How Do Water Towers Work?

iStock
iStock

As infrastructure goes, water towers are pretty picturesque. Some people turn them into houses once the city no longer needs them. The designers at Pop Chart Lab have created a visual ode to New York City’s water tower taxonomy. But why exactly do we need to store our water hundreds of feet above the city?

Most water towers are pretty simple machines. Clean, treated water is pumped up into the tower, where it’s stored in a large tank that might hold a million or so gallons—enough water to run that particular city for a day. When the region needs water, water pumps utilize the pull of gravity to provide high water pressure. Because they work with gravity, they have to be taller than the buildings they’re providing water to in order to reach the highest floors. Each additional foot of height in a water tower increases water pressure by .43 pounds per square inch.

Here's a basic diagram of what a water tower system looks like:

Image Credit: Jonathan Cretton via Wikimedia Commons // Public Domain

Keeping water high off the ground plays another important role for a city infrastructure. It allows regions to use smaller water pumps. In general, water demand for a city fluctuates throughout the day. Lots of folks are taking showers before work and school, but fewer people are running a lot of water at 3 a.m. Without a water tower, the municipality would have to buy a water pump big and powerful enough to keep up with peak demand in the mornings, which would then largely go to waste during less busy parts of the day for water usage (plus incur extra costs). Instead, municipalities can buy a pump just large enough to satisfy the region’s average water demand for the day, and let the power of the water tower take over during the times with demand that exceeds the pump’s capabilities. When water demand goes down at night, the pump can replace the water in the tower. Also, if the power goes out and the city’s water pumps fail, the water tower can keep water running smoothly for at least 24 hours.

Go inside a water tower in Edmond, Oklahoma:

And in Bloomington, Minnesota:

Look at that tank!

Screenshot via YouTube

And here's a 1-million-gallon water tank getting cleaned:

While water towers generally seem like the product of a bygone era, they’re still very much relevant today. The Louisville Water Tower in Kentucky, built in 1860, is the oldest surviving water tower in the country, and it's still in use. In New York City, millions of people still get water from water towers, though it's one of the last large cities to rely on the system. Stored on top of tall buildings, these water towers provide the pressure for water to flow even if the electricity goes off (especially during a fire).

And, of course, one cannot discount the cultural importance of the water tower:

Image Credit: Jonathunder via Wikimedia Commons // CC BY-SA 3.0

Every city deserves a skyscraper-sized civic monument to its favorite crop. Or beverage decanter.

What Is the Kitchen Like on the International Space Station?

iStock/Elen11
iStock/Elen11

Clayton C. Anderson:

The International Space Station (ISS) does not really have a "kitchen" as many of us here on Earth might relate to. But, there is an area called the "galley" which serves the purpose of allowing for food preparation and consumption. I believe the term "galley" comes from the military, and it was used specifically in the space shuttle program. I guess it carried over to the ISS.

The Russian segment had the ONLY galley when I flew in 2007. There was a table for three, and the galley consisted of a water system—allowing us to hydrate our food packages (as needed) with warm (tepid) or hot (extremely) water—and a food warmer. The food warmer designed by the Russians was strictly used for their cans of food (about the size of a can of cat food in America). The U.S. developed a second food warmer (shaped like a briefcase) that we could use to heat the more "flexibly packaged" foodstuffs (packets) sent from America.

Later in the ISS lifetime, a second galley area was provided in the U.S. segment. It is positioned in Node 1 (Unity) and a table is also available there for the astronauts' dining pleasures. Apparently, it was added because of the increasing crew size experienced these days (6), to have more options. During my brief visit to ISS in 2010 (12 days or so) as a Discovery crewmember, I found the mealtimes to be much more segregated than when I spent five months on board. The Russians ate in the Russian segment. The shuttle astronauts ate in the shuttle. The U.S. ISS astronauts ate in Node 1, but often at totally different times. While we did have a combined dinner in Node 1 during STS-131 (with the Expedition 23 crew), this is one of the perceived negatives of the "multiple-galley" scenario. My long duration stint on ISS was highlighted by the fact that Fyodor Yurchikhin, Oleg Kotov, and I had every single meal together. The fellowship we—or at least I—experienced during those meals is something I will never, ever forget. We laughed, we argued, we celebrated, we mourned …, all around our zero-gravity "dinner table." Awesome stuff!

This post originally appeared on Quora. Click here to view.

Clayton "Astro Clay" Anderson is an astronaut, motivational speaker, author, and STEAM education advocate.

His award-winning book The Ordinary Spaceman, Astronaut Edition Fisher Space Pen, and new children's books A is for Astronaut; Blasting Through the Alphabet and It's a Question of Space: An Ordinary Astronaut's Answers to Sometimes Extraordinary Questions are available at www.AstroClay.com. For speaking events www.AstronautClayAnderson.com. Follow @Astro_Clay #WeBelieveInAstronauts

What Do the Numbers and Letters on a Boarding Pass Mean?

iStock.com/Laurence Dutton
iStock.com/Laurence Dutton

Picture this: You're about to embark on a vacation or business trip, and you have to fly to reach your destination. You get to the airport, make it through the security checkpoint, and breathe a sigh of relief. What do you do next? After putting your shoes back on, you'll probably look at your boarding pass to double-check your gate number and boarding time. You might scan the information screen for your flight number to see if your plane will arrive on schedule, and at some point before boarding, you'll also probably check your zone and seat numbers.

Aside from these key nuggets of information, the other letters and numbers on your boarding pass might seem like gobbledygook. If you find this layout confusing, you're not the only one. Designer and creative director Tyler Thompson once commented that it was almost as if "someone put on a blindfold, drank a fifth of whiskey, spun around 100 times, got kicked in the face by a mule … and then just started puking numbers and letters onto the boarding pass at random."

Of course, these seemingly secret codes aren't exactly secret, and they aren't random either. So let's break it down, starting with the six-character code you'll see somewhere on your boarding pass. This is your Passenger Name Reference (or PNR for short). On some boarding passes—like the one shown below—it may be referred to as a record locator or reservation code.

A boarding pass
Piergiuliano Chesi, Wikimedia Commons // Public domain

These alphanumeric codes are randomly generated, but they're also unique to your personal travel itinerary. They give airlines access to key information about your contact information and reservation—even your meal preferences. This is why it's ill-advised to post a photo of your boarding pass to social media while waiting at your airport gate. A hacker could theoretically use that PNR to access your account, and from there they could claim your frequent flier miles, change your flight details, or cancel your trip altogether.

You might also see a random standalone letter on your boarding pass. This references your booking class. "A" and "F," for instance, are typically used for first-class seats. The letter "Y" generally stands for economy class, while "Q" is an economy ticket purchased at a discounted rate. If you see a "B" you might be in luck—it means you could be eligible for a seat upgrade.

There might be other letters, too. "S/O," which is short for stopover, means you have a layover that lasts longer than four hours in the U.S. or more than 24 hours in another country. Likewise, "STPC" means "stopover paid by carrier," so you'll likely be put up in a hotel free of charge. Score!

One code you probably don’t want to see is "SSSS," which means your chances of getting stopped by TSA agents for a "Secondary Security Screening Selection" are high. For whatever reason, you've been identified as a higher security risk. This could be because you've booked last-minute or international one-way flights, or perhaps you've traveled to a "high-risk country." It could also be completely random.

Still confused? For a visual of what that all these codes look like on a boarding pass, check out this helpful infographic published by Lifehacker.

Have you got a Big Question you'd like us to answer? If so, send it to bigquestions@mentalfloss.com.

SECTIONS

arrow
LIVE SMARTER