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Wednesday, May 27, 2015

Catenaries, Square Wheels, and Washboarding

      The square-wheeled bike at Macalester College in St. Paul, Minnesota, is the inspiration for this week's PEOTS. 


     Mom, ZoĆ«, and I had fun riding the blue-wheeled trike along the catenary curves:

     It really is a smooth ride and one does not feel the bumpiness of a washboarded dirt road as the length of the squares' sides roll perfectly into the endpoints of the catenaries. It is intriguing that quarter circles were used to move large square blocks of marble around the pyramids.

       So all those jokes about square wheels really aren't quite as funny any more. . .

     Jan's questions about washboarding on dirt roads dovetails into our square wheel discussion:

     This article discusses why wash board ripples or corrigations form whenever a vehicle travels more than 5 miles (8 km) per hour over a gravelly or sandy surface. My best guess as to why they extend over the whole road is that drivers try to avoid existing ripples, thereby inevitably creating more right next to them. 

      The most mysterious part of the researchers' results is that the ripples appear even when the springy suspension of the car and the rolling shape of the wheel are eliminated.

       Letting some air out of tires when going over washboarded roads approaches traveling over catenary-like bumps with a square-ish tire.

         What other questions spring from square wheels, catenaries (which makes me think of a cat who ate the canary) and washboarded roads?

Sponge Steph, Square Pants

Monday, May 18, 2015

Blue Earth, Green Giant, and Tidings from Mac

      We are taking a detour from the traditional PEOTS meanderings to our return road trip from The Cities through southwest Minnesota:

     We had a great time in Blue Earth as Maizie frolicked beneath the giant's size 78 shoes.

     Of course, in all the cement arrow searchings, this was the definite highlight. Congrats to Zoe, Macalester Class of 2015. May your meanderings in Ethiopia be long, safe, and fruitful! 

        What a great, l o n g trip it's been! Thelma and Louise-ing it. . .

Very bittersweet moments here,

Tuesday, May 12, 2015

Road Tripping the Cement Arrows Fantastic and Ten Geologic Images

          Road tripping here in search of large cement arrows. ;-) Perhaps you can tell where Mom, Maizie and I have been from a few photos and knowing what time of year it is:

       And for this shortened week, enjoy Ten pictures that will "make you want to become a geologist."

     Checking my quiver carefully.

Steph and Co

Tuesday, May 5, 2015

Century-Old Cat Tongue: Papillae-On

      I'm short on time this week so will present you with this link to a 100-year-old image of a cat's tongue in today's Science Friday :

      The text from the NPR Science Friday link is also reproduced below:

       "You’re looking at a 3 mm-wide section of a cat tongue more than a century old. David Linstead’s captivating image was a winner in this year’s Wellcome Image Awards.

       "The picture is actually a composite of 30 polarized light micrographs, or photographs taken with a digital camera and a microscope. A retired cell biologist, Linstead used microscopes professionally as a research tool, and later formed his “hobby addiction” after purchasing one, then another, and still more microscopes on eBay (also his go-to source for specimen-plated slides like this one). His particular interest is in combining modern illumination techniques with vintage slides dating from 1860 to 1910, the heyday of slide-making."

      “The original person who made this slide likely had no thought of how it would be used in 100 years’ time,” says Linstead, who estimates that it dates back to the 1890s. “But when I saw it, I immediately knew it had great potential.”

     "The promise lay in the way the slide was prepared. It wasn’t stained, for one, which allowed the cross-section’s true colors to be observed with polarized light—a feature of most cutting-edge microscopes of the Victorian age. Those yellow streaks, for instance, are horizontal muscles, and the sparse purple ones are muscles that run vertically."

      "Furthermore, the original tissue had been injected with a dye—probably a solution of iron salt in warm gelatin, Linstead surmises—to make the capillaries, seen here as black squiggles, apparent. (The only alteration Linstead made to the image was to Photoshop the background gray, because the original magenta “didn’t go well with the rest of the slide.”)"

      "Colors aside, the serrated ridge may be the most intriguing aspect of this picture. Those rough bumps, or papillae, are the reason that a kitty’s tongue feels like sandpaper when it licks you. When a cat grooms herself, the papillae

 act like a comb to remove dirt and loose hair. But they also serve a grislier purpose: rasping meat off of bones. Fluffy might look sweet, but Linstead’s striking image is a reminder that the cat napping on the couch is a fierce predator."

       The other 19 images in this year's Wellcome awards, including these specialized Purkinje brain cells, are also quite intriguing.

     Let me know what you think. . .Hoping the cat doesn't have your tongue, er, thumbs. 

     [With fond thoughts of Lego's Noosie.]



Purkinje cells showing well-defined organization: