COOL METAMATERIALS
I was fascinated by “Tricking Light,” Andrea Alù's report on the metamaterials that can now be made that can modify light waves. What particularly interested me was the claim that materials could be constructed that could absorb more radiation than they emitted in an equilibrium state, or vice versa. Does this mean that a cladding could be made that would warm or cool the building it covered? Enormous amounts of energy are used to keep us warm or cool, and this sort of development could help save the planet.
ROBERT EAST London
ALÙ REPLIES: Indeed, metamaterials have been opening exciting opportunities in the context of green energy applications. Metasurfaces engineered at the nanoscale are being explored to enhance the efficiency of photovoltaics and energy harvesting, as well as for passive daytime radiative cooling, which cools a surface through thermal emission without requiring any external energy source.
I want to emphasize that these surfaces still operate in equilibrium. As I mentioned in the article, by breaking time-reversal symmetry, it is also possible to realize more sophisticated thermal emission responses, such as surfaces that thermally emit in one direction but absorb from a different one.
REDUCING RACISM IN THE CLASSROOM
I enjoyed reading “In Schools, Talk about Racism Can Reduce Bias,” by Camilla Mutoni Griffiths and Nicky Sullivan [Mind Matters]. Not only does talking about general racism in society reduce bias, as the article describes, but recent evidence reveals that providing children an opportunity to reflect on and discuss peer exchanges involving social exclusion based on gender, race and ethnicity does so as well. Additionally, it promotes positive academic and social expectations about others in children and increases their desire to play with peers from different backgrounds.
My team and I at the University of Maryland recently completed testing the effectiveness of our Developing Inclusive Youth intervention program in third, fourth and fifth grade students in public schools. The program involves watching a web-based curriculum tool that portrays everyday peer-exclusion scenarios, followed by a teacher-led classroom discussion. We used a randomized control trial in 48 classrooms, and the results are very promising.
In contrast to the control group, children in the program were more likely to view interracial peer exclusion as wrong, to assign more positive traits such as “friendly” and “hardworking” to diverse peers, and to have more positive math and science competency beliefs about those with different racial and gender backgrounds. Our results were published in the May/June 2022 issue of the journal Child Development.
Talking about peer exclusion based on race, ethnicity and gender helps students to understand what makes it wrong and how it feels and to recognize that many peers experience these forms of exclusion. Changing group norms in the classroom is the first step toward rejecting individual explanations for group differences and learning about structural explanations that reflect prejudice and bias. Creating a safe space to talk about these issues in the classroom is necessary for promoting positive learning environments for all students.
MELANIE KILLEN University of Maryland
The article notes that a law in Iowa effectively prohibits teaching about race, partly on the basis that “teachers must ensure that no student feels ‘discomfort, guilt, anguish or any other form of psychological distress on account of that individual's race or sex.’” I was immediately struck by the dangerous possible generalization of this rationale to all educational subjects. What child struggling to learn to read or to do mathematics does not experience psychological distress?
The real issue is not the distress but how it is managed. Teachers can help students to do that, to try harder rather than give up, to understand and to grow as humans. Truly, this is a fundamental life lesson. Otherwise we have the perverse outcome described in the article.
BILL JONES Toronto
BE AWARE
In “Hidden Consciousness,” Jan Claassen and Brian L. Edlow discuss how some patients who appear to be in a coma may be aware of their surroundings. Almost immediately after I began to read the article, my recollections of Dalton Trumbo's 1939 novel Johnny Got His Gun and his 1971 film adaptation came to mind.
In the story, intended as an antiwar cautionary tale, a young World War I veteran awakens in a hospital bed with massive injuries—amputations in both legs and both arms and the complete erasure of his face. He has total consciousness but is trapped in a body that is incapable of communicating with the world. Unable to commit suicide, he eventually gets through to his day nurse by banging his head repeatedly on his pillow in Morse code.
Whether by Trumbo's book or the movie or this article, one's empathy is aroused for folks trapped in their own body. All must hope that the reported techniques for opening communication with patients with “covert consciousness” make dramatic improvements. Finally, we have to wonder how many sentient beings in the past who were in that state had their life support withdrawn and knew what was about to happen.
JOHN KOPP Eastvale, Calif.
RELIGION AND MORAL INJURY
I was very happy to read “An Invisible Epidemic,” by Elizabeth Svoboda [December 2022]. Her description of “moral injury” rang true to the experience of many people I have dealt with in my priesthood, ranging from women facing clearly their decision of years earlier to seek an abortion to those who, out of fear or material self-interest, did not report financial or sexual misconduct of their religious superiors.
Svoboda is right to portray this problem as a moral one rather than another instance of post-traumatic stress disorder or depression. It is a conflict within oneself over deeply held moral principles succumbing to outside pressure or inner weakness. One must be honest about one's past actions, regret one's failure to live by one's principles, even if nothing better could have been done at the time, and then trust that peace may be achieved by a clearer understanding of one's situation and a renewed commitment to those moral values.
It was encouraging to see Svoboda's recognition of the role that religious leaders—priests, rabbis, ministers, imams—may have in dealing with moral injury. They often have experience in counseling in such situations.
MARK E. BRENNAN Bishop of Wheeling-Charleston, Wheeling, W.V.
ERRATA
“Hidden Consciousness,” by Jan Claassen and Brian L. Edlow, should have said Maria Mazurkevich is now working as a pharmacy technician, not a pharmacist.
“Dialogues with the Dead,” by Piers Vitebsky [January 2023], should have described mourners stitching leaves from a sacred Sal tree into bowls before a ritual involving a trance state, not after. And it should have described Sora men drinking palm wine outdoors, not in the jungle.
