These original Kirt's Cogitations™
may be reproduced (no more than 5, please) provided proper credit is given to me, Kirt
– noun: Concerted thought or reflection; meditation; contemplation.
Kirt [kert] – proper noun: RF Cafe webmaster.
One Man's Summer is Another Man's Winter
As we roll into July in the northern hemisphere and begin to strain
our air conditioning systems, it's hard to believe our neighbors to
the south are hunkering down for a long winter's night. At around midnight
on July 5-6, the Earth reaches aphelion - the point in its elliptical
orbit the farthest from the sun - at around 94½ million miles. The apparent
brightness of the sun is reduced to about 93% of its level at perihelion
- around 91½ million miles away. Now, it hasn't always been this way,
nor will it be so in the future. Seasons of course, are caused by the
23½ degree tilt of the Earth's rotational axis relative to the ecliptic
plane. Gyroscopic precession causes the axis of rotation to cycle ever
26,000 years. So, in 13,000 years, aphelion will occur near the winter
solstice in the northern hemisphere. Hmmmm, I wonder if this natural
cycle contributes to the apparent heating and cooling eras in the Earth's
history that some like to blame entirely on recent human activities?