3 ms·

WHY would you pick an example number that's not divisible by 7?! Academics facing the real world are the strangest creatures. Also this is really cool.

dmerrick 11y ago
This didn't bother me. I assumed they picked that number _because_ it didn't work, to emphasize that only some numbers would end up back at the white node.
- stevebmark 11y ago
  Clear, simple communication is a skill that takes time and practice to develop! Pointing out that you're not bothered by this strange example will hopefully be a good point for you to reflect on later.
  - tempestn 11y ago
    Similarly, it can be difficult to recognize when you may come across as snarky and passive-aggressive. Perhaps it will be useful for you to reflect on this comment later.
    - chris_wot 11y ago
      This is the first example of self-recursive snark I've seen on HN. Congrats.
Johnny555 11y ago
Thank you, I was thinking the same thing. I followed the graph twice and thought I was doing it wrong before I mentally divided 325 by 7 to find that it's not a multiple of 7
keithpeter 11y ago
I agree the OA would be improved by two examples, one of each. An answer: Counter-examples are important in Maths. Anecdote: Oliver Sacks wrote about autistic twins [1] who could not speak or communicate well to people but who could perform prodigious feats of calculation, including factorising large pimes. Sacks sat with them with a table of prime numbers, and swapped some really large ones after which they took him seriously. Sacks took their reaction to his large primes as proof of their arithmetical ability. The mathematician John Conway (the game of life chap) was quoted on an online forum decades later as saying that Sacks should have suggested some large non-prime numbers as a test of the twins. I'm searching for a reference! [1] http://math-frolic.blogspot.co.uk/2013/02/prime-savants-fascinating.html http://math-frolic.blogspot.co.uk/2013/02/prime-savants-fasc...
- cjg 11y ago
  I liked your anecdote. It led to this more detailed analysis of the twins abilities to detect primes: http://www.pepijnvanerp.nl/articles/oliver-sackss-twins-and-prime-numbers/ http://www.pepijnvanerp.nl/articles/oliver-sackss-twins-and-...
alex-g 11y ago
Why not? The point is to be able to distinguish the cases.

dmerrick 11y ago

This didn't bother me. I assumed they picked that number _because_ it didn't work, to emphasize that only some numbers would end up back at the white node.

stevebmark 11y ago
Clear, simple communication is a skill that takes time and practice to develop! Pointing out that you're not bothered by this strange example will hopefully be a good point for you to reflect on later.
- tempestn 11y ago
  Similarly, it can be difficult to recognize when you may come across as snarky and passive-aggressive. Perhaps it will be useful for you to reflect on this comment later.
  - chris_wot 11y ago
    This is the first example of self-recursive snark I've seen on HN. Congrats.

Johnny555 11y ago

Thank you, I was thinking the same thing. I followed the graph twice and thought I was doing it wrong before I mentally divided 325 by 7 to find that it's not a multiple of 7

keithpeter 11y ago

I agree the OA would be improved by two examples, one of each. An answer: Counter-examples are important in Maths. Anecdote: Oliver Sacks wrote about autistic twins [1] who could not speak or communicate well to people but who could perform prodigious feats of calculation, including factorising large pimes. Sacks sat with them with a table of prime numbers, and swapped some really large ones after which they took him seriously. Sacks took their reaction to his large primes as proof of their arithmetical ability. The mathematician John Conway (the game of life chap) was quoted on an online forum decades later as saying that Sacks should have suggested some large non-prime numbers as a test of the twins. I'm searching for a reference! [1] http://math-frolic.blogspot.co.uk/2013/02/prime-savants-fascinating.html http://math-frolic.blogspot.co.uk/2013/02/prime-savants-fasc...

cjg 11y ago
I liked your anecdote. It led to this more detailed analysis of the twins abilities to detect primes: http://www.pepijnvanerp.nl/articles/oliver-sackss-twins-and-prime-numbers/ http://www.pepijnvanerp.nl/articles/oliver-sackss-twins-and-...

alex-g 11y ago

Why not? The point is to be able to distinguish the cases.