Schoolyard Science #1: Atmospheric Pressure. You can try this at home.

  

Okay class,
Today's lesson is altitude and atmosphere...
Air gets 'thinner' as altitude increases, right?

Bogota is one of the highest cities in the world  (Denver's at 5,300 ft.  Bogota's at 8,300 ft / 2,500 meters.) Check out the graph from Wikipedia...
Bogota has about 77% of the air that Miami has.

When we first got here, we were huffing and puffing.  Climbing a stair was challenging.

Luke pointed out that soda pop was really fizzy.

#1.
I went on flight from high Bogota (8,300 ft) to the coast (0 ft).  I started with a plastic water bottle filled with air.  (Now class, Keep in mind that this air is at Bogota's lower pressure.)

When the plane landed near the coast (altitude ~0 ft), this is what the bottle looked like (below). Crushed.
The more dense air at the coast (outside the bottle) squeezed the less dense air inside the bottle until the air inside and outside were at the same pressure.  (When the pressures were different from each other, the walls would be moved by the difference.  And, they were!)

This is the same sort of thing that happens to your ear drums when your ears 'pop' in a plane or tall elevator.  A pressure difference builds up across your eardrum, and your eardrum bends, until either:
1) you clear your ears and relieve the pressure difference (which usually happens naturally when you yawn), or
2) Your eardrums explode.

But is this case, we just measured the volumes of air that were in the bottle before and after the compression. Without compression...600 ml.  With compression...about 440 ml.
Ratio With/Without = 440/600 = 73%.  Which isn't too far away from the prediction of 77%

(Bonus question:  How can you measure the 440 ml volume of the compressed bottle?
Post your answer on this blog below.)

First Photos from Quito and the Ecuadoran Andes

We start with two days in Quito.  The trip was arranged by a grand-father friend from Luke's Miami school.  He had been a leader in the tourism industry in Ecuador.
First morning was visiting the ancient Spanish churches.  (Our favorites were the "back-stage" access to the Jesuit's church and the national cathedral.)

Walking between the ceiling and cathedral roof.

Afternoon spent visiting the equator and its adventures in physics.  See how the  water goes down the drain differently (circularly), even though the three basins are only about six feet apart.

North Hemisphere (above).

Southern Hemisphere (above)

On the equator (below)

An evening in the old town streets.  Lauren and I find a cozy place to listen to live Spanish guitar and singing.

Next day, and two hours to the north, Zuleta, a farm of a former president (1940s).  We visit a condor rescue station and see three wild condors there (of about 100 in the country).  We also spot a spectacled bear hanging out on a cliff near the condors' roost.  Horses provide a gentle ride.

We help milk cows. I'm evaluated as "not very good", but I try...a lot.

Our 'milkmaid'

We visit a commercial rose farm (big business in Ecuador and Colombia both) and ancestral home of the owners' family; previously a Jesuit mission.

Heading south we pass through large indigenous peoples' markets...and leave with matching hats.

Arriving near live volcano Cotopaxi (19,000+' altitude) at Hacienda El Porvenir (means 'good things to come').  Rains diminish the view, but not the beauty.  During a wet afternoon, we learn to make (great!) empanadas.

With the morning comes a horse ride to scenery.  We dress warmly in the manner of chagras (Andean cowboys).  I suspect the chagra guides are evaluating our horsemanship to see if we're up to the planned three-day-ride that's planned for the tomorrow.
We pass the test.

Geraldo, last year's champion chagra, and our host.

New horses with more spunk, clouds lifting (a little), and we set off on a 45 kilometer ride to a remote house on the other side of the volcano (Geraldo and his brother share the house).  No fences slow us through the national park and neighboring lands.
About 8 hours later...Hurrah! We make it! And not sore...due to great saddles and mucho padding.

Next day we ride and gallop (!  They won't let you do that in the US!), returning to fish, hike and listen to our chagra hosts sing.

The night is perfectly clear.  The Milky Way is mind-blowing.
Dawn shows us Cotopaxi full and clear.  The horses are eager to run and off we go.

Our two guides are themselves stunned by the mountain's view,  "Best in 20 years".  The horses know the way and run hard.  (No photos of galloping...I'm just hanging on.)

We're guided to a slow stream that comes directly out from a hill.

Once back, the hot tub and sweat lodge call.  Posh.

The last night, our Miami-host insists we stay at his Ecuador farm.  Of course he does, and we do.  He brings friends and student chefs. Fiesta follows.

Chefs in the outdoor kitchen

Long-tailed hummingbirds buzz the party.

Back to Bogota on Day 10, disoriented at the spectrum of the journey.
(300+ photos to sort through).

Puzzles to Solve

Why are there so many fire extinguisher recharge kiosks?
Why are there pillboxes in parking lots?
Why are there signs saying what land is Not for sale/lease/use?
What's that store that sells nothing but eggs?
Why do the soldiers wave from the sides of the roads?
Why are there no traffic cops? Traffic tickets?

Colombians are the fire-safest people in the world

The good people of Bogota to be the most fire-safe people in the world.  It's one of the very first things a visitor notices.  Fire extinguishers are everywhere. And these extinguishers are not the small couldn't put a candle out variety.  Commonly we see globe devices two feet across, side by side.

And apparently they get used. A lot.  I'm guessing this from the very large number of fire extinguisher recharging stations you see everywhere.  "Wait a minute" you might ask. "I've never even seen one recharging station".  And you'd be right, if you are in the States.  Not here.  You can't miss them.  They are sometimes literally on every street corner. (No, really, "literally") 

Want proof?  See the photos that follow.  I took these photos while driving along just a two mile stretch of Bogota's main road, the Autopiste Norte.  Each photo shows an independently owned and operated kiosk that sells or recharges fire extinguishers.  That's about one kiosk every other block.

I don't get it, but I'll add this puzzle to my running list. (See another blog entry on puzzles to solve.)  (And no, it's not a special national fire safety day.  This is every day.)

And it's not just the highways.  There are small fire extinguisher re-charge shops all over town.  They also sell other safety equipment (roadside reflectors, hi-viz vests, traffic cones).

So, Watson, I conclude that Colombians are the fire-safest people in the world. And a special hats off the the business hustle of Bogota's Chargers (Is that what they're called?)  They're out there making sure that the fire extinguishers of Colombia's capital are ready to save the day from fire.  Well done!