Where Do Deleted Files Go?

Hey, Vsauce. Michael here. But now I'm not. I'm gone like 90% of the original silent films ever made. Six of the seven wonders of the ancient world deleted, like that text you thought twice about sending or a Snapchat photo, right? When Stalin decided that Trotsky was an enemy of the state, he had Trotsky removed from photos he appeared in with Lenin. Plenty of software tools and professional services allow you to do the same. Don't just forget the actual attendees of a moment in time, delete them.

But where do things go when they're deleted? The Google Ngram Viewer allows you to search words and phrases in 5.2 million books published between 1500 and 2008. It's a great way to see how the words we use have changed over time. 1979 was a significant year. According to the Ngram Viewer, it was the first year we began to use the word "delete" more often than the word "erase." Biological deletion still wins though. Forget is by far more pervasive in our communication, but how does a computer forget?

Moving a file to the trash is just the beginning. To protect against accidental deletion, when thrown in the trash, a file remains on your computer in a temporary directory, a sort of purgatory, where it awaits a more ultimate deletion but can be resurrected if you wish. When you empty the trash, you are warned that you cannot undo the action. But when you empty the trash, the physical space inhabited by the file isn't actually emptied. It's marked as empty, available if and when new data needs to be stored somewhere.

The file's home has become available real estate, but the file itself hasn't moved out. Only the pointers have gone away. Pointers are another type of data on your drive that point to places in memory where the actual file they are referencing can be found. They're a bit like the table of contents, which means that on most operating systems, deleting a file and emptying the trash is like deleting a chapter from a book by turning to the table of contents and marking the chapter as empty. There's nothing here; do what you want with the pages.

To a computer reading the table of contents, it looks like the space is empty, but of course, that doesn't change the fact that the contents of the chapter are still there. Special data recovery tools look through memory marked empty available to see what's actually there. If you're lucky, they can even find a file and save it, bring it back, mark it not available, undeleted. But if some of the file has already been overwritten, there can be problems. The file can be corrupted, melded together with other data like some kind of digital Frankenstein's monster.

A couple of years ago, a laptop that belonged to photographer Melanie Willhide was stolen. It contained many of her recent digital photos. Luckily, police were able to return the laptop to her. They found it in a car they pulled over, but the thief had wiped the laptop's hard drive clean and had been using it for his own purposes. Data recovery experts were able to find some of her files, still there, on the now-empty space, but the files had been slightly overwritten by things the thief had done. They'd been corrupted but in a really cool way. So cool Willhide decided to exhibit the work. She titled the show after the thief who made it possible, "To Adrian Rodriguez, with love."

If you want to delete the file so completely it can't even be recovered in a cool, weird way, like Willhide's photos, you will need to overwrite the unwanted file completely. Deny the file a proper burial and rearrange its corpse with new data. One overwrite should be fine, but some people do as many as 35. Even 35 overwrites might not be enough. Sure, the overridden data is hidden, but what about bad sectors? These are parts of a drive that devices can't access because of failed transistors or physical damage. An overwrite won't be able to reach them, meaning any data that was ever put there stays there.

So, if you are the United States Department of Defense and you don't want to take any risks, you will also shred, physically polarize unwanted drives. The US, Europe, and Japan often send such electronics waste to dumps in Ghana, like this one. This city in Ghana is known as Earth's digital dumping ground. Why Ghana? Well, it is cheaper to send unsalvageable electronics to Africa, marked as a donation, than it is to properly recycle them. But there, in these electronic dumps, the files can still be brought back to life.

Organized criminals operating in Ghana have managed to successfully recover data from unregulated e-dumps. They've been able to find confidential multi-million-dollar agreements, involving the Defense Intelligence Agency, Homeland Security, and the TSA. Shredding paper to get rid of whatever used to be on the paper isn't even safe either. It's not easy and it doesn't always work. But by scanning shreds of paper, computer software can match the pieces together. But in the past, shredded documents have been unshredded by hand.

In 1979, Iranian students seized the US Embassy in Tehran. With the help of local carpet weavers and years of hard work, they managed to reassemble thousands of pages of confidential documents shredded by the CIA. The smaller the shredded particles are and the more of them there are, the more difficult the task. So, the Department of Defense requires that the majority of shredded particles not exceed 5 square millimeters. If you really want to delete something, destroy it, erase it, time is on your side.

In about 5.4 billion years, the Sun will become the ultimate shredder. A red giant large enough to swallow Earth whole. Everything will be fine for billions of years. But many accepted models of the universe predict that in 10 to the 100 years, whatever intelligence is left will witness the universe's dark era and its final Heat Death, the end of the universe, the end of any file or photo or memory of you ever being accessed again. Every time something happens, a little bit of energy is lost. For instance, friction through sound or heat. That energy goes out into the universe a little bit at a time, slowly more and more.

Eventually, in a closed system, energy becomes homogeneous, evenly distributed, the same everywhere. There's no gradient, maximum entropy. In a little glass of ice water, it's pretty quotidian, but given enough time, our entire universe may be no different. A gradient, a difference in energy from one place to another is necessary for things to happen, for files to be created and read, for life to exist. And in 10 to the 100 years, there may not be any usable energy left.

In Isaac Asimov's short story "The Last Question," humans are concerned about this. As the story leapfrogs billions of years into the future, their list of solutions doesn't get any longer than none. So, if we think across a grand timescale, is cosmic deletion the freezing of everything, heat death, all we have to look forward to in this universe? We went to the Moon. We brought flags with us that we planted on the Moon, representing a place on Earth. But those American flags on the Moon are likely erased now, their symbols and colors bleached by the intense radiation of the Sun on the lunar surface, unfiltered by any atmosphere.

The flags are still there; we didn't take them back with us, but now they are empty. White flags. White flags representing our surrender to the inevitability of deletion in the universe. But we, today, are preoccupied with just the opposite. What really saturates our language, what we really seem to talk about is creation. Things happening, not loss. Compared to erase, forget, and delete, "make" practically deletes deletion. The flags on the Moon are bleached out, but is that bleak? Are they deleted or blank, like a fresh sheet of paper ready for new stories?

Really, it just depends on what you make of it. So thanks for making things. And as always, thanks for watching.