Tag: colors

Signs

Posted on by Brian Garthwaite
Caution sign.
Caution. It’s like a welcome mat!

Signs! They’re all around, some not-so-subtle hints to remind you that you’re in a working machine shop full of dangerous things. There’s an informal ranking of which tools qualify as the most dangerous, but improper use can make anything a hazard. So it’s safety goggles required, watch your fingers, and don’t touch anything you haven’t been trained to operate safely.

Can we assume you understand that open-toed shoes are a no-go?

Hazard signs have a hierarchy, beginning with CAUTION, often in yellow. Caution tells you that you’re in a potentially hazardous place, and failure to take appropriate precautions could result in injury. Safety goggles around the machines, please. Don’t press any switches unless you know what they do.

Warning sign
Warning. Seriously, don’t touch anything if you don’t know what it is.

Next step up: WARNING. The situation here is moderately hazardous. Failure to take appropriate precautions could result in death or serious injury. Maybe not likely, but please don’t lose a finger to the bandsaw. Keep those knuckles well away from the business end of the belt grinder.

Danger sign.
Danger. These machines will bite.

And at the top, DANGER. Oh, danger. You get the quality of imagery that belongs on packs of cigarettes. Danger tells you that certain situations will result in death or serious injury. Not might, but will. Do not mess around with the table saw. Do not allow loose clothing or hair anywhere near the lathe. We like gallows humor for some very good reasons.

Nothing quite like the worst-case outcome for Charlie Chaplin in Modern Times laid out for you in stark silhouette.

Dice

Posted on by Brian Garthwaite
Box of dice
Quick! Add ’em up!

Dice! Bins of colorful dice, each with 178 of one bold color, plus two going their own way. Each bin arrayed in a 10 x 18 or 12 x 15 grid, per the shop tech’s preference at that moment. Beats counting them one by one.

Secure the lid and shake with all your might: you’re simulating radioactive decay! Loudly.

Pick a number from one to six. Say, three. Each die that turns up with three pips after a shake decays, and you remove it from the bin. With 180 dice in there, the chances of getting all threes – or zero threes – is vanishingly small. One-in-six raised to the 180th power, right? As a percentage that’s, what, nearly 140 zeros after the decimal point? Run the numbers, and you can look forward to around one-sixth of the dice in there decaying with each shake. Sometimes more, sometimes less.

You’ll also keep a close eye on those differently-colored dice. One for you, one for your partner. They’re the atoms you’re watching carefully, and unlike the sorta-predictable rolls of a large mass of dice, they’ll decay when they’re good and ready. Could be first, could be never. It’s an illustration of how probability works in systems of different sizes. Of how the random nature of radioactive decay produces a predictability with enough atoms and enough time.

In some idealized version of this experiment, you’d have 30 dice decay on the first shake. Then 25. Then 21. 17. 15. 12. 10. 8. 7. 6. 5. 4. 3. 3. 2. 2. 2. 1. 1. 1. After that… maybe one per shake? (The student experiment stops well before you’re down to a meager handful of dice.) The half-life arrives around four shakes. Every four shakes. Neat!

And should the effect with 180 dice not be enough? Compare your data to the rest of the lab, seeing how each rate of decay is nearly but not exactly the same. Then aggregate the data from all dozen lab benches. 2,160 dice decaying.

Loudly.