The sun Definition and 622 Threads

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...

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 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?

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...

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...

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...

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...

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.

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...

The temperature of the sun is so high that the matter exists in plasma state.At such high temperatures electrons are not bound to the atoms.Does it mean that the sun is charged? If the sun is neutral, where do the electrons reside?

A comet near the sun whose orbit is________ would never be near the sun again is called what? My options are elliptical (I know its not this one), circular, hyperbolic, apogee, and following an inverse square law.

Hi all Currently, Voyager 1 is about 120 AU from the Sun. I wonder how big (or small) and bright would the Sun be seen from aboard this spacecraft . What approximate magnitude?. Thanks in advance.

In a assignment problem, I had to calculate the relative number of hydrogen atoms in the fundamental state, first, second and third excited states for a temperature of 5000 K. I used Maxwell-Boltzmann's statistics and I found out that (from memory) the most populated state was the fundamental...

Hi! I was just wondering if anyone knows where I can find a software/algorithm that can give me the postion of the sun and the moon in ECEF coordinates? If not, do you have any clues to how I might start building one? I am an engeneering student, so I don't have a lot of knowlegde about...

Homework Statement This is a conceptual question. Does the Earth orbit the sun or does the sun orbit the Earth? I know this is silly of me to ask. After all, everyone learns at a young age the the Earth -obviously- orbits the sun. We can represent the Earth orbiting the sun by defining the...

Thank you

Hello, I have been trying to compute the velocity of the star with respect to its local medium from the proper motion measurements. Sure, you can calculate the corresponding velocities by v = 4.74*(proper motion)*distance (in suitable units), but this resulting velocity is now with respect to...

Venus will cross the Sun on June 5-6 of this year. Historically, the transit of Venus holds a significant place in the history of astronomy. As most know, Kepler's third law stated the square of the period of a planet is proportional to the cube of it's mean distance. Newton's Laws of...

Okay i want to stir something up...do we Earth dwellers move around the sun in a roughly circular path (ellipse) OR are we moving in a straight line in a curved space? Dave

Hello, I've recently been trying to find out what colour the sun is, but I've had no luck. If you take a look at this picture: http://apollo.lsc.vsc.edu/classes/met130/notes/chapter2/plank_e_sun.html You can see that the maximum wavelength is in the green section. If so, shouldn't we see the...

Why Don't Planets "Fall" into the Sun? Ok, guys, I am new to physics (just studying it on my own before taking it next year in school) and watched a bunch of videos online about general relativity and gravity. I'm sort of stuck, though, with why if general relativity explains gravity as...

Hi, I'm just after a definitive answer on how Hydrogen fuses into Helium in the Sun? Some places say the Sun is so hot that they overcome their same charge repulsivness and fuse together while other places say that our sun is not hot enough for that to happen and that they just get close...

Is the sun a passive or active blackbody? Thanks

What is the minimum angular distance from the Sun for Venus to be visible TO THE NAKED EYE?

I am currently doing a bit of research into the history of our understanding of the solar magnetic field. It is quite interesting. As I understand it, sunspots, which were observed at least as early as the time of Aristotle, were the first solar magnetic phenomenon to be observed. Can...

Hi, I'm a student doing a project that involves building a model house with passive solar heating system. I'm curious if there is a way to approximate the amount of heat I will absorb through a south facing window on a sunny day, in early April. I realize this depends on many variables, but...

Hi, We are using a radio interferometer to measure the angular diameter of the Sun. An in depth description of how this is done is not relevant to solve the immediate problem I have. But briefly, we rotate the interferometer in azimuth so that the direction it's looking at traverses across...

I'm a huge noob and I don't know much about physics and space and stuff, but I was thinking about this in the shower today.. Anyone care to comment? Or correct me on anything? Ok, so I was talking about to Daniel about Gravity, the Sun, and Black Holes.. (Yes we are ghetto nerdy xD) And i...

First of all, I apologize if this is not the right place - it's my first post (although I've lurked for a while), so... er. Doomsday question. I'd like to know how big the sun will get - visually (but please without °, I am not educated enough to understand those) - at the end of its life...

Homework Statement in part 1 i used the Saha equation to calculate that the hydrogen in the center of the sun was fully ionized (given temperature and central electron density). part 2 says: Re-examine the result by computing the average separation of atoms at the center of the sun knowing...

Homework Statement The question is what is gravitational force between the Earth and the Sun. We are given the formula F = Gm1m2/d2. I found the mass of the sun and the Earth the gravitational constant and the distance. my issue is the G of the equation. G=6.674 x 10^-11 m^3 / kg s^2 my issue...

Hi, ive been studying formation of solar system and couldn't find an explanation for why the sun didn't absorb heavy elements from early solar system? why they remained around the sun and formed planets and not get absorbed to the centre? thanks in advance

Is Quantum Tunneling necessary to explain why The Sun keeps shining , due to it not being hot enough to provide the necessary energy for protons to collide?

Homework Statement A comet is approaching the Sun from a vast distance with velocity V. If the Sun exerted no force on the comet it would continue with uniform velocity V and its distance of closest approach to the Sun would be p. Find the path of the comet and the angle through which it is...

In our Solar System, what is the best example of a planetary moon having its own satellite? What general properties do such satellites share?

okay so I don't want this to be an argument on whether dumping nuclear waste into the sun is feasible or practical or not, as I'm pretty sure it's not rather I'd like to ask a question that my mom asked me once when I was trying to argue the idea to her. She asked me: "well if you dumped so...

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...