24 Comments

  1. If only one person has ever been struck by lightning and survived the experience, logically, the chances of dying from being struck by lightning are less than the chances of being struck by lightning in the first place. Many things are said to be less likely than being struck by lightning; one of them is dying in the process.

  2. I’ve always been irritated by risk explanations that are given only in relative terms. “Subjects exposed to Bad Habit One were 1.5 times as likely to suffer Bad Consequence Two as abstainers.”

    Okay, but just what are those probabilities? If it’s 0.1% vs 0.15% chance of someone in my categories getting Consequence Two over the course of a year, do I have to care?

  3. Logic me this, then smart guy: When can you say someone DIDN’T die of something? Sure, lightning man is alive now, but he may have persistent health effects that shorten his life. Some victims of the US atomic attacks on Japan lived with impaired health for decades before dying from those complications. Mad cow disease affects human victims many years after consuming affected beef. After all, the odds that anyone struck by lightning will die are 100%.

  4. “The logic stinks.”

    In the sense that there’s nothing wrong with it. Count up the total number of all the people who have ever been struck by lightning. Now, count up all the people who have ever died from being struck by lightning. Which number is bigger?

    Rather, move on to blame the victim. Now that tall buildings are equipped with lightning suppression, a lot of people who are struck by lightning were struck by lightning because they ignored signs of lightning danger (such as, say, other lightning) and remained in a perilous position.

  5. “After all, the odds that anyone struck by lightning will die are 100%.”

    As far as you know. I was hit with man-made lighting, in the form of a defibrillator, and it EXTENDED by life. In fact, the number of times I have died remains constant at 0. Extending that trend into the future…

  6. Downpuppy/Powers: Yes, while the statement is technically true, it’s application to this particular scenario is quite bad. That’s part of the joke.

    SingaporeBill: If someone is struck by lightning, doesn’t immediately die, and a week later dies in a car crash, you can say that they didn’t die of lightning. (Assuming the lightning strike didn’t lead to the car crash.)

  7. Well, this cuts both ways for me.

    It’s joke on conditional vs. absolute probability and how a logician uses the one that is logically correct but not the one normal people would be concerned with. The probability of A *and* B is always less than the probability of just A (unless the A and not B is impossible). If one in a million people are struck by lightening and 1 in a thousand of those are survive then the probability of dying by being struck by lightening or 0.999 in a million, which is less than the probability of being struck by lightening is 1 in a million.

    Likewise the probability of being hit by a car while wearing clothes is less than the probability of being hit be a car.

    But a logician would never use absolute probability after a condition has occurred. A logician would never say the probability of Sam buy a chicken on Friday is 15% if Sam has been dead for a month. That’s the logic of creationists.

    In this case both the logician and the normal human being are on the same page and think, well, now that you’ve been hit by lightning the chances of you dying are… cripes, get to a hospital now!… Actually that fact that you’ve survived these to seconds after being hit is surprising.

    Where a logician differs would be where he’d be correct. It’s been heads three times, tails is due; or Hey, I was driving on the freeway and I saw a cars license plate that began with a K– mine begins with a K– that must be a one in 676 occurance! or Honey, we must buy this house! The probability of an airplane crashing into a bedroom twice must be practically impossble!

  8. “If one in a million people are struck by lightening”

    Any typo that isn’t caught by spellcheck will pop up in many places.

  9. ” A logician would never say the probability of Sam buy a chicken on Friday is 15% if Sam has been dead for a month.”

    He’s been dead for a month. Have all his online accounts been closed? Has his estate been settled? Maybe he has a standing order on file. Maybe he had futures contracts while he was still alive. A logician avoids making assumptions.

  10. Question: You toss a coin 31 times and each time it comes up heads. What are the chances that it will come up heads the next time you toss it?

    Answer: Given that the normal probability of a coin coming up heads 31 times in a row is somewhere in the vicinity of one in a billion, it is VERY likely that your coin has two heads and no tail. You can be pretty sure the 32nd time will come up heads too.

  11. Mark in Boston. But it isn’t *zero* it will come up tails. Now do you know how to model the question to actually calculate the answer. Or if you flip four coins in a row what is the likelihood.

    Okay a tangent… but curious. How many heads in a row would it take to convince you that there is exactly a 50% chance you have a rigged coin.

  12. carlfink: But we all have different priors for the probability that the coin is fair. (And for the probability that the coin has both a head and a tail, but is biased.) And those priors are context-dependent.

  13. A coin with a head and a tail don’t necessarily have equal probability of coming up. Ordinary US Lincoln cents, for example, have a demonstrated unequal probability.
    Also, the possibility of landing on edge is non-zero.
    Don’t forget to factor in these effects when you do the calculation.

  14. One of the more famous non-fatalities was Lee Trevino, who was struck by lightning on a golf course in 1975. He said that in the future, ‘
    he would take out his 1-iron and point it to the sky, “because not even God can hit a 1-iron”
    .’

Add a Comment

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.