The sun Definition and 634 Threads

How much is space bended at the surface of the sun, only due to gravity? And how can it be calculated ?

Would someone please correct my train of thought on this? I understood that the Earth's position in the Solar System is related to the gravitational attraction between the Earth and the Sun. If this thought is correct, then when the Sun enters its Red Giant phase, the Earth should be pushed...

For my engineering class, my professor asked us to estimate the total energy output of the sun. The only tools we are allowed to use (for now) are: 1) A thermometer 2) A graduated cylinder 3) A container of water 4) An umbrella We are only allowed to use information that we ask for, or...

Consider a photon of a certain frequency emitted from a distance slightly greater than the event horizon of a black hole. It seems possible that if a certain low frequency photon is not able to escape (due to becoming infinitely red-shifted), then a photon of a higher frequency emitted from the...

How much slower is time ticking inside the Sun, compared to the surface, and how can it be calculated?

I was just wondering why, if the gravitational force exerted on it by the Sun is greater than the one exerted on it by the Earth, the Moon stays in orbit around the Earth? Is it due to angular momentum or are there any other factors?

I have been doing some study on the theory of relativity and it has got me thinking. We say that the Earth revolves around the Sun but from what reference frame? From the reference frame of Earch, we are stationery and the Sun simply spins. Why is any reference frame more accurate than another...

Q. Our present theory of the sun and the mechanism of thermonuclear fusion inside it predicts that the following reactions occur in the sun. 1H + 1H --> 2H + antielectron + neutrino 1H + 1H --> 2H + antielectron + neutrino electron + antielectron --> photon + photon electron +...

Homework Statement Our present theory of the sun and the mechanism of thermonuclear fusion inside it predicts that the following reactions occur in the sun. 1H + 1H --> 2H + antielectron + neutrino 1H + 1H --> 2H + antielectron + neutrino electron + antielectron --> photon + photon...

Homework Statement Assuming that the Earth describes in one year a circle, of 92500000 mile radius, whose center is the sun, how many miles does the Earth travel in a year? The Attempt at a Solution How does knowing the radius of the Earth help me with this problem? I don't need...

I've recreated one of the first experiments I did in Chemistry many times - Water electrolysis to split it into Hydrogen and Oxygen, and prove the existence of hydrogen with a burning splint that goes "pop" in the test tube. The Sun is a massive ball of hydrogen, that uses Nuclear fusion to turn...

Hy. I need to read about the sun. What do you recommed ? Also i found some bibliography here but couldn't find. http://solar-center.stanford.edu/magnetism/bibliography.html

I ran into a theory that stated that the Earth is actually expanding due to added mass from the sun's energy. Is this true and if true by how much?

"Dec. 13, 2010: On August 1, 2010, an entire hemisphere of the sun erupted. Filaments of magnetism snapped and exploded, shock waves raced across the stellar surface, billion-ton clouds of hot gas billowed into space. Astronomers knew they had witnessed something big. It was so big, it may...

Homework Statement The Milk Way galaxy rotates about its center with a period of about 200 million yr. The Sun is 2 X 10^20 m from the center of the galaxy. How fast is the Sun moving with respect to the center of the galaxy?

Okay, this is not a homework question, but a conceptual question already answered in the book. Problem: Suppose the Earth's orbit around the sun is perfectly circular. What is the work done by the gravitational force of the sun on the Earth through a small displacement over a small time...

Hi I'm trying to calculate the energy of a proton in the sun. I know the temperature so I thought to use the equation E=3/2kT but in my textbook it says that I should only use E=kT. I don't understand why this is because surely each proton has 3 degrees of freedom? Thanks

It is often safely assumed that the sun and the orbits remain relatively stationary(let's not consider precession) and the motion of the sun around the barycenter (without which the sun would be pulled towards the planets) can be neglected, but the resultant force of gravity on the sun is always...

I understand that the sun is made of 91% hydrogen, 8.7% Helium, and 0.3% other stuff. I looked up the atomic spectrum for helium and hydrogen [within the visible portion] and they leave most of the spectrum blank, albeit few lines of colour here and there, yet the white light that reaches us has...

We know that heat is transferred from the sun to the Earth via electromagnetic radiation, right? Since no other form of heat transfer can occur in a vacuum that must be the case. We also know (?) that electromagnetic radiation does not dissipate over distance (could be wrong here). If that is...

Homework Statement The Sun is presently about 20 pc out of the midplane of the disk, and moving away from the midplane at about 7.4 km s−1. Using these as the current position, z(tnow), and velocity, vz(tnow), what is the maximum height zmax (in pc) the Sun will reach before turning around...

Lets say all the helium in the sun fused to make oxygen, if that and the hydrogen combined to make water, even though it doesn't work out perfectly, let's say it did, and the sun turned completely to water, would it freeze because of temperature cause it to freeze, or the pressure cause it to boil?

(imagining a perfect Earth without rotation around its own axis etc) In which way does it; and which way doesn't it?

Hello! I moved this at the recommendation of another mamber (namely, Andre). I have a question regarding the position of the sun in the sky. Since it depends on where you are, I am thinking of the Northern hemisphere above the Tropic of Cancer. Say, Northern Europe, Canada, etc. As the sun...

I need to calculate the radial velocity of the sun. Every time I try using Newton's Laws of Gravitation, I end up getting a value of 0.733 m/s. Apparently the actual value is 220000 m/s. Mass of Sun = 1.99 x 10^30 kg (3sf) G = 6.67 x 10^-11 Nm^2kg^-2 r = distance of Sun from galactic centre...

Hello! I have a question regarding the position of the sun in the sky. Since it depends on where you are, I am thinking of the Northern hemisphere above the Tropic of Cancer. Say, Northern Europe, Canada, etc. As the sun moves across the sky, at noon the sun is often referred to as being...

Each month a different zodiac constellation follows around the sun day and night. The constellation is in the house of the zodiac sign but the actual constellation is the zodiac before. Example: the constellation of date is Libra but the constellation that follows the sun around is...

Lets say for a place that is at a latitude of 55 degrees, how high above the horizon the sun would be on the vernal equinox, summer solstice and winter solstice. Any hints on how to figure this out would be helpful I Know Vernal Equinox-When the sun crosses the Celestial Equator moving...

Homework Statement What is the totaly power emitted by the sun over all wavelengths (frequencies) according to the (incorrect) classical Rayliegh-Jeans expression for ρt(v) Homework Equations ρt(v)dv=8piv^2kT/c^3 dv The Attempt at a Solution I'm not sure how to start this one...

Homework Statement A asteroid is approaching our solar system from a great distance (r->infinity) and is headed straight for the Sun. Because of the gravitational pull of the Sun the asteroid is constantly accelerating. Radius of Earth's Orbit around the Sun (R_{e}) 1.5*10^11 Venus is given...

When did humanity realize that the Sun is similar to the night-time stars? I can find no reference to this in Wikipedia or anywhere else. It seems that ancient man thought that the Sun was unique of it's kind (similar to how we perceived the Moon before Galileo observed Jupiter in his...

Hey, um i am really new to this, so i hope i am doing this right... If I am wrong i am sorry... Homework Statement Ok, so its probably really easy and I am just being dumb but i am trying to explain why the differential rotation casues sunspots Homework Equations The Attempt at...

I want to make an order-of-magnitude estimate of the Sun's present-day luminosity. For this, I want to use just the following two pieces of information in a simple idealised model of (the mechanism of energy production in a star): 1) the mass of a helium nucleus is about 1 percent less...

The Earth rotating on its equitorial axis spinning on its poles. The Sun has its orbit on the ecliptic 23 degrees away from the spin if the Earth. Is the time frame different at the Earth on the Ecliptic plane rather than the Equitorial?

why is the light from the sun a continuous spectrum in the visible range , and of course it emits other frequencies of light . But if the sun is made mostly of Hydrogen and helium , in the nuclear reactions and all the high temperatures in the sun , are we oscillating electrons and...

Homework Statement 1. (a) Given that the distances to the sun and the moon are approximately 150 million km and 400,000 km respectively. and that the radius of the moon is 1740 km , estimate the radius of the sun.[Hint:k=9*10^9 Nm^2/C^2, g=10ms^-2) ] (b) Ancient astronomers knew that the...

I always hear people saying "Ptolemy thought that the Sun moved around the Earth, but it is the other way around: the Earth moves around the Sun". I think that's wrong. I think that Copernicus's theory is not "truer" than Ptolemy's. It is just that Copernicus's theory is simpler! But both...

In classical general relativity it is known that angle of deflection is proportional to radius-1 from the center of the sun. If radius is large, this angle is very small, what happens already at the radius of the sun. But what happens to this photon, when we include quantum gravity (QG)? I know...

How much dark matter is in the Sun, and does it have any effect on any process in the Sun? What percent of the total mass and volume of the Sun is DM by weight, and by volume? Does the high density of the Sun impede movement of DM? Is there a lot of DM trapped by the Sun's gravitational...

Me and a friend have been wondering if it would be possible for a person to outrace the sun. more accurately, in a plane. One of us is argueing that we would need to outrace the Earth's rotational velocity, the other is argueing that we could calculate the velocity of the sun by assuming that...

This was shown in a textbook about the two body problem, and they compared it to the energy potential of two atoms, but the sun and comet don't experience charge so that 'when it gets too close the nuclei repel each other'. It mentioned something about centrifugal force, but I don't understand...

I've read that along with the moon, the sun also has an effect on our tides. I understand how the moon would have an effect on tides, but I don't quite get why the sun would. According to my physics book, when something is in orbit, it's really just in free fall around the thing it's...

Bear with me, I am not even sure if I know how to properly word the question. Few days ago there was summer solstice - that means Sun was visible all day north of arctic circle. My question is - when will the Sun set down at 71°11'? Now, Sun is not a point, so perhaps better question is -...

We did an experiment to find out how water is heated as a result of sunlight. We had a bowl of water which we heated with a copper plate on the water surface, through which we sent a sinusoidal current. We didn't use a lamp, because water doesn't absorb visible light very well and since our bowl...

I'm witnessing an argument elsewhere about whether a vacuum is a good insulator in space. Person 1 said this: Person 2 said this: I said this: what would really happen if the vacuum between us and the sun were replaced with steel?

Homework Statement how many photons does the sun generate to knock one electron across the bandgap in a PV panel? I am doing a college level night school course on Photovoltaics and I have to do a short presentation on photons and how they produce useable energy. I thought it would be...

Sounds a bit crazy. But you have an almost infinite energy supply on tap. Easy to get to as well.

G'day. i'm a 2nd year Aero engineer student from Australia. I've had this question on my mind for the past few days now and can't seem to find much material on it. i was just wondering how the lightest elements (hydrogen and some helium) managed to come together in the center of the solar...

Hello, I am trying to revise for my Solar System exam and going through a past paper i have a question relating to something that we don't seem to have covered: "By estimating the energy output of the Sun's corona (in watts), comment on whether can be treated as a blackbody radiator...

Why does the Moon keep the same face toward the Earth but the Earth not keep the same face toward the Sun?