Scalia’s death will be felt through 2060

When Justice Antonin Scalia passed away last Saturday, political commentators wasted little time on eulogies. And while the influential jurist certainly deserves a moment of memorializing, the press can hardly be faulted for focusing on his successor. The battle currently raging over Scalia’s replacement will have an impact on American democracy lasting decades beyond his death.


I used actuarial tables (that is, death statistics) to build a Supreme Court tenure simulator. Each run of the simulation plays out one possible future, with each justice having a probability of dying each year in accordance with his/her age and gender. For example, if Stephen Breyer lives to see 2030, he will, as a 92-year-old man, have a 20.5% chance of passing away that year.
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Manhattan subways — an explainer for transplants

The Manhattan subway map looks like a confusing mess, but it’s actually pretty simple. Even the most fresh-faced transplant can make sense of it, if you just break it down into what you really need to know:

1.  Manhattan is pretty much a rectangle.


2.  Most trains run up and down the island.


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New Hampshire randomizer: Read tomorrow’s headlines

Sanders and Trump are favored to win tonight, but the exact details could play out several different ways. Using FiveThirtyEight’s projections, I made a New Hampshire randomizer. It generates a vote breakdown, and then writes headlines accordingly.


Seeing the variability on the Republican side in action is a good reminder of how much is at stake tonight for some candidates.


Play with the randomizer here:

Romy asks, “What’s the relationship between space and time?”

When you’re planning to meet up with someone, what do you specify? Just saying Grand Central isn’t enough, and just saying noon isn’t enough either. You need both a place and a time.

The same is true in physics. Physics explains the world of matter, moving and changing and interacting with other matter. All these events—motion, change, interaction—happen somewhere in space and somewhen in time.

It’s not too hard for us to think of space as a big, concrete whole and ignore our place in it. It’s very hard to do this for time. We think of “now” as absolute in a way that we don’t think of “here” as absolute. We look at events like this:

But why take time-slices? Why not look at it like this?

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Romy asks, “Why are politicians constantly arguing about everything instead of actually getting something done?”

Representative Joe Wilson once shouted “You lie!” in the middle of a speech by Obama. He received a formal slap on the wrist from the House. He also received $1 million in donations over the next three days. Politicians bicker because that’s what they’re paid to do.


Well, first we have to see how a bill really becomes a law.


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Romy asks, “What is color?”

Here are two puzzles about color:

  1. Is color cyclical (like a color wheel) or linear (like a spectrum)?
  2. How come some people can’t tell red and green apart?

Here’s the key: Color isn’t an actual property of any object on its own. An apple isn’t red. The apple, the sunlight, your eyes, and your visual cortex work together to create the sensation of red.



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Romy asks, “How do airplanes work?”

I want you to try a little experiment. Really, you should try it—it’s super easy!

Find a piece of paper. Pinch two adjacent corners between your thumbs and pointers, with your thumbs on top. Now press that edge of the paper up against your lower lip. (Don’t get a papercut!) Breathe all the way in, as far as you can go… and blow out.

What happened?

The reason the paper defies gravity is actually pretty simple. You just need to know two things:

  1. Air sticks to air, just like water sticks to water when rain droplets bead together and run down a car window.
  2. Any time there’s a vacuum—totally empty space, without even air in it—something has to fill it up.

When you blew air over the piece of paper, here’s what happened. The air behind the paper stuck to the air you were blowing, so it also moved forward. This left a vacuum behind the paper.

So the paper and the air compromised, and both filled in part of it.

This is called the Coandă effect (pronounced QUAN-duh). And it’s also how airplanes work. Airplanes seem totally magical, but they’re really just following this simple rule.

An airplane wing is shaped to take advantage of the Coandă effect. As the plane is flying forward very quickly, a lot of air has to make its way around the wing. The air that rushes over the wing is just like the air you blew over the piece of paper—just way, way faster.

The wing is rigid, so it can’t bend up like the paper. Instead, it has to move up to fill the vacuum… and it pulls the entire plane with it. The plane is also pushed up from the bottom by the air going under the wing.

When the wing is tilted more, both of these effects are stronger. (Try to think about why.) When the plane takes off, the wing is tilted enough that the “lift” is stronger than the weight of the plane, so it rises. In the air, the wing tilts back a little until the lift balances out the weight, and the plane stays steady. On the way down, well, you get the idea.

Does this still seem a little magical? It certainly does to me. Well, you can use the Coandă effect right now to make something hover in mid-air. All you need is a ping pong ball and a straw. (This actually works—I just tried!)

All you have to do is blow through the straw at a slight angle from directly up, and put the ping pong ball in the line of the straw. If you do it just right (you might have to try a few times) the ping pong ball will hang in the air until you run out of breath.

Okay, I’ll be honest: it seems even more magical now. I can understand why the ball is floating in midair, but it’s still crazy to see it hovering there. Sometimes understanding how something works doesn’t make it any less incredible.

More on this: Marshall Brain, How Airplanes Work

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