It's a question children ask as often as they ask why the sky is blue. Why is pee yellow? Any answer outside of "I don't know" was most likely more entertaining than the truth, which scientists have revealed to us. A previously unknown enzyme called bilirubin reductase is behind it. Bilirubin reductase is not yellow, but it factors into the process.

Our bodies are always producing new red blood cells and eliminating old ones. Old red blood cells release an orange pigment called bilirubin as they die. Several species of gut microbes in our bodies use the enzyme bilirubin reductase to break down the bilirubin into urobilinogen, which turns yellow as it degrades. Biochemists who've been studying the question for more than a century (not the same scientists) knew about bilirubin and urobilinogen, but the step in between them is the discovery that makes it all work. Those microbes producing bilirubin reductase are doing us a great favor, because too much bilirubin causes jaundice. You can read up on the experiments that revealed the new enzyme at Ars Technica.

But what if your urine isn't yellow? You might need to see a doctor.

(Image credit: Turbotorque)

The tschäggättä are villagers who roam the narrow streets of the valley, clanging bells and making mischief dressed as Sasquatch-like creatures. https://t.co/WqyozsgJti

— Smithsonian Magazine (@SmithsonianMag) January 30, 2024

Name a holiday celebrated anywhere, and there will be some kind of legendary monster associated with it. Carnival is the season of gluttony before the Christian fasting time of Lent leading up to Easter. In most places, Carnival involves parties, parades, masquerade balls, eating, drinking, and various debaucheries that will be forbidden beginning on Ash Wednesday. In Switzerland's Lötschental Valley, they have the added festivity of monsters roaming the streets.

These creatures are called tschäggättä. Villagers dress in fur with padding to make them look taller and wooden masks carved with scary human faces. They ring cowbells and make mischief that once included fights, theft, and assaults, but now involve mainly harmless teasing to folks who come out to see them. We have evidence of the tschäggättä going back more than 200 years, but the tradition could be much older. How did it start? No one, not even those who participate every year, knows. Read what we do know about the tschäggättä of the Lötschental Valley at Smithsonian.

From an individual point of view, time moves in a line from your past to the present and then into the future. All we experience is the present, but we remember the past, and anticipate the future -although we cannot know it until it is the present. But the theory of relativity states that time moves differently for beings moving through space at different speeds, so is their "present" different from ours? And how would different "presents" work? The idea of multiple presents warps the idea of an unknowable future that can be affected by the choices we make in the present. If that's too mind-blowing, maybe we should look at time in a different way to make it mesh with our lived experience. Then there's always the possibility that we are wrong, but how would we ever know? Some scientists have even weirder ideas about how time works. Kurzgesagt takes us through these ideas in ten minutes with a video full of more or less obscure cultural references you may not catch the first time around; the rest of this video is an ad. -via Digg

Fonts hanging out pic.twitter.com/rXUzNNlQp7

— Elle Cordova (@ellerhymes) January 23, 2024

Elle Cordova is a professional musician turned comedian with a flair for intellectual humor. In a recent series of videos, she personifies different fonts. Or are they typefaces? It's hard to tell.Anyway, she perfectly embodies the personality nuances of these fonts.

Redditor 9oRo recently posted a photo of a rejection letter that Disney had sent a woman named Mary V. Ford who apparently applied to them in 1938 for a position related to preparing the cartoons (possibly sketching or drawing) or some other creative work associated with it.

Quite blatantly, the Disney representative who signed the letter told Ford that women were not considered for such positions, as they were only reserved for young men. Furthermore, it stated that the only work available for women were coloring and tracing, for which the representative bluntly advised against applying as there were few openings.

DetectiveAnitaKlew astutely pointed out in the comments that the letter was signed by a woman. While elgringo22 funnily adds how they even added a picture next to her signature.

Comments that followed tried to look at the brighter side of the situation, saying that at the very least, a rejection letter was sent, instead of having no udpate or response at all like what some companies do today. - via Messy Nessy Chic

(Image credit: 9oRo/Reddit)

I don't often go to coffee shops, especially independent ones which usually have that artisanal feel to them, but whenever I did, it always felt the same as with all the rest that I've gone to before. Almost all coffee shops these days follow the trend of the "millennial aesthetic" or some variation of it. And one can't blame them, since that's what it takes to keep their businesses afloat with consumer preferences leaning toward that kind of "experience" or the "Instagrammability" of the cafe.

In this piece, Kyle Chayka dives deep into the tyranny of the algorithm, and how it has shaped, not just coffee shops, but also co-working spaces, startup offices, and every other physical space out there. It breeds homogeneity and monotony. In a diverse world, that does seem odd. But it shouldn't come as a surprise with the rise of the millennial cohort, whose digital savvy brought such aesthetics to the forefront.

Still, what strikes me as the most crucial in this analysis is the irony of the disproportionality of benefits that platforms such as Instagram or Yelp offer businesses. Although they are great tools to use for promotions and advertising, in the long run, they make it harder for businesses to maintain engagement without being taxed by the platforms themselves.

In the end, the biggest winners are still just the big corporations who have monopoly over these spaces and means to reach millions. Even we, the consumers, are at their mercy as our information, likes, dislikes, shares, and follows become commodified. In an age when individuality and uniqueness are celebrated, it does get to the point when the sameness of it all becomes mundane. - via Messy Nessy Chic

(Image credit: Jonas Jacobsson/Unsplash)

We know that the earth is in constant motion, not just rotating on its axis or revolving around the sun, but also from within its crust and mantle. The tectonic plates have been shifting around and that has caused many geographical changes to occur.

The video above from ArcGIS gives us a short timelapse of how the supercontinent, pangea, broke apart and drifted such that the seven continents arrived at their current locations that we know today. The video starts from 200 million years ago and moves at a pace of 5 million year increments at the rate of 2.5 million years per second.

Not only that, Open Culture also explores what the future of earth's geography will be as well with the help of a video from Christopher Scotese titled Future Plate Tectonics: Pangea Proxima.

In it, Scotese postulates that in 250 million years, the seven continents will once again merge together to form Pangea Proxima.

The supercontinent is formed in multiple stages which starts with the merging of Africa, Europe, and Asia in 25 to 50 million years; which then proceeds with the movement of Australia and Oceania to merge with Southeast Asia from the 50- to 100-million-year mark; and from the 150- to 200-million-year mark, the Americas and the Africa-Eurasia-Australian mega-continent will drift toward each other until they eventually become Pangea Proxima with parts of the former Indian Ocean at the center.

Beyond this, another study suggested something somewhat similar to Scotese's Pangea Proxima, but with a different name, Pangea Ultima, and a more tragic end for mammals as the extreme temperatures would make 92% of earth's surface uninhabitable.

(Video credit: ArcGIS/Youtube; Christopher Scotese/Youtube)

British novelist Wilkie Collins met Charles Dickens when they were both doing amateur theater. They became good friends, which was sometimes a drawback when critics pointed out that Collins' novels weren't as good as Dickens. Collins' may not have been as gifted as his friend, but he left a lasting legacy in his works. Collins wrote melodramatic stories in what were called "sensation novels" at the time, that were written to play to the emotions and stir a physical reaction in the reader. Many of them used supernatural elements to elicit a response, but Collins never did. His horrors were real and based on the laws of the time.

See, Collins had a law degree, even though he never practiced law. But he understood the laws of the day, and his novels incorporated them into "the worst that could happen" scenarios for women. Married women had no rights at all, even to their own property. They were at the mercy of their husbands, who, in Collins' stories, could control their autonomy and their very lives. He also explored the themes of poverty, adultery, abuse, inheritance, illegitimacy, divorce, power, and murder. His years of writing coincided with a push for reform in women's rights (which his sensation novels no doubt contributed to), and each story was carefully vetted for contemporary legal accuracy in consultation with Collins' own lawyer. Read about Collins, his works, and the changing laws involving women's rights in Victorian England at Smithsonian.

Could there be a more perfect or hilarious crossover than the Muppets doing Mad Max: Fury Road? There isn't a movie (yet), but the idea is looking pretty good in a series of 20 images by redditor InkSlinger1983 using the artificial intelligence program Midjourney. He's been working on this for some time- this is version 6.

AI still isn't all that great at recreating images of humans, which honestly is a good thing, but putting Muppets into the vehicles works because they come with their own permanent expressions that lend a certain levity to the two-hour chase scene we know as Fury Road. Muppets fit into the roles of the War Boys, the Doof Warrior, Immortan Joe, and the other drivers. InkSlinger1983 tells us he tried, but couldn't recreate Mad Max or Furiosa because Midjourney kept wanting to render them as humans.

   

See all 20 images in a slideshow at reddit, or in a one-page gallery at Geeks Are Sexy.

Some pretty high-profile crimes have been solved by examining how the perpetrators, or accused innocents, use language. The way a person uses words, grammar, and puctuation creates a personal style and vocabulary that's somewhat like a fingerprint. Linguists know how individual these styles can be, and forensic linguists detect these patterns as clues to uncovering the truth in crimes.

When I listened to this video, I was deeply impressed by what forensic linguists can do, but I could also see how we all can learn these skills with time and effort. I'm no linguist, but having dealt with the written word for so long (and the spoken word before that), I know my own writing habits and try to correct for their overuse, not always successfully. I also recognize the styles and habits of writers whose words I proofread and edit. Avid readers recognize the style of their favorite author even when the byline is different. And everyone knows when someone close to them is drunk when they are texting. Language is something we all learn as children, but the way we use it eventually gains its own personal stamp.

Men sort themselves within status hierarchies. Some people might assume that men at the top of these hierarchies are more likely to have more sexual partners. Although this assumption might be true for other fields, heavy metal guitar playing is not one of them.

A psychological study published in Evolutionary Behavioral Sciences found that male metal guitarists who spent more time practicing generally had a greater desire for casual sex than those who spent less time practicing. But, PsyPost reports they were not more successful than lower-skilled players at achieving those sexual goals. The researchers hope to expand the study in the future to include professional heavy metal guitarists.

-via Marginal Revolution | Photo: Rob Faulkner

We previously wrote about the case of Randy Gardner and his attempt at breaking the world record for longest time without sleep, at the time, which was held by a Honolulu DJ who hadn't slept for 260 hours straight. This year marks the 60th anniversary of Gardner's record.

Years ago, he revealed something interesting after achieving all that. In 2017, he shared with NPR how he developed insomnia as an adult ten years before. It hasn't been confirmed whether he still suffers from it today, but he did quip that it must have been some kind of "karmic payback" for what he put himself through 60 years prior.

For all it's worth, Gardner did think about quitting midway through or, at least, he hinted at it in the video above, but since he and his friends had already garnered so much attention from media, he just resolved to power through the whole experiment and broke the record with 264 hours of no sleep.

Furthermore, the record was actually broken in the same year that Gardner achieved his, but Gardner's experiment has been the most well-documented case of it. The last time that a Guinness world record was awarded for sleep deprivation was in 1986, and afterward, in 1997, the GWR stopped as it posed a risk on those who attempted to break the record.

(Video credit: Guinness World Records/Youtube)

Dark matter has been a tricky subject to broach over the past few decades, and according to the video above, some have taken to calling it "bunk science", but Sabine Hossenfelder does clarify that the original idea for dark matter was decent in order to explain the huge amount of data being detected that couldn't be explained by anything else at the time.

However, as technology improved and telescopes became more precise, the data that they gathered also increased in precision, and when juxtaposed with the theory of dark matter, it just didn't fit. So proponents of dark matter tried to make the theory fit the data but that reduced its explanatory power.

Now, there are two competing models of cosmology, dark matter and modified gravity. And although there are cases in which one model is preferred over the other, modified gravity seems to fit the data better and dark matter has become too complicated that it makes it difficult to get at a good conclusion with it.

In any case, the video above is a fun watch. It gives an overview of the theory of dark matter, and explores the progress of the theory over the years, and why it has received more criticism in recent times.

(Video credit: Sabine Hossenfelder/Youtube)

You might have heard the expression 'listening to your body' before, as a means of determining the limits that you can reach when exerting pressure or effort with respect to your physical capacity.

We sometimes go beyond our physical limits in the hopes of achieving a goal as quickly as we possibly can, or simply because we think that we can produce more results by exerting more effort, much like the adage 'no pain, no gain'. At times, we tend to ignore, for example, hunger and the signals that our body sends because we want to discipline ourselves in order to achieve our fitness goals.

But there is now a growing interest in what these signals actually mean, and how they work in the context of brain-body integration. Scientists and researchers have now placed quite a considerable amount of attention to this dynamic, which is called interoception, defined as the process of sensing internal bodily signals that give us an idea of our current physical and mental state or condition.

In The Conversation's weekly podcast above, Gemma Ware, executive producer for the show, interviewed neuroscientist Sarah Garfinkel from the Institute of Cognitive Neuroscience at the University College London to learn more about interoception and how it works, and how we can use the knowledge of it to better take care of ourselves, both physically and mentally.

For example, Garfinkel's focus in her work is helping people with autism, particularly in regulating anxiety. People on the spectrum generally have difficulty in identifying sensations of hunger, satiety, and anxiety, so they are unable to course-correct before it becomes unbearable.

With interoceptive training, people with autism were able to become more attuned to their internal bodily signals so that they can respond with the proper course of action to prevent their anxiety from getting worse, among other things.

One particular exercise you can do to check whether you are in tune with your body's internal signals is to count the number of heartbeats you make without any physical contact, similar to the one done in the podcast. Using an oximeter, you can check how you fared, and that will give you an idea of how interoceptive you are.

There are sensations that our body gives off and sometimes we don't understand why we're feeling such or from where they're originating, but being aware of them is one path toward maintaining our health, physically and mentally.

The quote mentioned at the beginning of the podcast, I think, perfectly summarizes the point of interoception, and it was by René Leriche, "Health is life lived in the silence of the organs."

(Video credit: The Conversation/Youtube)

Without many people noticing, the US has effectively gained more land over the course of the holidays, equivalent to the size of about an Egypt or two Californias. That's because the State Department announced on December 19, 2023, that they have defined the area of America's extended continental shelf (ECS). With it, the US added approximately 1 million sq. km. (roughly 386,000 sq. mi.) of seabed and subsoil.

Just to make things clear, the ECS is different from a country's territorial waters and exclusive economic zone (EEZ). Territorial waters are defined as the portion of the waters that extend out to 12 nautical miles from a country's shoreline, on which a country has full sovereignty.

A country's EEZ means that they have economic jurisdiction over that part of the water, and thus they have the sole right to harvest, harness, or make use of the natural resources within that area. Meanwhile, the ECS only refers to the land mass under the water, and not any resources above it which is under the term EEZ.

The US ECS, as defined, currently consists of seven distinct maritime areas. As you can imagine, being bordered on different sides by at least three different bodies of water, there's much underwater ground that the US covers.

So, there's the Arctic ECS, the Atlantic ECS, the Pacific ECS, two different patches on the Gulf of Mexico, the Bering ECS, and the Mariana ECS. This is considered the largest addition to US land since the 1867 Alaska Purchase.

(Image credit: US State Department)