Thursday, March 17, 2016

A Tilted Perspective

A thought occurred to me the other day.  How far is it until you start to experience curvature of the earth, excluding topographical irregularities?  Well, right away, technically.  But I decided to use one degree of curvature to represent significant change. 

Before I did the simple calculation, I wanted to see what my gut sense of mileage would be equaling one degree of curvature.  Without thinking about it too much, I decided it would be between 125 miles and 250 miles (between 201 and 402 Kilometers), and to pick a number, I chose 125 miles. 

I did the calculation and found that at the equator, one degree of curvature would be just a bit over 69 miles (111 Kilometers).  This surprised me as it is a smaller number than I thought it would be.  So, when I drive up to my girlfriend’s mother’s house and back in a day as I am sometimes prone to do, which is about 244 miles (392 Kilometers) round trip, I experience a combined total of 3.5 degrees of earth curvature there and back.  That’s quite a bit in just a few hours. 

Then, I jumped to another thought.  I live in Burbank, California.  New York is about 2,448 miles as the crow files.  This means that the difference in the earth’s curvature between Burbank and New York is about 35 degrees of earth curvature.  The following assumes that you live in Los Angeles, but you can do this kind of calculation between any two points by taking the mileage between the two and dividing it by 69 miles.  That will give you the approximate degrees of surface curvature change.

So, now, take your iPhone, open up the Utilities App (that one that has the Calculator, the Voice Memo and the Compass) and tap open the Compass.  If you need to roll the ball around to orient your compass since you haven’t used it for a while, then do it.  Now, swipe the compass screen to the left, and you'll land on your digital spirit level.  Did you even know you had one of these? This gives you the proper degrees for any surface, like the flatness of a table or window sill.  I suppose that it makes carpenters very giddy to have this feature on their iPhone. 

Now, tilt your phone, preferably eastward (if you don't know where east is from where you are sitting, then swipe right on your screen back to the compass...then swipe back), until the spirit level screen shows a 35 degree change toward the east.  This is what “flat” is in New York this very moment.  Now, imagine that all of the sky scrapers are all tilted up into the air in that direction relative to where you are sitting.  It’s not imagination; it’s true!  Isn’t that wild?  We all know that the earth is curved, but as you are tilting your phone, realize that all of those CNBC anchors at the New York Stock Exchange are all sitting tilted this same 35 degrees from your own orientation.  Cab drivers are terrorizing Manhattan streets that parallel the glass on your iPhone, and school kids are bouncing balls up and down perpendicular to your screen.  Pretty funny I think!