Blacklight and Beemers

April 1, 2005 3:31 PM

A while ago, BMW started playing with UV / blacklight bulbs in its cars. What happened? [possibly UK-centric question]

the idea was a great one, so I assume they went ahead with it, yet i've never seen a car with blacklight obviously showing. Were they released in the UK? My google searches come up blank.

I'm guessing there was a legal problem with them (being nearly blue) yet every 12 year old has suddenly put blue lights all over his SR Nova, so is it worth trying? Where does one get hold of bright UV lamps at car voltages?

posted by twine42 to travel & transportation (8 comments total)

I'm not sure I'm familiar with what you describe, but I somehow think you mean "high-intensity" instead of UV/black light, that is, if you're talking about the headlamps. The only real function of the very blue lamps is to pester other drivers, in my experience. The super-bright blue lights really screw with peoples' night vision in an especially annoying way. The reason your eyes see black/UV light as "intense" is because your iris doesn't react to the wavelength as well as it does to normal light. So, you can get the same effect by dialating your pupils and walking around on a sunny day.

Obviously, though, this is bad for your eyes. I'm sure the health concerns aren't really that serious with headlamps, but no company is going to take the chance of putting themselves up for critique unnecessarily.
posted by odinsdream at 3:41 PM on April 1, 2005

No no, I genuinely mean black light.

The concept was that you could have sigificantly higher wattage (and therefore throw) without blinding outher drivers because the light was virtually invisble, however it tends to make objects glow - so road markings and clothing lights up significantly farther away than if it were illuminated by standard headlights.

Sorry if I didn't explain very well.
posted by twine42 at 3:44 PM on April 1, 2005

I see. Well, while I'm not a physics professor or anything, I'm going to have to question that "invisible" notion. Black light is just mostly UV radiation, which is bad for your eyes as far as I know. You may not "see" it, but it certainly is hitting your retinae. I'm going to vote that BMW is avoiding (possibly senseless) litigation.
posted by odinsdream at 3:55 PM on April 1, 2005

it tends to make objects glow - so road markings and clothing lights up significantly farther away than if it were illuminated by standard headlights.

UV makes some things glow, but not most. Road signs are already highly reflective with normal headlights; I think more brightness would be blinding. White clothing tends to glow brightly in UV, but dark clothing doesn't. If you got used to seeing people wearing white at extreme range, that Goth kid in your path would be quite a surprise.
posted by Kirth Gerson at 4:13 PM on April 1, 2005

I believe chronic exposure to UV lights has been found to contribute to the formation of cataracts.
posted by Fupped Duck at 5:20 PM on April 1, 2005

I think you're talking about a proposed system for the 7-series that would use UV light and sensors to superimpose an image of things outside your range of vision on a heads-up display across the windscreen at night.

They're still working on it, as far as I know.
posted by bonaldi at 1:01 AM on April 2, 2005

I think you're talking about a proposed system for the 7-series that would use UV light and sensors to superimpose an image of things outside your range of vision on a heads-up display across the windscreen at night.

IR light would work much better, I think.
posted by delmoi at 10:47 AM on April 2, 2005

Quite a few years ago I did see the idea of using blacklights in addition to regular car headlights on Tomorrow's World, or perhaps some program on the discovery channel. It has been considered anway (though the non-visible light + sensors might be more effective. However, if you're going that route, why not use sonar instead?).
posted by fvw at 6:18 PM on April 2, 2005