The sun Definition and 634 Threads

We are studying Energy at school The book said that "All Energy on Earth can be traced back to the Sun" I know there is mechanical energy chemical energy electrical energy Are they talking about everything? I mean cars, fireplaces, ect...

helloooo new to this forum...and a total science noob who comes to you seeking knowledge... :rolleyes: Anyway - i recently saw the new danny boyle movie 'sunshine' - the story is about the sun dying and a rescue team who's on a mission to save the sun by reigniting it. My question...

I've been reading Kip Thorne's book "Black Holes and Time Warps" and was wondering about a couple of things. They're really basic questions that have been floating around in my head, but I can't ask any of my friends because none of them know anything about these topics, so...I came here...

No big rocky planets? Why are there no big rocky planets - all the big planets are gaseous. Did big rocky planets get smashed up and end up in the Kuiper belt?

Photons born deep inside the sun take millions of years to reach the surface. This makes it unlikely that the warming of the Earth's atmosphere today(greenhouse effect) can be attributed to increased solar output from a "deep sun" process - the timing would be too unlikely.Could a surface...

Nature decides that instead of inverse square law for gravitational forces the law will be inverse cube law. In that case what among the following will be true? a) The force of gravity from the sun will be weaker b) The period of the planet will be proportional to the square of the distance...

Even though in optics experiments we assume that the sun rays are parallel, we can clearly see that the sunlight seems to diverge from the sun when coming through the clouds. Whats the reason of this discrepancy?

I've been hearing these talks that the sun will run out of hydrogen in 4.5 to 5 billion years from now. My question is, how did we arrive at this estimate. Is it based on the mass or something? It would be good if you can show me the mathematical calculations. --thanks.

The Earth is subject not only to the gravitational force of the moon but also to the gravitational pull of the sun. However, the earth is much farther away from the sun than it is from the moon. In fact, the center of the Earth is at an average distance of 1.5 x 10^11 m from the center of the...

a)calculate the mass of the sun from the radiuos of the Earth's orbit (1.5 x 10^11m), the Earth's period in its orbit, and the gravitational constant of G. Sohere we are given the speedof light, 3x10^8, and G as 6.673x10^-11 so i get that v=2pi x r / T and that r= ct how do i continue...

Whenever something interesting happens on the side of the sun that faces earth, is there any orbiting satellite that can simultaneously view the opposite side?

Astronomy Help Please! :) I am having a problem figuring out this question. On all my other work the questions have been different. Could anyone help me with this Astronomy problem and show me how to work it out? Thank you! Anything would be greatly appreciated. What is the absolute...

How far from Earth must a space probe be along a line toward the Sun so that the Sun's gravitational pull on the probe balances the Earth's pull? I'm actually just confused as to how to set this up. I know that I need to consider d being the distance from the Earth to the sun and r being the...

The sun exerts a force of 4.0 X 10^28 N on the earth, and the Earth travels 9.4 X 10^11 m in its annual orbit around the sun. How much work is done by the sun on the Earth in the course of a year? Explain.

The Sun subtends an angle of about 0.5 degrees to us on the Earth, 150 million km away. What is the radius of the Sun? theta=l/R (2pi rad/360 degrees)0.5 degrees=2pi(150,000,000 km) This should be simple, but the answer I get seems to not sound right at all Have i set this up correctly?

Don't know how long they keep these linked, but it's a great shot! http://news.yahoo.com/photos/ss/photos_highlight_fp;_ylt=Atn756jNDFDUJDaq4wjpvw.s0NUE;_ylu=X3oDMTA2Y3J1dWFkBHNlYwNwaA--

We know, that photon change direction for 1.75'', when it flies close to the sun. This angle is proportional to radius of the sun. If we calculate clasically the angle is 0.82'' (arc second). Which is momentum, which is given to sun (or black hole) by the photon change of direction. Is the...

Does anyone else find this scary yet cool at the same time?:rolleyes:

How deeply into the Sun can we see? What are we actually seeing? Is wavelength related to how much we can see into the sun?

The Solar System is traveling around 155 miles a Second around the Milky way Galaxy. There are 31,556,926 seconds in a year. We will round off the Age of our sun from 4.76 Billion to 5 Billion Years for easier figuring. If we Multiply 31,556,926 seconds by 5 Billion Years we get...

Question says: Approximately how much energy would be required to ionize all the hydrogen in the Sun? How does this ionization energy compare with the thermal energy of the Sun? (Assume the uniform density approximation. The ionization energy of a single hydrogen atom is 2.18e−18 J.) Am...

http://www.acme.com/jef/singing_science/sun_shine-32.mp3

In about 5 billion years the sun will become a red giant. Would it be possible to stop with furtristic (super extrme) technology. Like by putting more hydorgen in the sun or somthing. It might be possible assuming that if were still alive that we could have the technology to that five...

Cornell's award-winning solar house to be auctioned April 7 By Susan S. Lang http://www.news.cornell.edu/stories/March06/solar.house.auction.ssl.html

If I am to understand correctly, light speed is the speed at which light travels through space. As I also am led to believe, our sun is some four lightyears away. I recall hearing that since it takes roughly four years for light to travel from the sun to us, the light we see during the day...

Nuclear Power Plants and the Sun I need some help again...:frown: 1. What are the fuel sources? 2. How is the fuel used to produce/release energy? 3. What are the similarities in the way they produce energy? 4. Are there any health hazards associated with the way they produce...

Now, the conventional way of viewing the solar system is that all the planets orbit the sun, but since you can declare anything at rest in space, can't you just as easily say that the sun is orbiting the earth, since it will appear that way if you hold the Earth at rest?

my evil teacher is making me and my friend to do a 12 page report. and the question is "how does the distance of a planet from the sun affect the temperature?" i would really apperciate it. thanks.

and does the sun also genrate the full EM spectrum? why does it do that and not a certain wavelength, is it possible to have certain ones, is that what dead stars do, like pulsars only emit radiowaves?

Does intensity of the sun affect this? I keep trying to do it, and when you have a square shape you should still see an image of the sun.. right? Well it is not working! I live in a place with VERY intense sun and no clouds... could this be the problem? Any help!? Thanks so much...

Why do total eclipses of the Sun by the Moon reach maximum eclipse about 40 seconds before the Sun and Moon's gravitational forces align? :bugeye:

I believe I have put together a pretty compelling case to demonstrate that the sun has a solid surface made of calcium ferrites that form structures and emit electrical arcs. This model is based on observations from the Sert program and SOHO, TRACE and YOHKOH satellite data. You can get the...

I believe that I have compiled compelling evidence from the TRACE, SOHO and YOHKOH satellite programs to suggest that the sun has a solid, electrically conductive surface that lies underneath the photosphere. You can find my website with lots of video and photographic evidence to support this...

is the sun moving simple harmonically up and down also?

My Professor posed a riddle in class today. He said "Question: Name two things that signify a trip around the sun". I not very good at riddles, but I know that Earth travels around the sun once a year. Thus the changing of seasons could be argued as signifiers (earth rotates on it's axis as...

The problem is this: Given sun of mass M and a body of mass m (M>>m) a distance r from the sun, find the time for the body to 'fall' into the sun (initially ignoring the radius of the sun). Our first equation is therefore \ddot{r} = \frac {GM}{r^2} . I am able to integrate this...

I am beyond lost with the question, so any help would be greatly appreciated. Consider a solid, rigid spherical shell with a thickness of 100 m and a density of 3900 kg/m^3. The sphere is centered around the sun so that its inner surface is at a distance of 1.5×1011 m from the center of the...

Orbits What does our galaxy orbit? more questions will follow once previous ones are answered

I have a question for you all. I asked my Physics teacher this in school not so long ago. I made an animation of it on a little art thing (which rocks btw, I suggest you all use it for your examples or theoreys) http://artpad.art.com/gallery/?idilmbnxbps In a nut shell: You're on a...

i have a feeling this was answered a while ago. however, my problem is, a shere of water (as it is in space) is launched into the sun from here, assuming it hits no graviational fields and continues on it's path into the sun, the following will happen: 1. the water, frozen from its trip...

Could it be that all the stars we see in the sky no longer exist?

This is relevant to solar astronomy, defining the edge of Sol's supremacy as the overwhelming provider of all light and heat to our Solar System - On any interstellar journey going outward from Earth, one eventually reaches a point where the total amount of light received from our Sun is...

We all know that stars, for example the sun, are made up of particles such as hydrogen, but a friend challenged me recenlty asking HOW we know this, and I was forced to admit that I didn't know the answer... so how do we know? probably a simple question, but my so-called "expertise" is more...

Can somebody explain how to calculate the sun's angle in the sky at a certain time of day? It is wanted to calculate the length of an object by it's shadow.

Was the sun ever a blue star in the early stages of its life? does this mean for a proportion of the time of the 5 initial billion years of the suns lifetime, the planets were cooking because of the suns initial powerful (blue) heat?

Hi everyone, I am fairly new to PF. So I start off with a rather strange idea, derived from SR. According to the first postulate of Special Relativity, it would be more accurate to say that the sun revolves around the earth, because we are stationary relevant to the earth, right? Correct...

Alright. Now, I understand that the Sun is 1/2 way through its complete H-He fusion cycle, and I realize that after this fusion cycle, it will pass through all the elements until Fe, (i don't know whether it passes through each element in 7 seconds, or it takes 7 seconds for each element). My...

I can't seem to obtain the right answer using the escape velocity formula. I think my problem is with the gravitational constant. I would like to find the escape velocity of the sun. v_e=\sqrt{\frac{2GM}{r}} or v_e=\sqrt{\frac{2\mu}{r}} v_e_\odot=617.54(km/s)...

Why isn't there a more pronounced effect from the Sun on tides? The distance from the Earth to the Sun seems negligible considering the mass of the Sun. While typing this out and thinking about it, the most reasonable explanation I can come up with is that the Sun has so much mass that the...

Why does a bight object like the sun have negative magnitude? TY