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

[MexicoDoug 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