7 ms·

What does randomness look like? (2012)

62 points by xsace 12y ago

mnw21cam 12y ago
What isn't mentioned is the fact that British intelligence fed false news article back to the Germans saying that the bombs had fallen short of their target. The Germans then adjusted their flight paths to make the bombs fly further, causing many of them to fly straight over London and land in the countryside the other side.
- beejiu 12y ago
  Actually, the bombs were already falling short of the target. The British instructed captured German spies to report they were hitting their targets. They were quite subtle about how they did it -- they would simply omit news about the bombs that fell short. My favourite story is about Battle of the Beams (http://en.wikipedia.org/wiki/Battle_of_the_Beams http://en.wikipedia.org/wiki/Battle_of_the_Beams), where German bombers were guided by radio navigation. The British started broadcasting their own radio signals to make it appear to the German planes that the beam was slightly bent. It meant they could get the bombers to drop their bombs in the middle of nowhere.
- lotharbot 12y ago
  The last word of the references section of the article ("teaser") links to a more detailed comment about this -- from Hacker News 2 years ago: https://news.ycombinator.com/item?id=4955201 https://news.ycombinator.com/item?id=4955201
autokad 12y ago
i read somewhere that showed the V1's had a higher kill rate of RAF pilots than German fighters, with no losses of german pilots. Couldnt find it though, anyone else?
- vecter 12y ago
  That's extremely unlikely. How is kill rate defined?
  - etrevino 12y ago
    I believe he means kill ratio. So, the number of planes shot down versus the number of V-1s shot down. If one RAF fighter was shot down for every two V-1s the ratio would be 2:1 in favor of the RAF. This is a little bit plausible. This is how the RAF shot down V-1s: http://i.dailymail.co.uk/i/pix/2011/05/08/article-1384740-0BF424C400000578-18_636x774.jpg http://i.dailymail.co.uk/i/pix/2011/05/08/article-1384740-0B... (picture courtesy of the Daily Fail) So, the kill ratio of V-1s might have been higher against the RAF because it was so hard to down V-1s and doing so was hazardous. We're still talking a tiny fraction of the craft engaged, though.
    - autokad 12y ago
      Yes, according to the chart above it took down 351 aircraft. The toppling method wasnt the only one implemented, they also tried shooting them down with their guns; however, they would have to get close and often resulted in the destruction of their own aircraft as well.
      - etrevino 12y ago
        I wish I'd noticed that chart earlier. You're right, the V1 ratio was much better.
- pacaro 12y ago
  Part of the data are at... http://en.wikipedia.org/wiki/V-1_flying_bomb#Assessment http://en.wikipedia.org/wiki/V-1_flying_bomb#Assessment
myfonj 12y ago
Other thing that wasn't mentioned is the actual mechanism that caused that 'controlled randomness': http://en.wikipedia.org/wiki/V-1_flying_bomb#Guidance_system http://en.wikipedia.org/wiki/V-1_flying_bomb#Guidance_system
sramsay 12y ago
The British worried about the accuracy of these aerial drones. Were they falling haphazardly over the city, or were they hitting their intended targets? This is the seed of Thomas Pynchon's 1973 novel Gravity's Rainbow -- a masterful, if difficult, novel about (among other things) paranoia.
- arethuza 12y ago
  I've never made it very far through Gravity's Rainbow (although I have tried multiple times) but I'm pretty sure it's about the ballistic V-2 missiles rather than the cruise-missile like V-1s.
  - sramsay 12y ago
    That's true. It's about the V-2s (in particular, one mysterious weapon the Germans appear to be building called the "Schwarzgerät," with serial number 0000). But that business of trying to figure out whether the bombs are random or not is central to the book. There are a lot of statisticians running around trying to figure out why the pattern of bomb blasts corresponds to the Poisson distribution. (Of course, there's also a character whose erections appear to predict bomb blasts. Postmodernism, ftw).
- krylon 12y ago
  I just finished reading GR a couple of months back, I wish I had read this article before... I'll be sure to re-read this article before I read GR the next time...
- ArkyBeagle 12y ago
  Gravity's Rainbow is also a tribute to Richard Fariña's "Been Down So Long It Looks Like up To Me". Pynchon and Richard Fariña were friends. The two are very linked conceptually. BDSLILLUTM is decidedly about paranoia. Beware girls with green knee socks.
thanatropism 12y ago
what does Poisson-distributed randomness look like? Events generated by Poisson processes or amenable to the small-p binomial approximation look like Poisson. Events not amenable to the small-p approximation look Gaussian. Extreme value measurements (flood water levels, auction prices) look Weibull, Fréchet or Gumbel. Appropriate statistical methodologies are appropriate. sigh
artumi-richard 12y ago
http://search.dilbert.com/comic/Random%20Number%20Generator http://search.dilbert.com/comic/Random%20Number%20Generator
- jschulenklopper 12y ago
  And of course this one: http://xkcd.com/221/ http://xkcd.com/221/
deleted 12y ago
[deleted]
cshimmin 12y ago
Both distributions are random, they're just different kinds of random. The one the article refers to as "random" is _uniformly distributed_, while the other is not. Similarly, different _kinds_ of random distributions sound different! Wikipedia has a nice article on various noise distributions with audio samples: http://en.wikipedia.org/wiki/Colors_of_noise http://en.wikipedia.org/wiki/Colors_of_noise
- sillysaurus3 12y ago
  Brown noise sounds lovely, like a waterfall: http://en.wikipedia.org/wiki/Brownian_noise http://en.wikipedia.org/wiki/Brownian_noise

62 points by xsace 12y ago

What isn't mentioned is the fact that British intelligence fed false news article back to the Germans saying that the bombs had fallen short of their target. The Germans then adjusted their flight paths to make the bombs fly further, causing many of them to fly straight over London and land in the countryside the other side.

beejiu 12y ago
Actually, the bombs were already falling short of the target. The British instructed captured German spies to report they were hitting their targets. They were quite subtle about how they did it -- they would simply omit news about the bombs that fell short. My favourite story is about Battle of the Beams (http://en.wikipedia.org/wiki/Battle_of_the_Beams http://en.wikipedia.org/wiki/Battle_of_the_Beams), where German bombers were guided by radio navigation. The British started broadcasting their own radio signals to make it appear to the German planes that the beam was slightly bent. It meant they could get the bombers to drop their bombs in the middle of nowhere.
lotharbot 12y ago
The last word of the references section of the article ("teaser") links to a more detailed comment about this -- from Hacker News 2 years ago: https://news.ycombinator.com/item?id=4955201 https://news.ycombinator.com/item?id=4955201

autokad 12y ago

i read somewhere that showed the V1's had a higher kill rate of RAF pilots than German fighters, with no losses of german pilots. Couldnt find it though, anyone else?

vecter 12y ago
That's extremely unlikely. How is kill rate defined?
- etrevino 12y ago
  I believe he means kill ratio. So, the number of planes shot down versus the number of V-1s shot down. If one RAF fighter was shot down for every two V-1s the ratio would be 2:1 in favor of the RAF. This is a little bit plausible. This is how the RAF shot down V-1s: http://i.dailymail.co.uk/i/pix/2011/05/08/article-1384740-0BF424C400000578-18_636x774.jpg http://i.dailymail.co.uk/i/pix/2011/05/08/article-1384740-0B... (picture courtesy of the Daily Fail) So, the kill ratio of V-1s might have been higher against the RAF because it was so hard to down V-1s and doing so was hazardous. We're still talking a tiny fraction of the craft engaged, though.
  - autokad 12y ago
    Yes, according to the chart above it took down 351 aircraft. The toppling method wasnt the only one implemented, they also tried shooting them down with their guns; however, they would have to get close and often resulted in the destruction of their own aircraft as well.
    - etrevino 12y ago
      I wish I'd noticed that chart earlier. You're right, the V1 ratio was much better.
pacaro 12y ago
Part of the data are at... http://en.wikipedia.org/wiki/V-1_flying_bomb#Assessment http://en.wikipedia.org/wiki/V-1_flying_bomb#Assessment

myfonj 12y ago

Other thing that wasn't mentioned is the actual mechanism that caused that 'controlled randomness': http://en.wikipedia.org/wiki/V-1_flying_bomb#Guidance_system http://en.wikipedia.org/wiki/V-1_flying_bomb#Guidance_system

sramsay 12y ago

The British worried about the accuracy of these aerial drones. Were they falling haphazardly over the city, or were they hitting their intended targets? This is the seed of Thomas Pynchon's 1973 novel Gravity's Rainbow -- a masterful, if difficult, novel about (among other things) paranoia.

arethuza 12y ago
I've never made it very far through Gravity's Rainbow (although I have tried multiple times) but I'm pretty sure it's about the ballistic V-2 missiles rather than the cruise-missile like V-1s.
- sramsay 12y ago
  That's true. It's about the V-2s (in particular, one mysterious weapon the Germans appear to be building called the "Schwarzgerät," with serial number 0000). But that business of trying to figure out whether the bombs are random or not is central to the book. There are a lot of statisticians running around trying to figure out why the pattern of bomb blasts corresponds to the Poisson distribution. (Of course, there's also a character whose erections appear to predict bomb blasts. Postmodernism, ftw).
krylon 12y ago
I just finished reading GR a couple of months back, I wish I had read this article before... I'll be sure to re-read this article before I read GR the next time...
ArkyBeagle 12y ago
Gravity's Rainbow is also a tribute to Richard Fariña's "Been Down So Long It Looks Like up To Me". Pynchon and Richard Fariña were friends. The two are very linked conceptually. BDSLILLUTM is decidedly about paranoia. Beware girls with green knee socks.

thanatropism 12y ago

what does Poisson-distributed randomness look like? Events generated by Poisson processes or amenable to the small-p binomial approximation look like Poisson. Events not amenable to the small-p approximation look Gaussian. Extreme value measurements (flood water levels, auction prices) look Weibull, Fréchet or Gumbel. Appropriate statistical methodologies are appropriate. sigh

artumi-richard 12y ago

http://search.dilbert.com/comic/Random%20Number%20Generator http://search.dilbert.com/comic/Random%20Number%20Generator

jschulenklopper 12y ago
And of course this one: http://xkcd.com/221/ http://xkcd.com/221/

deleted 12y ago

[deleted]

cshimmin 12y ago

Both distributions are random, they're just different kinds of random. The one the article refers to as "random" is _uniformly distributed_, while the other is not. Similarly, different _kinds_ of random distributions sound different! Wikipedia has a nice article on various noise distributions with audio samples: http://en.wikipedia.org/wiki/Colors_of_noise http://en.wikipedia.org/wiki/Colors_of_noise

sillysaurus3 12y ago
Brown noise sounds lovely, like a waterfall: http://en.wikipedia.org/wiki/Brownian_noise http://en.wikipedia.org/wiki/Brownian_noise