Yesterday, the NY Times Education supplement included a question in its Quiz feature that I think may have had a wrong answer. (Which is disturbing, considering that the Quiz questions and answers were taken from the New York State Regents exam in geography. Historically, passing the Regents exams would give students a sort of gold-star “Regents” diploma, useful for the college bound. But soon, all students will have to take the Regents in order to graduate at all.)
The question asked, in New York City on July 4, from what direction does the sun appear to rise? The answer given, north of due east, makes no sense to me - given that (a) the date is after the solstice and (b) New York City is well north of the Tropic of Cancer in any event. I had answered that the sun would appear to rise south of due east. If I’m wrong, why? Is it that the earth’s tilt is enough to make the sunrise appear to be north of due east, even though NYC is itself so far north? (Sorry, that’s badly phrased - I hope some astronomy type can make sense of it anyway!)
Note that on an equinox, the Sun rises (more or less) due east for all places on the globe. So between spring and fall equinoxes, the Sun appears north of that. Think of your answer this way: The Sun is higher in the sky on July 4 than on March 21. Why would that make it appear farther south??
seems right to me. rises due E at the equinoxes. in the northern hemisphere, N of E in summertime, S of E in wintertime… .
at the summer solstice it will rise furthest north then move to due east at the autumnal equinox.
try this link… might convince you.
The sun is just so blasted far away that a few thousand miles here on Earth don’t mean squat.
Try to visualize it like this. Imagine you’re in a room with one window (that’s the light source, standing in for the sun) and you have a globe sitting on a table in front of you (ideally, the window would be at the same height as the table top). Since we’re talking about the summer, turn the base of the globe so that the top of the axis is leaning toward the window. Now turn the globe on its axis until it’s dawn in New York City. Make sure the sun comes up in the east, Europe should be facing the window.
Now imagine yourself standing on that globe in New York (or anywhere else where the sun is just coming up). Because the top of the globe is tilted toward the window, when you look due east you’re looking down toward the floor of the room. If you want to look at the window dawning majestically in the sky, you have to turn your head a little to the north.
The following information is provided for New York, New York (longitude W73.9, latitude N40.7):
Friday - 4 July 2003 - Eastern Daylight Time
Sunrise - 5:30 a.m.
The Altitude and Azimuth of the Sun on July 4, 2003, at 5:30 am EDT will be:
Altitude: -0.8
Azimuth: 58.3
Using the definitions provided,
"Altitude is the angle up from the horizon. Zero degrees altitude means exactly on your local horizon, and 90 degrees is “straight up”. Hence, “directly underfoot” is -90 degrees altitude. Azimuth is the angle along the horizon, with zero degrees corresponding to North, and increasing in a clockwise fashion. Thus, 90 degrees is East, 180 degrees is South, and 270 degrees is West. Using these two angles, one can describe the apparent position of an object (such as the Sun at a given time).
The altitude and azimuth values are for the center of the apparent disk of the Sun or Moon. The altitude values include the effect of standard atmospheric refraction when the object is above the horizon. The azimuth values are computed with respect to true north (not magnetic)."
You can figure it out yourself. On the day in question the Sun will rise North of due East
I think you’re remembering the azimuth of the ‘high noon’ sun. At the Tropics (of Cancer and of Capricorn), the sun peaks (reaches a 90 degree altitude angle) directly overhead on the equinox. Farther north/south (away from the equator), the peak will be towards the equator at all times of year. (North of the Arctic Circle, or south of the Antarctic circle, you may need to wait more than a day for this to happen. Yet another good reason not to get lost in the Arctic. ) Corollary: the rising and setting sun can give you rough bearings, but to get true north, you need to plot the arc of the shadow of a stick. The line from the stick to the closest point on that arc (the end of the stick’s shadow at astronomical noon) will be precisely due north. (In the northern hemisphere, north of the Tropic of Cancer.)
If you try “sun path diagram” in your browser it will direct you to numerous sites that show diagrams used to show a suns path during different times of the year. There are different diagrams for different latitudes.
Most of these show sun rises north of due east in the summer even though it may arc to the south then set north of west.
We used to use these diagrams in architrcture school to tell where shadows would fall during different times of year.
