syrinx

red robin

birds of texas: american robin. first sighting in the back yard ground level water source as I returned from behind the fence with the camera. Took a few looks at me to see whether I was a moving object or part of the house, finished drinking, and flew off, but not before I snapped a few shots, including this one.

tags: birds robin photography texas native nature american

According to an article published in Scientific American, we have no trouble perceiving the following shaded pattern of 2D circles as having 3D qualities:

If we see light coming from the left, the row with the lighter side on the left appears to be a bump, the row with the darker side on the left appears to be circular cavities. Switch the light source to the right and the reverse is true. (More after read more link)

tags: scientific moon spoon visual american perception depth

New article in the latest issue, article now online
Key Concepts

• Migraine is more than a headache: it is intensely painful and has distinct phases.
• The disorder used to be considered a vascular one, but recent research reveals it to be neurological, related to a wave of nerve cell activity that sweeps across the brain.
• The root of migraine may reside in brain stem malfunctioning.
• Although debate swirls about the precise cause of migraine, discoveries are already permitting the development of new treatments

More at SciAm online

tags: migraine headaches scientific american