If you are traveling to catch a glimpse of the upcoming Solar eclipse, make sure you’re well into the projected path. Eclipse expert John Irwin says the original map—the path of the shadow of totality—has moved.
And no, it wasn’t “climate change.” But, it was something … racist. Math!
You can see his updated map for the whole of the US below. It is interactive, so you can zoom in and out to drill down to wherever you live, keeping in mind that this is neither confirmed nor denied, but according to the Western Journal (quoting Forbes), Irwin (whose map this is) is “a master in eclipse computations.”
The issue, or the problem, is the size of the sun. No one knows exactly how big it is, leading to a discrepancy at the edges of the estimated path of totality. This minor difference of opinion affects the exact location of the shadow during an eclipse.
For well over a century, scientists have generally used the “standard value” of 959.63 arc seconds — “an arc second being one 3,600th of a degree,” Forbes explained.
“Measurements and observations in the last decade have demonstrated that this value is slightly too small,” Quaglia said. The actual diameter is now thought to be more like 960 arc seconds.
And while most of the math is known,
Other measurements are important, of course, and we know those with some confidence — the distance between the sun, moon and earth, for example, and the size of the moon that will be casting the shadow that we call an eclipse.
There’s room for debate.
But the size of the sun? One scientist who has been working for over 10 years on solar eclipse calculations told Forbes that that number is basically up to the person doing the math.
On the ground, this difference amounts to about a third of a mile, which doesn’t seem like much—and it’s not unless, as the note in the cited article adds, you were planning to enjoy a total eclipse from the comfort of your own yard.
If you happen to live at the edge of the projected path and were hoping to watch a total eclipse from a lawn chair behind your house, it might not turn out as planned, but taking your lawn chair about 1800 feet toward the center of the path should fix it—six football fields. Since you’re already moving, try half a mile. You won’t even get your heart rate up high enough for it to count as exercise unless it’s all uphill.
They enjoy, but whatever you do, don’t eclipse someone elses view when the moment arrives wherever you gather to watch.
