Sun Definition and 1000 Threads

Homework Statement The sun moves through the collection of stars in it's neighborhood with velocity v=10 km/s. (A)Assuming n*=1 pc^(-3) and that all starts have the same radius R*, what is the typical time we must wait before the sun collides with another star? Express your answer first in...

I would like to know how much light passing close to the sun will be deflected by the suns magnetic field and the increase in density of space around the suns corona.

Photons activate hormones in us which cause us to wake up. I'm wondering if there is a different between the photons coming from the sun and the photons coming from a light bulb? Do these both have the same effect on the body? I've put this in the classical category because of optics.

I want to find the rotational energy of the sun. Erot=1/2*I*ω2 m=1.9891*10^30 kg r=6.955*10^5 km When I am using the formula for a sphere's moment of inertia: I=2/5*m*r2 I'm getting 3.848671797*1047 km*m2 Can i find the moment of inertia in another way? the moment of inertia needs...

Hello, One or two years ago I had a mathematics lecture where one part of it was using basic formulae, a pendulum and the distance to the centre of the Earth to find out what the distance to the sun was. Recently, I came across a question which asked me to figure out the distance to the...

My friend told me that the sun is going to get smaller and smaller every year because it's getting used up? I've read that the power output is 4 x 10^26 Watts. How can i figure out how much mass it's losing a second? because then I will be able to find how long the sun will be able to shine on...

Homework Statement Earth orbits around the sun at roughly 1.5x1011 m. Mass of Earth is 6x1024 kg. Mass of sun is 1.98892x1030 kg. There is a point between the sun and the Earth at which the gravitational force by the sun equals that of Earth and the forces cancel each other out. How far is...

My son is a 3rd grader and wanted to do a science fair project on solar cells. So we devised an experiment to see if reflecting light with a mirrow would increase power output. We constructed a circuit using an amp-meter, solar cell, and 10Kohm resistor. He hypothesized that reflecting sun...

The Earth orbits the sun in an approximately circular orbit of radius 1.496 * 10^11 m (about 93 million miles) in a period of 365 days. Use these data to determine the mass of the sun. Solution: F = (Ms)(Me)(G)/r^2 I have two unknowns... F and Ms... please give suggestions because I...

This is one of the questions on a small exercise but I don't understand it. I thought that the Earth is in orbit because the mass of the Earth and the Sun combine perfectly such that the orbital velocity is exactly the same as the pull of the sun so the Earth is forever falling towards it. If...

Why do we have only one sun and moon on planet Earth , while there are more than one sun on other planets ? Is there a possibility that one day in the future we might have another sun or moon on planet Earth ?

In a thread that was just open and almost immediately closed: https://www.physicsforums.com/showthread.php?t=546278 there was a link to a possible crackpot site, but one part of the discussion said simply that the sun (the whole solar system) moves through space. A graphic demonstrating this...

http://www.youtube.com/watch?v=Ex283trHBgE&feature=player_embedded I am in a debate with someone who is defending this guy vehemently on another forum. Does anyone know of any link debunking what this guy is saying? The “adherent” of this point of view is quite vehement and I’d just love to...

Sunlight takes eight minutes to reach Earth. Meanwhile the sun and Earth have moved/rotated. Suppose that the sun emitted two types of light, the 8-minute light and a spooky “zero-time light”. Where in the sky would we see/measure the second spooky sun - the real position of the sun? The...

Homework Statement Find the gravitational force of the sun on Mercury M_sun = 1.98892 x10^30 kg M_mercury = 3.3022 x10^23 kg Distance of sun and mercury = R = 6.863 x10^10 G = 6.67 x10^-11 Homework Equations FG = GMsunMmercury/R^2 The Attempt at a Solution I simply plugged...

How to simulate planets orbit curve around the sun ? Hi I'm about to write a java program where I wish to simulate planets orbit curve around the sun, so that I can set the speed of a planet and mass of planet and sun and simulate the curves around the sun (just basic simulations). I only...

I was astonished recently to find myself able to look directly into the sun without experiencing impairment of vision as a result. I have done so many times since but there are occasions when the light is too bright. What I saw when I looked at the sun was quite awe inspiring. The outer rim...

Calculating the equation of time and the declination of the sun Hi, I'm trying to calculate the equation of time and the declination of the sun in the prettiest way possible: https://gist.github.com/1278755" But right now I'm getting some unexpected values: 1) Failure...

Do the sentence "when the sun is shining then it is hot" is a logic sentence ?

This seems like a naive question that I ought to know the answer to, but autumn is upon us and it seems like a good time to ask. The sun sets much earlier in autumn than in the height of summer, and it follows a higher or lower angle (shortening dusk) to the horizon, resulting in a change in...

Homework Statement "Determine a surface temperature value for the Sun from the angular diameter of the Sun and the solar constant." Homework Equations L=4π(R^2)σT^4 The Attempt at a Solution At this point my only stumbling block is I don't understand the relationship between the solar...

I am trying to understand an example in my Modern Physics textbook (Example 3.1, page 5 in thishttp://phy240.ahepl.org/Chp3-QT-of-Light-Serway.pdf" or pg 69 using the book numbering) I don't understand why the average earth-sun distance is being used in the conservation of energy equation...

Homework Statement Is it possible to use the heat of the sun to heat a liquid (arbitrary liquid) to a temperature that is hotter than the sun, say 5 times hotter? Homework Equations Concepts in thermal equilibrium The Attempt at a Solution My answer is no since you can't get more...

I tried calculating the mass of the core of the sun but keep coming up with a number that exceeds the entire mass of the sun. I used http://en.wikipedia.org/wiki/Sun" facts on the sun. It says the core of the sun extends from its center to .2 to .25 times it's radius. I used the number .225 as...

Hello everyone. I'm working on a video-game that takes place on a distant Earth like planet. A key part of the gameplay revolves around a special day and night cycle. I'd like this planet to be tidally locked to it's red dwarf star making it's habitable zone limited to the terminator. Of...

Hi! When it comes to physics, I'm a total layperson (so, please, be kind ;-)), I actually study English, but recently my interest in physics has been growing more and more. So, yesterday I started watching the first of Feynman's Cornell University lectures. And that led me to the question: why...

In wikipedia I've read that the Sun's surface temperature is about 5700K. The emission spectrum graph can be seen there: http://en.wikipedia.org/wiki/File:EffectiveTemperature_300dpi_e.png. I don't understand why the irradiance (or intensity I guess) of the Sun is greater than the one of a...

Will the Earth be destroyed?

May be this question has been asked multiple times here i was just unable to search it by topic or search term. The Question is if every thing is falling towards the sun (i.e planets). Why planets are not falling towards sun in a spiral fashion and ultimately crash into sun ? This may be...

Hi, I am currently studying the internal structure of the sun and I was wondering if there exists scientific information regarding the pressure distribution along a hypothetical line from the core to the, let´s say, convection zone. You can find frequently in the internet that the pressure in...

suppose there are two bodies,one revolving in an orbit around the other[like the Earth moon system]Differences in orbital and axial rotation of a small body results in a torque applied on it by the larger body. This results in the smaller body being tidally locked. THEN WHY ISN'T THE EARTH...

I've looked into optics and the biology of the eye, and I know that, although the fovea is an area with our highest visual acuity, light is still focused on the retina around the fovea even when we're not looking directly at something. Clearly it is not safe to look direct at the sun, but people...

Is the reason behind the vibrating the movement of electrons from a stable to a excited state? My quest for knowledge began with this question..."How exactly does light transform into heat--for instance, when sunlight warms up a brick wall? I understand that electrons in the atoms in the wall...

Hi, new here. This came up briefly elsewhere and we didn't have the cerebral fire power to get very far with it. Consider very, very long wavelength photons, (or conversely, very very low energy photons) produced inside the sun. Wavelengths we are looking at are in the range of 1 light...

why density of core of the sun is changing ? please give me brief explain with calculation

No, not right now. But when it cools down, billions and billions of years from now?

I've to show , " at the spring equinox for a place of latitude ø, the sun will become visible at the top of a tower of height " H " feet, about " 13.94(root over )H * sec ø " But as far i made calculations, i got the amount of "4.24 root over H * sec ø " I used all the measurements in...

Assuming that the sun is absolute black body, what portion of radiation coming from the sun, hits the earth? I know there are some approximations but what is true part arriving at the earth? At some point in time.

Hi everyone, There is problem that asks how many hydrogen atoms are there in sun for each helium atom. I don't know which solution is correct: 1) to count all the hydrogens and heliums participating in one solar pp chain, or, 2) as X=0.71 and Y=0.26, there is (0.71/0.26)*2 H for each He...

While making a projection of the sun on a paper with a Newton telescope, I’m able to see a white ball or to make burning holes in paper. My idea however is to be able to see something more spectacular , like sunspots or protuberances. Does someone has an ideas how to do this practically...

http://www.sciencedaily.com/releases/2011/06/110623145430.htm http://www.msnbc.msn.com/id/43513975/ns/technology_and_science-space/ This is either a hoax or colossal blunder from NASA, or it is the most disturbing news I've had all week. Apparently, we are cosmic orphans, adrift in an alien...

No doubt the core, photosphere, and corona are all integral features of the sun. The solar wind and heliosheath come under similar consideration. Currently it appears certain solar features at several scales are undergoing dynamic changes which look something like weakening. Ulysses has...

Does all (i.e. 100%) of the energy generated in the Sun's core via nuclear fusion eventually escape out into space (as photons, neutrinos, ... and umm solar wind?), or is some energy lost to internal processes? Surely the photons must lose energy as they take their long, indirect path from the...

I'm not sure if this is in the right forum. If the Sun disappeared, would the Earth's velocity change? Since the space-time fabric would 'spring' back into it's normal position, the effect of gravity on the Earth would dissipate? Thus, resulting in the Earth being thrown out of it's orbit?

1. Homework Statement Part One: Calculate the magnitude of the gravitational force between the Moon and an m = 6.45 kg mass on the surface of the Earth nearest to the moon. The distance to the center of the Moon from the surface of the Earth is 3.76×105 km and the mass of the Moon is...

Homework Statement http://imgur.com/93CdT Is the photo upside down? Homework Equations I do not understand the following: - Why can the image of the sun in reflection not be higher above the horizon than as it is viewed directly? - "What about the people in the photo? Try to draw a diagram...

In the temperate latitudes of the northern hemisphere, the sun is due south when it reaches the highest point in the sky (see for example http://www.solarplots.info/pages/definitions.aspx" ). What about latitudes between the Tropic of Cancer and the equator? Is the sun due north when it reaches...

Homework Statement The Sun radiates away energy at the rate of 3.9*10^24 Watts. At what rate it it losing mass due to this radiation? Homework Equations E = Δmc^2 E = mc^2 - m0c^2 Where m0 rep. rest mass. The Attempt at a Solution For this one, I am unsure as to how I would go...

Hi guys, this is a homework question, but i didnt think it belonged with the physics questions. I have the spectrum of a star, it has hydrogen gamma and hydrogen beta absorbtion lines, but a very very strong hydrogen alpha emission line. What is the significance of this, I would expect a...

Tides in sea are caused not by moon but by sun. Though the force of attraction caused by sun is much more than that by moon.