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 overtime.

1979 was a significant

year. According to the Ngram Viewer, it was the first year we begin 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 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, 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 unshred

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

shred 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 millimetres.

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 day 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.