Lasers, aliens and ancient pyramids are more involved in preserving our culture than you'd think.

As far as we know, we're the only animals that stash stuff just for the sake of nostalgia (then again, maybe that's why squirrels "forget" to dig up their acorns sometimes). Just about everybody keeps around old toys, letters and other knick-knacks to remember their pasts.

As a society, we sometimes stash things away in time capsules for tens, hundreds or even thousands of years so future generations will remember us (and be impressed by our amazing predictions about the future). These endeavors can get pretty interesting. For instance ...

The Apollo 11 capsule

The "supermoon," as seen from Jerusalem. (Photo: ChameleonsEye/Shutterstock)

This famous time capsule is currently on the moon. Yes, the moon, that mysterious, ethereal orb that was beyond our reach until we got there and walked on it and took soil samples and stuff (we'll probably turn it into a theme park in a few decades). Seventy-three country leaders around the world left statements on a quarter-sized silicon disk in 1969, which the Apollo 11 astronauts left on the moon. The plaque on it read, "We came in peace for all mankind."

The disc also contained the names of a bunch of U.S. government officials and NASA managers, which seems a bit random (why would future people and/or aliens care that the late Dr. T. Keith Glennan was NASA's deputy administrator?) but makes sense if you assume that everyone wants to be remembered forever, and some of those people are in charge of time capsules.

Beautiful Knowledge capsule



"Beauty is truth, truth beauty, – that is all. Ye know on earth, and all ye need to know," wrote 19th-century English poet John Keats. Whether or not you think this Romantic Era poet was being overly romantic (knowing truth and beauty is great, but knowing how to make breakfast also seems useful), this exhibit proves he was right about something: knowledge is beautiful. Especially when you mix it with a bunch of cool lights and digital art.

This art exhibit, which was hosted by Israel's Polonsky Academy of the Van Leer Jerusalem Institute this June, was a multimedia bonanza based on decades of scientific research that celebrated the 60th anniversary of the Fulbright program. The showing featured exhibits like scientific articles represented as stars in a digital installation. It also included a time capsule that contained predictions about the future of human knowledge; it'll be opened on the Fulbright's 100th anniversary in 2056.

Yahoo capsule

https://www.youtube.com/watch?v=MaI2WnYGlGQ

You thought we were finished with space capsules, but we're just beginning. Yahoo collected 170,857 digital recordings from people around the world (largely twentysomethings) and put them in a capsule so future people will know what digital life was like for 20-year-olds back in good ol' 2006.

The original plan for this capsule was literally out of this world: they were going to use lasers to beam it into space from a Mexican pyramid so extraterrestrials could find it (for real!). The plan ran into problems when Mexican authorities said they didn't want to shoot lasers from their Pyramid of the Sun, because damaging one of their favorite ancient sites wasn't, like, a great deal for them. So Yahoo gave it to the Smithsonian Folkways Recordings in D.C., where it'll remain until 2020. It might be for the best; we're probably a lot more interested in our old Facebook photos than aliens would be.

Miguel de Cervantes capsule

Windmills still fear Don Quixote. (Photo: BestPhotoStudio/Shutterstock)

In 2009, the city of Madrid unearthed a time capsule that had been buried under a statue of Miguel de Cervantes, the famous author who wrote "Don Quixote." Workers found a calendar, travel guides, a manuscript and no less than five 1819 copies of "Don Quixote" (which Einstein read in his book club). Because that's what you want if you're discovering 19th-century Spanish culture – five copies of the same book.

Madrid must have liked the finding, because it decided to plant another capsule under the same statue so future civilizations could read "Don Quixote" five times in a row.

Burbank capsule



An anonymous photographer took this photo of 1950s Burbank, Calif., and stashed it in the capsule. (Photo: Burbank)

This silver-plated 1959 capsule was buried inside the Magnolia Boulevard Bridge located in Burbank, Calif., during the bridge dedication ceremony where it was ... totally forgotten. Luckily, a historian happened across an old article about the capsule in 2009. Workers removed the bridge's city dedication plaque and found the capsule inside, which is probably about as close to finding buried treasure as anyone gets these days. They found 47 photos of the city and predictions about the future, including a prediction that people would be making "short-haul" flights using "vertical take-off" crafts. Still waiting on those. But they sound awesome.

One Burbank resident, Stan Lynch, was there for the original 1959 bridge dedication ceremony. He walked half a mile to the ceremony because bridges are incredible. Just kidding; he went because, as Lynch explained, "there wasn't a lot to do back in 1959."

Helium Centennial capsule



If you happen to drive through Pittsburgh, you might notice a weird-looking monument by the Don Harrington Discovery Center. This structure, which was built in 1968 to commemorate the discovery of helium, contains four time capsules.

Interestingly enough, the capsule's creators stored a passbook for a savings account in one capsule. They put $10 in it originally, and it's been collecting 4 percent interest a year, so in 1,000 years, it'll be worth over a quadrillion dollars (that's not an exaggeration; it'll actually be worth around $1,000,000,000,000,000). At least, assuming our government and economy don't change substantially over the next 1,000 years. Personally, I'm not sure the ancestors of a Chinese person who put away some ancient Jiaozi money around 1000 A.D. are reaping a whole lot of yuan at the moment. Not that I've asked.