surface, they transfer momentum to the solar sail and therefore the spacecraft is accelerated. The thrust is small but when applied over long periods of time can provide a very efficient way to propels small spacecraft. The first successful deployment of a sail occurred in 2010 with the IKAROS (Interplanetary Kite-craft Accelerated by Radiation of the Sun) spacecraft launched by the Japanese space agency JAXA. 

    IKAROS spaceprobe with solar sail in flight (artist’s depiction) showing a typical square sail configuration. Credit: Wikimedia Commons/Andrzej Mirecki

    The Advanced Composite Solar Sail System (ACSSS) was developed by NASA to test the technology. The boom that supports the sail is made of lighter and more durable composite materials. By testing the deployment of the booms and efficient sale operation NASA hopes to prove the viability of the technology. The ACSSS uses lighter more flexible materials than previous attempts and will enable more efficient deep space exploration, asteroid rendezvous and other missions requiring low-thrust propulsion. 

    ACSSS orbits the Earth in a low orbit with an altitude of between 500-600 kilometres. Following launch, it was released purposely without attitude control and was as a result tumbling through space. Once the analysis has been completed, and the boom and sail deployment has been understood the team will re-engage the attitude control to stabilise the spacecraft. The next phase then begins as the team analyse flight handling and dynamics to adjust the spacecrafts orbit. 

    An artist’s concept of NASA’s Advanced Composite Solar Sail System spacecraft in orbit as the Sun crests Earth’s horizon. Credits: NASA/Aero Animation/Ben Schweighart

    Since the deployment of the sail, the operations team continue to receive images and data to help them understand how the boom technology has deployed. So far so good it seems for demonstrating the deployment and initial operations. The team will continue to monitor and analyse the incoming data and images in preparation for further technology tests and demonstrations in the week ahead.

    Any keen eyed sky watchers may be able to spot the spacecraft as it passes overhead. The high reflectivity of the sail will make it clearly visible to the unaided eye.  NASA have added a new feature to their app so that users can setup notifications to get alerts when it is visible from their location. NASA is inviting the public to share their pictures of the spacecraft online using the hashtag #SpotTheSail.

    Source : NASA Evaluates Deployed Advanced Composite Solar Sail System

    The post NASA’s Putting its Solar Sail Through its Paces appeared first on Universe Today.

    Categories: Science

    Evidence mounts that saline nasal drops and sprays help treat colds

    New Scientist Feed - Thu, 09/05/2024 - 4:01pm
    Saline drops and sprays have already been linked to reduced cold symptoms in adults and now a study suggests they also work in children
    Categories: Science

    There are Important Differences Between the Ice Caps on Mars

    Universe Today Feed - Thu, 09/05/2024 - 1:48pm

    In the 17th century, astronomers Giovanni Domenica Cassini and Christian Huygens noted the presence of hazy white caps while studying the Martian polar regions. These findings confirmed that Mars had ice caps in both polar regions, similar to Earth. By the 18th century, astronomers began to notice how the size of these poles varied depending on where Mars was in its orbital cycle. Along with discovering that Mars’ axis was tilted like Earth’s, astronomers realized that Mars’ polar ice caps underwent seasonal changes, much like Earth’s.

    While scientists have been aware that Mars’ polar ice caps change with the seasons, it has only been within the last 50 years that they have realized that they are largely composed of frozen carbon dioxide (aka. “dry ice”) that cycles in and out of the atmosphere – and questions as to how this happens remain. In a recent study, a team of researchers led by the Planetary Science Institute (PSI) synthesized decades of research with more recent observations of the poles. From this, they determined how the Martian poles differ in terms of their seasonal accumulation and release of atmospheric carbon dioxide.

    The team was led by Dr. Candice Hansen, a Senior Scientist with the Planetary Science Institute (PSI) and a member of the HiRISE imaging team. She was joined by researchers from the Lunar and Planetary Laboratory (LPL) at the University of Arizona, the University of Nevada, the U.S. Geological Survey’s Astrogeology Science Center (USG-ASC), the Laboratory for Atmospheric and Space Physics at UC Boulder, IUCLA, the Astrophysics Research Centre at Queen’s University Belfast, the German Aerospace Center (DLR), and NASA’s Jet Propulsion Laboratory. The paper that details their findings recently appeared in the journal Icarus.

    Mars’ south polar ice cap imaged by the HRSC camera on the ESA’s Mars Express. Credit: ESA/DLR/FU Berlin

    For their study, Hansen and her colleagues relied on data acquired by Mars orbiters over the past few decades. They then compared this with more recent data from the High-Resolution Imaging Experiment (HiRISE) instrument on the Mars Reconnaissance Orbiter (MRO). This allowed them to track the growth and recession of the Martian ice caps, which cycle about a quarter of the planet’s atmosphere throughout a Martian year. The ultimate purpose was to learn more about the processes that shape the planet’s surface and overall environment. As Hansen summarized in a PSI press release:

    “Everybody knows there’s a difference in how carbon dioxide interacts with the poles, but how many people understand why? That was what I was setting out to describe. And fortunately, I have a whole bunch of really talented co-authors who were willing to fill in their own pieces.”

    Like Earth, Mars experiences seasonal changes due to its axial tilt, about 25 degrees relative to the orbital plane, compared to Earth’s tilt of about 23.5 degrees. But since Mars has a much longer orbital period (~687 days), the seasons last about twice as long as they do here on Earth. In addition, Mars has a greater orbital eccentricity – about 9% compared to 1.7% – which means its orbit is more elliptical. Because of this, Mars is farthest from the Sun when its northern hemisphere experiences Spring and Summer, while the south experiences Fall and Winter.

    This means that summer in the southern hemisphere is shorter (while winter is longer in the north), coinciding with the dust storm season. As a result, the northern polar seasonal cap contains a higher concentration of dust than the south polar cap. “So ultimately, southern fall and winter bring the most freezing and lowest atmospheric pressure since so much of the atmosphere is frozen as dry ice,” said Hansen. “These are the major drivers of differences in seasonal behavior of carbon dioxide between the hemispheres. They’re not symmetric seasons.”

    Mars’ Barchan Dunes, captured by the MRO’s HiRISE Camera. Credit: NASA/ HiRISE/MRO/LPL (UofA)

    There are also significant differences in terms of elevation between the northern and southern hemispheres—i.e., the Northern Lowlands and Southern Highlands. Differences between the northern and southern polar terrain also influence seasonal change. For example, black dust fans are distributed across the southern landscape, resulting from dry ice sublimating and causing dust plumes. As Hansen explained:

    “A layer of carbon dioxide ice builds in the southern hemisphere fall, and over the course of the winter, it thickens and it becomes translucent. Then in the spring, the sun comes up, and light penetrates this ice layer to the bottom enough that it warms up the ground underneath. Now, gas is trapped under pressure. It’s going to look for any weak spot in the ice and rupture like a champagne cork.”

    Once the gas finds a weak spot and ruptures the ice, it blows dark plumes of dust into the atmosphere. The dust is blown in different directions depending on the wind direction and lands in fan-shaped deposits. This process shapes the landscape by creating gully channels, colloquially called “spiders” (araneiforms) because of their arachnid-like appearance. While the northern hemisphere also experiences dust plums in the Spring, the relatively flat terrain causes them to form dune-like features. Said Hansen:

    “When the Sun comes up and begins to sublimate the bottom of the ice layer, there are three weak spots – one at the crest of the dune, one at the bottom of the dune where it meets the surface and then the ice itself can crack along the slope. No araneiform terrain has been detected in the north because although shallow furrows develop, the wind smooths the sand on the dunes.”

    These findings demonstrate that Mars is an active place, not only over the course of eons but on a seasonal and even daily basis.

    Further Reading: PSI, Icarus

    The post There are Important Differences Between the Ice Caps on Mars appeared first on Universe Today.

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