[meteorite-list] Nebraska Man Says He Was Nearly Hit By Meteorite

From: MexicoDoug_at_aol.com <MexicoDoug_at_meteoritecentral.com>
Date: Fri Jul 1 15:01:54 2005
Message-ID: <12f.60503a7d.2ff6ed02_at_aol.com>

Sterlng W. wrote:

>This (unnamed) expert needs a basic course in statistics. Assuming
>one defines this approach (65 feet) as a criteria for "close", then the
>number of cases of a fall being within 65 feet of a human being are
>substantial....Integrating for the varying size of the human population
>over this time period, I get odds of about 4,000,000,000 to one per year.
>Lifetime odds are less than 100,000,000 to one!... 65 feet is far enough
>away that the fall of a small fragment... A 130 foot circle has over 53,000
>square feet, a big target. Assuming that those humans don't bunch up
>too much (they do, but they all count as one person only in this survey)...

Hola Sterling, List,

This reminds me of two things:

1. That the amount of falls has less bearing on the probability of a human
hit. The factor that determines that is simply the average size of the strewn
field and the number of meteorites that have big strewn fields.

2. My favorite book, "Le Petit Prince" once again...when the wise author
discusses how much space people perceive they occupy vs, what they really do.
The updated figure is that if you put everyone in their private 1 meter X 1
meter box in a grid, the whole human population today would easily fit in a big
field 80 km X 80 km (50 miles X 50 miles) - just a bit bigger than
Metropolitan Paris...(the same comparison I think I recall the book gave over 50 years
ago).

Let me volunteer my comments:

I would give the 'unnamed' expert a break and say that he has solved an
easier problem than you. Remember, Sterling, you are writing-off the claimant as
a "wacko," so anything the claimant says doesn't count.

An easier problem is: The targetted wacko is in the grandstands (called
planet earth) and a homerun is hit (single meteorite stone falls into the
grandstands). What is probability the wacko will be the lucky one to catch THAT
PARTICULAR BALL (his mit has a reach of 65 feet)?

Statistics has always been so misused precisely because people want numbers
but are not interested in doing the work and understanding how they are
derived and what their constraints are. We can't be guilty of that!

The answer to that question of odds can be at least as great as 400 billion
to one (event probability, not time-probability). Four times even greater
than the quoted 'expert'...

Of course, you are thinking several homeruns could be hit in that game
(strewn field), and there are many games going on (many meteorites), but a fan
might say "It will never happen to me again in a 100 billion years...", viewing
it like playing a lottery. OK, you can't run and you can't hide from
meteorites...but I don't think we are dealing with a fan using that sort of
scientific logic. Thus, your back of the envelope and the 'experts's' calculation is
a factor of 6, 60, or even 1000 different...but we need the 'expert' to
clarify which one, and if it is only 6, that's not bad.

On your chosen and defined problem, I went this route: There is a recovered
witnessed fall in the USA-48 very nearly annually of 1, what's the area of
the region, about 7.5 million square km? That gives odds in one year of 6
billion to one, and over what's left of his lifetime you assigned 40 years that
leaves 150 million to one...and you and I are in basic agreement!! No big
surprise...

I would go on to sensibly fudge: a factor of say, 10-100 due to forgetting
about witnessed falls and concentrating on witnessed falls with sizeable
strewn fields, leaving, say 15 million to one (on the conservative end). And then
there is the factor of say, 2 for the falls that are never registered,
leaving true odds in 40 years at 1.5 million to one, according to my
interpretation - which now deviates from yours (in which we agree). If you don't agree
with my fudge factor of 10, I'll dispute your area of the circle of
diameter=130 (you were 4 times too large):

Your odds actually would state odds of 16 billion to one in a given year
according to your methodology, if you need to correct for the proper circular
area.

You then get a weighted average for a lifetime, but if you read the article
carefully, there was no time period stated by the "expert": "The chances of
this close of an encounter are one in 100 billion, expert said..." I'd
definitely agree with you to that point that we can have some fun with the sloopy
journalism, but if you read the article, is the alleged targeted man-not the
'expert'= who says "Only once in a 100 billion years, and it will probably
never happen to me again," but this is not the 'expert' talking. And it sounds
like the problem defined by the baseball game to me, not the meteoriticist...

So we are all in the same ballpark, as far as I can tell, even the 'expert',
until proven to be a quack in his own right...or that's how it looks to
me... save any stupid errors I could have committed:)

Saludos, Doug

USA (BM Catalog)

1990s 7
1980s 5
1970s 6
1960s 5
1950s 7
1940s 8
1930s 19
1920s 13
1910s 12
1900s 9
Received on Fri 01 Jul 2005 03:01:22 PM PDT