Questions tagged [sun]

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

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11 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 ...
213 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 ...
54 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 ...
5k views

How can we calculate the temperature of the atmosphere, including the greenhouse effect?

I've been struggling to find equations that express how many degrees of warming greenhouse gases contribute, given the composition of an atmosphere (and solar insolation). What I did find was the ...
32 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 ...
66 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 ...
248 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 ...
30k 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 ...
21k views

What time and date is the sun directly overhead a given place on Earth?

In different regions, the sun is directly overhead at different times of the year. When do these event happen?
101 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 ...
67 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 ...
737 views

Light at the coast - is it different?

I have heard artists talk about the unique quality of light near the sea, and now I live near the coast I want to know if there's any truth in it. Does being near the ocean affect light inland? I'm ...
82 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 "...
63 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 ...
57 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 ...
266 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?
81 views

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? ...
135 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 ...
61 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 ...
77 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 ...
641 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 ...
3k 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 ...
176 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 ...
68 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 ...
510 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 ...
201 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 ...
85 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.
5k views

Why does it rain during the sunny day?

What are factors that cause rainfall while the sun is still shining. The phenomena is known as sunshower? The information I found so far is very limited. Please help me answer this question if you ...
1k 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 ...
208 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 ...
610 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 ...
565 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 ...
251 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 ...
113 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 {...
5k 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 ...
13k 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 ...
65 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 ...
252 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 (+-...
154 views

Is there an instance where the sun sets or rises partly, then return back?

I am reading Longest Sunset from XKCD. At first, I've thought that he mentions these phenomena just for fun, but it turns out to me that it might happens, based on the level of somewhat seriousness ...
724 views

Why is the part of the earth tilted towards the sun warmer? Which factors matter more?

The part of the earth tilted towards the sun is warmer. For example, in the Northern hemisphere, the earth is tilted towards the sun in the months around June and tilted away from it in the months ...
1k views

Why isn't the sun due south at noon? [closed]

I was going to ask a question about why the sun is not due south at noon throughout the year. There was a discussion on this site about daylight savings time, GMT, longitude, time zone boundaries and ...
68 views

Is there any way to measure the amount of radiation the earth receives from the sun?

My understanding is that it is difficult to measure the amount of radiation the earth receives to the sun and that due to variability in a number of different quantities such as the changing distance ...
118 views

Difference in sun activity between two towns (Eastern and Western hemispheres)

I grew up in a small town on a sea shore with hot and sunny summers (up to 30-35° C). I remember myself, my friends and relatives being outdoors for 12 hours a day. We never needed sunscreen, and ...
2k views

Earth's Internal Heat Engine

What is the internal heat engine of the Earth? Doing research, I found out that the external heat engine of the Earth is the Sun. However, when I did research on the internal heat engine of the Earth,...
667 views

Sun's Highest Point on June 21

Where would you have to be for the sun to be highest overhead at noon on June 21? Since the rays of the Sun are perpendicular to the Tropic of Cancer on June 21, shouldn't the Sun be overhead in this ...
390 views

Latitude and Daylight Hours

What is the relationship between the latitude and daylight hours for each season? When I interpret the answer for the question, I believe the number of daylight hours decreases as the latitude ...
900 views

Equator and Hours of Daylight

Since the equator is closest to the sun, would it have more daylight hours compared to, say, the Tropic of Cancer? I am using an example, however, would it be true if the farther one is from the ...
317 views

Sun Appearing to have Stopped Shining [closed]

What could have caused the Sun to appear to have stopped shining from noon 'till 3 in the afternoon? According to the Bible, at Jesus' crucifixion, darkness covered the land because the sun stopped ...