<span style="font-weight: bold; font-family: ‘Lucida Sans’;" class="R~sep~ACopyBody">How do I get hold of a Louisiana state income tax booklet or forms? I’ve called a number in Baton Rouge and you just go around in circles. I didn’t want to give them my Social Security number.</span>

<span class="R~sep~ACopyBody">Visit the state Department of Revenue’s website — www.revenue.louisiana.gov — where you can download and print out forms and instructions; request that forms be mailed to you; or file your return online.</span>

<span class="R~sep~ACopyBody">To do any of the above, click the “2015 Filing Options” link under the “For Individuals” column.</span>

<span class="R~sep~ACopyBody">“The expected refund processing time for returns filed electronically is up to 60 days,” reads a page on the website. “For paper returns, taxpayers should expect to wait 12 to 14 weeks.”</span>

<span class="R~sep~ACopyBody">The deadline for filing state income tax returns is May 15. For more information, call the Louisiana Revenue Department at 855-307-3893.</span>

<span class="R~sep~AHeadBrief" style="font-size: 16px;">Back-spinning wheel an optical illusion</span>

<span style="font-weight: bold; font-family: ‘Lucida Sans’;" class="R~sep~ACopyBody">I have a question that’s been on my mind for years. Why do car rims look like they’re turning in reverse when the car’s going forward?</span>

<span class="R~sep~ACopyBody">The Informer first addressed the topic in 2002, when a reader asked about tires in film and television:</span>

<span style="font-weight: bold;" class="R~sep~ACopyInfoBox">Why do wheels on cars in movies and commercials appear to turn backward?</span>

<span class="R~sep~ACopyInfoBox">It’s an optical illusion based on the strobe effect — how the frequency of light affects what we see — and it doesn’t just happen in the movies.</span>

<span class="R~sep~ACopyInfoBox">Movies, like the illusion, are based on “persistence of vision”: The frames move so fast — 24 different shots per second — that our eyes can’t discern each frame individually and we see only one continuous, changing image.</span>

<span class="R~sep~ACopyInfoBox">Filming humans in motion is no problem, but wheels — whose spokes can spin at a faster rate than humans can move in</span> <span class="R~sep~ACopyInfoBox">1</span><span class="R~sep~ACopyInfoBox">⁄</span><span class="R~sep~ACopyInfoBox">24</span> <span class="R~sep~ACopyInfoBox">of a second — present filmmakers with a challenge.</span>

<span class="R~sep~ACopyInfoBox">If the wheel spins too slowly, its spokes may end up in alignment in each frame, making the wheel appear stationary.</span>

<span class="R~sep~ACopyInfoBox">But if the wheel doesn’t spin fast enough in</span> <span class="R~sep~ACopyInfoBox">1</span><span class="R~sep~ACopyInfoBox">⁄</span><span class="R~sep~ACopyInfoBox">24</span> <span class="R~sep~ACopyInfoBox">of a second, the spokes will appear to move backward because each one won’t have time to catch up with the one before it in the subsequent frames.</span>

<span class="R~sep~ACopyInfoBox">Backward-moving wheels were most famously noted in Hollywood Westerns, earning the phenomenon the name “wagon-wheel effect.” To counter physics, many filmmakers began to use wheels with unevenly spaced spokes.</span>

<span class="R~sep~ACopyInfoBox">This reduces the risk of overlapping or lagging spokes, and it gives the illusion of continuous forward motion.</span>

<span class="R~sep~ACopyInfoBox">But the backward-moving-wheel phenomenon isn’t something one only sees in the movies.</span>

<span class="R~sep~ACopyInfoBox">Neurobiologists at Duke University have found that a similar effect occurs in continuous light, suggesting that humans “see motion, as in movies, by processing a series of visual episodes.”</span>

<span class="R~sep~AHeadsubhead" style="font-size: 14px;">Another explanation</span>

<span class="R~sep~ACopyBody">In October 2004, the journal Vision Research published the results of work by University of Texas scientists who concluded that the motion reversal that people see in continuous light stems from “perceptual rivalry” — the brain’s response to ambiguous images.</span>

<span class="R~sep~ACopyBody">“We found that when observers watched a rotating drum and its mirror image, almost all illusory motion reversals occurred for only one image at a time,” reads the report, by neuroscientist David Eagleman.</span>

<span class="R~sep~ACopyBody">“This result indicates that the motion reversal illusion cannot be explained by snapshots of the visual field.”</span>

<span class="R~sep~AZaphdingbatdot7pt">l</span>

<span style="font-size: 8pt;" class="R~sep~ACopyEditors~sep~endnote">The I</span><span style="font-size: 8pt;" class="R~sep~ACopyEditors~sep~endnote">nform</span><span style="font-size: 8pt;" class="R~sep~ACopyEditors~sep~endnote">er answers questions from rea</span><span style="font-size: 8pt;" class="R~sep~ACopyEditors~sep~endnote">ders each Sunday, Monday a</span><span style="font-size: 8pt;" class="R~sep~ACopyEditors~sep~endnote">nd Wednesday. It is re</span><span style="font-size: 8pt;" class="R~sep~ACopyEditors~sep~endnote">searched and written by</span> <span style="font-weight: bold; font-size: 8pt;" class="R~sep~ACopyEditors~sep~endnote">Andrew Perzo</span><span style="font-size: 8pt;" class="R~sep~ACopyEditors~sep~endnote">, an</span> <span style="font-style: italic; font-size: 8pt;" class="R~sep~ACopyEditors~sep~endnote">American Press</span> <span style="font-size: 8pt;" class="R~sep~ACopyEditors~sep~endnote">staff wri</span><span style="font-size: 8pt;" class="R~sep~ACopyEditors~sep~endnote">ter. To ask a question, call</span> <span style="font-size: 8pt;" class="R~sep~ACopyEditors~sep~endnote">494-409</span><span style="font-size: 8pt;" class="R~sep~ACopyEditors~sep~endnote">8 and leave voice mail, or ema</span><span style="font-size: 8pt;" class="R~sep~ACopyEditors~sep~endnote">il informer@americanpress.com.</span>