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 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.