Sunday, September 30, 2012

English postcard #8

Fountains Abbey, North Yorkshire

I hope you don't mind if I continue to "send postcards" from England even though we're home by now.  I also hope you don't mind another picture from Fountains Abbey.  I thought this view was interesting in that four arches could be lined up and captured at the same time.  I don't think I'll ever tire of arched window and doorways, perhaps because they're so rare in our part of the world.

Beans in the backyard 2012, weeks 19, 20, & 21

September 10

Thanks to my trusty assistant, Emil, we have photos to document the bean development in my absence.  These pictures for September 10 show quite a few more yellow leaves than our last photos of the field, but the fact that there were so many leaves visible means harvest is still weeks away.  Another sign of development was the coloring of the pods that were mostly brown instead of mostly green as they've been until these photos were taken.

September 18

Many more leaves had fallen by the time this photo was taken on September 18, but there was still enough green vegetation in the field to indicate that harvest was not imminent.  One can see a distinctive trait of mature beans in this photo: the nearly straight stalks with clearly visible pods, and a noticeable absence of leaves.  This phase in bean development always amazes me, that what looked like a bushy plant a few weeks ago can look like such a straight stick at this phase.

September 23

The beans appear nearly ready for harvest in these photos from September 23.  I believe any green leaves in these photos actually belong to weeds in the field, and not bean stalks.  The stick-like appearance of the stalks is evident again in this photo, and the stalks have clearly reached the R8, full maturity stage.

Even though we've had a pretty severe drought this summer, Farmer Wagenbach appears to have been blessed with beans that have a fair number of pods and seeds.  About the only thing that would reduce the harvest at this point would be storm damage that might make harvest difficult.

Thursday, September 27, 2012

An Experiment in Greenwich

I'm one of those people who enjoys watching the odometer on the car change from lots of nines to lots of zeroes, so when we decided to visit the Royal Observatory in Greenwich I knew I had an opportunity to do a little experiment.  In case you didn't realize, the Prime Meridian at Greenwich was established by Sir George Airy in 1851 and recognized by most of the world in 1884 as the zero longitude line for the earth, separating the Eastern Hemisphere from the Western Hemisphere.  As you can see in the photo below, the line is clearly marked on the ground and on one of the buildings of the observatory, so one can easily situate himself atop this important landmark.

I did just that with my trusty Garmin Nuvi GPS device confident I'd see so many zeroes it would make me giggle.  The photo below shows the device laying on the ground directly on top of the Prime Meridian.

The device did not display as many zeroes as I expected, so I naturally asked myself, "Why?"

I knew that all GPS devices have some error, and that automotive devices like mine are not as accurate as devices that might need resolution in inches.  I guessed the non-zero portion of my reading represented that error.  Since I'm a curious sort, I next set about trying to calculate how much distance is equivalent to the 0.00152 degree "error" displayed by the GPS.  Since the earth is not perfectly round, this calculation is not as trivial as it seems.  Fortunately there are many published estimates of the equatorial radius and the polar radius of the earth, so estimating distances at Greenwich should be possible.

My first attempt assumed the radius of the earth at Greenwich was equal to the average of the polar and equatorial radii.  That's a pretty rough assumption, but I was still surprised when I calculated that 0.00152 degrees was equivalent to about 105.21 meters on the ground.  That's a significant error that's big enough to put someone on the wrong street if it occurred while navigating.  I decided to try a different calculation.

My second attempt assumed the earth has an ellipsoid shape with the equatorial radius representing the semi-major axis, while the polar radius represented the semi-minor axis.  The radius of the circle of latitude passing through Greenwich is a little smaller by this method, but the distance equivalent to 0.00152 degrees is only a few centimeters smaller at 105.17 meters.  Given the agreement between these two calculations, it appears that my GPS thinks I'm 105 meters west of the prime meridian when I'm standing on the Royal Observatory's Prime Meridian.

What happens when I plug that latitude and longitude into an online map?  Bing seems to have the highest resolution image of the Royal Observatory, so this is what you'll see if you enter 51.47792, -0.00152 in the search bar for Bing Maps.  (Brief tangent: Bing's image of Greenwich seems to have been taken early this summer as you can see the Olympic beach volleyball venue partially constructed in the park between the Royal Observatory and the Queen's House.)

You'll have to trust me that the dot on the image above is only a meter or two away from where I was standing when I took the photo of my Garmin.  You can try the numbers in Google Maps or Mapquest, but the results should be similar to what you see above.  Why do the online map services agree with my Garmin, but none of them seem to realize that the line on the ground at the Royal Observatory is the true 0.00000 longitude mark?

After reading a bit on the subject of global positioning systems and international terrestrial reference frames, I learned that even though Airy placed the line on the ground in 1851 where the current meridian is marked, by  the late 1950s the Applied Physics Laboratory at Johns Hopkins University had developed the first satellite navigation system (TRANSIT) that would ultimately move the prime meridian upon which our modern navigation systems are based.  Although TRANSIT was intended to agree with Airy's prime meridian, some assumptions in the definition of its location caused other landmarks around the world to be shifted relative to their location based on Airy's work.  Eventually the International Reference Meridian (which was based on locations relative to TRANSIT) defined by the International Earth Rotation and Reference Systems Service came to be accepted as the prime meridian upon which our navigation systems are based, including my Garmin GPS.  Where is the International Reference Meridian relative to Airy's Prime Meridian at Greenwich?  About 102.5 meters east.

That seems to indicate that my GPS unit has an error of about 2 to 3 meters based on my earlier calculations. That much error seems more reasonable.  I suppose one could walk 102 meters east of the meridian at the Royal Observatory until the display of a GPS unit read 0.00000, but for some reason that doesn't sound quite as charming.  I probably wouldn't even giggle.

Thursday, September 20, 2012

English postcard #7

Broad Sanctuary, Westminster, London

These sites that I've seen many times in photographs really are bigger in real life.  I'm confident we're not in Tremont.

English postcard #6

Seven Sisters, East Sussex

Often mistaken for the White Cliffs of Dover, the Seven Sisters further west is preferred by many as a stunning example of the chalky southern coastline.  We didn't make it to Dover, so we can't compare directly, but we found this view particularly satisfying.

Wednesday, September 19, 2012

English postcard #5

Arlington Row, Bibury, Gloucestershire

William Morris called it "the most beautiful village in England," and I think he had a pretty good eye for beauty.  This row of cottages was built in 1380 as a monastic wool store and converted into a row of weaver's cottages in the 17th century.  Please ignore the satellite dish.

Tuesday, September 18, 2012

English postcard #4

St. Michael's Mount, Cornwall

We were blessed with favorable tides and sunny skies on our visit to St. Michael's Mount, an island that is connected to the mainland by a causeway that is covered by the Atlantic Ocean at high tide.  We crossed when the tide was about at its lowest, enjoyed a tour of the castle on the mount, and crossed back less than two hours later before the causeway was closed to foot traffic.

Friday, September 14, 2012

English postcard #3

Fountains Abbey, North Yorkshire

This abbey and the adjoining grounds of Studley Royal was one of the first historic sites Karen and I visited several years ago, but our girls had never enjoyed them.  The remaining structures of the Fountains Abbey grounds suggest a productive and prosperous community several hundred years ago.  One can only imagine the experience of visiting a place like this back then.

Wednesday, September 12, 2012

English postcard #2

Lake Windermere, Cumbria

For our friends back in Tremont we offer this view of the REAL Lake Windermere, not the 5-acre substitute in central IL.  This lake is truly a holiday destination, and we were glad to visit after the crowds had subsided.  The photo was taken from the roadside on our way over "The Struggle," a narrow road leading to the Kirkstone Pass.

English postcard

Lyme Park, Cheshire

We don't have many buildings like this in Illinois, and those that are this big and ornate are government buildings built with our taxes.  This building however, is a home.  At least it was originally built as a home when construction began in the late 16th century, but was donated to the National Trust in 1946 so we can all tour it and enjoy it.  Jane Austen movie fans may recognize this building.