Matthew:

Two questions that plagued me on a drive home from LA a couple of days ago. First of all, I have this blue pad of paper on my dashboard, and during one of the many times that traffic came to a complete stop, I got to wondering... Why does the sun bleach things? And the other question is, do cops have to obey speed laws? I saw three different cop cars pass me up on the road, and I admit even I was not going 65 or slower. So what is the law for them? Can I pull one over and give him or her a ticket? What are my rights?

-- Ryan, doin' 75 in the number-two lane

Well, you have the right to remain silent and call your attorney. And the elves and I have a right to be there when you try it. That is not to say you're wrong. If the cops weren't running with flashing lights or lights and siren, they were breaking the law. Emergency vehicles, including police/sheriff's department/Highway Patrol vehicles, must be driven in accordance with the same laws we proles have to follow unless they're responding to an emergency or pursuing a perp. But if this requires pulling a 180 on Ingraham or going 90 on the freeway, they must have their red lights flashing. They're only required to use a siren if they need to clear the road in front of them. The exemptions are all spelled out in the state Vehicle Code Section 21055. Highway Patrol officers can exceed the limit briefly without lights while pacing a speeder, but that's about it. Lunch and quitting time don't qualify as emergencies, by the way.

Your rights? The right to do a slow burn as the cop car breezes by, then the right to call the offending agency and give them details of the offense, time, place, unit number, whatever, and lodge a complaint.

But if you decide you want to cite them for speeding, don't leave your ticket book on the dashboard. It may not be there when your big moment comes. The blue pad turns some shade of pale pink or white when the energy in the short-wave UV radiation is absorbed by the blue dye. It doesn't make the dye disappear, it just changes its molecular structure so it no longer reflects back its original color. The cheaper the dye and the cheaper the paper, the faster it will fade. UV is the single biggest contributor, but even if you put SPF 50 sun screen on your window, the pad would still wither away. The visible light spectrum and heat from the infrared component of sunlight contribute to photochemical changes. Leave the pad there long enough and it would disintegrate. Nature's way of telling you to give up the idea of chasing speeding cops.