Questions tagged [sun]

The center of our solar system. Questions in regards to sunlight or solar related questions.

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name of this atmospheric phenomenon: possible crepuscular ray?

This morning I took this picture pointing East, just before Sun rise (also the Moon and Venus are visible there): there's a tilted blue vertical ray amidst the golden horizon: I suppose this can be a ...
circulosmeos's user avatar
2 votes
3 answers
520 views

Where does the sun set?

It's commonly said that the sun sets in the west. However from my balcony I can clearly see that it sets significantly farther in the south during winter, and much farther north in the summer. Why is ...
Sebastian Wozny's user avatar
2 votes
1 answer
117 views

Why do solar panels capture less energy at higher latitudes? [duplicate]

When confronting people with this question, I often get back something along the lines of "the higher the latitude, the smaller/wider the angle at which the sun hits the surface. As a result the ...
shamiv's user avatar
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The Sun's location in noon and tropic of Cancer/Capricorn [duplicate]

I came across this article and I would like to clarify a few moments: if you're located north of the Tropic of Cancer, the Sun will always appear south of the zenith. Does it mean if I am located ...
pacman's user avatar
  • 297
1 vote
1 answer
172 views

Tropic of Cancer/Capricorn and sun position

Let's consider 3 options for my position on Earth: North to tropic of Cancer Between tropic of Cancer and Capricorn South to tropic of Capricorn If I take a compass and point it to the Sun, will it ...
pacman's user avatar
  • 297
4 votes
0 answers
69 views

Highest amount of sun hours in the ocean

Solar panels create electricity from (sun)light. It stands to reason that more hours of light equals more electricity. This is a gross simplification of the problem, as light strength, heat, how ...
Trioxidane's user avatar
1 vote
2 answers
97 views

Measure of daylight brightness

I am looking for a meteorological measure of daylight brightness/luminosity. I can only find measures that are defined by the number of hours of sunlight during a day, but is there a measure that also ...
Maël's user avatar
  • 111
1 vote
0 answers
61 views

What does "red sun at night, sailor's delight" mean and is it true?

There is proverb that sounds like: Red sun at night, sailor’s delight; red sun in the morning, sailor take warning. Is it valid and if it is then what is it about?
Vashu's user avatar
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How to calculate greenhouse effect for planet as well as for the atmosphere?

I recently found a calculation on how to calculate the greenhouse effect for Earth from another question here, but I couldn't make heads or tails of the calculations that were provided in one of the ...
Vivaporius's user avatar
1 vote
1 answer
88 views

All longitudes experience the midday Sun. Why do all longituted experience the Midday sun?

Why do all longitudes experience the Midday sun? Any other information related will do. What is the Midday Sun? Any other earth or planet-related information is required. Thank you to those who have ...
Elizabeth's user avatar
1 vote
1 answer
115 views

In a picture taken in an unknown location, the sun shines on skyscrapers solely from the right. What direction was the camera facing?

My son reasoned that if the sun is shining on the right sides of the skyscrapers, then east is to the right. Therefore, the camera is facing north. Therefore my son answered "a) North". But ...
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1 vote
1 answer
168 views

In a picture taken in Northern Hemisphere, the sun shines on skyscrapers solely from the right. What direction was the camera facing?

My son answered e), but Scantron marked him wrong. Why? Please show the steps. How should he deduce the answer? A picture was taken in the Northern Hemisphere (e.g. Canada), featuring two ...
user avatar
20 votes
2 answers
6k views

In the northern hemisphere summer, why are places in the north cooler than those in the south?

As the Earth's axis is inclined, during summer in the northern hemisphere places in the north are exposed to the Sun's rays for longer, so days are longer during summer (say in June - Aug). Yet, ...
Leo's user avatar
  • 301
3 votes
1 answer
66 views

Can clouds increase the level of UV-A radiations received on the earth surface? If so, by how much, and in which condition(s)?

The American Scientist article nicely explains that clouds sometimes increase the level of UV radiations received on the earth surface. However, all the papers they cite focused on UV-B radiations. ...
Franck Dernoncourt's user avatar
6 votes
2 answers
2k views

Does the amount of UVA radiations one receives depend on the day ot the year?

The following quotes seem to be contradictory. From skincancer.org, the amount of UVA radiations during daylight hours stays constant throughout the year: UVA accounts for up to 95 percent of the UV ...
Franck Dernoncourt's user avatar
4 votes
0 answers
38 views

What is the formula to input date, time and longitude. Where i can get latitude of the civil twilight back?

I am making a watch app, where i need to know where there is currently sun, and where its not. I need to have some sort of formula/function to insert: date, time and longitude, and get back the ...
patchie's user avatar
  • 141
2 votes
1 answer
60 views

Seeing a varied change in brightness across the landscape during sunrise?

In this video of sunrise at Cadillac Mountain, Maine, the landscape closer to the horizon appears to brighten sooner than the foreground. It makes sense to me, the terrain at the horizon is ...
Bob516's user avatar
  • 334
1 vote
1 answer
41 views

Does the Sun and Moon basically appear to "move on the sky" identically regardless of location and date? [closed]

For a long time, I've been trying to use Stellarium (simulation) and many visualizations and animations in order to get a good idea of how the Sun and Moon move across the sky, as seen by a human from ...
MooMoo's user avatar
  • 11
1 vote
2 answers
178 views

Color of Sunsets

I heard that hot weather in the summer makes the pastel colors of the sunset sky more vivid and more red? Is this true? But I also heard that in the winter, the colors of the sunset sky are brighter ...
Ryan Amalfitano's user avatar
1 vote
1 answer
324 views

What exactly does it mean that Japan is the "land of the rising sun"? [closed]

Only in later years have I understood anything about how our planet moves around itself and around the Sun, and how it therefore appears to always "rise in the East" and "set in the West", apparently "...
Wynell S.'s user avatar
1 vote
0 answers
66 views

Does the hour thingie on a 24-hour clock represent the apparent "motion" of the Sun "around" the Earth? [closed]

While looking at this photo of a 24-hour clock: https://upload.wikimedia.org/wikipedia/commons/6/61/Greenwich_clock_1-manipulated.jpg ... it struck me that, maybe, it could be seen as a visual ...
Brytan Benko's user avatar
1 vote
1 answer
93 views

[How deduce from shadows, the angulation of the Sun that the Sun is 15 degrees over horizon?

At r/rbi, u/A11edge asked Can anyone determine an hour when the photo was taken? The author of the photo is suspected of spraying pesticides during daytime (which is illegal because it causes death ...
user avatar
5 votes
0 answers
98 views

How could the solar wind cause strange magnetic pulses on Mars at midnight?

24-Feb-2020 NASA News item A Year of Surprising Science From NASA's InSight Mars Mission says: A new understanding of Mars is beginning to emerge, thanks to the first year of NASA's InSight lander ...
uhoh's user avatar
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3 votes
0 answers
114 views

Do northern lights (aurora borealis) show the same visual activity all along their visible latitude range?

Probability aside regarding their visibility (I did read on Neil Davies Aurora watcher's handbook that probability is highest in the middle of their latitude range called aurora oval, lowering both ...
Domi's user avatar
  • 31
8 votes
2 answers
602 views

To what extent do the levels of UVA, UVB and UVC radiations on the earth surface increase during solar flares?

To what extent do the levels of UVA, UVB and UVC radiations on the earth surface increase during solar flares?
Franck Dernoncourt's user avatar
3 votes
1 answer
348 views

What is the lowest latitude for which if the ideal solar energy received each day for a year is graphed, the graph would contain one peak?

I asked a question with the same meaning on Quora, but it seems no one got it, so I'm asking it here with a very different wording. I'm actually not sure if this would belong here or on the Astronomy ...
Grant Hartlage's user avatar
2 votes
1 answer
117 views

Atmospheric conditions needed that blocks all bright light during sunsets and allows you to stare directly at the sun

Today (July 5th, 2019 just before 8 pm KST), along the Han River in Seoul, the surface of the sun could be viewed with my naked eye (no protection needed), and this was safe on the eyes. It appeared ...
Christopher Rucinski's user avatar
1 vote
0 answers
82 views

Can we predict the rising temperature of Earth?

Where can I find a model of Earth's past climates and future projections from combined possibilities like magnetic pole movement and other forms of global warming as a map? Without a reference it has ...
Muze's user avatar
  • 1
6 votes
3 answers
1k views

If the Sun disappeared, how long would it take for the Earth to freeze beyond excavatable depths?

If the Sun disappeared How long would it take for the earth to freeze beyond excavatable depths? How long until it freezes to the core? (Is this different than without removing the Sun?) Would we be ...
Speedphoenix's user avatar
7 votes
2 answers
660 views

Calculate the maximum power angle of a solar panel (photovoltaics)

I want to calculate the maximum power angle of photovoltaics depending of the coordinates on Earth. That means at which angle I should align my solar panel to get the maximum power over the year? I ...
KT Works's user avatar
  • 173
5 votes
1 answer
133 views

What is a Rotating Shadowband Radiometer, and how does it work?

This answer explains that the device labeled "B" in the photo below is a "Ultraviolet Multifilter Rotating Shadowband Radiometer." What is a Rotating Shadowband Radiometer, and how does it work? ...
uhoh's user avatar
  • 7,074
0 votes
1 answer
75 views

Solar Cycle 25: Can a strong solar storm trigger a violent geomagnetic shift? [closed]

In light of the material presented in the link, hopefully not disregarded as a complete mumbo-jumbo, I would like to pose a simple question, as mentioned above in the question - While we are ...
Wolves' Shepherd.'s user avatar
1 vote
1 answer
1k views

Southern Hemisphere: What is the most Northern latitude where the sun can be seen for more than 24 hours?

Is there a location, in the southern hemisphere, where I could pitch a tent that I would be able to see the sun at any time of day for, say, more than a week? How far north could I go and still be ...
Matt W's user avatar
  • 113
1 vote
3 answers
146 views

Why is it still day in Mumbai at 6:47 PM?

I captured this news channel picture on Sept 11 2018 from India. We can clear see It is live telecast from Mumbai, but it is still day time.
Mario Badstuber's user avatar
5 votes
7 answers
1k views

What is this Sun and moon photographic anomaly?

Below is a photo that my son took in Scotland showing the sun and moon at the same time. I immediately noticed this anomaly that the light illuminating the moon could not possibly come from the sun. I ...
Jackamus's user avatar
4 votes
3 answers
407 views

calculate UV index in vertical plane

Due to extensive damage to my face because of an accident, I am currently undergoing skin therapy (laser/IPL/medication), that makes my skin extremely sensitive to UV radiation. So I need to stay out ...
rogerwilco's user avatar
4 votes
1 answer
3k views

Are you more likely to get a sunburn at the pole than the equator?

After looking at this post I can see that a flat object is more exposed to the sun at the equator. Does this mean that a person walking around (standing up), is much more likely to burn at the poles ...
fileyfood500's user avatar
5 votes
1 answer
666 views

Every 202,500 years, Earth wanders in a new direction; does it affect climate?

I refer to this article on nytimes.com: Every 202,500 Years, Earth Wanders in a New Direction TLDR: Scientists believe the earth's orbit oscillates between circular and more elliptical due to the ...
Hessnov's user avatar
  • 151
1 vote
1 answer
217 views

Easy homework questions about seasons and daytime

The following homework assignment is supposed to be easy, but there seems to be information missing from the questions asked (or at the very least knowledge from OP). At which width circle does the ...
Lieven Keersmaekers's user avatar
10 votes
2 answers
963 views

What are the sunniest places on Earth? (including oceans)

This question did arise when thinking on offshore solar power plants, what's their potential, and how efficient would they be compared with land based counterparts. Recently, it is becoming more ...
Pedro's user avatar
  • 373
-5 votes
1 answer
4k views

Is there any correlation between Grand Solar Minimums (GSM) and earthquakes? [closed]

I've found many claims arguing that the periods of minimum solar activity are associated with increases earthquakes and volcanic activities. Some of these claims are supported by articles in ...
stormy's user avatar
  • 167
4 votes
1 answer
2k views

How much of one day can be considered nighttime, on average?

What is the split between night and day on Earth on average? To further clarify, assume we are on the equator, I want to know how long a time, as a percentage, you could consider to be nighttime on ...
Sam Chamberlain's user avatar
0 votes
2 answers
1k views

Sun's Effect on Water Vapor in the Air

If the air temperature remains the same, will adding more sun reduce the amount of water vapor in the air - that is, does the sun have any impact on water vapor in the air when temperature is removed ...
Ed S's user avatar
  • 1
1 vote
0 answers
316 views

Understanding the sunshine duration metric

I am trying to create a program that calculates the ideal climate based on a set of inputs and weights. Something similar to 400 cities but based on more climate based options that the user can ...
Iain Watt's user avatar
0 votes
1 answer
155 views

The sun rises up at 7:30 in 25°E, What time will the sun rise up in 15°E?

I've a question about time calculating. The sun rises up at 7:30 in 25°E, What time will the sun rise up in 15°E? What I've tried $$25° - 15° = 10°$$ By the way $$10° . 4 = 40 \space \text {...
Mark's user avatar
  • 1
4 votes
2 answers
39k views

Why was the sky SO yellow?

Today, I was coming back from music school, and it was raining heavily. An hour after I came back, the sun started coming out from one side, and the sky wa very brighr yellow. The lighting effects ...
KKZiomek's user avatar
  • 567
7 votes
2 answers
10k views

Why does the intensity of sunlight depend on your latitude? [duplicate]

People at the equator get to bask in more sunlight than Santa Clause and other inhabitants of the arctic regions. Not quite as pronounced, but they get more than me too. Why is the sunlight more ...
Aaron's user avatar
  • 351
25 votes
1 answer
15k views

Why were both the sun and the moon red today?

Today was a normal day, except the sun and moon colors were strange. After 5pm, the sky was covered with cirrostratus-like translucent clouds and the sky was a blend of blue and grey. Everything ...
KKZiomek's user avatar
  • 567
4 votes
0 answers
69 views

Where did clouds obscure the American eclipse of August 2017?

Emphasis here is did. I'm trying to find a source that will inform me about which locations in the United States actually had their view of the eclipse on Aug 21, 2017 obscured by clouds. I'd ...
theforestecologist's user avatar
3 votes
1 answer
504 views

Calculating Solar Noon from Sunrise and Sunset [closed]

I've seen the solar noon formula described as snoon = 720 – 4*longitude – eqtime. I'm curious if it is equally reliable within a relatively small margin of error (+-...
Brad's user avatar
  • 139