Aliens invade the earth and threaten to obliterate it in a year's time unless human beings can find the Ramsey number for red five and blue five. We could marshal the world's best minds and fastest computers, and within a year we could probably calculate the value. If the aliens demanded the Ramsey number for red six and blue six, however, we would have no choice but to launch a preemptive attack.
About this quote
- What does it mean?
- Erdos used a hypothetical alien threat to illustrate that computing some mathematical problems like Ramsey numbers is practically impossible.
- In plain terms
- He compared impossible math to an alien invasion to show we can't solve certain problems.
- What can you take from it?
- Some mathematical problems are so hard they are practically unsolvable.
Where it applies
Putting it to work
Questions to consider
- What problems are truly unsolvable?
- How do we explain complexity?
Another view
The joke relies on the listener knowing Ramsey theory basics.
More from Paul Erdos
A mathematician is a device for turning coffee into theorems.
Permalink to quote #2 God may not play dice with the universe, but something strange is going on with the prime numbers.
Permalink to quote #3 This one's from the Book!
Permalink to quote #4
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