38 replies to this topic

[Nankins]

I'm writing a paper on light pollution and want to state the percentage (roughly) of the world's population that can't see the Milky Way at night.  I know it's over 80%, but this estimate was from last year.  I can't find anything (yet) from this year.  This paper is due this Sunday, as it's my final paper for my ENG 215 Rhetoric and Argument class.  All I need is a rough number percentage.  I don't need articles as I already have my full limit of them (5 articles).  Not one article states a percentage (not even the one from this month's Astronomy magazine).  

[PEterW]

Hard to say, look at the “star count” results and see the range of numbers you get I. Similar areas. Will depend on the observer and the weather, 80% is pretty bad.

Peter

[rjacks]

I think you are fine going with last year's estimate and citing it. It won't have changed significantly in a year. PS, I'm a Professor. 

[John Berger]

I have never seen the Milky Way

 

nearest dark site is a few hundred miles away, AND COUNTING!  

 

I really wonder though, what do commercial fishing boats (and any big ships in general) see, when they're in the middle of the ocean

 

they have bortle 1; lucky guys!

Edited by John Berger, 17 July 2024 - 03:16 PM.

[happylimpet]

https://www.vox.com/...ution-night-sky

 

80% americans, 60% europeans, 33% of the world.

[db2005]

According to this source: https://www.astronom...-the-milky-way/, 80% of Americans can't see the Milky way, and one third of the world population can't see the Milky way.

 

I don't know how they came up with the numbers. But they seem about right to me - since about 80% of americans live in cities or urban areas, but this number is significantly lower in many other parts of the world.

 

So, It would seem that two thirds of the the world population can see the Milky Way to some extent - but it's another question how well they can see it. In my opinion, merely being able to glimpse a faint trace of the white haze doesn't qualify.

[auroraTDunn]

Numbers already given BUT this would be a GREAT topic for one of my grad Intro to Scientific Visualization classes. To bad I don't teach it anymore but it would be a perfect data topic for one of my new workshops!

Edited by auroraTDunn, 17 July 2024 - 03:33 PM.

[happylimpet]

I can just see it from my garden, JUST. But its entirely unimpressive. Just the weakest faint glow

 

So, It would seem that two thirds of the the world population can see the Milky Way to some extent - but it's another question how well they can see it. In my opinion, merely being able to glimpse a faint trace of the white haze doesn't qualify.

 

.

[Nankins]

I just asked my professor and I can have more than 5 articles.  Most of the sources I found are from 2016 when it seems the media really noticed the issue but there's not much since then.

[Nankins]

I have never seen the Milky Way

 

nearest dark site is a few hundred miles away, AND COUNTING!  

 

I really wonder though, what do commercial fishing boats (and any big ships in general) see, when they're in the middle of the ocean

 

they have bortle 1; lucky guys!

Where are you at?  Milky Way is visible from my home.  High B4.  Gets to the zenith and it can still make one suck in the breath on a quick glance.  Near the horizon it's not usually like that but the Great Rift is still usually visible. Nearest slightly darker site is a 30 minute drive.

[Jehujones]

According to this source: https://www.astronom...-the-milky-way/, 80% of Americans can't see the Milky way, and one third of the world population can't see the Milky way.

 

I don't know how they came up with the numbers. But they seem about right to me - since about 80% of americans live in cities or urban areas, but this number is significantly lower in many other parts of the world.

 

So, It would seem that two thirds of the the world population can see the Milky Way to some extent - but it's another question how well they can see it. In my opinion, merely being able to glimpse a faint trace of the white haze doesn't qualify.

I disagree, for the purpose stated by the OP, it should be a simple yes/no. Getting into the degrees of how well it can be seen would be an enormous undertaking for the OP’s project.

[db2005]

I disagree, for the purpose stated by the OP, it should be a simple yes/no. Getting into the degrees of how well it can be seen would be an enormous undertaking for the OP’s project.

It's a valid point, but I doubt the question can be answered as a simple yes/no without any reservations and qualifications.

 

And for the sake of the OP we might as well now begin to discuss the questions that others may ask to his paper.

 

Especially since the paper is for a class on Rhetoric and Argument.

Edited by db2005, 18 July 2024 - 11:07 AM.

[John Berger]

Where are you at?  Milky Way is visible from my home.  High B4.  Gets to the zenith and it can still make one suck in the breath on a quick glance.  Near the horizon it's not usually like that but the Great Rift is still usually visible. Nearest slightly darker site is a 30 minute drive.

San Diego area

 

I think a B3/B4 site is sort of near

 

but B1 is far away

 

I'm in B7 according to ClearOutside, and B5 according to lightpollutionmap, so I don't know what's the truth

[Sebastian_Sajaroff]

I have never seen the Milky Way

 

nearest dark site is a few hundred miles away, AND COUNTING!  

 

I really wonder though, what do commercial fishing boats (and any big ships in general) see, when they're in the middle of the ocean

 

they have bortle 1; lucky guys!

They see nothing, there are plenty of powerful lights on those big boats.

Same thing for cruises, horrible light pollution.

[Nankins]

San Diego area

I think a B3/B4 site is sort of near

but B1 is far away

I'm in B7 according to ClearOutside, and B5 according to lightpollutionmap, so I don't know what's the truth

If you can see only the Moon and bright planets and stars you are in a B7. B5 is the brightest at which the Milky Way is still visible. Go to the B4/B4 site if possible. If you have never seen the Milky Way you'll still be rather taken aback. That still happens to me sometimes and I've lived in the same spot my whole life.

How far away is the B1 site? California is closer to any of those areas than a majority of the Midwest (we need to drive out to Pennsylvania or West Virginia that gets anything better than a B3; from Indiana that's about an 8-9 hour drive).

It is hard to determine your area's exact light pollution level and maps tend to differ. Easiest thing to do is just find a definition of the Bottle scale then go outside on a clear night and look up and see what you can see. Note that this can change from night to night depending on the weather.

[Dave Mitsky]

The summer Milky Way is visible on a good night at the orange zone Naylor Observatory, which is a Bortle 5 location.  However, it is far from impressive.  I get high SQM-L readings of 19.8 mpsas and sometimes slightly higher.

https://www.cleardar...scope accessory

 

[dnayakan]

Ignoring things like sky glow and the moon, light pollution is very likely to be directly related to population density. There are good sources for population density figures (e.g., https://www.census.g...-data-text.html ). As a start, you could run correlations or regressions of SQM figures across population density figures for areas where SQM is known. You can get a pretty good sense for the degradation in the MIlky Way across different SQM levels. The regression could then be extended to predict the degradation in any part of the world where the population density is known. That would be just one general approach that could be used. 

[John Berger]

If you can see only the Moon and bright planets and stars you are in a B7. B5 is the brightest at which the Milky Way is still visible. Go to the B4/B4 site if possible. If you have never seen the Milky Way you'll still be rather taken aback. That still happens to me sometimes and I've lived in the same spot my whole life.

How far away is the B1 site? California is closer to any of those areas than a majority of the Midwest (we need to drive out to Pennsylvania or West Virginia that gets anything better than a B3; from Indiana that's about an 8-9 hour drive).

It is hard to determine your area's exact light pollution level and maps tend to differ. Easiest thing to do is just find a definition of the Bottle scale then go outside on a clear night and look up and see what you can see. Note that this can change from night to night depending on the weather.

well, the closest B2 site in CA is about 220 miles away (Mojave trails area)

 

and nearest B1 is in Mexico, in a biosphere reserve, which is farther than the B2 area

Edited by John Berger, 18 July 2024 - 10:10 PM.

[Jehujones]

The summer Milky Way is visible on a good night at the orange zone Naylor Observatory, which is a Bortle 5 location.  However, it is far from impressive.  I get high SQM-L readings of 19.8 mpsas and sometimes slightly higher.

https://www.cleardar...scope accessory

 

I would be happy to live where the Milky Way is far from impressive because that means it’s still visible.

[Tony Flanders]

Although this figure is widely publicized, I doubt there's much in the way of data to support it.

I can testify from direct experience that many people in the U.S. who have never seen the Milky Way could see it easily if only they stepped outside, walked 500 feet to a darker spot, and looked. Or turned out their porch lights.

 

I can see the Milky Way easily from most of the suburban area of Boston, Massachusetts -- just about anywhere outside Rt. 128 that isn't next to bright streetlights. But I doubt most of the people who live there have ever thought of looking for it, or would recognize it if they saw it.

[Rafael Amarins]

I've never seen a study that would come up with a number like that. Whenever I hear a number like that it is a generic youtube video about astronomy. Most of them have no idea what they're talking about. 

I guess you would have to create a model based on population density, human development index (Kisingani and Barcelona have ~ the same population but not the same light pollution right?) and other factors.

[Nankins]

Most of the time I read one of these numbers it's in a media publication, typically something like Smithsonian or Astronomy.  I think scientists have created models based on population density and human development index, or we would not even have a decent rough estimate of the percentage of the human population that can't see the Milky Way.  Yes, other factors would be needed as well.

 

Yes I've been amazed at the number of people who even in the middle of the city don't really notice that they can even see anything beyond the Moon.

[Jehujones]

Most of the time I read one of these numbers it's in a media publication, typically something like Smithsonian or Astronomy.  I think scientists have created models based on population density and human development index, or we would not even have a decent rough estimate of the percentage of the human population that can't see the Milky Way.  Yes, other factors would be needed as well.

 

Yes I've been amazed at the number of people who even in the middle of the city don't really notice that they can even see anything beyond the Moon.

Tony has a good point.

 

There are those who don't see it and there are those who can't see it. Two different things.

 

For that matter, there are those who won't see it even though they could see it.

[MrsM75]

Also there people expect to see the Milky Way like this though. So unless they see it exactly like this pic, they don't think it the Milky Way. If they see a large patch in their sky they think it clouds or sky glare.

 

I never know how the Milky Way suppose to look like beside this pic below, so unless I see it like this, I will never think I ever see the Milky Way. So there are people expect the Milky Way to look like this.

 

 

Edited by 34degN, 20 July 2024 - 12:52 AM.

[Nankins]

Good point 34degN.  That is exactly what many people who have never looked up at the sky but have seen astrophotos of the Milky Way often expect.  However they would need to travel to a very very dark sky site to see anything close to this.  Just ask some of the other CN members who either live in one of those areas or have traveled to one of those areas.  You will know when a video really was taken at a very dark sky site because you will be able to see the Milky Way in it (albeit it will appear faint and blurry as the camera will not have had the right settings nor the exposure time necessary, but because videos are composed of many frames per second the Milky Way would show up better than it would if it was a single exposure).  Others here can correct me if I am wrong.