Weather forecasts for the Fourth of July, 2017, are predicting high temperatures in the 90s across much of the central and southern United States, while triple-digit temperatures are expected across parts of the southwestern U.S., including west Texas, and parts of New Mexico, Arizona, and southern California. So it may surprise you to learn that on Monday, July 3rd at 4:00 p.m. EDT, Earth will reach that point in its orbit where it is farthest from the Sun in space, known as aphelion.
At the moment of aphelion, the Sun will be 94,511,923 miles away, or 3,104,641 miles farther as compared to when the Earth is closest to it (called perihelion), which occurred last January 3rd. Our planet is then 94,505,901 miles from the Sun (measured center to center), which is 3,101,579 miles, or 3.3% farther, from the Sun than we were in January; a change of only 1 part in 30, and makes a difference in radiant heat received by Earth of nearly 7%.
If you ask most people which month of the year they think Earth is closest to the Sun, most would probably say during June, July, or August. But our warm weather doesn’t relate to our distance from the Sun. It’s because of the 23.5-degree tilt of the Earth’s axis that the Sun is above the horizon for different lengths of time at different seasons. The tilt determines whether the Sun’s rays strike us at a low angle or more directly.
At New York’s latitude, the more nearly-direct rays at the Summer Solstice of June 21st, bring about three times as much heat as the more slanting rays at the Winter Solstice on December 21. Heat received by any region is dependent upon the length of daylight and the angle of the Sun above the horizon. Hence the noticeable differences in temperatures that are registered over different parts of the world.
A Climatological Fallacy
When I attended Henry Bruckner Junior High School in The Bronx, my ninth grade earth science teacher, Mr. Shenberg, told all of us that because we were farthest from the Sun in the July and closest in January, that such a difference would tend to warm the winters and cool the summers — at least in the Northern Hemisphere.
And yet the truth of the matter is that the preponderance of large land masses in the Northern Hemisphere works the other way and actually tends to make the winters colder and the summers hotter.
Interestingly, the times when the Earth lies at its closest and farthest points from the Sun roughly coincide with two significant holidays: we’re closest to the sun around New Year’s Day, and farthest from the Sun around Independence Day. Actually, depending on the year, the date of perihelion can vary from January 1 to 5; and the date of aphelion can vary from July 2 to July 6.
The Carborium X Story
I don’t want to end this blog by giving the impression that Mr. Shenberg was a poor teacher. Actually, he was one of the best teachers I ever had, and just thinking of him now reminds me of the occasion when I took the Earth Science regents exam.
Earth Science was my very favorite subject and I had no qualms taking the exam. In fact, I was so confident that on the day before the exam, I remember relaxing in front our TV watching an episode of the Adventures of Superman, starring George Reeves.
For those of a certain age who can remember this show, the episode I watched on the day before my big exam, had nutty Professor Twiddle (played by actor Sterling Holloway) who used his time machine to send Clark, Lois, Jimmy, Perry and himself back to 50,000 B.C., along with a notorious gangster. But then, in order to get back to the present, Twiddle needed a very special kind of metal called “Carborium X,” which apparently could only be found on asteroids. Clark, of course, changes into Superman, finds an asteroid in space, comes back with a sample of Carborium X, which the professor inserts into his time machine. Viola! Superman saves the day.
So the next day I took the Earth Science regents exam. I had no problems with it, save for one question concerning geology (not my favorite subject): “Provide one example of a pyroclastic rock.” I probably could have taken an educated guess and gotten the answer right, but instead I decided to write in “Carborium X”!
Several days later, as I was walking through the hallways of JHS 101 with my yearbook, getting autographs from friends and teachers, I noticed Mr. Shenberg alone in his classroom. Naturally I strolled in to get his signature. As he signed my yearbook, he said, “Well Mr. Rao, it certainly has been interesting having you as a student.”
He then handed the book back to me. I shook his hand and started for the door, when suddenly he called out: “Oh Mr. Rao! Mr. Rao!” When I returned to his desk, he said, “There was one question that you answered on the regents that I really didn’t understand, hold on for a minute.” He then opened a drawer, pulled out a stack of papers and quickly rifled through them until he found mine. He then looked at my answer sheet and said: “Yes! Here we go, question #46. What the heck is Carborium X?” Looking directly at him with a straight face, I said: “Carborium X is a substance only found on asteroids which can be used in time machines in order to go forward in time.” Mr. Shenberg could only give me a blank stare.
I continued, “I have to confess to you, however, that I realized right after I handed in the exam that I really shouldn’t have put down Carborium X as an answer.”
“Oh really?” said Mr. Shenberg. “And why is that?”
“Well, Carborium X is a metal and a pyroclastic rock probably wouldn’t fall into that specific category, so I guess I got that question wrong.”
The look on Mr. Shenberg’s face was priceless. He then slowly placed the stack of papers back into his drawer, shook his head in disbelief, shook my hand again and said, “As I said Mr. Rao, it’s been interesting having you as a student. And good luck!”
And yes folks this is a TRUE story!