Sunday, March 16, 2008

Five Little Ducks

Here is how the song goes: Five little ducks went out to play, over the hills and far away, Momma duck called "kwak, cuac, quaque," four little ducks came waddling back.... The song continues until no little ducks come waddling back. But, in the last verse, Daddy duck says "QUACK, QUACK, QUACK!" and all five little ducks come RUNNING back.

Yesterday Preston was at his friend Hyatt's house playing. Several hours later Sunnie and I went to pick him up, we told him he needed to come home and he ran from me and said "NO!". He locked himself upstairs in the play room and turned on a TV. Minutes past by he still wouldn't come down. Sunnie went to get him two more times, still no Preston. Anita went to unlock the door, he shut it and locked it again. Finally I told Sunnie to go tell Preston that if he doesn't come down Dad will come to get him. Sunnie went upstairs and peeked under the door. He was still watching TV. She yelled "get down here now or else Dad is going to come get you!" as soon as she said that Preston got up as fast as he could, turned of the TV, and ran downstairs.
(this post made possible with contributions by Chantra, Justin, Preston, and Sunnie.)

Sunday, March 2, 2008

Tyler gets his Eagle

Three things limit the human potential for clear vision. The first is the size of the eye itself. In a camera, larger film size can capture an image with greater resolution. Like the camera, a larger eye could capture more resolution.

Second, the number of photoreceptors on the retina and their spacing limit the resolution in the human eye to approximately 20/12. If there were more photoreceptors packed closer together, you could see more detail at a greater distance.

Third, blood vessels covering the retina obscure your vision. Your brain ignores this so you don't percieve it, but shine a flash light at different angles around your eye (needs to be bright and close) and you may see those vessels momentarily while light from the side projects a different shadow through the vessels.

The Eagle can see 6-8 times better than us (20/1 or 20/2?). It is reported that an eagle can see a mouse at a mile. Under the best of backgrounds, you might be lucky to see a mouse at 3 or 4 hundred feet. Eagles eyes are bigger than human eyes. They have many times more photoreceptors than we do--and they are double stacked and very tightly packed. We only have one area of tightly packed photoreceptors--the fovea, they have two. And an eagle eye has a structure called the Pecten that feeds its retina and reduces vision obscuring vessels in the retina itself.

God knew we didn't need to see a mouse at a mile to survive, but wouldn't it be cool?

Congratulations to Tyler for the foresight to get his Eagle Scout. It is an honor that speaks well of his mental and spiritual maturity. He earned it.