Sunday, March 4, 2012

Useless Information



Did you know:

More steel is used in the manufacture of bottle caps each year then used in the manufacturing of cars in the United States.
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7 comments:

lizardmom said...

wow! amazing
and wow :( sad state of our auto industry

March 4, 2012 at 8:32 AM
Anonymous said...

UMMM... I think that's because plastics have replaced lots and lots of steel.

Also there is more use of aluminum, especially in engine components.

It helps to make cars lightweight and get better mileage.

March 4, 2012 at 12:57 PM
kkdither said...

No wonder those darn beer caps are so hard to pop! :) I think anon has it... more lighter-weight items are being swapped out to improve on gas mileage and safety.

March 4, 2012 at 1:30 PM
OrbsCorbs said...

Steel caps are used primarily on beer, aren't they? Most soft drink bottles are plastic and have aluminum caps. Even with new construction materials in the auto industry, I'm still surprised by this.

March 4, 2012 at 7:46 PM
hale-bopp said...

Okay, Fermi problem time.

Car sales in the US are running annual rate of say 12 million. This says in the US so let's say maybe 6 million of those are made in the US (it's right to the power of ten at least!) Average car 3,000 lbs. Generously say maybe 1300lbs steel. 12 million times 1300 is 15,600,000,000 lbs of steel if I counted my zeroes correctly.

So now the question is how much steel is in a bottle cap. A few ounces maybe. Let's say five bottle caps to a pound. That would give 78,000,000,000 bottle caps per year. Okay, that's 780 BILLION bottle caps per year. Given the US population of about 320 million, is about 243 bottle caps for every man, woman and child in the U.S.

Now I just googled the only reference I could find to this was OMG Facts which doesn't site a source for this stat (but they say a car is 60% steel rather than my lower estimate which will add a few bottle caps to the total).

As for the number of cars, that's tricky, but Wiki Answers says four million passenger cars in the US and six to seven million commercial vehicles (some of which will be cars) so my estimate is plausible to a little low.

So far, I didn't do too bad. Turns out I goofed on the weight of the bottle cap! According to wiki answers, a bottle cap is about 2.3 grams. Since there are 454 grams per lbs, that means there are about 197 (call it 200 for this problem) bottle caps per pound, not the measly five I estimated. Given that I underestimated by a factor of 40, that means there would have to be 243*40 = 9720 bottle caps for every man, woman and child in the United States for this to be true.

Therefore, Fermi says bull! (That was fun!)

March 5, 2012 at 12:38 AM
SER said...

Boppster...I love it.

I was watching H2 and they had the Heinekens Brewery on. One just one of the bottling lines they produce 65,000 bottles and HOUR. Another line was running 48,000 an hour. I'm not sure what Bud or Miller run but that is a bunch of beer and bottle caps.

March 5, 2012 at 7:24 AM
hale-bopp said...

Okay, Ser, but those aren't in the U.S. now which is what the original statement said :)

But those do give a useful starting point. Let's use them, add in Bud and SAB and say we get 400,000 bottle caps per hour *24 hours per day * 300 days per year (give them Sundays/Christmas/Thanksgiving etc. off). That may sound like a lot, but it only comes out to 3.5 billion, still way below the 780 billion I calculated earlier. I know there are other brewers out there but we covered the big ones and still less than 1% of the way there. I doubt I am missing 99%!

I love this type of problem. There is no easy way to just look up an answer, but you can find useful tidbits of information on the web that helps you get there if you apply some thought to it. I do workshops at teacher conferences on Fermi Problems. I am going to add this one next time.

March 5, 2012 at 11:43 AM

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