These biting cold and clear January days the sun's a welcome sight.
Unless you're driving Atlantic Avenue and straight into its long slanting rays.
Then the questions come fast. Where's the visor? Where are the sunglasses? Where are the brakes?
Who turned on the brights?
Why, we wonder, does the late day sun have a dazzling presence.
We asked retired astronomy and physics teacher Jim Keating of Marblehead.
Jim, who taught science for 30 years at Marblehead High School, and helped design the sun circle at Preston Beach, agreed that driving at this time of the year is tough.
"But not only in the afternoon driving West, but in the morning driving East," he said.
"There is an Astronomical reason for this phenomenon. First, the Earth is at perihelion, which means it (Earth) is closest to the Sun in its yearly orbit. Though the distance (around 2 million miles closer) doesn't make the Earth any warmer at this time of year, the human eye is sensitive enough to notice a change in the brightness of our home Star.
"Second, the conditions for seeing are good, which means the atmosphere is dry (low humidity) and temperature is constant. (Cold)."
We also asked Jim, and those whose jobs take them to local roads day in and out, including Swampscott DPW Director Gino Cresta, for strategies to help drivers see in the blinding sun.
The answer was uniform: Good sunglasses and car visors.