Category Archives: Statistics

On Fermi Calculations

Big Falling Fermi Confetti

Take a piece of standard paper. Rip it up, roughly, into an 8 by 8 grid, which will net you 64 pieces of over-sized confetti. Hold them in your cupped hands at chest height, and let them fall to the ground.

What can you learn from doing this? Well, for one thing, it can help you estimate the strength of Trinity, the first atom bomb test explosion.

No, really, it can.

But I’ve left out two things. You have to have been at the observing site at the time when Trinity was actually detonated. And you have to be Enrico Fermi.

Enrico Fermi 311x300

Enrico Fermi in front of a machine he invented for toasting bread.

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Blueberries, the Base and the Outside View

Imagine you read a brief news report in a respected peer-review journal such as Nature. The report cites a conclusive study which states that by giving up eating blueberries, you can cut your risk of getting a certain type of normally fatal cancer by 90%. You like blueberries, and eat them fairly regularly.

Would you give up blueberries based on this?

Blueberries 315x315
Killer Blueberries

There are two obvious answers, and, at the risk of just plain speculating, I would suggest each has its typical justification.

A lot of people are going to say “Yes, I’ll give them up: it is not a big sacrifice to make, and if it cuts down the risk of a cancer by 90%, that has got to be good news.”

The No group is going to contain at least some people who are fed up with being told what’s good for them by “the Food Police”, and say “To hell with it, life is too short, I like blueberries, and am going to carry on.” (We saw a lot of this pushback recently in the UK, when the World Health Organization re-classified processed meats as carcinogens, in the same category as smoking, alcohol and asbestos. Although bacon sales went down, there were some people who stubbornly announced they were going to have a damn good fry-up Sunday morning.)

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