In the Douglas Adams story The Hitchhiker's Guide to the Galaxy, a supercomputer named Deep Thought is programmed to determine the answer to the ultimate question of life, the universe, and everything. The computer works on this problem for 7.5 million years and finally spits out the answer: 42. But after all that time, no one could remember the question.

However, in the 45 years since Adams told us about the amazing computer feat, we may have figured out the question. The problem is that there are several, five in fact, fundamental questions about the universe in which the answer is indeed 42. Two are mathematical, two are astronomical, and one has to do with physics. Which one was Deep Thought deep in thought about? We may never know, but we have some good contenders. Each of the five questions are explained in detail at Big Think. -via Real Clear Science

(Image credit: Ben Gibson/Big Think)

It wasn't easy being a beekeeper in the medieval Europe, but the honey that bees produced was exceptionally expensive and worth the effort. Instead of beehives with removable frames, bees were kept in woven baskets called skeps. Harvesting the honey meant scooping everything out of the skep, which destroyed the colony. So skeps were small, which encouraged the bees to swarm, looking for a new home when their numbers outgrew the skep. When that happened, beekeepers had to be ready to gather them up and lodge them in a new skep. That process involved throwing dust on the bees, banging metal objects together (called tanging), and reciting magical incantations. These were called swarm charms.

That's a lot of work to reproduce a hive, but it worked more often than not. Beekeepers were loathe to experiment to determine what part of that process actually did the job, as they didn't want to risk failure. Modern beekeepers say it was probably the dust, although things are much easier now that we've learned to identify and relocate queen bees. Read about swarm charms and the difficult medieval practice of beekeeping at Atlas Obscura.

The Sydney Opera House was officially opened on October 20, 1973. Every step to getting the building completed was fraught with controversy. Danish architect Jørn Utzon's design was rescued from the rejection bin and eventually became his greatest work, leading to a Pritzker Architecture Prize in 2003. Yet fights with Sydney authorities led him to quit the project before it was completed. The initial reaction from the public was mixed, with some calling it breathtakingly beautiful while others dubbed it ridiculous and referred to it as a dish rack. In the years since, it has become a beloved landmark and a UNESCO World Heritage Site. The Sydney Opera House hosts more than 1500 performances for more than a million people every year.   

To celebrate the Sydney Opera House's 50th anniversary, they posted a music video with a song written and performed by Tim Minchin called "Play It Safe." The video features a long list of those who have performed at the opera house (listed at the YouTube page). The lyrics belie the venue's actual mission to bravely stretch the limits of creativity by taking risks and to expand the very idea of art and performance. -via Metafilter

In 1984, Wes Craven launched the career of Freddy Krueger, the most terrifying movie monster ever, in the film A Nightmare on Elm Street. The reason he was so scary is that he invaded a victim's dreams while they were sleeping, when they were most vulnerable and unable to fight back. But the people Krueger killed in their dreams were also dead in real life. A brilliant idea for a horror film, yet it was inspired by real life events.

In the late 1970s and the '80s, a mysterious series of deaths occurred among young, healthy people in their sleep. All but one of the 117 documented victims were men, and the vast majority were Hmong refugees from Laos. They had no underlying illness, and their autopsies revealed no cause of death. The syndrome was named SUNDS for "sudden, unexpected, nocturnal death." The victims had horrific experiences during the Vietnam War, but why did they suddenly die years later, in a land where they were safe? Read about SUNDS, what we've learned about it in the years since, and how the epidemic inspired Wes Craven to create Freddy Krueger, at Mental Floss.

The athletic store Distance in Paris has a strange promotion in the run-up to the Olympics next summer. In the "Rob It To Get It" campaign, they say go ahead and shoplift from them- you can keep the merchandise if you can outrun the store's security guard. The twist is that the security guard is French Olympic sprinter Méba-Mickaël Zézé. In this compilation video, he caught 74 would-be thieves, while two people got away.

The stunt makes Zézé look really good. But what does it say about theft? If it wasn't completely staged, this had to be a low-key, limited time offer. There doesn't seem to be any consequences for attempted theft, and probably was pretty hard on Zézé while it lasted. Besides, they will never see those two potential champion runners again, unless they try again. Also, any American will unlock the secret to this stunt in about ten seconds. All you need is more than one thief making a break for it at the same time, running in different directions. -via Digg

There is an unnamed grocery store in rural Norway, near the border with Sweden, that apears to be haunted. For years, employees have experienced unexplained phenomena such as electrical malfunctions, shadowy figures, and broken flower pots. People who worked there questioned their own sanity, but eventually customers started noticing things, too. When a customer was hit with a flying potato, the news got out and paranormal investigators descended. So far there is no explanation for the eerie happenings. Well, no logical explanation, anyway- three ghosts have been identified.

Lars Birger Davan came to the store by accident and learned of its history. He is a doctoral candidate in sociology at Oslo Metropolitan University, and began to study the store. No, not the ghosts' mischief, but the employees' response to it. It turns out that experiencing paranormal activity can be very isolating, because people are afraid others will think them crazy. It's actually a relief to know that other people are observing the same things. Read about the haunted grocery and the people who must deal with it at Atlas Obscura.  

(Image credit: Lars Birger Davan)

Why did we ever think that robots had to resemble humans? Because that's what the science fiction novels told us. True, the earliest idea of a robot was a machine to replace a person and do a person's work. But as we came up with more and more uses for a robot, our ideas changed. Soft, flexible robots are more useful for getting around in uneven terrain, and tiny robots can go places and do things humans could never do.

The ultimate soft, flexible robot would be a liquid, right? Interesting Engineering introduces us to one. This robot is semi-liquid, made of polymers, borax, and alcohol, and embedded with neodymium particles throughout so it can be controlled by magnets. The slime is a non-Newtonian fluid that can become solid and then liquid again depending on conditions. It can squeeze through the tightest cracks and stretch to amazing lengths. This slime robot may have innumerable medical applications. It's not pretty, but that doesn't matter when you need it to go get that battery your toddler swallowed. -via Geeks Are Sexy

For the 49th year in a row, Nikon is recognizing outstanding microphotography (or photomicrography, if you prefer) in its Nikon Small World competition. The highest honor goes to Hassanain Qambari and Jayden Dickson of the Lion's Eye Institute in Perth, Australia, taking the image above. What you are looking at is the optic nerve of a rodent. Fluorescent dye shows the astrocytes in yellow, the contractile proteins in red, and the retinal vasculature in green. Got that? All the winning images are breathtakingly beautiful. The one that really drew my eye was the third-place image by Malgorzata Lisowska of Mazowieckie, Poland.

These are breast cancer cells at 40x magnification. The image involved brightfield lighting and image stacking, but I can't help but wonder whether there was some manipulation going on. Or is it just serendipitous pareidolia? See the top 20 images ranked with their descriptions in this gallery. Check out the honorable mentions, too. -via Digg

Some photographs are so intriguing that you see them over and over your entire life. The one above that became known as Lunch Atop A Skyscraper can give you the willies just looking at it. The picture itself was staged, but the subjects were real steelworkers building a skyscraper in 1932. The building in New York City is now known as 30 Rockefeller Plaza. In 1932, the men were lucky to have jobs at all, but their cavalier attitude as to the height they could have fallen from impressed us all.

They say a picture is worth a thousand words, but the story behind this one doesn't take all that long to read. You'll also find out about that picture of Princess Diana dancing with John Travolta, the Blue Marble, and the iconic image of Albert Einstein sticking his tongue out along with four other unforgettable photos, at Mental Floss.

Last month we had a new video from Cyriak called Honk. The new animation from Jonti Picking/Mr. Weebl is also titled Honk, but it's completely different. In this video, a trucker is tootling along in his tractor without a trailer, and he's in a really good mood. That is not allowed, so he gets pulled over by a cop. Then things get really weird. You start the video thinking that the "honk" will come from the truck's air horn, but that isn't the case at all. In fact you will find it hard to detect any honks in this story at all, despite seeing several possible honkers. Spoiler: there are extraterrestrials, but they don't come in a form we normally expect. There is also a banjo. It's not deep or thought-provoking, but it is silly and fun. What else would you expect from the guy who gave us Badgers? -via Metafilter

The 20th century saw an amazing rise in technology and innovation. It had both the first airplane and the first moon landing. We went from short, silent movie sequences to 24-hour streaming information. The list goes on, and those innovations were powered by fossil fuels, which led to the trajectory of climate change we are dealing with now. How different would our world be if we had solar power during all that time?

You might be surprised to learn that a Canadian inventor named George Cove started a business to install household solar panels in 1905. Really. His company garnered a lot of publicity about the possibilities of solar power. Then in 1909, Cove was kidnapped. The details of the incident are sketchy, but the kidnappers told Cove the price of his freedom would be for him to give up on solar power. Cove refused, and was freed anyway, but he lost all interest in promoting his business and it faded away. It would be another 40 years before anyone seriously began research into solar energy again, and even longer before it was available again to the public. What would our world be like if that kidnapping hadn't happened? Read about George Cove and the history of solar power at the Conversation.  -via Kottke

(Image credit: Popular Electricity magazine April 1910)

Last year, the Spanish band Broken Peach gave us a Halloween edition of the song "Don't You Want Me," originally by The Human League. This year, their holiday special video is Blondie's "One Way or Another." Watch them perform as a squad of skeleton cheerleaders and give the lyrics their creepiest interpretation ever!

Broken Peach has released a Halloween video every year since 2015. You can find a list of them at the YouTube page, although you will have to click "more"in the description to see it. -via Metafilter

In the video game Assassin's Creed, the Order of Assassins battle the Knights Templar. The Knights Templar were real enough, but the Order of Assassins is fictional. However, they are based on tales of the medieval Nizari Ismailis, a breakaway sect of Shiite Muslims that flourished between the 11th and 13th centuries. They were so devout in their beliefs that they were willing to kill and to die to bring the Nizari to power, and keep them there. It got to the point where any political assassination in Egypt or Syria was ascribed to the Nizaris.

The popular image of the the Nizari Ismailis in the West began with the travelogues of Marco Polo, which may have come from Sunni sources, and other wild legends that had been filtered through retellings, often with political aims. The Crusaders had plenty to say about the assassins, but those tales were greatly exaggerated and embellished. Strangely, the fictionalized version of the sect used in the game Assassin's Creed is more in line with the historical Nizari than traditional Western accounts. Read about the real Nizari Ismailis at Smithsonian. 

Tom Scott is going off on the peculiarities of the English language again. We use a lot of contractions, but there are a lot of other possible contractions that we could use, but we don't because they are weird. Oh sure, there is a logical explanation, which is what this video is all about.

The example he leads with is "Is this introduction weird? Yes, it's." Then he goes on to explain why that's weird. It sure is, because anyone who wants to use a contraction in this case would have said, "Yes, 'tis." The contraction "'tis" is old fashioned, but that has been the contraction of "it is" for quite some time. He eventually gets around to that one. Still, there are linguistic reasons we don't have words like "there'dn't've" (there would not have) but we do have words like "gonna" (going to). Tom explains them as clitics with syntactic gaps and stress patterns. Try to keep up, this is complicated.    

A cat owner will tell you that cats are perfect because they love their cats. You would expect that. But when an evolutionary biologist says it, it has a different meaning. Anjali Goswami explains that cats as a whole have perfected who they are and what they do so well that they don't need to diversify or evolve. The only real diversity in cat species is size. A lion isn't much different from a house cat or an ocelot underneath the skin. Other types of animals diversify, like bears, which range from completely herbivorous (giant pandas) to completely carnivorous (polar bears) and everything in between. Meanwhile cats hunt whatever prey animal is becoming too abundant according to their size, from deer to mice. And they do it well. 

Cats challenge standard biases in evolutionary biology. People have said to me, “What about bats? What about rodents? These groups have so many species doing all kinds of things.” And I’m like, “Yeah, because they suck.” They haven’t figured out how to do anything well, so they keep trying different things.

Goswami has plenty more to say about how cats have perfected the art of being cats at Scientific American. -via Strange Company

(Image credit: Shagil Kannur)