1. (and not the pacman kind…)
Ghosts in the Machine
(and not the pacman kind…)

3. The Computer Knows More…

4. The Modern Equivalent?

5. Digital Information is Not Analog Information
When things are converted to digital, they are converted to bits and bits behave differently than real-world things
Take the redacted text
Highlighting the text does not remove it
It makes it harder to see visually, just like in the olden days
But unlike the olden days, digital highlighting is easy to remove and the text is still there, perfectly…

6. Switching to Digital – What is Gained?
It is easier to search digital information
It is easier to store digital information
It is easier to send digital information

7. Switching to Digital – What is Lost?
Bits cannot perfectly encode real-world information
For example, if you record a symphony, small nuances of the music are lost

8. Data Leaks
The pervasive storage of data means that it can be easily stolen
It also means that features we use can haunt us
Criminals can be convicted based on texts or instant messages they send
Leaving Microsoft Word’s Track Changes features on can completely shatter your hopes of suing someone
Sensitive data about your CIA agents (like their name) can be extracted because you just highlighted over them rather than erasing the name

9. Bit Models Bits model reality enough to fool the eye…
But if you were to take apart the hard drive and peel away the abstractions, the bits do not resemble what they represent
Analog is a better representation of reality
In the old days, voices were carried over telephone wires and the electricity on the wire accurately represented the voice inflection of the speaker
Now, its just bits, we can send voice information faster, but its not entirely accurate

10. Metadata
Files often include metadata which is just information about the file itself like
How big it is
When it was created
When it was last modified
Which part of the file contains which piece of information

11. Just Binary But Many Things
The same string of 8 bits can be many things:
Text
Audio
Images
Formatting Information in Word
One way that computers (at least windows computers) know what the bits are is through file extensions
This method has the drawback of the document becoming nonsense if you change the extension

12. Changing Reality Bits can be easily altered
Time and date stamps can be changed, authorship information can be modified
Photos can be changed or created from nothing
Evidence can be forged
Child pornography can be created
There are methods that can be used to establish that a photo has not been changed, but they are subject to the limitations of all other digital things

13. Pictures = Pixels So what are digital pictures really…
Remember RGB?
Each picture is divided up into tiny, tiny squares known as a pixel and each pixel has a RGB value
When you take a picture with you camera, the camera has thousands of tiny receptors that interpret the light hitting your camera
That receptor converts the light into an RGB value and a pixel is born
Note: the receptors in modern cameras sometimes generate more than one pixel per receptor