Sun Definition and 1000 Threads

Are we just really lucky that the time it takes for Earth to orbit the sun is 365.25 days? I mean if it was something like 365.71 days, then we couldn't have our simple leap year every four years. We would have to have a 71 leap years every century, or even if we were to simplify it a bit, 7...

On Earth, fire needs oxygen. If space has no oxygen, how does the sun continue to burn? Thanks! :) Ω

Homework Statement Homework Equations The Attempt at a Solution I'm only stuck on part b). I make a) to be 3.87E26 W, but it gives that anyway in part b). OK, so here's my attempt: \int_{r=0}^{r=R}dT(r)T(r)^3 = -\frac{3L(r)}{16\pi acl_{mfp}}\int_{r=0}^{r=R}dr\frac{1}{r^{2}}...

If I was in the car driving westward, how fast would I have to drive in order for the Sun to appear as if it is not moving.. In other words if I start driving at 1pm, how fast do I have to go so I'm always at 1pm.?

This excerpt is from "The Universe and the Atom" by Don Lichtenburg: I was under the impression that photons made in the nuclear fusion bounced off of particles for a long time, before they inexplicably were able to escape from the sun. Why does the sun absorb the most energetic photons...

Homework Statement My physics teacher today said that the Earth exerts the same amount of gravitational pull on sun;as the sun exerts on the earth. Is this really true? Homework Equations There is no equation. The Attempt at a Solution I am very confused with this. How can the...

Hi, the problem is stated as following: The Earth (mass=5.98×1024 kg) rotates around the sun in an orbit that is approximately circular, with a radius of 1.5×1011 m. Find the orbital speed of the Earth around the sun. [itеx]F=mv/r2[/itеx] I get that I need to use this equation but I'm...

Homework Statement Calculate the relative change in the distance of the Earth from the Sun, if the mass of the Sun is 15% lower than today weight of the Sun. Suppose that the Earth moves and will move along a circular path and will maintain its angular momentum. Homework Equations...

- possible sun timeline - 3,130,000 years for molecular gas to condense into protostar - 40,000,000 for core to condense and heat up to 15 million K - 43,130,000 total - sun has only enough matter to 'burn' by gravitational pressure for 100/300 million yrs - first stage of...

I used this equation to find the time in seconds for the Earth to complete 1 orbit around the Sun. p=2\pi\sqrt\frac{\alpha^3}{\mu} I put in 149598261000 metres for the semi-major axis, and 1.33E+20 for the gravitational parameter. I got 3155391.8 seconds for the period. This I believe...

Homework Statement The Earth has a mass of 6 x 10 24kg and orbits the sun in 3.15 x 10 7 seconds at a constant circular distance of 1.5 x 10 11 m. What is the Earth's centripetal acceleration around the Sun? Homework Equations The Attempt at a Solution

I was wondering if a spacecraft (or any other object) could 'co-orbit' the Earth by orbiting the Sun beyond our Hill sphere. For example, could this object 'hover over' the North (or South) Pole at >1,500,000 km? Thanks in advance!

Alright, Not the best at math and need help with find a equation for the amount of energy needed for destroying the sun. This isn't based on real life, based on a TV series and I'm nerdy enough to want to know how much energy it would take lol. I have a number for how much energy it would take...

I'm recently studying heat transfer processes. I saw that the heat current emited by a radiating body is given by: \frac{dQ}{dt}=H=A e \sigma T^4 I was wondering how to calculate the H from the sun to a unit area here on earth. How should I do it? I've seen exercises where they use this...

1/ when serching for mesurement Earth-Sun distance, I got this in the sechon answer, to use this method, we need mass of the Sun but when I searched for Sun' mass http://en.wikipedia.org/wiki/Solar_mass 2/ r=GMT^2/(4(πr)^2)The Attempt at a Solution there are the other ways to caculate Sun...

Hi guys, can I say that since the sun orbits around the centre of mass of the solar system, it has angular momentum L=mvr. And since L=Iw, the sun itself will rotate about its own axis. Am I right to say that? However, conceptually speaking, is there a reason why the sun rotates? Also, what...

"Determine the relative distances of each of the planets from the Sun given [...]." Homework Statement Devise methods to determine the relative distances of each of the planets from the Sun given the information available to Copernicus (observable angles between the planets and the Sun...

A question was posed that I decided to have a crack at, and I want to check my understanding. This isn't homework by the way, just trivia. Also the thread title is not really correct but I didn't want to complicate things! Here's the question: What is the relative difference in the distance...

I would like to know a function or at least an approach toward developing a function that describes the change of gravity on the Earth's surface due to the sun, moon and if possible, the tides. I am quite familiar with the fundamentals but my math isn't up to this. Thanks in advance...

Homework Statement We consider that at the third Kepler's law the Earth mass is 0, that way we are making an error at the Sun mass calculation in comparison to the real Sun mass. In the same calculation we make another error by taking the common error at the gravitational constant, G. Which...

Hello fellow aerospace engineers and physicists, I am currently working on a project and trying to figure this out. I was wondering if you guys could help me out. Here is the problem statement: A nuclear waste disposal spacecraft is to be sent from Earth in order to carry radioactive waste...

Homework Statement The Earth orbits around the sun because it has angular momentum. If we stopped the Earth in orbit and then let it fall straight towards the sun, how long would it take to reach the sun in seconds? Details and assumptions The mass of the sun is 2×10^30 kg. The mass of the...

Hi all! If space isn't a true vacuum, why doesn't our Earth lose its speed due to friction? I know that it's a near vacuum outside our atmosphere and the friction would be almost negligable. But in the course of a billion years, shouldn't it have an effect? Why aren't we slowing down...

Imagine a big superfluid cloud the size of the Moon, at the same distance of the Moon in front of the Sun. A total eclipse of 7 minutes. What would happen with the light coming from the sun during these 7 minutes? Would we see a "night sun"? Another question. "Estimates of the photon...

HI I'm making a sun follower with a pic, and I need the formulas to calculate the position of the sun, I need to calculate azimuth angle and zenith angle (Is that enough to know at any time the position of the sun?). Thanks

Since the Sun is changing 4M tons of matter into energy every second and that energy eventually makes its way to the surface and is emitted as an outbound sphere of EM radiation, then the planets' orbits would change over time due to the less massive Sun at the solar system's core. It would...

Referring to following video, starting at 3 min. Earth's Magnetic Field deflat the Solar Storm. I would like to know more what is going on between the periods before Solar Storm hits Earth's Magnetic Field and after Solar Storm hits Earth's Magnetic Field? Does anyone know any...

Ok...My idea is a bit ridiculous.But i just wanted to know more about it from you experts. Scientists say that the Earth is revolving around the sun and so also the other planets. Newton and all the other guys who were experimenting and developping physics were observing our external world...

i understand that this may seem like a impossible theory but is it possible that ice could form inside a sun, i understand that the core of a sun is extremely hot but due to the incredible pressures invovled could hydrogen or another gas be compressed so much that it could form ice?

I just need someone to double check my answer and confirm they get the same answer as I do. Thanks. Question: Find the attractive force between Vneus and the sun. The distance between their centers is 1.08x10^11. Equation: F = Gm1m2/d^2 G= 6.67x10^-11 N.m^2/kg^2 m1 (mass of sun)=...

I know its impossible in a vacuum, but what if. Let's say in our lower atmosphere, what would the sun sound like. A really loud and continuous bomb?

Please see attatchment for qs. I really need help with number two mostly.

This is a question about electromagnetic waves and gravitational waves. Let's say we're on the Earth and we're looking up at the sun (safely). If the sun were --for some reason-- to violently and dramatically jerk from its position, how would we first find out? Would we first *see* the...

Hi all, I'm having some trouble understanding conflicting information on the web. 1) I know that a gravitational assist on a spaceship around a planet can increase the spaceship's speed with respect to the solar system. A gravitational flyby will not work for ships that stay within the...

Homework Statement Assume that a satellite can be modeled as a thermally leading sphere with radius 0.5m and its energy consumption is 200W, and its surface can be described with α=0.3 and ε=0.9. Determine the equilibrium temperature of satellite in these cases: a) Satellite is between Earth...

Homework Statement What is the period of Earth's (nearly) circular motion around the Sun? (2*pi*r)/T 1 year (1 year)/(2*pi) (2*pi)/(1 year) 2*pi*(1 year) Homework Equations There is only one speed that a satellite can have if the satellite is to remain in...

Homework Statement I've solved part (a), but part (b) puzzles me as I am of 103 orders of magnitude away from the answer. The Attempt at a Solution Intensity on dust particle = 1600 W m-2 Earth-Sun Distance = (8*60)(3*108) = 1.44 * 1011m Mass of Sun = 1.99 * 1030 kg g-field...

Hey everyone. Let me preface this by saying, I love physics and astronomy, but am by no stretch an expert in either subject. I had a question that I thought someone on this site might be able to answer, I have been looking around the internet, but couldn't find one. So, I understand that The...

Homework Statement The sun radiates about 4.0E26 J/s. a) How much mass is released as radiation each second? b) If the mass of the sun is 2.0E30 kg, how long can the sun survive if the energy release continues at its present rate? Homework Equations Not sure, but I think I'm...

Can we give an analogy for nucleus to sun and electrons to planets...... Hi all, Can we give an analogy for nucleus to sun and electrons to planets...... like this in several galaxies... and galaxies together form some other material in larger scale. Also can we say wave nature of...

The Sun, on average, is 93 million miles from Earth. How many meters is this? Express using powers of ten. Express your answer using two significant figures. Okay so: Okay so, 1 Meter = 1609.344 x 93 = 149668.992 1.5 x 10^5 (2 significant figures) When I put 1.5x10^5 in, it says 'The...

My educated guess is that you can see the sun if you were standing on the moon. Having said that, why isn't there any pictures of the sun taken by astronauts who've "supposedly" walked on the moon..? This seems odd to me.

I read this Scientific American link and I found it very interesting. I have a problem understanding it, though, because I had read that one of the explanations for the existence of Solar Systems is based on Angular Momentum. The argument goes that if all the mass were concentrated in the host...

[b]1. The surface temperature of the sun is approximately 5800K. Given that the radius of the sun is 6.96x108m calculate the rate of energy output of the sun, taking the sun as a blackbody. [b]2. H = εσAT4 [b]3. Surface temp = 5800K, Radius of the sun = 6.96x108, Emissivity of a...

If we had an array of detectors in an orbit around the sun could we magnify the image of distant star systems. Would this help to detect planets using this magnification?

Einstein predicted a slightly quicker orbit for planets very close to the sun that will deviate from Newton’s gravitational laws very slightly. Later observations, as we know, have proved correct and General Relativity holds up. But what is the perceived reason as to why this is? What is the...

Could there be a portal inside or near the sun? Consider the magnetic field and energy of the sun.

Light requires some medium to pass through, what's the medium in the space, and How does sunrays enters into the earth.

I'm considering writing a story in which we Earthlings have a few years to prepare for a cosmological catastrophe in which our planet will lose its energy source and be adrift in space. This would mean the end of life on Earth - but not right away. We could insulate giant underground chambers...

Homework Statement Consider the extreme case that the comet is released from rest at a distance R_max from the sun. In this case L is actually zero. Use the technique described in connection with 4.58 to find how long the comet takes to reach the sun. The radius of the sun for now is zero...