The sun Definition and 622 Threads

Just a quick question Are the planets totaly locked in there orbits forever or do they slowly get drawn in closer to the sun?either by the sun's gravitational pull or simply by the sun expanding? Thanks in advance for any replys mike

By just knowing the clues like the force of attraction between two masses and angular momentum conservation principle , linear momentum conservation principle and geometry..can we derive the trajectory of the Earth around the sun is ellipse..if so please tell me your ideas..

This might sound like an unoriginal question but what is gravity? Why does the Earth and the sun and other planets have gravity? Does everything have gravity? What causes gravity? Thanks ahead of time :smile:

I read in a paper the following passage: "We take the sun to subtend a linear angle of 32 arc-minutes. The solid angle is derived as \Omega=\pi sin^{2}16'=6.8x10^{-5} sr" I don't understand how the formula to go from linear angle to solid angle is just found by taking the area treating...

I had a friend who told me that there is a distance between the Earth and the Sun which the components of gravity add to zero. Is this true? If so, does this mean that something could get stuck there in that spot?

I'm doing physics of uniform circular motion, while I'm working out this equation It occurred to me , is it possible to find out how many rotations of Earth around the sun until it hits the sun. By the way I'm at a very NOOB level lol but seriously? *thinks of possible equation* :( not...

Hi all. Is the explanation for the fact that it is hotter at equator than other places at the Earth that the intensity of the Suns waves are greater at equator, since the number of beams per area is larger (since they are not scattered that much because of the lack of curvature)? I hope...

Hi, This might sound like a simple question, but it's not for me. I'm standing at the Tropic of Cancer - what would be the declination of the Sun on the Spring equinox. I believe it should be zero degrees, but my brother says it's 23.5 degrees. Can anybody shed light? Thanks in advance...

Homework Statement Using the table that follows, justify dividing the interior of the Sun into two separate functional layers (as regards energy production) and describe the average properties of those two layers.http://img26.imageshack.us/img26/8356/er3z.jpg Homework Equations R/R0...

Could anyone give me a figure (in joules/kilo joules) for this? Wikipedia says (on it's gravitational binding energy page) that the gravitational binding energy of a star is equal to about two times it's internal thermal energy. I looked for "internal thermal energy" and could not find...

what is the percentage of heavy element (heavier than helium) of the sun? (not the photospheric composition)

Homework Statement A planet moves in an elliptical orbit around the sun. The mass of the sun is M_s. The minimum and maximum distances of the planet from the sun are R_1 and R_2 , respectively. Using Kepler's 3rd law and Newton's law of universal gravitation, find the period of...

By "Is the sun anchored" I am referring to its place relative to the planets. I am pretty sure the answer is yes, as the planets also exert a gravitational force upon the sun (Newton's third law). This would cause the sun to "move" somewhat, no matter how small the force exerted. Then again...

A few weeks ago I saw a web page (I believe it was at NASA) that allowed you to enter a date and see Earth's distance to the sun on that date. I searched but can't find the site again, does anyone know where I can find this page?

Homework Statement The Sun rotates about its own axis once every 26.0 days. Its mass is m_sun = 2.0E30 kg and radius is r_sun = 7.0E8 m. Assume that the Sun is a solid sphere with uniform density. Astrophysicists predict that the Sun will collapse into a white dwarf in some billions of...

In the world we live in, we can convert and use energy in the form of radiation and turn it into a significant power source. Gravitatoinal energy, which exists throughout the whole universe could be used someday as a power source. Think of it. A power source abundant throughtout the universe...

... as the sun was traveleing at a closer distance towards the Earth , would Earth bound objects start to fly away from the Earth surface and head towards the sun's surface , or would everything on Earth surface fly towards the sun's surface as the same time the Earth itself flew towards the...

Hello everyone, good day, So I understand that gravity travels at the speed of light and such. So naturally, if the Sun were suddenly gone, it'd take ~8 minutes for us to fly off and die. But I was reading Michio Kaku's "Parallel Worlds" and he used the trampoline/bowling ball analogy for...

Obviously we all know the sun generally rises in the east and sets in the west. But due to axial tilt, it is only really due east and due west at the equinoxes. At other times of the year, the sunrise will be somewhat north of east or south of east (and likewise for the sunset, but let's focus...

Homework Statement Consider the Sun to be a sphere of hydrogen gas of uniform density equal to its average density (1440 kg/m3). a) Integrate the equation of hydrostatic equilibrium for dP/dr from the Sun’s radius to the core to estimate the central pressure in Pa and in atmospheres...

I have a Van der Graaff machine here. When I touch it with my finger I get zapped by a big blue spark. Does this spark of light have any relationship or commonality with the light I see all around me from the sun? If not, can someone please try to convince me that it does...

Sorry if this is the wrong forum (its difficult to tell) What is the electric field strength of the Sun, how is it measured and what is its origin? Thanks

When the sun goes down over the horizon, we can still see the sun because the light of the sun is bent by our atmosphere. I would imagine that if one were outside of our atmosphere on the far side of Earth away from the sun, yet in a path in line with that light they would also see the sun...

Homework Statement (b) If an object of 0.1 Solar masses fell into the Sun (starting at rest at infinity) calculate what its final speed and energy would be. Mass of the Sun = 1.99 x 10^{30} kg Radius of the Sun = 6.96 x 10^8 m The Attempt at a Solution Having done the rest of...

Homework Statement How long does it take the Sun to melt a block of ice at 0 celcius with a flat horizontal area 1.0 m^2 and thickness 1.0 cm ? Assume that the Sun's rays make an angle of 30 with the vertical and that the emissivity of ice is 0.050. Homework Equations delta [Q] /...

Why do the planets travel in elliptical orbit around the Sun?

How do you see the sun after it has set?? Homework Statement The density of the atmosphere decreases with height, as does the index of refraction. Explain how one can see the sun after it has set. Homework Equations Snell's Law: sin x1 * x1 = sin x2 * x2 The Attempt at a...

Hello I wanted to ask why at the south hemisphere the sun rises from the west? We know that Earth rotates reversely than the watch pointers(this happeness to both hemispheres),so all the "sky" (the stars etc..) goes to the opposite direction. If someone could explain me.. Thank you!

Here's a question. Where do the ecliptic longitude and the right ascension ( of the Sun )reach their maximum difference? What is the declination for these events? What calendar dates do you suppose this happens? I know the answer. I've never heard anyone make this observation except me. These...

I am wondering if there is a source of the magniude of the Dipole moments of all the planets and the sun, m. m(earth) is 8*10^22 A*m^2. The Magnetic Field and the Electric Field such that: Br = Mu0/4/pi*2*m*cos(Theta)/r^3 Btheta = Mu0/4/pi*m*sin(Theta)/r^3 Mphi = 0 Er =...

How do you know where the Longitude of the Sun begins?

To help me you will need tho know Excel VBA very well. Earth has an elliptical orbit around the sun. JPL's website has the data to calculate this orbit: http://ssd.jpl.nasa.gov/txt/p_elem_t1.txt In the spreadsheet the parameters are calculated from widely used equations and some of my...

I wonder if the whirlpool that was recently discovered on the sun effects our weather on earth. http://space.newscientist.com/article/dn14878-hurricanesized-whirlpools-spotted-on-the-sun.html

Is the sun actually dying because I have heard a lot of good scientists near where I live say that it is and is not, and, of course, argue. I'm really wondering will t happen, I know if it does it'll be in like 4.4 Billion years but I want to know is IF it will happen.

Homework Statement (a) Compute the specific energy generation rate of the Sun as a whole. (b) Assume a human of weight 100 kg has a “luminosity” of 100 W. Compute the specific energy generation rate of a this human. Homework Equations Need help with the equations part. The...

HELP! (again) Homework Statement The sun sets, fully disappearing over the horizon as you lie on the beach, your eyes 20cm above the sand. you immediately jump up, your eyes now 150cm above the sand, and you can again see the top of the sun. if you count the number of seconds until the sun...

Homework Statement Find some combination of G, the speed of light c, and some arbitrary mass M, that has units of length. Then evaluate your expression for the mass of the Sun (that is, find the characteristic length associated with that mass). Give your answer in units of km. The...

Homework Statement I'm carrying out a lab to investigate the power of the sun. I'm supposed to compare the light intensity of a 100W light bulb with the light intensity from the sun, by comparing the radiating heat on my cheeks (one cheek pointing to the sun, the other to the bulb). I found...

Is the Pioneer Anomaly really directed towards the Sun ? How sure are we ? Why not directed around the Sun ?

If the Earth's period is 365.25 days and its distance to the (center of the) Sun is one astronomical unit (AU), what is the period, to the nearest day, of an asteroid in a circular orbit about the Sun with a radius of 3.04 AU? please show steps so that I can learn. thanks a lot.

Someone I know recently stated according to General Relativity, the following statements are both correct: 1. The Sun rotates around the Earth. 2. The Earth rotates around the Sun. Is this true?

Homework Statement Mars's orbit has a diameter 1.52 times that of Earth's orbit. How long does it take Mars to orbit the Sun? in years. Homework Equations I tried using T^2=4(pi)^2r^3/GM I got 1.88years...but its wrong... The Attempt at a Solution

A surprisingly small number of photos submitted for a theme that is right smack in the middle of the summer months here in the northern hemisphere. Still, we have a good group of photos. Please choose a photo that best depicts the spirit of having fun in the sun. 1. matthyaouw 2...

[FONT="Comic Sans MS"][SIZE="5"]Fun in the Sun This week's theme involves all the fun activities we do during the warm days of summer. Zz. [SIZE="4"]Contest Rules: 1. Any digital photo or digitally-scanned photo relevant to the theme will be accepted within the contest period. In...

Homework Statement Which of the following is a true statement concerning a comet passing near the sun? (Mass of comet and mass loss are negligible) 1. The momentum of the comet is nearly conserved because the interaction with the sun is similar to an elastic collision. 2. The momentum of...

I need to check a calculation for reasonableness. When I plug in the values for Earth and the Sun, I get a rough approximation of tidelock about 5.5 Gy after formation of the solar system. Is that anywhere close to the right answer?

If the sun is converting matter to energy it must be losing mass at roughly one Earth mass per 43 million years (calculated from the solar constant). How would the loss of solar mass affect the Earth's orbit?

How do scientists know that the Sun orbits the Milky Way? Is this something more ancient scientists knew or could have known hundreds of years ago?

Just sitting around BS'ing with a couple of friends this morning about the solar system and gravitational balance- and I began to wonder how long the Earth and its inhabitants would last if the sun suddenly quit emitting energy. How long would our atmosphere retain enough heat to keep us from...

that it would burn everying in a 90 mile radius, or something like that, is this correct? Would this be the same as if the equivelant amount of hydrogen atoms fused all at once together?