Optical illusions, and “Bloody Mary” images

October 24, 2010

Take a look at this.  Focus on the “+” in the middle, and describe what you see.

Troxler Effect, the purple chaser

Troxler Effect image

No, the purple dots don’t disappear, though that’s probably what you “see.”  Worse, there’s no green dot.  Your brain sees green when the purple disappears — and even when your brain refuses to let you know the purple dots are still there, it will tell you you see a green dot when the purple dots you can’t see, disappear.

So, is it so hard to understand that people might see weird things in the mirror, if they stare at their own faces for a while?

Cortical Hemming and Hawing has the full story, with a history of the Bloody Mary story.  Go see.


Texas State Fair long past

October 24, 2010

Texas State Fair 1912 - LOC panoramic photo - 6a28033r

Texas State Fair, 1908 - Library of Congress panoramic photo

Click on the photo to see a much larger version.

From the astonishingly vast vaults of the Library of Congress, a panoramic photograph of the main entrance of the Texas State Fair, in 1908.  This is almost certainly Dallas, and this is probably the same entrance where today the short-rail mass transit trains pass by — a century later, and Dallas has once again got mass transit.

This photo contrasts starkly with Fair Park in Dallas today, a week after the closing of the 2010 Texas State Fair.

Details from the Library of Congress:

Item Title

Texas State Fair, Main Entrance.
Created/Published  c1908.

Copyright deposit; H. Clogenson; December 8, 1908; DLC/PP-1908:43634.
Copyright claimant’s address: Dallas, Texas
Medium:  1 photographic print : gelatin silver ; 9.5 x 43 in.

Call Number:  PAN SUBJECT – Events no. 31
REPRODUCTION NUMBER:  LC-USZ62-125457 DLC (b&w film copy neg.)

Who was H. Clogenson?  What other treasures did he leave around?


Butterflies are free, to move about the country

October 24, 2010

Great mysteries of science, history and spirit call to us:  How do the monarch butterflies do it?

Monarch butterflies (Danaus plexippus) fly north from their enclave in Mexico every spring, stopping to lay eggs on milkweed plants.  After a migration of several hundred miles, that first group that left Mexico dies off.  Their offspring hatch in a few days, devour the milkweed, make a chrysalis, metamorphose into butterflies, then fly farther north, where they repeat their parents’ behavior:  Lay some eggs, and die.  Within three generations, they’ve spread north into Canada.

Kathryn's butterfly plantings, October 2010 - photo by Ed Darrell

Inviting the monarchs in: You can see how Kathryn worked to attract butterflies. In this photo, you can see the butterfly weed (a milkweed), red Turk's cap, and blue ageratum especially for the monarchs.

Then the fourth generation does something so strange and wonderful people can’t stop talking about it:  They fly back to Mexico, to the same trees their great-great-great grandparents left.  There they sip some nectar, get some water, and spend a lot of time hanging in great globs, huddling over the winter, to start life for generations of monarch butterflies the next spring.

Sometimes in Texas in October, we can see clouds of monarch butterflies winging south.  If we’re lucky, they stop to visit our backyards and gardens, and we might provide some water and nectar to urge them homeward.  Kathryn, of course, plants the stuff the monarchs like, to help them, and to give us a chance to see them.

Monarch habitat in Mexico is under severe stress and threat.  Late storms and early freezes decimated monarch populations over the last decade [yes, that's the proper use of "decimated;" look it up].  Human plantings are more critical to the monarch butterflies than ever before.

Two years ago Kathryn and I spent a September morning outside the library at Lawrence University, in Appleton, Wisconsin, watching monarchs sip nectar from local flowers for their journey.  Those same butterflies — we hope — passed through Texas a couple of weeks later.

Two weeks ago . . . well, see for yourself:

Monarch butterfly on blue porterweed, Dallas, TX October 2010 - photo by Ed Darrell IMGP5343

A monarch butterfly feeds on blue porterweed in Kathryn's garden, October 2010 - photo by Ed Darrell

Monarch butterfly on blue porterweed, Dallas, October 20101 - photo by Ed Darrell IMGP5347

. . . we're here with the camera, little guy, just open up those wings, please . . .

Monarch  butterfly on blue porterweed, Dallas, Texas October 2010 - photo by Ed Darrell IMGP5345

That's it! Beautiful! Have a safe trip, and come back next spring, will you?

Resources, more:

Conoclinium coelestinum


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