is a dangerous business
• If you want knowledge: bite the apple.
– Welcome to responsibility and shame.
• Make a choice
– Take charge? Study ideas?
– Leave paradise?
• Would you want it any other way?
If Eden then no sex
no anesthetics (anyone you know had a baby? had a tooth pulled?)
no air travel (no spring break in Miami)
no space program (we landed on Mars? wow)
no internet, no smart phones, no Xbox
Case study 1
How computers killed
people in WW-II
• Bletchley Park,
• Massive banks
– looking for
• Massive kludgey machines
– run by an army of 10,000 woman
– Winston Churchill: “The geese that laid the golden eggs
- but never cackled.”
• Alan Turing:
– Defined what it means
to be computable.
• By the way, he was gay
– we’ll get back to that.
The curse of information
• Thanks to Turing,
– the allies knew the location of
• But they had to be careful
– If the Germans knew they
knew, they change the codes
– Take years to break the new
• So they had to let (some)
boats get sunk and (some)
bombs fall on England
– In order to mount the
invasion and win the war
• Dead sailors
• Dead civilians
• Bletchley Park hastily
records quickly forgotten
Case study #2
Computers and hydrogen bombs
were developed by the same people
at the same time for same reason
How to build a thermo-nuclear bomb
(don’t try this at home)
separation of stages into a
triggering "primary" explosive and
a much more powerful
"secondary" explosive, compression
of the secondary by X-rays coming
from nuclear fission in the primary,
a process called the "radiation
implosion" of the secondary,
heating of the secondary, after cold
compression, by a second fission
explosion inside the secondary.
All in a microsecond
• To design "radiation
– Need massive simulations
• Enter the king of
the shock wave
– John Von Neumann
• Built computers at Princeton
– using Turing’s designs
– Ran the sims
– Built the bombs
His favorite computer programmer
• His wife, Klara von Neumann
– Famous ballerina
– Bored by her first husband (a banker)
– Left him for Johnny, moved to
– While Johnny wined and dined the
– She ran the clunky computers back at
• Did not do well when Johnny died
The curse of information
• Thanks to Von Nuemann,
– American got the h-bomb
• Which leads to the arms
race and the cold war
• Global annihilation
• Nuclear proliferation
• In this case, it is not true that
– “someone would have done
• Von Neumann’s Princeton
team was … unique
Alan Turing won the war
• Taught Von Neumann how to build computers
• His theories are the basis of all modern computers
• And his reward?
Persecuted to death
Homophobic rejection in the 1950s
Security clearance revoked
driven to suicide … by apple (sprinkled with arsenic)
2009: A public apology
• British Prime Minister Gordon Brown
– issued a public apology for the British
government's "appalling" actions,
– after an online petition seeking the same gained
30,000 signatures and international recognition.
– “The debt of gratitude he is owed makes it all the
more horrifying, therefore, that he was treated so
Turing’s challenge to us all:
• Be responsible.
• Leave the shame behind us.
• Build a different future.
CS = building blocks
• In times past, computers were very expensive
– Tools for the military
– For code breaking and designing bombs
• Computers today are cheap
– $30 for Raspberry Pi
– Now, computers are tools
– What will do with that?
We do more if we do it together
• Alan Turing, 1939:
– “The well-known theorem of Gödel (1931) shows that every system of logic
is in a certain sense incomplete, but at the same time it indicates means
whereby from a system L of logic a more complete system L′ may be
obtained. By repeating the process we get a sequence
L, L1 = L′, L2 = L1, ...
– each more complete than the proceeding. A logic Lω may then be
constructed in which the provable theorems are the totality of theorems
provable with the help of logics L, L1, L2...” .
– We are all incomplete
– We all know part of the answer
– We know more if we work together
Teams, working together
• Linus Torvalds
– a guy sitting on his Mum's lounge room floor
– invented a way to build software
– that now powers the internet.
• Mark Zuckerberg
– Some guy in his dorm room at Harvard
– created a web site used daily by a billion people.