A common theme of apocalyptic movies is a small set of survivors trying to build thriving communities after a worldwide disaster. But how small could that number of survivors really be in order to repopulate the earth? Scientists, as well as scriptwriters, have been studying the issue.

The short answer is, it depends. Different catastrophes would create different doomsday conditions for surviving human populations to endure. For example, a nuclear war could trigger a nuclear winter, with survivors facing freezing summer temperatures and global famine, not to mention radiation exposure. However, putting some of these conditions aside and focusing on population size, the minimum number is likely very small compared with the approximately 7.8 billion people alive today.

"With populations in the low hundreds, you can probably survive for many centuries. And many small populations of that kind have survived for centuries and perhaps millennia," Cameron Smith, an adjunct assistant professor in the Department of Anthropology at Portland State University in Oregon, told Live Science.

An article at LiveScience looks at the numbers, by looking to the past and how small populations worked in prehistory, and by looking to the future when people may travel to other planets. -via Damn Interesting

Brian David Gilbert and Karen Han like to watch birds, and they've wrote a nice little song about it. How wholesome! If you think that's all this is, you are in for a shock. From Gilbert's Tweet introducing it:

we like watching birds!
enjoy our normal video about the normal birds that we like watching (normally)!

 -via Laughing Squid

Are you considering a road trip to celebrate your vaccine status and re-enter the world of travel? Star Wars fans now have a valid argument for visiting the Udvar-Hazy Center in Chantilly, Virginia, which is an extension of the Smithsonian Institution. The Smithsonian has acquired Luke Skywalker's X-Wing fighter!

The famous but fictional spacecraft of the blockbuster Star Wars film franchise is on long-term loan to the Smithsonian from Lucasfilm Ltd. Fans can now watch while the X-Wing undergoes conservation at the Restoration Hangar alongside World War II aircraft and other historic airplanes and space vehicles. Late next year, the famed film prop will go on display outside the Albert Einstein Planetarium at the Smithsonian’s National Air and Space Museum on the National Mall in Washington, D.C.

“We are thrilled to have an X-Wing on exhibit,” says Margaret Weitekamp, space history chair at the museum. “It is a real screen-used vehicle from the 2019 film Rise of Skywalker. This display speaks to that crossover connection between people who are excited about space flight and have been inspired by the visions Star Wars has been putting out since 1977.”

Read about this particular model of X-Wing and what the Smithsonian is doing with it at Smithsonian magazine.

(Image credit: Jim Preston, NASM)

This remix by the YouTuber known as There I Ruined It (previously) combined Sir Mix-A-Lot with Leonard Bernstein to produce this mess. It's not the first time that "Baby Got Back" has been given the classical treatment, far from it, but the world has room for one more such project. -via reddit

Cat owners know that they are the perfect pet, except for climbing the curtains, skewing the upholstery, waking you up early, and knocking everything into the floor from any elevated surface they can reach. Why do they do that? Are they jealous of any possessions their human might like? Are they doing it to piss us off? Or is it to exert dominance over their environment? The answer is simpler than any of that.

It shouldn’t surprise you to learn that cats knock stuff over because it’s fun. That’s it—that’s the whole explanation. If you want to stop it, you need to know why this particular hobby is so enjoyable so you can give your cats better, less destructive outlets for that energy.

An article at Lifehacker goes on to explain in detail why cats find it fun to knock your stuff to the floor, and more importantly, what you can do to stop this madness.  -Thanks, WTM!

Believe it or not, the song "Stairway to Heaven" is 50 years old. Led Zeppelin first played it in public in March of 1971, and the recording was released on their fourth album in November of that year. The song quickly became a prog-rock favorite but eventually was overplayed. As it was discovered by succeeding generations, that cycle continued over and over again for 50 years -so far. You could say that "Stairway" has everything -a ballad at one end and a rocking climax at the other, the hipness of a permanent album cut, a killer guitar solo, and lyrics that were just confusing enough to act as a Rorschach test: everyone interpreted them in their own way.

What if the lyrics to “Stairway” are so strange and convoluted because they’re actually meant to be played backwards? That was the theory of televangelist Paul Crouch, who decided in 1982 that the verse beginning around 4:19 (“If there’s a bustle …") offers a satanic message when played in reverse. This, according to Crouch, is the hidden message: “Here’s to my sweet Satan/The one whose little path would make me sad, whose power is Satan/He will give those with him 666/There was a little tool shed where he made us suffer, sad Satan.” In the book Hammer of the Gods, one of Zeppelin’s recording engineers offers this rebuttal: “Why would they want to spend so much studio time doing something so dumb?”

That's just one of 11 facts about "Stairway to Heaven" that you can read at Mental Floss. The last one makes it all worthwhile.  

This is exactly what it looks like. A raccoon in Toronto tore a hole in a roof and tried to enter the attic, where he no doubt thought he'd live the best week of his raccoon life. But his butt was too big for the hole. Yeah, he got stuck, rear end up.



The raccoon was there long enough for the homeowner to notice and call a pest control company. Liddle Rascals Wildlife Control Inc. responded and saw that this was a great opportunity for a video. The guy extracted the raccoon in one piece; the roof wasn't so lucky.  -via Digg

Pamela and Sam Coffey had quite an adventure last week. They found something unusual while cleaning up their yard, a metal object with Japanese lettering engraved on it. She posted the story to Facebook.

Some of our yard is still somewhat unexplored due to overgrowth and part of it just being really steep. We've been cleaning it all up and have been finding some really odd things. This was today's find. Sam Coffey wanted to start cleaning the dirt out with sharp objects... on the off chance it's a real mortar shell, he let it be. Can anybody tell me more about this thing? Or who could?

Update: Bomb and arson squad just arrived and confirmed it to be a WW2 Japanese Navy mortar. There's a bomb robot on its way to retrieve it. Never a dull moment.

Never a dull moment, indeed. Experts determined that the World War II-era bomb was still live and could detonate at any moment! Read the rest of the story at NBC. -via TYWKIWDBI

(Image credit: Pamela Coffey)

In developing language, regular people use words for things that we can recognize and agree on, like what a “tree” is. Then scientists got involved and tried to identify and categorize every species of tree. And once genes began to be studied, scientists realized that trees are not all related to each other at any level, and maybe even our definition of what a tree is cannot be trusted.  

“Trees” are not a coherent phylogenetic category. On the evolutionary tree of plants, trees are regularly interspersed with things that are absolutely, 100% not trees. This means that, for instance, either:

The common ancestor of a maple and a mulberry tree was not a tree.
The common ancestor of a stinging nettle and a strawberry plant was a tree.
And this is true for most trees or non-trees that you can think of.

I thought I had a pretty good guess at this, but the situation is far worse than I could have imagined.

So, what is a tree? You might say it’s a plant made of wood, but our definition of wood is pretty muddy, too. It turns out that an awful lot of non-woody plants have genes to make wood, and could be trees if conditions are right. And it gets weirder from there. Read how nature keeps making trees out of other plants, and vice versa, at Eukaryote Writes Blog. -via Metafilter

Japan has a mascot for every product, agency, sports team, town, company, and public service campaign. The cute costumed characters draw attention and engender fan clubs, as each mascot has their own backstory and personality. Over the past year, a new masked superhero has joined their ranks- a pink cat called Koronon, who promotes health measures to fight COVID-19. Koronon walks the Ikebukuro and Shinjuku districts of Tokyo, handing out face masks and reminding people to keep a social distance.

The soft creatures can also be a balm. “Mascots help take the edge off when grim and serious matters are being discussed,” says Carlier. Kaila Imada, an editor at Time Out Tokyo who has previously reported on mascots, echoes that sentiment. “I think part of it is about bringing a bit of joy,” Imada says. Taizo Hayashi, designer and manager of Koronon (and Al-pha Co., an event promotion company), says he hopes the mascot helps make “the world peaceful” by providing a bit of light-heartedness against a backdrop of tough times.

While Koronon (whose name loosely translates to “no corona”), appears to be the only mascot created in response to the coronavirus in Japan, it isn’t alone in its fight against the pandemic. Throughout the country, mascots have been repurposed to educate the public on issues surrounding the virus.

Read more about Koronon and how other mascots are dealing with the pandemic at Atlas Obscura.

BBC Earth has compiled clips of various bird species from their shows into one video showcasing extreme bird behavior, including fishing with bait, adoption, and cooperation with other species. It's 15 minutes long, but you can watch it in parts, because there are a lot of birds here, all interesting. -via Laughing Squid

Modern drivers are very much used to going 100 km/h (62 mph), although we do it on paved highways in enclosed vehicles with windshields. None of those things were in play when Camille Jenatzy broke the land speed record in an automobile in April of 1899. Jenatzy drove an electric car he designed himself, called Le Jamais Contente (The Never Satisfied) that resembled nothing so much as a torpedo.

When asked to describe the feeling of traveling faster than anybody had ever done before on a road vehicle, Jenatzy said: “The car in which you travel seems to leave the ground and hurl itself forward like a projectile ricocheting along the ground. As for the driver, the muscles of his body and neck become rigid in resisting the pressure of the air; his gaze is steadfastly fixed about two hundred yards ahead; his senses are on the alert.”

Jenatzy reached the speed of 105.88 km/h (65.792 mph) that day, a record which stood for three years. Read the story of that vehicle at Amusing Planet.

To enjoy a science fiction action film, one must always approach the story with a certain suspension of disbelief. Filmmakers, and storytellers in general, take certain liberties to keep the plot rolling, and even more so for a series of films spanning four decades and an entire  fictional galaxy. Overanalyzing the minutia of the Star Wars universe has become a cottage industry, but some questions are better left without a thorough explanation. For example, how does the Force work?

In the original movie, Obi-Wan gives one simple, succinct explanation of the Force: It gives a Jedi power because "it surrounds us, penetrates us, binds the galaxy together." Otherwise, the old General opted to show, not tell, what the Force could do (bamboozle Stormtroopers, mostly). Yoda did much the same in Empire Strikes Back, moving rocks and adding a touch of spiritual poetry: "luminous beings are we, not this crude matter."

Then came The Phantom Menace, where Lucas unveiled the concept of midichlorians — tiny cellular creatures that are present in large quantities in the blood of the Force-sensitive. Fans feared that a deeply spiritual concept was now being given a biological explanation. Lucasfilm tried to explain that midichlorians are markers of the Force, not the cause of it, but the damage was done. (Lucas never cared about the backlash, and his plans for the sequel trilogy, shelved by Disney after he sold the company, delved even deeper into the microbial world.)

Midichlorians were completely absent from the later films, and rightly so. Mashable explores seven mysteries of the Star Wars universe and why they don’t need to be explained.

We know that the Wright Brothers are credited with the first flying machine, actually the first successful, manned, powered, heavier-than-air flying machine. You might not know that there were dozens of engineers and inventors working on the problem of powered flight in the years leading up to Wilbur and Orville’s breakthrough in 1903. You probably have not heard of the Aerodrome, a flying machine that made a spectacular flight in 1896, although with no pilot aboard.  

History would be made that day, May 6, 1896, as this apparatus—a flying machine, known as Aerodrome No. 5—was started and then launched from a spring-loaded catapult. The Aerodrome would take off and travel for 90 seconds some 3,300 feet in an effortless spiral trajectory and then gently land in the river.

The third Secretary of the Smithsonian Institution, Samuel Pierpont Langley, an astronomer who also enjoyed tinkering with his own creations, was aboard the boat. His winged invention had just made the world’s first successful flight of an unpiloted, engine-driven, heavier-than-air craft of substantial size.

This experiment led to a manned flight of Langley’s followup aircraft called the Great Aerodrome, which had a pilot, in October of 1903. Because you know the Wright Brothers and not Langley, you can infer that it was not successful. Read the story of Langley’s flying machines at Smithsonian.

In the evening of Christmas 1895, two friends got into an arguments at a saloon in St. Louis. It ended when Lee Sheldon shot and killed William Lyons. It was reported in a newspaper that Lyon had taken Sheldon's hat and would not give it back. Alcohol was involved.  

There were four other murders that Christmas night in St Louis, but this was the one that counted. Work songs, field chants and folktales describing how Lee 'Stack Lee' Shelton killed Billy Lyons started to spring up almost immediately. The earliest written lyrics we have date back to 1903, and the first discs to 1923. There have been well over 200 versions of Stack's story released on record since then, giving him a list of biographers which includes some of the biggest names in popular music. Duke Ellington, Fats Domino, Jerry Lee Lewis and James Brown have all recorded the song at one time or another, as have Wilson Pickett, The Clash, Bob Dylan, Dr John and Nick Cave. Even Elvis Presley had a stab at it in a 1970 rehearsal session which later surfaced as a bootleg CD.

The new century's seen other media join in too. In 2006, Derek McCulloch and Shepherd Hendrix published a fat graphic novel telling Stagger Lee's story in careful detail. Movie versions have come from Samuel L Jackson, who gives a storming live rendition of the song in 2007's Black Snake Moan, and Eric Bibb, who uses it to comment on the action unfolding around his character in the following year's Honeydripper.

Songs about Stagger Lee varied widely in their details over the past century, so what was the real story? Paul Slade did a deep dive into the story of Lee Sheldon, first setting the stage in late 19th-century St. Louis and then following what is known of the crime and what  might be inferred. He also looks into the evolution of the song-story and what different versions meant for their time. -via Strange Company