More than a century after the bulb appeared above Thomas
Edison’s noggin, electrical light is shifting into a new phase.
Perhaps you’ve noticed the new style of Christmas lights, but
the illumination revolution is having an especially noticeable
effect on driving. Since the late 1990s, a lot of cities have
changed the type of bulbs used in overhead street lamps, subtly
changing the feel of urban night-time. Aesthetics may be ignored
in the drive toward cheaper, more reliable light sources, but
the changes to the darker half of our lives are considerable.
Scientists have long played around with different gases as a way
to amplify the light that comes from electricity, and perhaps
the biggest change to the roadside came over a half century ago,
brought to you by neon.
50 years
later, it’s the light-emitting diode that is altering the way we
look at the street, especially at intersections. Although
devised three decades ago, LEDs have now been perfected and are
rapidly replacing incandescent bulbs in traffic signals. Each
unit costs more, but needs a lot less juice and burns out
gradually, saving municipal governments from replacing them
every year. For similar cost reasons, many large vehicles have
been fitted with LEDs as rear and brake lights.
Some cars
have them too, but the more noticeable change on personal
vehicles is up front. If you’re like me, your introduction to
the newest form of headlight was like transforming into a deer,
staring into a strange, bluish headlight. The new hue seemed to
first appear on German cars for the most part, but the HID
revolution is about to take over. High Intensity Discharge
headlamps are coming to many makes of autos, according to
Transport Canada’s Marcin Gorzkowski. He says they are also
known as GDLS, for Gaseous Discharge Light Source but somehow I
don’t think that’s going to catch on.
I must admit
this roads scholar is not a techy guy. My father did his own
repairs, and while I regret it now, I apparently spent more time
as a teenager staring at the newest Rand McNally road atlas
instead of leaning over the engine with him. Thankfully, Marcin
caught me up on decades of headlamp evolution. It seems HID
represents a major shift for autos, finally shedding the
reliance on filaments to produce light. As with household bulbs,
thin pieces of tungsten have long been used in headlights,
holding up to the worst roads dispute their seeming fragility.
Decades ago,
headlights used vacuum bulbs. But those gas-loving scientists
eventually found a way to surround the tungsten filaments with
halogen, increasing the amount of light available for pouring
over the road ahead. According to Gorzkowski, there are still
ongoing advances in the purity of tungsten and the gas used in
incandescent bulbs,but candle-power is taking another leap
forward with HID. “Now what we have is a new technology that
does not involve a filament. We have an electric arc in the
presence of gas,"
The
electrical current is exposed largely in xenon, which I always
associated with movie projectors. Again not really new, except
that it is coming to a road near you. The next cost hurdle is
making HID practical for high beams, which are still largely
incandescent. Gorzkowski says the new style of filament-less
bulbs cannot
light up
instantaneously, something you really need at 100 kilometers an
hour. He says new technology will just switch the position of
the reflector behind the bulb to change the beam pattern. As an
oncoming driver, I can’t wait. Next week, let’s talk about
getting blinded.