Two illusions: one online, one real-life, both freaky

Before we get to the Sagamore Bridge falling down, here's the online illusion that's been bending minds around my office the past few days.

Pretty weird, huh? Presuming you can make the spinning character change directions - and the few I've spoken to about it can - perhaps you will be able to answer this question: How can it be that the direction one sees the character spinning indicates a right-brain or left-brain bias, as claimed in the article, if a person can make it spin in both directions?

Now on to that bridge in Massachusetts. The Sagamore Bridge did not really fall, of course, or else you would have heard about it through some other media outlet even more vigilant than this one. The Sagamore is one of two spans - the other being the Bourne Bridge - that funnel traffic over the Cape Cod Canal, making them the only options for motorists who do not have a Cape Cod Canal Tunnel Permit.

Last Friday, oh, about 1 p.m. or so, I had driven down Rte. 495 from the north and across the Bourne Bridge, where I picked up Rte. 6A running parallel to the canal headed toward Sagamore and the Mid-Cape Highway, better known hereabouts as Rte. 6. Traffic was light, this being early afternoon and off-season, so I was moving along at a pretty good clip, maybe 40 to 50 mph.

Now I've made this trip a couple of hundred times over the past 49 years, so my mind was not on the scenery or even the road; in fact, it was wandering aimlessly who knows where when I glanced suddenly to the upper-left of my peripheral vision - and the upper-left of the windshield - just in time to see the crown of what I immediately knew to be the Sagamore Bridge plummeting toward Earth behind the tree-tops.

No word of a lie, I let out the faintest of gasps, a fraction of a second ... before snapping to full awareness and realizing that I had not seen the calamity that my mind had so hastily identified; rather I had simply experienced ordinary motion parallax. It was the perfect combination of speed, inattentiveness and nearby trees that had me ever-so-briefly horrified.

Even so, it was a lot freakier than that spinning silhouette in illusion No. 1.

But here's my lingering question about the bridge experience: Would my mind have been so quick to embrace the improbable had this drive to the Cape happened a year ago? In other words, did seeing endless TV images of the all-too-real collapse of that bridge in Minnesota - a bridge my sister had been on a mere two hours beforehand - play a role in "training" me to believe that the Sagamore actually could be falling?

I'm no expert, but I'm thinking maybe it did.

Anyone care to speculate?

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