Sun Definition and 996 Threads

Hello, Here is my question: Just imagine the sun would stop shining, without exploding. It would just totally disappear without causing harm. How long would human race survive without the benefits of the sun? 10 minutes? 10 hours? 10 days? Could it stand the cold longer? How long would it...

I don't know what forum this belongs in. Move it at will. I have already posted this on the APOD discussion site. Today on the way home from work, I saw a pair of sun dogs. At first I could only see the left one which was in a location where there were some wispy clouds. On the right, I could...

I can "understand" the gravitational pull of the sun on the Earth and the Earth mass effect toward the moon, but what pull the sun? a neophyte.

Homework Statement Using the data on the solar wind given in this chapter, compute the averagerate of mass loss of our Sun(M(sun)/year) from: a)the solar wind b)energy generation Homework Equations possible equations: Energy density =(#density)*(energy per particle)= n*(3kT/2)...

A comet is in an elliptical orbit around the Sun. Its closest approach to the Sun is a distance of 4.5 1010 m (inside the orbit of Mercury), at which point its speed is 8.9 104 m/s. Its farthest distance from the Sun is far beyond the orbit of Pluto. What is its speed when it is 6 1012 m from...

Homework Statement The flux from the Sun above the Earth's atmosphere is about 1370 watts/m^2. This quantity is called the solar constant S and equals pi*f(sun). Use the angular radius of the sun as seen from the Eart to find pi*F , the surface flux of the sun. Homework Equations...

I know that it took approximately 3 minutes for lights to travel from sun to earth. Let say the sun is gone now. Like erased, click-n-drag out of the universe in an instant! So until 3 minutes later, no one on Earth would realize it, because nothing travel faster than light! But, could I argue...

I am not an astronomer or astrophysicist but lately, I have been reading a lot of books to upgrade my knowledge in cosmology. I have encountered two issues that I am baffled about and wonder if anyone can help me throw some light on them (1) If the planets are parts of the sun or came from...

Homework Statement [FONT="Fixedsys"][SIZE="2"][SIZE="4"]How does the temperature of the Earth change when the sun suddenly stop radiating?:confused: how will the temperature vary with time? Please help me solve this one. can we answer this one using models or simply through theories? can you...

I might already know the answer to this but i just need to make sure. Does a suns mass reflect its volume? I ask because... The formation of a star simply put is: a planet gathers mass there-by gathering gravity there-by igniting and becoming a star…it becomes a star with x amount of mass...

I was trying to come up with a solution to the timeline when hypothetically speaking the sun would stop shining ( or emitting radiation). Now, gravitational issues aside (the sun as a body still there), how long would it take for median temperature to drop beyond freezing point around the globe...

Sun is an "ordinary" star I've read in different books the Sun is an "ordinary" star, and an "atypical" star. Anyone know which description is the correct one?

How do plants grow towards the sun? Thanks.

Homework Statement On October 15, 2001, a planet was discovered orbiting around the star HD68988. Its orbital distance was measured to be 10.5 million kilometers from the center of the star, and its orbital period was estimated at 6.3 days. Question A: What is the mass of HD68988? -- I...

Hello everyone, I've been on Electrical Engineering for a little while but new to this aspect of science. I'm not sure of course but when sunlight travels through space, would it be the approximate temperature of its' surrounding area, pretty cool? And when it hits our oxygenated atmosphere...

Homework Statement How long does it take the Sun to melt a block of ice at 0°C with an area of 1.10 m2 and thickness 1.07 cm? Assume that the Sun's rays make an angle of 31.1° with the normal to the area, and that the emissivity of ice is 0.0400. Homework Equations Q/t = IeAcos(theta)...

Why does the sun appear to have such low surface gravity? Most would say the the nuclear reactions inside the sun continually pushes matter outward against the force of gravity, but this does not account for the slow fall of solar flares and speed of solar wind. According to the current...

Hi. I'm really not sure if I'm posting this in the right place. If not, I'm sorry. Anyway, here's the thing: I'm doing research for a fantasy novel I'm writing. I know virtually nothing about any kind of science, so I need help with the following question: if the sun were to rise in the west and...

I'm going nuts trying to figure this out... in textbooks and online, everything i read says that the moon and Earth have a much stronger gravitational force between them than the sun and the earth, and this is why the moon has greater effect on tides than the sun. They all say that this is...

How much does the moons mass contribute to the Earth's orbital distance and characteristics around the sun. If the mass of moon and the Earth were not joined At the hip or say the moon magically disappeared :rolleyes: would the Earth's orbit around the sun still be within the habitable zone...

Could one design an effective sun block which passes the spectrum necessary for Vitamin D synthesis?

I'm building a solar powered project to light a room. From what I find on the internet, the average of sun light is given. It seems like to make my calculations I need to know what the minimum amount of sunlight could be. I haven't been able to find a website that shows the min and max sun light...

Hello everyone, I was wondering where I could get complete ecliptic longitude/latitude data over the course of as many years as possible of the Sun and Moon. Of course, by definition the ecliptic latitude of the Sun would be zero. The equatorial coordinates would be fine. Thank you for...

this just appeared in the peer-review journal Physical Review Letters. I noticed the preprint of it on arxiv last year and thought it was pretty far out. Here is the revised October 2006 preprint: http://arxiv.org/abs/astro-ph/0610844 Shining light through the Sun Malcolm Fairbairn, Timur...

Hi, Will a sun sensor work if the satellite is in the Earth's shadow? thanks!

Hi, Earth follws a straight path in 4-d space time.ok.now the Earth moves over the geodesic formed by the sun's gravity.now we also have other 7 planets.So does it mean that the sun forms different geodesic for different planets. if my question does make some logic than please explain me.

I recently did a school project about Copernicus, and after researching him, I have found that he believed the Sun was the center of the Universe, rather than the solar system. So, I was wondering: who was the person who discovered that the Sun was actually just the center of the Solar System -...

I have three questions. 1. Why are galaxies disk shaped and not spherical? 2. Theoretically speaking, if there were a hollow sphere at the exact center of the Earth and you were in it then what would you feel from a gravitational point of view? Would you hover and be able to bounce from...

Homework Statement The Earth's orbit around the sun is very nearly circular, with an average radius of 1.5x10^11 m. What is the average speed of the Earth in orbit around sun.Homework Equations d/t= 2pi/tThe Attempt at a Solution 2pi*1.5x10^11/ 31556926 it comes out to be 29865.95 answer is...

Hi all, I was hoping for a little advice and some insight on these pictures I took. Here is the first (orig_small1.jpg): And the Second after I realized and waited for a break in the traffic (orig_small2.jpg): I was on the Skyway Bridge in the passenger seat driving from St. Pete...

Hello, I've got this problem: The sun converts 1.91exp19 kg of Hydrogen to Helium per year, given that the sun started out with 75% Hydrogen by mass, computer how long the sun would shine if it converts all it's Hydrogen to Helium. I computed the total energy of the sun as 3.81exp41...

during the sunrise and sunset, we find the sun reddish in color...why is it so...my view is that as the distance to Earth during these times is longer than mid-day, and applying doppler effect, as the sun nears the apparent wavelength decreases and so is the perceived color...is this approach...

What is the effect (if any) of the sun's movement around the galactic center in relation to planetary orbits?

We are studying Energy at school The book said that "All Energy on Earth can be traced back to the Sun" I know there is mechanical energy chemical energy electrical energy Are they talking about everything? I mean cars, fireplaces, ect...

I'm trying to make a program which makes use of Newton's law of universal gravitation to model planetary motion. I've set up a system very similar to the earth-sun system (i.e., masses and distances are similar to the actual earth-sun system). When I run the simulation, the "earth" orbits the...

Homework Statement In six steps, explain how energy was transferred from the sun to your moving mousetrap car. Homework Equations None, I think. The Attempt at a Solution For the most part, I don't have the slightest idea. I do know how the energy transfers to the spring and powers...

I read somewhere (Wikipedia I think) that charges particles are leaving our Sun and heading for Earth faster than can be explained by current solar models.Is it possible that there is some Hawking radiation inside the Sun imparting extra energy to these particles? Or does Hawking radiation only...

helloooo new to this forum...and a total science noob who comes to you seeking knowledge... :rolleyes: Anyway - i recently saw the new danny boyle movie 'sunshine' - the story is about the sun dying and a rescue team who's on a mission to save the sun by reigniting it. My question...

I've been reading Kip Thorne's book "Black Holes and Time Warps" and was wondering about a couple of things. They're really basic questions that have been floating around in my head, but I can't ask any of my friends because none of them know anything about these topics, so...I came here...

No big rocky planets? Why are there no big rocky planets - all the big planets are gaseous. Did big rocky planets get smashed up and end up in the Kuiper belt?

Homework Statement What is the acceleration due to gravity of the sun at the distance of the Earth's orbit? Homework Equations Confused on which one to use The Attempt at a Solution

hey since the Earth turns around itself , turns around sun, sun turns around galaxy, galaxy is in movement (or maybe orbiting something bigger, who really knows ?) Well with all these movements, our velocity must be close to c ? thus , what is galaxy turns around ..., which turns around...

Nature decides that instead of inverse square law for gravitational forces the law will be inverse cube law. In that case what among the following will be true? a) The force of gravity from the sun will be weaker b) The period of the planet will be proportional to the square of the distance...

Even though in optics experiments we assume that the sun rays are parallel, we can clearly see that the sunlight seems to diverge from the sun when coming through the clouds. Whats the reason of this discrepancy?

I was thinking of a scenario where the sun suddenly disappeared into thin space as if it were blinked out of existence. Aside from this being an absurd possibility, the more interesting question is how space around the sun would react to the giant loss of mass. Would it be correct in thinking...

I have been trying to understand how our ocean tides work and read about the effect of our moon's and sun's gravitation. I have learned there are diurnal, semi-durnal and mixed semi-diurnal tidal patterns When the moon is directly overhead equatorially (near side), I've seen illustrations...

I've been hearing these talks that the sun will run out of hydrogen in 4.5 to 5 billion years from now. My question is, how did we arrive at this estimate. Is it based on the mass or something? It would be good if you can show me the mathematical calculations. --thanks.

Ok so if the center sun of our gallaxy is in sagattarius then what degree is it in sagattarius. If the Earth and the sun and the center sun were in aline once a year then would I have to see the oppisite consalation of sagattarius at the oppisite degree of the center sun in the center of the...

Last night I watched a program on TV that made the statement that in the interior of our sun the gravity is so intense that a photon of light can travel only several thousandths of an inch per minute. It takes hundreds of thousands of years for a photon of light to travel from the interior of...

The Earth is subject not only to the gravitational force of the moon but also to the gravitational pull of the sun. However, the earth is much farther away from the sun than it is from the moon. In fact, the center of the Earth is at an average distance of 1.5 x 10^11 m from the center of the...