Sun Definition and 1000 Threads

Hi pf, I'm fairly new to QM so this may seem like a trivial question. As I understand it, an electron (or any small particle) does not have a definitive position in space until it is observed which causes the quantum wave like nature of the particle to disappear (collapse of the wave function)...

The Chandrasekhar Limit is defined as the maximum mass of a white dwarf which is said to be 1.44 solar masses. My doubt here is if it is defined as being the mass of 1.44 suns then the sun should not even be burning fuel right now. Only then will its mass remain the same. The Sun keeps burning...

So I don't feel as freaked out as I did before reading the Tips sticky about making sure every bit of science is plausible. I would like to try and keep it believable for the immersion though. http://gizmodo.com/could-the-sun-be-extinguished-by-a-bucket-of-water-just-1669914928 It all started...

Homework Statement So, if the Earth stopped moving(supposing Earth's orbit is a circle) how much time would it have to pass before it hit the Sun? Homework Equations I've tried with Kepler, and Newton's derivations of Kepler's 3th law The Attempt at a Solution Well I'm pretty sure you need to...

How are solar flares and solar winds generated due to the magnetic field of the sun ? Please elaborate and provide detailed explanation if possible.

Ok, we had a discussion in class: If we build solar panels all over the Earth's surface we can collect a good amount of energy. If we use this energy to power el-cars where does the energy end up? The energy law states that no energy can be lost from a system.

Hey! Here's a question. This is Mercury as seen from some telescope during one of its transits The white disk in the background is the Sun. So suppose now that I am where this telescope is and start approaching Mercury. As I approach, both the Sun and Mercury would become larger from my point...

Hello, I've been reading astronomy books for some time now but after leaving things for a while I seem to forget rotation directions. For example, I know that the Earth spins in the anticlockwise direction. That is easy to see why. They say that motion of the Earth is eastwards. Because of the...

Imagine a stream of photons moving from the sun to the Earth (A, B, C, D, E, F, G, etc.). Now imagine 2 different men measuring the speed of the photons, and (somehow) recording which photon is hitting them. They are in the same position, but one is traveling 1/2 the speed of light (relative...

I'm trying to work out the luminosity of the sun. 1630 Watts/m2 apparent magnitude reduces with distance squared so 1/(1.496*1011)2 = 4.468*10-23m2 has the same brightness 1630 Watts from earth Surface area of the sun divided by 4.468*10-23m2 = # of 1630 Watt sections *1630 = 2.21*1044...

Let's say an alien race developed a powerful enough weapon to destroy** a star the size of our sun. How long would it take for humans on the surface of Earth or perhaps on the surface of another planet/moon in the solar system to feel the effects of this process? **"Destroy" is obviously...

Yesterday I had a bizarre idea. I supposed that a black hole (which I assumed to be a sufficiently dense sphere) became our sun. I know this is completely wrong, but please humor me and see what I've done. Suppose we have a sphere sufficiently dense, so that the Schwarzschild radius, r_s, is...

Hi guys, so I know the sun is losing mass because it is radiating energy away. This leads me to wonder about some things - I have been trying to figure out what the mass of the sun was ~4.5 billion years ago (current age of the sun). Also I am interested in knowing what the mass will be ~6.5...

Got this problem on a standardized test Suppose scientists wanted to land a probe ON the Sun. The probe is being launched from the Earth. What direction should they aim launch the probe if they are launching it from the Earth? 1) Directly towards the sun 2) Directly away from the Sun — obv...

I know that the schwarzschild radius is proportional to the mass. But in case of black holes the mass remains the same only the size and density changes. So does the schwarzschild radius stay same when it is the sun and when it becomes a black hole?

Hello, here is the question I have to answer; I am aware that the gravitational energy of one layer of thickness dr is dU=-\frac{GM(r)dm}{r} and that ultimately I will have to integrate this over all radii but I am unclear about the expression for \rho_{center}. The only thing that springs to...

Homework Statement During fusion of hydrogen to helium, 4 billion kg of matter are converted to energy each second. What fraction of the Sun’s total mass is lost each year to this process? Homework Equations None. The Attempt at a Solution First: Convert how many seconds are there in a year 1...

Homework Statement Nuclear fusion reactions at the center of the sun produce gamma - ray photons with energies of about 1 MeV (10^6 eV). By contrast, what we see emanating from the sun's surface are visible light photons with wavelengths of about 500nm. A simple model that explains this...

Sun emits 153.6 x 10^15 J of energy onto a region that is 20km by 20km in area. The intensity of the sun on this region is 685W/m^2. How many days would it take for the sun to put that amount of energy onto the region? I went intensity = power/area and got to a time of some 44000seconds...

Does anyone believe that the solar system has a second star? There is a theory that the solar system has a second, larger star called Nemesis. It has an oval shaped orbit around the sun, curving very close to the sun and then traveling 1 light year away, interrupting the asteroid belt...

I'm rather new here so please forgive me if this is answered somewhere else, but I was unable to find it while searching around. For some calculations I'm looking to perform I need to know the geocentric equatorial coordinates of the sun on a given date. However, the only place I know they...

if the sun disappears, the Earth would go dark and life would end ... it would also go out of orbit but how soon? immediately? even the light takes 8 minutes to reach earth, as they are so far away... if the whole mass of sun disappeared suddenly... would Earth go out of orbit...

Do white dwarf planets ever die and eventually there will be no remains of the sun? What will happen to the gas giants with no sun to orbit?

Dear friends ,I have the following doubt: We know our SUN is in a stage of equilibrium having an internal thermal pressure and opposing gravitational pressure. Why doesn't internal matter find ways through matter of sun and get released out to collapse the sun.

Hello! I'm not entirely sure this is very "scientific", but I have an idea that I would like some feedback on. I remember reading an article related to radioactive decay varying with the rotation and distance from the sun on Phys.org a few years back (http://phys.org/news202456660.html) and was...

Why the Earth is rotating around the sun? I know the centripetal force is required for the rotation of Earth around the sun. But initially there is required some force on Earth to rotate around the sun.

It was estimated that the heat inside the core of the Sun inside around 15 000 000 °C - this value is extremely enormous. How did scientists estimate this value?

Light from the sun can be dispersed into its spectrum of colours. But when we look around us, and at the sun, it appears yellow. Then shouldn't it only be emitting the yellow part of the spectrum? We also use 'white light' sources when diffracting light through double slits, but then I couldn't...

If size of the sun is increased million times ( trillion times or gazillion times), keeping its mass same and then the planets are redistributed outside of it. Will the planets still revolve around it

[b]1. the distance between the sun and Saturn is approx. 8.9x10^8 mi. The speed of light is approx. 1.9x10^5 miles per second. How long does it take light to travel from the sun to Saturn? Answer in units of seconds. Homework Equations [b]3. The Attempt at a Solution I have...

Hi,does exist any simulation of Sun and Earth circulation with data of lasting of day and night in different places on Earth during seasons? Thanks a lot

Did gravity effect the suns output? arXiv:1405.4369 [pdf, ps, other] Can a variable gravitational constant resolve the Faint Young Sun Paradox ? Varun Sahni, Yuri Shtanov Comments: 9 pages, 1 figure Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Cosmology and Nongalactic...

I've read previous threads that the color of our sun from outer space is white, but on Earth it is yellow because oxygen and nitrogen scatter the blue light. First, I am wondering if this is accurate. Second, if this is true, why do we see stars in the night sky as white? I would think the...

The maximum mass-energy allowable inside a sphere to ensure a static Star is obtained from Buchdahl’s Theorem: M(max)=4/9*R/G*c^2 Calculations show that Sun can absorb almost 200,000 more Suns and remain it its current radius and stay away from collapsing. Is this correct?

I had this question given in my class A spectral line from iron (mass 55.934 amu) atoms in the sun is measured as 637.4 nm. It's width is measured to be 0.053 nm. Calculate the temperature of the sun?Now I done this using a formulae I was given but it yielded an answer no where near 5778KAbove...

Homework Statement If the mass of the sun were 1/2 it's current mass suddenly show the orbit of the Earth would be a parabola... The Attempt at a Solution I'm not sure what kind of approach to apply here, if the total energy equals zero then the orbit is a parabolic trajectory, if it is less...

I have tools that are made of metal and very reflective and shiny. If shiny objects reflect light waves, how is it that my tools get too hot to touch if I leave them in the sun (in the summer months)? Are the tools absorbing other forms of EM radiation?

Homework Statement If Earth stops rotating Sun suddenly , how long would it take for Earth to collide with Sun ? G = gravitational constant m_s = 2e30kg m_e = 6e24kg where m_s is the mass of the sun and m_e , mass of earth x = 1au =1.5e11m 2. The attempt at a solution Gravitational...

Homework Statement What will be the irradiance (power per unit area) in the image, if the Sun's irradiance at the sea level is I = 500W/m^2 Lens is 200mm f Sun is 150x10^9 m away Diameter of sun is 1.4x10^9 m Homework Equations The Attempt at a Solution I know that at the...

Hello everyone. In my computational physics class, I am supposed to use numerical method to solve for equations of motion of the Earth and moon orbiting the sun, at which I place the origin of my coordinate system. However, I have a physics related question. Before I pose the query, allow me to...

Homework Statement A planet P orbiting the Sun S is acted upon by a force F= -(mu*r)/r3 (itex won't work here for some reason :S ) per unit mass where \mu is a positive constant and r is the vector \stackrel{\rightarrow}{SP} If the orbit of the planet is a circle of radius a, show that the...

How is electromagnetism different from gravity in that accelerated objects radiate EM waves when accelerated in an electric field but no gravitational waves are generated when objects are accelerated in a gravity field? Why do not planets orbiting the sun generate gravitational waves and...

Hi. I need help please with a textbook illustration that has confused me. Is the caption a typo? Should be "neutrons into protons" instead? Thanks.

Hey guys, I am trying to create a 2d simulation of the Earth going around the sun. However I am facing an issue. I am not sure what are the forces that apply on the Earth in a 2d aspect. I know there is the gravitational pull GM1M2/R^2. I know there is momentum, which is P = V * R...

I am working on a question: Doing this, the Sun produces it luminosity, the 3.8 × 10^26 Joules of energy it emits each second. Use this information to determine the percentage decrease of the Sun’s mass over its total lifetime of 10 billion years. It's a multiple choice question and each...

Homework Statement An underwater scuba diver sees the Sun at an apparent angle of 44.5° above the horizontal. What is the actual elevation angle of the Sun above the horizontal? (Use 1.333 for the index of refraction of water.) Homework Equations n1sin(Θ1) = n2sin(Θ2) The Attempt at...

Homework Statement The sun has a mass of 2*10^30kg and gives off energy at a rate of 3.9*10^26 watts. If the source of the sun's energy energy were ordinary combustion of methane how long will it last. Homework Equations delta Enthalpy of the combustion of methane is -802 kj...

Homework Statement A comet revolves around the sun in a closed elliptical trajectory. Ignore any force acting upon it besides gravity. Prove that the angle between the position vector (sun in the origin) and the velocity vector of the comet at its perihelion and aphelion is 90º. The...

I'm trying to figure out which layers of the sun emit different types of radiation For instance; I know that most of the visible light is emitted from the photosphere but what about IR, UV, x-ray, etc...? Anyone know?

If i rip the sun and make it into tiny packets, a size of about a normal house and then align it in a straight line, each box having 10 cm separation, then how strong will be the gravity at the end of the line? Will it have gravity stronger than a normal sun?