Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

What has a 1 in a million chance? (2010)

stat.berkeley.edu

Post reply on HN
Print view View original

131–140 of 199 posts

Re: What has a 1 in a million chance? (2010)

#131

Post by nine_k »

adrianN wrote: post #78
nine_k wrote: post #69

Earlier quoted context omitted.

Given a finite amount of sample.values, you can always find a polynomial to match the values. You can only proclaim that something is "truly random" on epistemological grounds, assuming that true randomness is somehow exposed by the universe. This holds under quantum physics, but not under classical mechanics. Unless there is some quantum effect, RNGs based on fluid dynamics, like lava lamps, may be completely determ…

Your polynomial has no predictive value in almost all cases.

Yes. Finding out the nature of a PRNG and its initial state would allow one to predict next values, at least theoretically, that is, if it can be computed faster than the values are generated by the process we're looking at.

But the presence or absence of such a function for a naturally occurring process is, again, an epistemological question. That is, whether we can reverse-engineer the universe deeply enough. Unless we find its source code, we're stuck with retrofitting some formulas, and a "random process" is such for which we can't retrofit any better description than a statistical one.

Re: What has a 1 in a million chance? (2010)

#132

Post by EricMausler »

strken wrote: post #65
mewpmewp2 wrote: post #57

Earlier quoted context omitted.

Someone offering that bet though would also alter the odds though. Because why would someone offer such a ridiculous bet after you've told your name, unless they had special information about your name? Although it being a possible YouTube prank channel would make it also possible that you actually have a chance to win for the reactions.

This is part of a very important principle: if someone approaches you about something, you should be far more suspicious than if you had randomly picked someone off the street. The most well known application of this is teaching kids to ask a random shopkeeper for help if they get lost, but to not get in a stranger's car when offered a lift.

This also applies to self defense. If someone has targeted you, the odds of you beating them in a fight is different than the odds you can take on a random person, or a random thief even

Re: What has a 1 in a million chance? (2010)

#133

Post by erostrate »

The following are all ~ 1 in a million chance of death, or 1 micromort:

Travelling 6 miles (9.7 km) by motorcycle

Travelling 17 miles (27 km) by walking

Travelling 20 miles (32 km) by bicycle

Travelling 230 miles (370 km) by car

Travelling 1,000 miles (1,600 km) by jet

Travelling 6,000 miles (9,656 km) by train

But switching from car to bicycle for short trips still increases life expectancy due to health effects.

Sources: https://en.wikipedia.org/wiki/Micromort https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2920084/

Re: What has a 1 in a million chance? (2010)

#134

Post by bee_rider »

I wonder if it would be worth it to express unlikely events like this in powers of Dunbar’s number? Round it down to 100 to make the math easier, and also because there’s a lot of overlap in social networks. One million is 100^3, so in your acquaintances-of-acquaintances-of-acquaintances network there’s an expected value of one person who has to deal with this one in a million problem, I think, right?

Re: What has a 1 in a million chance? (2010)

#135

Post by pavlov »

mathstuf wrote: post #86
pavlov wrote: post #79

Earlier quoted context omitted.

This article seems to twist the definition of “extraordinary” to something clearly not intended by the original quote about claims and evidence. Mark is a very common first name. Xu is a Chinese surname shared by over ten million people (according to Wikipedia). It’s entirely ordinary that someone would have this combination of names.

Someone , yes. The person in front of you? Unlikely. Analogy: someone has a winning lottery ticket. Is it the one in your hand? Probably not.

That’s a good analogy for my point, because just having a lottery ticket isn’t extraordinary even though all of the tickets are unique.

If somebody claims they are holding a winning lottery ticket and will sell it to me for a 50% discount because they are leaving the country in two hours and don’t have time to cash it out, that’s an extraordinary claim and I would need extraordinary evidence to take the deal.

If someone says their name is Mark Wu, it’s like saying they are holding a non-winning lottery ticket with serial number 12345654321. It’s at best a curiosity.

Re: What has a 1 in a million chance? (2010)

#136

Post by nonameiguess »

bee_rider wrote: post #134

I wonder if it would be worth it to express unlikely events like this in powers of Dunbar’s number? Round it down to 100 to make the math easier, and also because there’s a lot of overlap in social networks. One million is 100^3, so in your acquaintances-of-acquaintances-of-acquaintances network there’s an expected value of one person who has to deal with this one in a million problem, I think, right?

Only if there is no overlap whatsoever in who is an acquaintance versus who is an acquaintance of an acquaintance. That is extremely unlikely. I'm sure there exists some data out there on how quickly an average social graph grows as a function of degrees of separation that can be used, however.

Re: What has a 1 in a million chance? (2010)

#137

Post by nonameiguess »

ithkuil wrote: post #74
nabla9 wrote: post #44

"Not in a million years"–something that might happen once in a million years for an individual–happens over 8000 times per year for people on earth. Many of them have smartphones with camera to record the event. That's why we have an actual video where quick brown fox jumps over the lazy dog.

My chance of dying because of a dinosaur-estinction-event-class asteroid hit is one in a 65 million years, thus every two and a half days on average a random person on earth dies being hit by an asteroid of that size.

This is quite a good point. People often fail to make the distinction between something that happens once every million years to all individual organisms separately versus something that happens once ever million years to the planet itself. Our language is usually ambiguous about this.

Re: What has a 1 in a million chance? (2010)

#138

Post by madcaptenor »

jameshart wrote: post #128
TomK32 wrote: post #80

Earlier quoted context omitted.

The cheese-loving aviators have the Swiss-cheese-model to visualize how small unimportant errors can stack up to a catastrophic outcome. Though in my opinion there's a flaw in this thinking as no sane cheese seller would shuffle their layers of cheese after cutting them: Hence 1-in-million chances happen all the time. https://www.aviationfile.com/swiss-cheese-model/

I don’t know if I’ve ever seen it investigated as a mathematical puzzle but there’s probably some interesting number stuff to be found in investigating the mathematics of an idealized swiss cheese risk model. If you take a series of unit squares and from each one remove a random circle (ah, the origin of every protracted probability argument among mathematicians: a random circle selected from which distribution ?), t…

No, you get axis-aligned square holes when you get your milk from cubical cows.

Re: What has a 1 in a million chance? (2010)

#139

Post by anamexis »

mewpmewp2 wrote: post #57
Recursing wrote: post #50

Reminds me of https://markxu.com/strong-evidence «One time, someone asked me what my name was. I said, “Mark Xu.” Afterward, they probably believed my name was “Mark Xu.” I’m guessing they would have happily accepted a bet at 20:1 odds that my driver’s license would say “Mark Xu” on it. The prior odds that someone’s name is “Mark Xu” are generously 1:1,000,000. Posterior odds of 20:1 implies that the odds ratio of me…

Someone offering that bet though would also alter the odds though. Because why would someone offer such a ridiculous bet after you've told your name, unless they had special information about your name? Although it being a possible YouTube prank channel would make it also possible that you actually have a chance to win for the reactions.

The OP covers this a bit as well:

> 20 coin tosses (by me) all coming up Tails. YES

> If you tossed the coins then the first answer would be NO, unless I'm very confident you lack the ability to fool me …

Re: What has a 1 in a million chance? (2010)

#140

Post by nonameiguess »

austin-cheney wrote: post #37

I used to tell people I was an order of magnitude more likely to die from a traffic related accident driving to work than from any hostile action during the two years I was in Afghanistan. People seemed challenged by that.

This often remains true even over smaller scales. For instance, between 2009 to 2012 I was in a combined arms battalion that deployed to Iraq twice and we experienced three deaths in combat and nine in traffic accidents near Fort Hood during those years. Another drowned in a lake near post. Also, one death due to suicide in theater.
Post reply on HN