Sun Definition and 1000 Threads

Okay, I know that sun won't become BH (Black Hole) , and I know about Chandrasekhar limit and Tolman-Oppenheimer-Volkoff limit, etc. But my question is different. We know, M = m × √(1-v^2/c^2 ) . where m is rest mass. ( Don't know much latex, sorry :frown: ) So now we do know the rest mass...

Homework Statement During its lifetime a massive star converts about one solar mass of hydrogen into iron in its core, releasing about 0.7 percent of the rest-mass energy in the form of radiation. When it explodes as a supernovae, the outer envelope of the star (with a mass of 10Msun, say)...

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...

Homework Statement Hi, A spinning shiny red-appearing planet at 130 billion km from the sun, has a diameter of 1700km. Estimate temperature of planet using simple heat balance equation. Estimate also the temperature obtained by Wien displacement law. Homework Equations I've been...

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

I am after a reference or an explanation as to how the Voyager 2 spacecraft was used to determine the semi major axis (largest diameter) of the orbits of both Uranus and Neptune? These measurements were performed at Jet Propulsion Laboratory (JPL), NASA, during the Voyager 2 encounter with...

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...

Homework Statement Two math students erect a sun shade on the beach. The shade is 1.5 m tall, 2 m wide, and makes an angle of 60° with the ground. What is the area of shade that the students have to sit in at 12 noon (that is, what is the projection of the shade onto the ground)? (Assume the...

Homework Statement Two math students erect a sun shade on the beach. The shade is 1.5 m tall, 2 m wide, and makes an angle of 60° with the ground. What is the area of shade that the students have to sit in at 12 noon (that is, what is the projection of the shade onto the ground)? (Assume the...

as we know "energy can neither be created nor destroyed it can be transferred from one form to another " . so the energy we receive from sun is dissipated here & some amount goes back . so the sun has more energy which gives energy out . so from where does this sun energy goes ??

Homework Statement Mars travels around the Sun in 1.88 (Earth) years, in an approximately circular orbit with a radius of 2.28 x 10^8 km Determine a) the orbital speed of Mars (relative to the Sun) b) the mass of the Sun Homework Equations acceleration centripetal = 4(pi^2)(r) /...

Hi everybody, I apologize if this has been asked already - I searched for a similar topic to no avail. My question regards something touched upon briefly in Olaf Stapledon's book Star Maker. Stapledon writes of interstellar travel being acheived by detaching a planet from a solar system and...

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...

I've been reading and reading and trying to figure this out, but I just can't. Any help anyone can give will be appreciated. It is probably simple as hell, but for some reason my stupid brain can't get it.. The formula/equation is: What I have to do is: Now, I'm not looking for...

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...

I have to write a routine that reads in csv data and appends it in an xml template and saves it. I am not allowed to use C# or C++. It must be in C. I am running it on a Sun machine. Our team has come up with the reader for the nodes of the xml. I've checked several websites looking for example...

Lets assume if we were able to gather ALL the Radioactive waste on Earth, eg. depleted Uranium, and also other un-recyclable materials - drink bottles, plastic bags etc... and fire them into the Sun. Would then, the sun be contaminated for the next billion years since most radioactive materials...

... 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...

OK, so people say that wearing white is better than wearing black in the sun because white reflects light whereas black absorbs light. But at the same time it is said that black is better for sun protection (for example, darker skinned people are much less likely to get skin cancer than...

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...

I am using the following C library for a variety of solar position calculations: http://rredc.nrel.gov/solar/codesandalgorithms/solpos/ In the library, they use the function srss() to compute sunrise and sunset times. Unfortunately, it seems that their equation is for the time that the...

I'm a physics student in the penultimate year of my degree. I'm quite good at programming and was thinking this summer I'd put in 3 months of effort and get Sun Java Certification. Would this be worth the effort? Would it be something which would be very attractive to a prospective grad...

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...

Please help! 1. Homework Statement Find the point between Earth and the Sun at which an object an be placed so that the net gravitatinal force exerted by Earth an the sun on this object is zero. Me=5.98 x 10^24kg Ms=2 x 10^30kg Distance from sun to earth= 1.5 x10^11m 2. Homework...

Homework Statement Find the point between Earth and the Sun at which an object an be placed so that the net gravitatinal force exerted by Earth an the sun on this object is zero. Me=5.98 x 10^24kg Ms=2 x 10^30kg Distance from sun to earth= 1.5 x10^11m Homework Equations F=Gm1m2/r^2...

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...

Homework Statement Alright, so I've given this guy a few cracks, and I think I'm close to it, but apparently I'm not right, so here's how it goes. Simple in concept. A meteor moves toward the solar system with speed v0 in a direction such that it would miss the sun by a distance d if it...

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 =...

Hello All, Just from the stand-point of the Sun itself and it's environment, is it possible or not to utilize the Sun to safely dispose of spent radioactive waste fuel from reactors and what would be the possible ramafications (positive or negative) for the Earth and it's environment as a...

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

Homework Statement For a spacecraft going from the Earth toward the Sun, at what distance from the Earth will the gravitational forces due to the Sun and the Earth cancel? Earth's mass: Me the Sun's mass: Ms Earth-Sun distance: r Homework Equations F=Gm1m2/r^2 The Attempt...

Regardless of the measured flux, is the expected neutrino flux from the sun greater or less than the expected flux from nuclear reactors? I don't know if I'm using the word flux correctly. I mean number of neutrinos per square meter per second on the surface of the earth.

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...