[meteorite-list] 1 in 3200 odds of human impact (help)

[Becky and Kirk]

WOW---some pretty good calculations and science there Doug----BRAVO!!
NASA screws up yet again!!

Kirk.....:-)

----- Original Message ----- 
From: "MexicoDoug" <mexicodoug at aim.com>
To: <Meteorite-list at meteoritecentral.com>
Sent: Saturday, September 24, 2011 11:31 PM
Subject: [meteorite-list] 1 in 3200 odds of human impact (help)


> Hi listers
>
> I'm very suspicious of this widely quoted 1 in 3200 that is being passed 
> off as a scientific number by NASA.
>
> Not 1:3000, nor between 1:1000 to 1:10,000: but 1:3200.
>
> This foolishly precise assertation, which if you've read "The Little 
> Prince" you immediately suspect it is overstated due to the author's 
> calculations 70 years ago there...where a similar calculation is actually 
> done ...
>
> Average cross sectional area of a person? (Depends if it is in the morning 
> when everyone is praying, I guess, or in the afternoon when everyone is 
> running out of work)...let's say:
>
> Cross section per person:18 inches by 18 inches (1.5 x 1.5 sq. feet)
> World population: 6.964 X 10^9 living souls
> World Area: 196,939,900 sq miles
>
> Calculations:
>
> * Cross section per person = 2.5 sq. feet
>
> * current world population occupies 624.3 square miles
> (a wee bit bigger than Guam, and smaller than Singapore)
>
> * people that could fit on Earth's surface: 2,196,000,000,000,000 (2.2 
> million X 10^9)
>
> * Fraction of Earth's surface that's "people"  = 6.96 / (2,196,000)  = 
> 0.00000317
> = People occupy *ONLY* 3.2 parts per million (3.2 ppm) of the earth's 
> surface
>
> So, saving rounding till the end, each piece of UARS actually has a 
> 1/315,457 chance of falling on people (1/0.00000317).
> In rounded numbers, that's about 1:320,000 per fragment ==> 26 fragments 
> approximately 1:12,000 chance.
>
> I guess if you are American you need more space than if you are 
> Indonesian, and changing it to a 18 inches X 17 inches would change the 
> result by 6% ie, if 3200 were right for 18X18 it would now be about 
> 1:3000, and that is one of so many assumptions making the 3200 number a 
> total joke of fake scientific confidence.  If you gave everyone a square 
> yard ((91.4 cm)^2) instead, it would be in the 3000 range.
>
> But here are the defficiencies I think of looking at it this way:
>
> * this looks at the whole world vs. the limited satellite trace.  A true 
> measurement would do a little calculus along the path considering the 
> population density and the probability of earlier or later entry which 
> could change probabilities by an order of magnitude easily.
>
> * I think what I did would work for 26 darts, but not hunks of significant 
> size compared to a person's area unit.
>
> * Finally there is the Sylacauga effect for bouncing material that will 
> affect things another factor of 2, 3, 4 who knows...
>
> There must be a half dozen other complicating factors to do this right. 
> Does anyone know what has been considered to arrive at the bogusly precise 
> 3200-1 odds being fed to us?
>
> Love to hear any improvements on the above model (if you can call it a 
> model) which I got the 1:12,000 as a streaming (unverified) starting point 
> ...
>
> Kindest wishes
> Doug
>
> ______________________________________________
> Visit the Archives at 
> http://www.meteoritecentral.com/mailing-list-archives.html
> Meteorite-list mailing list
> Meteorite-list at meteoritecentral.com
> http://six.pairlist.net/mailman/listinfo/meteorite-list