Learn about whether being too clean makes kids sick; an ancient coronavirus epidemic; and a black hole-neutron star merger. Is being too hygienic making kids sick? These researchers say the public has it all wrong by Grant Currin Being clean and hygienic need not impair childhood immunity. (2021). EurekAlert! https://www.eurekalert.org/pub_releases/2021-07/ucl-bca070221.php Rook, G. A. W., & Bloomfield, S. F. (2021). Microbial exposures that establish immunoregulation are compatible with targeted hygiene. Journal of Allergy and Clinical Immunology, 148(1), 33–39. https://doi.org/10.1016/j.jaci.2021.05.008 Cara, E. (2021, July 6). Being Clean Doesn’t Have to Be Bad for Our Immune System, Scientists Say. Gizmodo; Gizmodo. https://gizmodo.com/being-clean-doesnt-have-to-be-bad-for-our-immune-system-1847238686 Genome study reveals East Asian coronavirus epidemic 20,000 years ago by Cameron Duke Souilmi, Y., Lauterbur, M. E., Tobler, R., Huber, C. D., Johar, A. S., Moradi, S. V., Johnston, W. A., Krogan, N. J., Alexandrov, K., & Enard, D. (2021). An ancient viral epidemic involving host coronavirus interacting genes more than 20,000 years ago in East Asia. Current Biology. https://doi.org/10.1016/j.cub.2021.05.067 Queensland University of Technology (2021, June 24). Genome study reveals East Asian coronavirus epidemic 20,000 years ago. Phys.org. https://phys.org/news/2021-06-genome-reveals-east-asian-coronavirus.html We got the first ever detection of a black hole gobbling up a neutron star by Briana Brownell Black holes swallow neutron stars like “Pac Man.” (2021). EurekAlert! https://www.eurekalert.org/pub_releases/2021-06/anu-bh062521.php Astrophysicists detect first black hole-neutron star mergers. (2021). EurekAlert! https://www.eurekalert.org/pub_releases/2021-06/nu-adf062821.php Abbott, R., Abbott, T. D., Abraham, S., Acernese, F., Ackley, K., Adams, A., ... & Boudart, V. (2021). Observation of gravitational waves from two neutron star–black hole coalescences. The Astrophysical Journal Letters, 915(1), L5. https://iopscience.iop.org/article/10.3847/2041-8213/ac082e/pdf Betz, E. (2020). How Big Are Neutron Stars? Discover Magazine; Discover Magazine. https://www.discovermagazine.com/the-sciences/how-big-is-a-neutron-star By Pallab Ghosh. (2021, June 29). Rare black hole and neutron star collisions sighted twice in 10 days. BBC News; BBC News. https://www.bbc.com/news/science-environment-57639520 What Is a Black Hole? (2015). NASA. https://www.nasa.gov/audience/forstudents/k-4/stories/nasa-knows/what-is-a-black-hole-k4.html Follow Curiosity Daily on your favorite podcast app to learn something new every day withCody Gough andAshley Hamer. Still curious? Get exclusive science shows, nature documentaries, and more real-life entertainment on discovery+! Go to https://discoveryplus.com/curiosity to start your 7-day free trial. discovery+ is currently only available for US subscribers.
Learn about whether being too clean makes kids sick; an ancient coronavirus epidemic; and a black hole-neutron star merger.
Is being too hygienic making kids sick? These researchers say the public has it all wrong by Grant Currin
Genome study reveals East Asian coronavirus epidemic 20,000 years ago by Cameron Duke
We got the first ever detection of a black hole gobbling up a neutron star by Briana Brownell
Follow Curiosity Daily on your favorite podcast app to learn something new every day with Cody Gough and Ashley Hamer. Still curious? Get exclusive science shows, nature documentaries, and more real-life entertainment on discovery+! Go to https://discoveryplus.com/curiosity to start your 7-day free trial. discovery+ is currently only available for US subscribers.
Find episode transcript here: https://curiosity-daily-4e53644e.simplecast.com/episodes/hygiene-hypothesis-ancient-coronavirus-black-hole-eats-neutron-star
CODY: Hi! You’re about to get smarter in just a few minutes with Curiosity Daily from curiosity-dot-com. I’m Cody Gough.
ASHLEY: And I’m Ashley Hamer. Today, you’ll learn about whether being too hygienic is really making kids sick; a newly discovered coronavirus epidemic that took place 20,000 years ago; and the first ever detection of a black hole gobbling up a neutron star.
CODY: Let’s satisfy some curiosity.
Covid has kept everybody killing germs and sanitizing surfaces for well over a year now. But there’s an idea out there that says maybe all that cleanliness isn’t protecting us — instead, it might be making us sick. That’s kinda confusing, which is why it’s good news that a team of researchers has just published a study that offers fresh insight into this idea. They say that most of us are getting it very wrong.
Here’s the down and dirty: we’ve known for centuries that germs cause disease. It’s why we wash our hands. But around the 1980s, researchers started to think that something else was going on. They suspected that more kids were getting asthma because they were growing up in excessively sterile environments that didn’t give their immune systems the chance to learn from bacteria, viruses, and other pathogens early in life. They called this idea the “hygiene hypothesis.”
So... is it better to keep the house as clean as possible? Or should kids be exposed to germs for their own good? A lot of people have been convinced that it’s the second one. After all, some studies do show that kids who grow up on farms or in houses with a lot of animals running around tend to have a lower chance of developing allergies.
In this new study, researchers looked at a lot of papers that have studied different aspects of this debate, and they came to some concrete conclusions.
They found that yes, kids definitely need to be exposed to microbes when they’re young. But the microbes that will help them develop healthy immune systems aren’t the kind that live in a typical house. Instead, many are found outside, in what the authors call the “natural green environment.” So go out and play!
But the researchers also found that when it comes to strengthening the immune system, microbes pale in comparison to the power of vaccines. That’s because vaccines don’t just teach the body to recognize individual viruses — they seem to make the immune system more effective in general.
The researchers did find a risk to living in a home that’s too clean, but it’s not the lack of microbes. It’s the cleaning products that get into kids’ lungs and make them more susceptible to asthma.
Parents have a lot on their plates right now. This research says that worrying about the house being too clean shouldn’t be one of them. So go ahead and sanitize that doorknob and wash those hands — then, maybe take a walk to the park for good measure.
In 2020, many of us became well acquainted with a particular coronavirus. In that time, you may have learned about other coronaviruses that have been problems in the past, like SARS and MERS. But our problems with these viruses go back much further than that. A new genetic study has revealed traces of a coronavirus epidemic from 20,000 years ago. And this lesson about the past could help us prepare for the future.
Humans and coronaviruses have been enemies for a long time, but it’s unclear exactly how long. Our knowledge of viruses certainly doesn’t go back that far, but there is a record that does: the human genome. Just like paleontologists can dig into rock to study the history of the Earth, researchers can study the human genome to discover genetic artifacts from our distant past.
Researchers from Queensland University of Technology in Australia dove into our genetic history by examining data from the 1000 Genomes Project. That’s a repository of human genetic data voluntarily donated from people all over the world. The researchers were interested in the evolution of genes that interact with coronavirus proteins. Once they identified these genes, they used them to synthesize proteins to see how they interact with coronavirus proteins.
As they did this, one thing stood out: the gene variants from East Asian lineages such as those in China, Japan, Mongolia, Taiwan, and the Koreas handled the coronavirus proteins much better than the variants from all other lineages. The reason for this would likely have been an ancient epidemic. Natural selection during a viral outbreak would have led to the survival of genes that can better fight the virus. And when they dated the specific variant they found, evidence suggested that this coronavirus outbreak swept through the region 20,000 years ago.
So, does this mean that people of East Asian descent were better protected during our most recent battle with a coronavirus? The researchers say no: evidence suggests that socioeconomic factors had a much, much bigger role than genetics during the SARS-CoV-2 pandemic. But understanding the genes that evolved during ancient pandemics could help us predict and prevent future ones, and possibly develop new drugs to fight these viruses.
But one thing’s for certain: the recent pandemic was the latest battle in a long war with an old foe.
Both black holes and neutron stars are pretty extreme. But strangely, before last year, they’d never been seen together as a pair. Scientists came up with all sorts of reasons why that might be. But recently, an international group of scientists reported spotting not one, but two separate instances of a black hole swallowing a neutron star. That means these pairings might not be so rare after all.
Here’s the thing. Our star is solo, but most stars in the universe come in binary or trinary systems. Even our closest neighbor in the galaxy, the Centauri system, is a system of three stars. So that would suggest that we should see pairs of neutron stars, pairs of black holes, or one of each.
But we’ve been looking for a black-hole-neutron-star pair for nearly 50 years and have come up empty until now.
Neutron stars form when a star nears the end of its life and it explodes into a supernova. Gravity compresses matter left inside to -- essentially -- neutron soup. They are extremely dense.
By volume, our sun is about 100 times the size of the Earth. Imagine a star that’s around twice as massive as our sun, squished into the size of Manhattan.
Black holes are formed when even bigger stars collapse. Because of this extra mass, gravity compresses them even more -- so tightly that even light cannot escape.
When these supermassive objects collide, they stretch and squeeze space in phenomena known as gravitational waves. Scientists on Earth can detect this oscillation.
The waves are extremely small — smaller than an atom — but their detection was evidence of something really big. The proportion of heavier elements like iron, carbon, and oxygen is related to the proportion of neutron-star-black-hole pairs that there are in the universe, and these results led the team to conclude that there must be less of these elements in the universe than they assumed. It also changed our understanding of how stars behave; that’s because the number of pairings are also related to the force that stars use to push these materials out into the universe. The team concluded that this force was smaller than previously thought. This means scientists will have to update their current understanding of star and planet formation.
And the discovery has even more implications. Now that scientists have figured out the gravitational wave signature of the black-hole-neutron-star collision, they intend to look back through the detector data to figure out whether there were other instances that they missed.
Although this is the first time we’ve seen a black hole swallow a neutron star, it almost certainly won’t be the last star feast we see.
Let’s recap today’s takeaways
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ASHLEY: Today’s writers were Grant Currin, Cameron Duke, and Briana Brownell.
CODY: Our managing editor is Ashley Hamer
ASHLEY: Our producer and audio editor is Cody Gough.
CODY: [AD LIB SOMETHING FUNNY] Join us again tomorrow to learn something new in just a few minutes.
ASHLEY: And until then, stay curious!