Curio Cabinet

A train that doesn’t pollute? That’s the holy grail of the rail! A new kind of train is debuting in Los Angeles County, California—one that runs on hydrogen and emits nothing more than water vapor. Designed by Stadler, a Switzerland-based company, the train is a zero-emissions multiple unit, or ZEMU. The first of its kind in the U.S., ZEMUs will begin carrying passengers commuting from San Bernandino and Redlands on Metrolink, the region’s rail-based transit system, starting in 2025. As part of Metrolink, commuters will be able to transfer to any of the other trains in the system. What sets ZEMU apart is that it uses a hybrid hydrogen-battery system. Instead of burning hydrogen gas, fuel cells split apart the hydrogen molecules and use the energy generated to charge the train’s batteries. In addition, the train is equipped with a regenerative braking system that charges the batteries. Currently, the trains have three passenger cars and need to refuel just once a day, but there’s a catch. Although the technology to produce “green” hydrogen (hydrogen produced with renewable energy) exists, California doesn’t have the means to manufacture enough of it for the trains. That means that ZEMUs will be relying on hydrogen produced from fossil fuels and will therefore contribute to carbon emissions somewhere along the line. However, the trains can start running on green hydrogen anytime that it becomes available, and there will be no emissions along its route, aside from water vapor. Another advantage of ZEMUs over electric trains is that they don't require any track modifications to carry electricity, meaning that only the trains themselves need to be replaced over time. And while trains that run on overhead lines can run all day without refueling, such systems prevent freight trains from sharing the tracks, which isn’t a problem with ZEMUs. It seems these new trains show rail promise.

 
[Image description: Train tracks surrounded by trees at sunset. There are power line poles in the distance.] Credit & copyright: Krivec Ales, Pexels

Bat deaths are an ecological disaster; infant deaths are tragedies. But how can these two things be related? A researcher at the University of Chicago recently published a paper in Science linking the continuing decline of the bat population in New England to a rise in infant mortality rates in the region. It sounds almost like a non sequitur, but environmental economist Eyal Frank, the author of the paper, believes there’s a compelling link. For decades, bat colonies have been succumbing en masse to a deadly fungal disease called white nose syndrome. Since bats can consume about 40 percent of their own body per night in insects, their presence serves as a natural form of pest control. However, with lower bat populations, farmers in areas affected by white nose syndrome have been using 31 percent more pesticides on average to compensate. Frank found that these areas also began to see an increase in the infant mortality rate by eight percent, or about 1,300 deaths so far. While the numbers have a correlation (a statistical relationship) to each other, it doesn’t yet prove causation (that one event caused the other).
 
According to Tracey Woodruff, an environmental health scientist at the University of California San Francisco who was not involved with the study, there are a number of other factors that may have led to the increase in infant mortality, such as air pollution. Also, Frank’s paper didn’t find a correlation between the pesticide use and birth weight, which is often correlated with infant mortality. On the other hand, Frank has factored in issues like opioid use, unemployment, and GMOs, and found nothing else that could explain the rise in infant deaths. They say that numbers don’t lie, but this is one instance where you’d almost hope they do.

[Image description: A little brown bat hanging upside down, with white fungus growing on its nose and mouth.] Credit & copyright: Marvin Moriarty/USFWS, Wikimedia Commons. This image or recording is the work of a U.S. Fish and Wildlife Service employee, taken or made as part of that person's official duties. As a work of the U.S. federal government, the image is in the public domain.
 

Dye is used to make things colorful, not see-through. Yet, researchers at Stanford University have found that a certain dye used in snack foods can make the skin of mice translucent. As horrifying as that sounds at first, it might actually be a good thing. Tartrazine, also known as Yellow Dye #5, is used in many processed foods to lend them an appetizing yellow tone. It’s also used in everything from cosmetics to medications to make them look distinct. But this seemingly innocuous yellow powder has been hiding a secret: when mixed with water, it can make skin translucent. Researchers initially tested the dye mixture on mice tissue samples and chicken breasts before moving on to live mice. When applied on the skin of live mice, the dye allowed researchers to see the deeper layers of skin, muscles, and even connective tissue. Once the dye is washed off, the skin returns to normal, and any dye that was systemically absorbed is apparently excreted harmlessly through the urine.
 
The science behind this mind-bending effect is actually pretty simple. The dye is simply good at absorbing blue and ultraviolet light, allowing more light to pass through skin. Of course, researchers aren’t just interested in looking at mice innards for fun. They hope that the dye might one day be used to perform noninvasive exams for conditions under the skin, but there are obstacles to making that happen. For one, human skin is around ten times thicker than that of mice, and it’s not known whether the amount of dye needed to recreate the translucent effect in humans would be as safe. Second, it’s not clear what the best route for administration would even be. If it is used for medical purposes, the good news is that tartrazine is cheap and already widely produced. At the same time, researchers are still planning to look for other substances that can do the same thing. According to one of the Zihao Ou, one of the researchers working with Yellow Dye #5, even if the dye can’t be used on live subjects, it can be used with microscopes and tissue samples. In a statement from the university, Ou said, “It will completely revolutionize existing optical research in biology.” You can really see the possibilities.

 
[Image description: A close-up photo of a brown mouse’s face.] Credit & copyright: kcthetc1, Wikimedia Commons. This file is made available under the Creative Commons CC0 1.0 Universal Public Domain Dedication.

Fungus-powered robots might not sound that cool at first, but they’ll grow on you. Scientists have found a way to use live fungi to drive small, robotic machines called “biohybrid” robots. This type of machine could represent a big leap forward for robotic engineering. After all, biology has already figured out how to detect and send a variety of stimuli through self-replicating cellular structures, whereas today’s robots still rely on things as crude as circuit boards and copper wires. Scientists at Cornell University decided to switch things up by building a biohybrid robot that uses mycelium (the root-like parts of fungus) to control its movements.
 
Previously, biohybrid robots have been made using cells and parts from vertebrates, insects, and even sea slugs, but the Cornell team is the first to use fungus. For their robot, they grew mycelium directly on an electrical interface which converts electrophysiological activity from the fungus into signals that are sent to actuators. That’s not too far off from what fungus already does in nature, where expansive mycelium networks intertwined with root systems can transport nutrients between plants and communicate using chemical signals. So far, they’ve made a robot with wheels and another with legs. Both versions are quite capable of moving around based on the mycelium’s responses to stimuli. For now, the researchers are experimenting with using light to control the movement of the robots, but they are planning to use chemical signals in the future. Since mycelium are already capable of responding to different stimuli, there’s no need to have different sensors for light, chemicals, and pressure; the fungus acts as an all-in-one sensor unit. In the future, scientists believe that this technology could be used to create mostly autonomous robots, with applications in fields like agriculture, where they could freely roam about to dispense fertilizer or pesticides based on the chemical composition of the soil. Fungal farmers? Funny, but feasible!

 
[Image description: A cluster of white oyster mushrooms surrounded by grass.] Credit & copyright: Teknad, Wikimedia Commons. This file is made available under the Creative Commons CC0 1.0 Universal Public Domain Dedication.

Do dinosaurs still walk among us? It may sound like a question for bigfoot hunters and Nessie enthusiasts, but scientifically speaking, the answer is (sort of) yes. Birds, after all, are direct, living descendants of dinosaurs, and no bird illustrates this fact more plainly than the cassowary. These massive, flightless birds, with their head crests and bright coloring, look like something straight out of Jurassic Park. Rather than running from them in terror, though, people all over the world are doing their best to save this endangered creature. In fact, a bird park in England’s Cotswolds region, called Birdland, recently made international headlines when a cassowary chick was born there. Cassowaries rarely breed in captivity—in fact, it took 25 years for a chick to be born at Birdland, and it’s only the fourth cassowary to ever be hatched in Europe. It goes to show the importance of saving cassowaries’ native habitat, the rainforests of Australia, New Guinea, and their surrounding islands.
 
Cassowaries are the third largest birds in the world, standing up to six feet tall and weighing as much as 175 pounds. Their bodies and wings are covered in shaggy, black feathers, while distinctive, bright blue heads and necks are bare. Both males and females have head crests, known as casques, which are thought to help them shed excess heat. While cassowaries’ ancient ancestors were velociraptor-like dinosaurs, around 60 million years ago these evolved into birds in the order Struthioniformes, the only living member of which is the ostrich. It was just 10 million years ago that cassowaries broke away from the Struthioniformes order and began changing into the colorful birds they are today. The three living species of cassowary are now members of the order Casuariiformes, along with emus.
 
Despite their fearful appearance, strong legs, and wickedly sharp talons, cassowaries primarily eat fruit, including black palm berries and figs. While cassowaries are omnivores and do hunt, their prey consists mostly of small rodents and reptiles. While cassowary breeding habits remain somewhat mysterious, they are typically thought to mate between June and October. They lay clutches of three to five eggs, which hatch into fuzzy, yellow-and-brown-striped chicks. The chicks may look drab compared to adult cassowaries, but they do hatch from bright green eggs. It seems these birds can’t help but live colorful lives, right from the beginning.

 
[Image description: A cassowary standing in thick, green brush. It is a large, flightless bird with a blue neck and head, a black body, and a brown head crest.] Credit & copyright: Dave Kimble, Wikimedia Commons. The copyright holder of this work has released this work into the public domain. This applies worldwide.

Oof, that must have hurt! Our solar system’s many moons and planets have, throughout their long history, dealt with plenty of asteroid impacts. These destructive collisions left many scars still visible today, but scientists at Kobe University in Japan have found one case that stands out from the rest. Jupiter is no stranger to asteroid impacts, as its immense gravity attracts drifting space rocks. But when Jupiter casts its gravitational net, not all of the asteroids reach the planet’s surface. Instead, they often collide with one of Jupiter’s many moons, like Ganymede. The largest of Jupiter’s moons, Ganymede bears innumerable craters on its surface from eons of such asteroid impacts, but there’s one that left more than just a scar. The largest crater visible on its surface features a circular furrow that seems to spread out from a single point—the site of impact. This four-billion-year-old crater is so large that much of its visible detail has been obscured by a smattering of smaller craters from other asteroids. Naoyuki Hirata, a planetologist at Kobe University, knew that whatever left the crater must have been massive.
 
Figuring out exactly how massive was tricky. One of the clues to the size of the asteroid was the location of the crater that the furrow system emanates from, almost directly on the other side of the tidally-locked moon. That, along with the angle of impact, indicates that the asteroid was large enough to shift the rotational axis of the moon significantly, enough that the impact site, which faced Jupiter, now faced away. It’s not an event without precedent, as discoveries made through the New Horizons space probe indicate that Pluto once experienced something similar. Hirata estimates that the Ganymede asteroid must have been around 186 miles wide, or 20 times larger than the asteroid that created the Chicxulub crater 66 million years ago on Earth. That asteroid famously caused the extinction event that wiped out the dinosaurs. If the Ganymede asteroid had hit the Earth, it’s safe to say we’d be missing a lot more than dinosaurs.
 
[Image description: A dark night sky with stars visible.] Credit & copyright: Kai Pilger, Pexels