How fast does a germ move? Well, when it's not being helped along by your 100-mile-per-hour sneeze, the average bacteria moves along at a blistering land speed of 0.00045 miles per hour. That is 67 times slower than the average garden snail. So what happens when you drop your donut? Does the five-second rule still apply?
細菌移動的速度有多快？這個嘛，沒有你那時速一百英里的噴嚏幫忙時，一般細菌以每小時 0.00045 英里的超快陸上速度移動。那比普通花園裡的蝸牛慢六十七倍。所以在你把甜甜圈弄掉時發生了什麼事？五秒規則還有用嗎？
Is the five-second rule legit?
We've all heard of the five-second rule—get to the cookie within five seconds and it's good to eat. But is there any real science behind that? Let's go find out.
Free cookies! In the name of science! Cookies? Anyone? Hello, sir, how are you doing today?
I'm offering free cookies to everybody at the park. I hope that's not too weird.
All right, then. Here's your free cookie. There's one catch, though. Gotta eat it off the ground. That's the five-second rule, so it should be good, right?
You...you keep it.
One free cookie for you.
Let me get it for you. That was less than five seconds. You wanna eat it now?
You think it's been that long?
Don't eat that!
No, it's not. That's gross.
It's nothing, like, you see the crumbs on...?
It fell on—don't eat that! It fell on the ground!
So, is she right? Or is he right? It depends—the five-second rule is really the 30-second moisture-and-surface rule. When any food flops on the floor, small amounts of bacteria will jump aboard immediately. But moist foods left longer than 30 seconds collect 10 times the bacteria than those snapped up after only three. E. coli, salmonella, and listeria love wet environments. They absorb water for the nutrients they need to grow and multiply.
But moisture isn't the whole story. Rugs transfer fewer germs than linoleum because the little tufts have less surface area touching the food. So, is the five-second rule legit? Yes! (for the most part)
If you drop that cookie on dry ground, you should have plenty of time.
People walk on here.
God made dirt, and dirt don't hurt.
Thank you, guys. Have a good day!
The next time you see a rocket scientist toss his cookies...
Anybody else want free cookies? Free cookies!
Take a bite! Time is on your side.