(May 11 – written by Dave)

Ah, a rest day – no alarm and no pressure to get up.  Nice.  Could get used to this.

We had a bit of a look around Pasto today.  Nothing overly strenuous, a cafe, a few churches, bit of a walk through the streets and a visit to the street merchants in the Carnaval Square.  At the square we tried the Colombian version of a toasted cheese sandwich.  That is two arepas (corn like pancakes) grilled with cheese in the middle.  Yes, more bread with cheese.  We always ask about bread, in search of nice grainy types, when we visit local bakeries.  It’s almost a joke for us now as the answer in Colombia of what’s inside bread is nearly 100% guaranteed to be cheese.  Anyway, the sandwich was good, adding a bit of Vegemite for flavour would have been my only suggestion.

Pasto is actually quite large, with about 450,000 folks living here.  It doesn’t feel too big, having a working class feel to it.  When we were in the square today some local police stopped us to give us some flyers and talk to us about how to stay safe.  It was all very friendly and to be honest, we haven’t felt any threat here or for that matter, anywhere in Colombia.  Still it was nice to have police approach us – unlike in places like Mexico where they stand stony faced the M16s at the ready.  It feels more “normal” here.

Pasto sits pretty high up –at about 8,300 feet above sea level.  Yesterday we rode over the pass that was over 9,300 feet high.  But we aren’t really feeling the altitude that much.  It could be the amazing fitness that we’ve developed over the past year (Senior editor’s note – Haha!) or perhaps something a lot simpler.

In fact, I’m pretty sure that “easy breathing” is down to what’s known as the Equatorial Bulge.  The bulge is not something you get from eating too many pan de queso(*), but rather a condition where the earth’s spinning makes the troposphere much thicker at the equator.  The troposphere is basically where everything on earth lives.  It’s 11 miles thick at equatorial latitudes and only 3.7 miles thick at the poles at the coldest time of year.  The extra thickness of the air at the equator creates higher air pressure thus making it easier to breath; easier than it would be at the same elevation nearer the poles.  Pasto is at 1.2 degrees north, right at the thick point in the troposphere.

The Equatorial Bulge is caused the force of the earth rotating.  I hadn’t thought much about the bulge until writing this post but it causes some pretty interesting phenomenon.  Our round earth is actually not a completely round ball, rather it’s a sphere with a thicker middle (technically called an oblate sphere).  A person standing at sea level at the equator is 21 km further from the centre of the earth than a person standing at sea level at one of the poles.  It also means that the tallest mountain on earth (if measured from the centre of the earth) is not Mount Everest, but rather Mount Chimborazo in Ecuador.

The earth’s crust bulges, but so do the oceans and atmosphere.  So, while Mount Chimborazo is further from the centre of the earth, it is not further from the average sea level.  So Everest hangs onto its highest mountain award.  We measure sea level as the average level of the earth’s oceans – this creates a common baseline for measuring many things.  If we measured sea level from the centre of the earth, sea level would be sea “un-level”.  And we’d mess up a whole bunch other things that we want to measure.

If that’s all a bit too technical, just know that breathing at 8,300 feet at equatorial latitudes is easier than breathing at 8,300 feet at a high northern or southern latitude.  If that doesn’t work, maybe just stick with “Nancy and Dave are amazing athletes”, yeah, that’s the ticket…

While Pasto sits pretty high up, hanging nearly 6,000 feet above the city is Galeras, the most active volcano in Colombia.  There hasn’t been a major eruption since 2007 but it is still considered active.  In fact, the experts say that it’s been active for close to half a million years.  I’m not sure how they figure these things out – certainly our hotel’s rooftop observation post has not existed that long.

We couldn’t see Galeras yesterday as the clouds built up by the time we reached the city.  I was up early this morning just to be sure not to miss out again.  There are no obvious signs from our hotel rooftop of volcanic activity.  Hopefully it will stay that way for the next 24 hours as tomorrow we have to ride over its shoulder as we make our way out of town and further south.

Tomorrow we are working our way towards the Colombia/Ecuador border.  We have one or two days of riding left in Colombia.  We’ve been doing all the research on getting across the border as it seems like a difficult proposition these days.  The economic crisis in Venezuela has created a big issue with refugees at many South American country borders.  We’ve been told that Venezuelans believe that Ecuador and Peru offer better treatment/services so they often only pass through Colombia in route to those countries.  Anyway, we’ll deal with that issue in a few days.  We have more eating, resting and “easy” breathing to do here in Pasto today, and in Colombia the next few days.

(*) while not accepted as a scientific phenomenon, eating too many pan de queso can also lead to individual cases of the equatorial bulge.  We have to keep riding our bikes in order not to encounter this other form of bulge.  Eat to ride, ride to eat!