SCI Scientists Warn Eclipse Totality Path Has Shifted from What Was Previously Projected

Kathy in FL

Administrator
_______________
Question is, did Jill tell it to do it now for some reason. [/sarc]

Scientists Warn Eclipse Totality Path Has Shifted from What Was Previously Projected​


Forget everything you think you know about the path of Monday’s solar eclipse.

Well, OK… maybe not everything. But the projected “path of totality” has shifted enough that some people who were expecting to see the full monty without leaving their homes may be disappointed.

“A new eclipse map — based on an updated figure for the radius of the sun — was published recently by John Irwin, a master in eclipse computations,” Forbes reported last weekend.

We’ve included the updated map below, because if you’ve been thinking how lucky you are to be right on the fringe of the area where the total eclipse will be viewable, well, that might not actually be the case.

The issue stems from the fact that no one is absolutely certain about the diameter of the sun, Forbes said.

This surprised me, by the way. Scientists confidently state where pandemics come from (or don’t) or by how many degrees the earth’s average temperature is going to rise over the next five decades, but they don’t know how big the sun is?

I mean, humans have been looking at the sun for … well, forever. Since there have been humans. No one has figured out how to measure it yet?

It’s only the source of all our planet’s energy, the largest object in the solar system. Or is it, even? Apparently there’s no way to know for sure.

Anyhoo, if you don’t know how big a light source is, it’s going to be challenging to predict the size of the shadow it might cast.

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.

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.

“The solar radius is one of the parameters that enter into eclipse computations,” Luca Quaglia said in an email to the outlet. “But the choice of its value is really left to the eclipse computer.”

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.

Related:
Officials Along Path of Eclipse Quietly Declaring States of Emergency
That’s enough of a difference to shift the path of totality by more than a third of a mile, Forbes said.

At any rate, the new, updated map appears below. [Map is interactive at the article link]

1712409755154.png

It should be noted, however, that this map is based on that 960 arc second estimate that no one is apparently certain is accurate.

Caveat emptor.

 

JMG91

Veteran Member
God forbid scientists find they've made an error and correct themselves. That's not how science is supposed to work!
That’s not the issue. People make mistakes. I’ve just been burned too many times by “experts” shoving their god complexes down my throat, then expecting immediate forgiveness when they’re wrong—or refusing to admit they’re wrong at all. These people don’t know as much as they think they do, and they’ve made people believe that they’re the end all/be all. I realize that this particular situation is not a covid-19 scenario, but I’m pretty jaded at this point, so...
 

VinceU1

Contributing Member
Question is, did Jill tell it to do it now for some reason. [/sarc]

Scientists Warn Eclipse Totality Path Has Shifted from What Was Previously Projected​


Forget everything you think you know about the path of Monday’s solar eclipse.

Well, OK… maybe not everything. But the projected “path of totality” has shifted enough that some people who were expecting to see the full monty without leaving their homes may be disappointed.

“A new eclipse map — based on an updated figure for the radius of the sun — was published recently by John Irwin, a master in eclipse computations,” Forbes reported last weekend.

We’ve included the updated map below, because if you’ve been thinking how lucky you are to be right on the fringe of the area where the total eclipse will be viewable, well, that might not actually be the case.

The issue stems from the fact that no one is absolutely certain about the diameter of the sun, Forbes said.

This surprised me, by the way. Scientists confidently state where pandemics come from (or don’t) or by how many degrees the earth’s average temperature is going to rise over the next five decades, but they don’t know how big the sun is?

I mean, humans have been looking at the sun for … well, forever. Since there have been humans. No one has figured out how to measure it yet?

It’s only the source of all our planet’s energy, the largest object in the solar system. Or is it, even? Apparently there’s no way to know for sure.

Anyhoo, if you don’t know how big a light source is, it’s going to be challenging to predict the size of the shadow it might cast.

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.

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.

“The solar radius is one of the parameters that enter into eclipse computations,” Luca Quaglia said in an email to the outlet. “But the choice of its value is really left to the eclipse computer.”

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.

Related:
Officials Along Path of Eclipse Quietly Declaring States of Emergency
That’s enough of a difference to shift the path of totality by more than a third of a mile, Forbes said.

At any rate, the new, updated map appears below. [Map is interactive at the article link]

View attachment 468932

It should be noted, however, that this map is based on that 960 arc second estimate that no one is apparently certain is accurate.

Caveat emptor.

Not that it really matters, this being Indianapolis and all, but it will probably be cloudy as all get out and we ain't gonna see nuffin!
 

tanstaafl

Has No Life - Lives on TB
This surprised me, by the way. Scientists confidently state where pandemics come from (or don’t) or by how many degrees the earth’s average temperature is going to rise over the next five decades, but they don’t know how big the sun is?

As late as the 1980s they were still correcting maps because they didn't actually know exactly how wide the Atlantic Ocean was. Some of the corrections moved things like coastlines by several miles. And that was on Earth across distances humans had been travelling for centuries and even millennia. Is it really all that surprising they don't have firm numbers for places we've never been? Pick a random asteroid or a moon circling one of the outer gas giants or one of the near-Earth asteroid flybys and you'll find a range of estimates of sizes, not single numbers that everyone agrees on. I think the OP author is a little too ready to just accept whatever an authority figure tells them.
 

Southside

Has No Life - Lives on TB
We are possibly going to stay in the South Chicago area, and only have 90+% totality, but chance of cloud cover is 15% or less. If it is cloudy, you see, well just some darkness. Not interested in that.

The map changes by the hour.
Remain flexible.
 

tanstaafl

Has No Life - Lives on TB
I'll bet the OP author would be gobsmacked to learn that the thickness of Earth's atmosphere changes week by week. If the Earth's atmosphere isn't constant, why would the Sun's photosphere be? Not to mention those outer bits of both Earth's atmosphere and the Sun's photosphere aren't remotely as consistent (or as dense) as you might think.
 

Delta

Has No Life - Lives on TB
We are possibly going to stay in the South Chicago area, and only have 90+% totality, but chance of cloud cover is 15% or less. If it is cloudy, you see, well just some darkness. Not interested in that.

If you are close enough to get into clear-atmosphere totality, do it. A partial is a nothing burger compared to the "real thing". I saw the one in Oregon in 1979. Went for the desert as best odds for clear skies. If possible, get on a ridge top where you can face into southwest. Until sun goes total, you cannot look directly at it, but if you're facing into the path, you can see the moon's shadow racing toward you. That is a real cool experience. Then you can turn around and gawk. A partial, right up to the last few minutes, is about the same as a cloudy day.
 

foreverkeeps

Veteran Member
I’m still in the 99-100% coverage path in SE Missouri. :)
I’m wondering if I can set my camera up with a tripod because I have a pull out large viewfinder and looked through the pop out screen and also have some kind of glasses on? Or will it ruin my camera? I’m hoping since you’re in almost 100% you can devise a way to Share photos you can take? Last time in 2017 I got pretty good pictures because the building I was in was a total glass building and I was able to get some good reflections, but that was only 80% .
 

psychgirl

Has No Life - Lives on TB
Not that it really matters, this being Indianapolis and all, but it will probably be cloudy as all get out and we ain't gonna see nuffin!
Don’t you ever watch the weather news?

We ARE having beautiful weather tomorrow now
Thousands have changed plans; they’re coming here now instead!

I’m on several eclipse groups on Facebook just for personal monitoring.
We’re being swamped with questions of where to go, where is best place, plans have changed; it goes on and on!

And now, we’re ALSO in the spotlight with Purdue playing in the championship game tomorrow night!

Purdue in in Lafayette Indiana, city is in the path of totality. It’s a HUGE madhouse of a party up there right now!
 
I’m wondering if I can set my camera up with a tripod because I have a pull out large viewfinder and looked through the pop out screen and also have some kind of glasses on? Or will it ruin my camera? I’m hoping since you’re in almost 100% you can devise a way to Share photos you can take? Last time in 2017 I got pretty good pictures because the building I was in was a total glass building and I was able to get some good reflections, but that was only 80% .
What kind of camera?
 
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