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That Daily Shower Can Be a Killer

nytimes.com

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Re: That Daily Shower Can Be a Killer

#21

Post by mauvehaus »

JoeAltmaier wrote: post #5

A handy technique for evaluating situations is this: how many mistakes am I away from death/injury? If I drive without a seatbelt, I've put myself 1 accident away in many cases. My Scouts are young, and love to climb things. I tell them, I know you're strong and skilled. But a loose rock or slippery foothold puts you at risk anyway. So wear the harness - now it takes two mistakes to kill you (e.g. loose rock + badly…

In the climbing example as presented, you should be at least three mistakes away from injury. The belayer should check the climber's harness and knots before allowing the climber to climb. Naturally the climber should check that the belayer's harness is fastened securely and that the belay device is rigged properly before climbing too.

Realistically, there are still several single points of failure in the system:

1) The space between the belayer's ears 2) the rope if it has become damaged since it was flaked and inspected or gets cut while catching a fall. Yes, that happened, though not to me [1]. 3) The protection on the wall, due to improper use. although depending on how high you are, the next piece down might still keep you off the deck. 4) The harness itself, although barring invisible damage this should be caught by the belayer/climber him/herself and the cross check. 5) The protection on the wall due to gear failure.

The above are listed in what I would consider descending probability, although 2 and 3 are pretty close, with 3 probably jumping 2 in trad climbing. I would rate the probability of 5 being negligible barring manufacturing defects, the prevention and possibly detection of which is probably outside the expertise of virtually all climbers.

Moral of the story: safety is complicated. (edited to add) I'd believe that trying to get people to apply a simple model of "how many mistakes" is better than none, but I wonder to what extent it reduces safety by making people complacent about having done a risk analysis when the system is too complicated to be analyzed that way.

[1] http://www.redriverclimbing.com/viewtopic.php?f=21&t=132...

Re: That Daily Shower Can Be a Killer

#22

Post by davidroberts »

nathan_long wrote: post #18

Yep. This is why every dollar spent on the TSA would be better spent on preventing car accidents, heart attacks, and falls in the shower. http://www.schneier.com/blog/archives/2010/01/the_comparativ... But I like the OP's more practical point: personal attention to normal activities that are actually risky, based on a realistic view of those risks.

Especially since the TSA actually accomplishes almost nothing in preventing deaths. All a terrorist about to be discovered at the airport security gate would have to do to complete his deadly mission would be to detonate his bomb right then and there. It would cause people to fear airports and security gates and mess up the whole system. Terrorism is all about sowing fear that the government can't protect you. The TSA just shifts some of the risk from the airplane to the airport. You can't security check everything in life. Better to figure out why people want to detonate bombs in the first place and solve that problem. But symbolic solutions are so much easier.

Re: That Daily Shower Can Be a Killer

#23

Post by Tichy »

jessedhillon wrote: post #20
roflc0ptic wrote: post #19

Earlier quoted context omitted.

Guns, Germs, and Steel was most certainly not about "how and why European societies were able to advance themselves so much farther ahead of all other civilizations". The concept of "advanced", or being "ahead of" is inapplicable. It's a book about sociocultural evolution. Additionally, Diamond is pretty ambivalent about the "winners". Diamond wrote an essay on the subject of agriculture called "The Worst Mistake in…

No. I'm pretty sure it was about why and how European civilizations were able to conquer technology and the world, and specifically why many of the developments critical to the rise of European supremacy are not found in other societies. Yes, the judgments made in the book tend to be more fact-based and objective, e.g., a gun is more effective than a spear. It is not a screed extolling the virtues of European civiliz…

It's been a while since I read it, but it think it would be more about why one "tribe" developed guns and the other didn't. (Minor nitpicking by someone who also heard of Jared Diamond).

Re: That Daily Shower Can Be a Killer

#24

Post by shin_lao »

Author doesn't understand how statistics/probabilities work and it ruins the article.

If you roll a dice six times, you have no guarantee to get a six. Each time you roll the dice, you have 1/6th chance of getting a six and this doesn't change no matter how many times you roll.

If you roll a dice six times, you have around 66,51% (1-(5/6)^6) chance of getting six at least once.

For the same reason, if you have 1/1000th chance of dying under the shower, and you take 5,000 showers, you won't die 5 times...

You will have 1-(999/1000)^5000 chance of dying, that 99,32%. That's not 1. So you won't die 5 times.

Re: That Daily Shower Can Be a Killer

#25

Post by JumpCrisscross »

shin_lao wrote: post #24

Author doesn't understand how statistics/probabilities work and it ruins the article. If you roll a dice six times, you have no guarantee to get a six. Each time you roll the dice, you have 1/6th chance of getting a six and this doesn't change no matter how many times you roll. If you roll a dice six times, you have around 66,51% (1-(5/6)^6) chance of getting six at least once. For the same reason, if you have 1/1000…

That's a relief, I prefer only dying once. Pedantic silliness aside, it was clearly an illustration of how frequency can amplify small probabilities to near-certainties, evidenced by the repetitive use of the one-in-a-thousand statistic.

Re: That Daily Shower Can Be a Killer

#27

Post by Tichy »

shin_lao wrote: post #24

Author doesn't understand how statistics/probabilities work and it ruins the article. If you roll a dice six times, you have no guarantee to get a six. Each time you roll the dice, you have 1/6th chance of getting a six and this doesn't change no matter how many times you roll. If you roll a dice six times, you have around 66,51% (1-(5/6)^6) chance of getting six at least once. For the same reason, if you have 1/1000…

I guess to die 99,32% is not dying at all, so you actually die never. Taking a shower is perfectly save.

Re: That Daily Shower Can Be a Killer

#28

Post by tomjen3 »

Tichy wrote: post #27
shin_lao wrote: post #24

Author doesn't understand how statistics/probabilities work and it ruins the article. If you roll a dice six times, you have no guarantee to get a six. Each time you roll the dice, you have 1/6th chance of getting a six and this doesn't change no matter how many times you roll. If you roll a dice six times, you have around 66,51% (1-(5/6)^6) chance of getting six at least once. For the same reason, if you have 1/1000…

I guess to die 99,32% is not dying at all, so you actually die never. Taking a shower is perfectly save.

And surprisingly enough, if you add the many-worlds quantum theory[1] that is exactly what you get. Non-death.

1)http://en.wikipedia.org/wiki/Multiverse#Level_III:_Many-worl...

Re: That Daily Shower Can Be a Killer

#29

Post by sparky_z »

shin_lao wrote: post #24

Author doesn't understand how statistics/probabilities work and it ruins the article. If you roll a dice six times, you have no guarantee to get a six. Each time you roll the dice, you have 1/6th chance of getting a six and this doesn't change no matter how many times you roll. If you roll a dice six times, you have around 66,51% (1-(5/6)^6) chance of getting six at least once. For the same reason, if you have 1/1000…

You're apparently the one who doesn't understand how statistics/probability works. You're correct about his chance of dying once, but there's also a chance of dying twice, a chance of dying 3 times, etc. The expected value of the number of times he would die is 5000(1/1000), or 5.

If you replaced "deaths" in your post with "coin flips", this becomes obvious. I'll repeat your post with some different numbers so you can see how absurd your argument is.

    If you have a 1/2 chance of flipping heads and you flip 10 coins, you won't get 5 heads.

    You will have 1-(1/2)^10 of flipping heads, that [sic] 99.902%. That's not 1. So you won't get 5 heads.
See how that doesn't make sense?

Now, obviously a real person can't die more than once, but if you think he was mistaken about that then his supposed error has more to do with biology than statistics. Any reasonable reader would understand that it was just his rhetorical way of describing a large number of independent statistical events. If it helps, think of it as a population of 5000 equally-careless people taking 1 shower each, not a single person taking 5000.

Re: That Daily Shower Can Be a Killer

#30

Post by [deleted] »

shin_lao wrote: post #24

Author doesn't understand how statistics/probabilities work and it ruins the article. If you roll a dice six times, you have no guarantee to get a six. Each time you roll the dice, you have 1/6th chance of getting a six and this doesn't change no matter how many times you roll. If you roll a dice six times, you have around 66,51% (1-(5/6)^6) chance of getting six at least once. For the same reason, if you have 1/1000…

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