# Let’s talk numbers!

Two neat things from an AskReddit post.

## One:

cubosh said: Take every planet in our solar system, line them up so they are all touching, and they will fit inside the space between earth and our moon, with room to spare.
>to which jbhall36 said: Take every planet in our solar system, line them up so they are all touching, fit them in the space between Earth and our moon, and the gravitational force would be catastrophic and likely kill everything on Earth.
>>to which Rogukast1177 said: You don’t need the “likely”
>>>to which pinkbutterfly1 said: You do need the “likely”. Because Tardigrades. http://www.bbc.com/earth/story/20150313-the-toughest-animals-on-earth

## Two:

A while ago I write about Graham’s Number, which is really migraine inducing. Another (much smaller) number is how many ways you can shuffle a standard deck of 52 cards. Here’s what VerbableNouns said (which really was written by techniforus):

One of my favorite is about the number of unique orders for cards in a standard 52 card deck.

I’ve seen a a really good explanation of how big 52! actually is.

• Set a timer to count down 52! seconds (that’s 8.0658×1067 seconds)
• Stand on the equator, and take a step forward every billion years
• When you’ve circled the earth once, take a drop of water from the Pacific Ocean, and keep going
• When the Pacific Ocean is empty, lay a sheet of paper down, refill the ocean and carry on.
• When your stack of paper reaches the sun, take a look at the timer.

The 3 left-most digits won’t have changed. 8.063×1067 seconds left to go. You have to repeat the whole process 1000 times to get 1/3 of the way through that time. 5.385×1067 seconds left to go.

So to kill that time you try something else.

• Shuffle a deck of cards, deal yourself 5 cards every billion years
• Each time you get a royal flush, buy a lottery ticket
• Each time that ticket wins the jackpot, throw a grain of sand in the grand canyon
• When the grand canyon’s full, take 1oz of rock off Mount Everest, empty the canyon and carry on.
• When Everest has been levelled, check the timer.

There’s barely any change. 5.364×1067 seconds left. You’d have to repeat this process 256 times to have run out the timer.

Now, that gives you some inkling of how big 52! is, but that’s nothing compared to Graham’s Number which I mentioned earlier.

# This is why we can’t have nice things

My 6th grade is studying waves. Part of this involves making waves using slinkies. I know that slinkies are fun toys, so there’s a whole harangue about treating them carefully and not playing with them. Nonetheless, it didn’t take 2 days until someone turned one into abstract art.

Now, I know that slinkies aren’t expensive, but it’s the principle of the thing. Now I don’t have enough for all the groups.

😢

# March for Science

On Saturday I went in to NYC for the March for Science. While I wasn’t able to go to the main one in Washington DC, this one was pretty big, with about 20,000 people attending. After the rally, we marched from Central Park West to Times Square. I was wearing my “I Teach Science, What’s Your Superpower?” shirt, and three people took my picture. 🙂

Hopefully the worldwide turnout will lead to some attitude changes in Washington DC. But given the rampant anti-intellectualism of this administration, I’m not holding my breath.

Here are some of the best signs I saw:

Carrie Poppy has a great story about how she went from believing that her home was haunted, to finding out what the danger really was. And yes, it was life threatening. But there’s more, about why skepticism is a good thing.

# Self serving biases and your own knowledge

How much do you know? Really? That much? Are you sure?

It turns out that there are lots of ways to think that you know more than you really do. Here’s a good scischow youtube about it. One of my favorites is the Dunning-Kruger Effect, which I see lots of. Basically, the less you know about something, the more you think you know. As a teacher I see this when students think they understand the topic, but then proceed to bomb the test. It works like this: When you have a beginners knowledge of something, you don’t know the intricacies of it. You don’t know just how much more there is to know.

I teach middle school science, so the material has been simplified—there’s a lot more to it than what I teach. Some students don’t get the simplified version, and they think that what they’ve gotten (the very simplified) is easy. Then they have to take a test on what they should know, and they have trouble with it. And when they get to a question on higher-order thinking skills … watch out!

The thing is, I think they could do much better. But when they’re studying, they think they know it, so they don’t study much. If they understood how much more they need to know, I think they’d realize that they needed to study more.

Anyway, watch the video.

# Large numbers are hard to understand

Lots of people have a blind spot for numbers. Especially large numbers, like a million or a billion. Lots of people think that numbers like a million, a billion, and a trillion are evenly spaced on the number line, like 1, 2, and 3 are. But the amount of space between a million and a billion dwarfs the distance from 1 to a million. A billion is a thousand millions.

Here’s another way to look at it. It takes about 12 days for 1,000,000 seconds to elapse. But it takes about 32 years for 1,000,000,000 seconds to elapse. They are so far apart. But most people just stop thinking about what these numbers really mean, and kind of lump a million and a billion together. Kind of like “they’re big numbers, and a billion is bigger than a million”. Well, yes, that’s true. But it loses how much bigger, and it’s a lot.

# Save lives for under a buck

A previous student of mine showed me this video, which actually ties in with something I had just found out about a few weeks previously. By combining a cheap, paper microscope that cost about \$0.50 to make, and a child’s spinning toy, it is possible to diagnose malaria, which kills millions each year. The microscope is called the Foldscope. It’s printed on a heavy piece of die-cut paper, and then gets cut out and folded into a surprisingly powerful microscope, able to see blood cells. You can preorder these yourself (I have!). The other piece, the spinning toy, replaces expensive centrifuges to separate the blood into components. Coupled together (along with a doctor) you can do the lab work for diagnosing malaria for under \$1.

# Antibacterial dragonflys

There are a number of things that are naturally antibacterial. Silver, for one. For a long time, people have been using silver in things to help stop diseases. There’s also dragonfly wings. Now, scientists are making surfaces similar to the dragonfly wings to destroy bacteria. These are called nano-textured surfaces (NTS) and might lead to new materials that help prevent diseases.

# What happens when you stop smoking?

My parents smoked. They tried to stop a few times, but always started again. Maybe if they knew how quickly the body starts to repair itself after you stop smoking, they would have stuck with it. Here’s a good video from ASAPscience about this.