You've probably seen the trope in a movie. A group of kids digs up a rusty Maxwell House coffee can under a sprawling oak tree, pries open the lid, and finds a soggy Polaroid and a friendship bracelet. It’s a classic image. But if you're asking what's a time capsule in a literal sense, it is basically a deliberate attempt to communicate with people who haven't been born yet. It's a message in a bottle, but instead of tossing it into the Atlantic, you’re tossing it into the dimension of time.
People do this for all sorts of reasons. Sometimes it’s ego. Sometimes it’s a genuine fear that our culture will be wiped out and we want to leave a "how-to" guide for the survivors. Most of the time, though, it’s just a way to feel connected to a future we know we won't get to see.
Honestly, the history of these things is way weirder than you’d think. We haven't always called them time capsules. That term didn't even exist until the 1930s. Before that, they were "safe boxes" or "cornerstone deposits."
The Moment We Actually Figured Out What's a Time Capsule
Back in 1939, the Westinghouse Electric & Manufacturing Company decided to do something flashy for the New York World’s Fair. They created a bullet-shaped container made of "Cupaloy"—a copper, chromium, and silver alloy designed to resist corrosion for five thousand years. This was the first time the specific phrase "time capsule" was used.
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It was a massive PR stunt, sure, but the contents were dead serious. They packed it with a pack of Camel cigarettes, a Mickey Mouse watch, a Sears Roebuck catalog, and some microfilm. They even included a "Key to English" to help future linguists decipher our slang. Imagine some person in the year 6939 trying to figure out what a "Sears catalog" says about our religious beliefs. It’s kind of a funny thought, but it highlights the inherent problem with these projects: we have no idea what will actually be relevant to people in the future.
We tend to pack the things we’re proud of. We rarely pack the trash, the bills, or the boring stuff that actually defines a life.
The Crypt of Civilization: A Room That Won't Open Until 8113 AD
If the Westinghouse project was a hobby, the Crypt of Civilization at Oglethorpe University is an obsession. Dr. Thornwell Jacobs, who was the president of the university back in the 30s, felt like our records of ancient Egypt were too spotty. He didn't want the same thing to happen to us.
So, he built a 2,000-cubic-foot room. It’s literally a room-sized time capsule.
He didn't just throw in some newspapers. He filled it with "modern" technology from 1940, including a set of records, a device to play them, and even a small windmill to generate power just in case the future forgot how to make electricity. It’s sealed with a stainless steel door that is welded shut. According to the plaque, nobody is allowed to open it until the year 8113.
Why 8113?
Jacobs calculated that 1936 (when he started) was exactly the midpoint between the start of the Egyptian calendar and the future. It’s a bit arbitrary, but it’s a bold commitment. It makes you realize that what's a time capsule to one person is a sacred tomb to another.
Why Most Time Capsules Are Actually Total Failures
Here is the truth nobody likes to talk about: most time capsules end up as a pile of mush.
If you bury a cardboard box or a wooden chest in the ground, the earth will eat it. Groundwater is relentless. Soil acidity is a nightmare for metal. In 1957, the city of Tulsa buried a brand new Plymouth Belvedere in a concrete vault to celebrate Oklahoma’s 50th anniversary of statehood. They called it "Miss Belvedere." They thought the vault was airtight.
They were wrong.
When they dug the car up in 2007, it wasn't a shiny vintage treasure. It was a 3,000-pound lump of rust. The vault had leaked, and the car had spent decades marinating in muddy water. It looked like something pulled from the bottom of the Titanic. This happens more often than not. The International Time Capsule Society (yes, that’s a real thing based at Oglethorpe) estimates that there are thousands of "lost" capsules because people forgot where they buried them or the markers were destroyed by construction.
If you're going to make one, you can't just dig a hole. You need archival-grade materials. You need acid-free paper. You need to stay away from PVC plastics, which off-gas and destroy everything around them.
The Digital Dilemma: Can You Bury a Hard Drive?
In the modern era, the question of what's a time capsule has shifted toward the digital. People want to "bury" their Instagram feeds or their Bitcoin keys.
This is a terrible idea.
Bit rot is real. Data degradation happens faster than physical decay in many cases. If you put a USB thumb drive in a box today and open it in 50 years, there is a very high chance the drive won't work. Even if it does work, will there be a port to plug it into? Try finding a computer with a floppy disk drive today. Now imagine trying to find a USB-C port in the year 2125.
The most "permanent" way to store information is still etching it into stone or using high-quality microfilm. Even the Voyager Golden Record, currently screaming through interstellar space, is a physical phonograph record made of gold-plated copper. NASA knew that digital formats are too fragile for the long haul.
How to Actually Build a Time Capsule That Survives
If you’re planning on making one, don't just wing it. You've got to be methodical.
First, forget the ground. Burying things is the worst way to preserve them. The temperature fluctuations and moisture are brutal. The best place for a time capsule is actually a climate-controlled indoor environment. A stainless steel box in a closet is infinitely more likely to survive than a "treasure chest" under a tree.
- Use a high-quality container. Look for 304 or 316-grade stainless steel.
- Seal it with a gasket. Oxygen is the enemy; it causes oxidation and decay.
- Don't include batteries. They leak acid and will ruin everything in the box.
- Avoid food or liquids. I don't care how "sealed" that Twinkie is; don't do it.
- Include a "Letter to the Future." Context is everything. Explain why you chose these items. Without a narrative, a bunch of 2024 artifacts just looks like a pile of junk to someone in 2124.
Think about the mundane stuff. A grocery store receipt showing the price of eggs. A local map before the new highway was built. These are the things that actually fascinate historians. They don't need another newspaper with a "History in the Making" headline; they can find that in an archive. They want to know what your Tuesday afternoon felt like.
The Ethical Side of "Preserving" Our Time
There is a bit of arrogance in time capsules. We are essentially choosing what the future gets to remember about us. We curate a "best-of" version of ourselves.
Some critics argue that time capsules are just glorified littering. If the seal breaks and the contents rot, you’ve just buried a box of trash for a future construction crew to deal with. That’s why the International Time Capsule Society tries to track these things. They want to ensure that if something is buried, it’s actually retrieved.
Knute "Skip" Berger, a writer who has studied these for years, often points out that the most successful time capsules are the ones that are unintentional. The ruins of Pompeii tell us more about Roman life than any deliberate "safe box" ever could because Pompeii caught people mid-stride. It wasn't a performance.
When we build a time capsule, we are performing. We are posing for a photo that won't be developed for a century.
Actionable Steps for Your Own Project
If the idea of a time capsule still calls to you, start by narrowing your scope. Don't try to save "The World." Save your world.
- Pick a "Retrieve Date": Don't make it 1,000 years. You won't be there, and neither will anyone who cares about you. Pick 20 or 25 years. That’s long enough for the world to change, but short enough that you (or your kids) can actually enjoy the payoff.
- Use Archival Supplies: Buy acid-free envelopes for photos. Regular paper has a high acid content and will turn yellow and brittle within a few decades.
- The "Now" Factor: Include a printout of your current "Recent" photos on your phone. We take thousands of pictures but print none of them. In 30 years, those digital files might be gone, but a physical print will still be there.
- Register It: If you’re doing this for a school or a town, register the location with the International Time Capsule Society at Oglethorpe University. It sounds nerdy, but it’s the only way to make sure your capsule doesn't become "lost" history.
What's a time capsule if not a way to talk to ourselves across the years? It's an act of hope. It's the belief that someone will be there to open the box, and that they will care enough to look inside.
To make sure your project actually lasts, focus on physical stability over digital convenience. Use a stainless steel container with a silicone seal and store it in a cool, dry place above ground. Avoid putting any rubber or cheap plastics inside, as these degrade and can damage other items. Write your "message to the future" on 100% cotton paper using pigment-based ink, which is much more resistant to fading than standard ballpoint pen ink.