concepts · updated 2026-08-01
Consider perihelion
confidence: medium volatility: cold verified: 2026-08-01fresh
A short essay by Steve Baer (Zomeworks Corporation) dated January 4, 2004 — perihelion day that year. Baer argues that despite widespread attention to climate and temperature, "few are aware that the
A short essay by Steve Baer (Zomeworks Corporation) dated January 4, 2004 — perihelion day that year. Baer argues that despite widespread attention to climate and temperature, “few are aware that the sun is 7% stronger in January than July.”
The orbital fact
Earth’s elliptical orbit brings it 3½% closer to the sun at perihelion (early January) than at aphelion (early July). Because radiant intensity follows the inverse-square law, this produces a 7% difference in solar radiation between the two dates. For the Northern Hemisphere, winter sunlight is slightly more intense than sun-angle alone would predict, and summer sunlight slightly less.
Perihelion as a clock
Baer is most interested in perihelion as a slow timekeeper. It is not fixed to the solstices: it drifts later by about 25 minutes per year — one day every 57 years — completing a full cycle in roughly 21,000 years. He frames this as a “giant century hand”:
In “perihelion time” the atom bomb was invented a day ago, the steam engine a week ago, and fire a year or two ago. We might remember that perihelion coinciding with winter in the Northern Hemisphere is a big favor we enjoy that will pass.
The piece contrasts perihelion with more visible astronomical events — solstices, equinoxes, eclipses — noting that perihelion “can be identified only with exact instruments,” yet the climate we live in is a consequence of it. Humanity has only known about it “since Johannes Kepler discovered the earth’s elliptical orbit in the seventeenth century AD.” This connects to the archive’s broader emphasis on measurement over intuition.
The analemma
The essay includes an appended note — evidently editorial rather than Baer’s (it refers to “last month’s column” and stresses that the elliptical orbit “has nothing to do with seasons,” which come from axial tilt) — explaining the analemma: the figure-eight traced by the sun’s noontime position over a year. The analemma results from combining Earth’s 23.5° axial tilt with its elliptical orbit. This is the visual signature of the perihelion effect.