Sun Definition and 1000 Threads

Hi. I'm new and hoping for some discussion. I've been looking at some physics at home on my own while Covid-19 restrictions keep me off work. I'm not registered as a student anywhere and so don't have any chance to chat with other students or university staff. Hence, I'd be grateful for some...

I recently found out that for nuclear fusion to occur the temperature needs to be around 100 Million Kelvin and that the hottest part of the sun is only at 27 Million Kelvin. And that the reason nuclear fusion is occurring in the sun is because of quantum tunneling—allowing a very small fraction...

For the first part I thought you'd have either, p + anti-v -> n + e+ and n + v -> p + e-, but I thought it'd probably be the latter as it's a 'normal' neutrino not an anti neutrino? But do I need to include the actual elements in the equation? For the second part I have multiplied the density...

I had read that the Sun will become a white dwarf and then gradually cool down to a black dwarf, but this figure at Wikipedia says it will go supernova. (Yes, I know I should not trust Wikipedia, which is why I'm posting the question.)...

Hi, In my textbook it says that if you consider the electrostatic repulsive barrier that protons in the Sun need to overcome in order to get into the range of the strong nuclear force to fuse together then it fails to fully account for the measured power output of the Sun. It says that the...

L = mvr = mr (dr/dt) = 2m*r*(dr/dt)/2 = 2m*(dA/dt) So, A = (L/2m)T so, ## L = \frac{2 \pi a b m}{T}## Now, ##T^2 = \frac{4 \pi^2}{GM} a^3## So from all these, I get ##L = \sqrt{ \frac{GM m^2 b^2}{a}}## But answer given is ##L = \sqrt{ \frac{2GM m^2 ab}{a+b}}## (This, they have derived from...

Thought experiment - the sun suddenly disappears. Light stops after 8 mins and, according to LIGO and Albert, so will gravity. The light part is easy to understand - the photons are already in flight so they get here 8 mins later. But what about the gravity? Assuming that the gravity did...

I have to give a presentation about natural Radiation and I am very happy about it because it includes Astrophysics. I want to explain to my audience how the stars produce cosmic rays. I thought about explaining to them how nuclear fusion and that kind of stuff works but then I realized that I...

when electron is moving around it like it accelerate and so it create magnetic field. and when mass accelerate it create gravity radiation , we also know that the gravity is not actuall force and it just change the time so when the Earth move in 4 direction it change it path becuase time change...

I would like to understand, for a science fiction book idea, if there is a possibility to create a theoretical energy plant that would circle the sun and tap into it's core and drain energy from the core (to use for human needs) and in the process would "drain" the sun or "shorten" it's life...

Summary:: Given statement: according to one model of the sun, the central mass density is 1.53x10^5kg.m^-3 and the mean opacity at the center is 0.217m^2kg^-1 Given statement: according to one model of the sun, the central mass density is 1.53x10^5kg.m^-3 and the mean opacity at the center is...

Here is a nice example which shows how far popular science and actual science are apart. On one hand we have the eye catching photos of the sun's surface: whereas the corresponding scientific paper on the other hand is very different: GREGOR: Optics redesign and updates from 2018–2020...

suppose suddenly the sun disappears at a time t. at this arbitrary time t, the Earth should fling off tangentially to the point in its orbit at time t as there is no centripetal force keeping it in orbit. we know light takes about 8 minutes to reach the earth. so will humans on Earth experience...

Stunning and mesmerizing,

Summary:: At what distance from the Sun will the speed of the planet be equal to the average orbital speed? I'm not sure where to place this question, please move it in the right thread. [Mentor Note -- thread moved from the technical forums, so no Homework Template is shown] At what...

I’ve been watching =AT2AcUch2CYj2r40rQ431p1Rt1SQ-YzVLo-ryJHYFIT8s9ZlMJ5pcWH9lN17FRuz2eLTlNPVb4fP2yk4PPLqjJK_6lpeWheAbATLZd7foljjUg2sOFxm-mZbhhcw3G9ApCzWIWNjgBGcGjoXMqdW6Jv-Rb8P2yA']https://www.youtube.com/watch?v=l3QQQu7QLoM What is the scientific name of the enigmatic long linear dark features...

This might be total nonsense, but the thought popped into my head while I was trying to get to sleep, so I thought I see if I could find any advanced help with the following hypothetical: If light were instantaneous, how far from Earth would the sun have to be to cause a quark orbiting in place...

Let's suppose a solar electron moving directly towards Earth's equator at a high speed. This electron meets Earth's magnetic field, which points to the north, at a distance ten times the Earth's radius, where magnetic field is almost uniform. Which will be the direction this electron describes...

Hello. I am a filmmaker writing a screenplay and I am in need of technical support to validate a method being used in the film. I am going to post this in the Earth Science forum but I'll copy it here, in case anyone reading this might know. Thank you all! "I am wondering if shadows cast...

It's well known that the tidal effect of the Moon on the Earth causes the Earth's rotation to slow down and the radius of the Moon's orbit to increase over time. However, the Sun also exerts a tidal effect on the Earth, which should also contribute to slowing down the Earth's spin. This raises...

Probably a silly question and a simple one for yourselves which I can't figure out myself. Hopefully I can explain it properly. Lets say I am standing on the equator and the sun is directly overhead. I am probably in the middle of a desert and it's around 50 degress centigrade. Assuming I could...

How much brighter is the sun when seen from space than it is when viewed from Earth?

This is a question about GR. If the sun hypothetically disappeared in an instant, would our planet Earth immediately fly off into space or, would it continue to orbit for the 8 or so minutes that the light continues to travel to the surface?

The exercise is to compare numerical and analytical solution. I have worked out the code from earlier exercise (see code under this text), but I don't understand how the analytical solution works. I have tried to use the equation r(theta) = a(1-e^2)/(1+e*cos(theta)), which is OK but I don't...

The Earth's orbit around the Sun is an elliptical orbit. Why is that so? Does that mean Sun, much like Earth bulged at some points which makes the gravitational force between Earth and Sun stronger at some points and weaker at some comparatively?

When first introduced to the concept of the ecliptic, I was under the impression that the ecliptic was the path taken by the Sun across the sky over the course of a day. That is to say, the rising in the east and setting in the west, due to the Earth's (daily) rotation from west to east. (Image...

So the sun is largely hydrogen atoms and those hydrogen atoms are undergoing fusion all the way up until they reach iron. My question is are the electrons orbiting around the nucleus just as they are in any normal object? Or is the sun just like a pool of electrons and protons floating around...

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I came across a question recently which involved calculating the change in wavelength of a photon between being emitted from the surface of the sun and arriving at the Earth. The method that was implied involved calculating the GPE's of the photon (assuming the photon to have a mass h/[c...

Pardon the very naive question, but why does the atmosphere in these gas giants seem to have, from a distance, a very clear, sharp and distinctive boundary? When one looks at Earth's atmosphere from space, it seems to have a fuzzy bluish boundary, gracefully vanishing into the black. I read...

If a (maxwells) demon were to snatch the core from the sun, what would the result be? would the remaining outer layers coalesce into a red dwarf and just continue on without much fuss? Would the core, removed from the sun, undramatically just expand out to become a red dwarf also? Just a silly...

I think this question is important so posting it here. To cut a long story short there is a person in our country who is totally anti-science and anti-Western citilization. He says science is a big lie. < remainder of post deleted by moderator >

In this video, around 2:28 He explains Earth maintain its same angular momentum even after sun disappears. I didn't get it. How Earth maintain its same angular momentum even after sun disappears?

I watched a documentary where it's said that light coming from the core of the sun takes thousend of years to reach the surface of the sun. Why is this so?

Suppose a sphere were to be placed around our Sun with a radius equal to the radius of the orbit of Earth, it would have a volume of 6.266x1022 m3. At any instant in time there would be 3.846x1027 Watts of energy within this volume in the form of photons from the Sun. Since...

How does GR predict the Earth's orbit around the sun? Newtonian mechanics predict a gravitational force that is a function of the two masses. Is the geodesic path of the Earth a function of both the sun's and Earth's curvature of space?

I'm referring to proposals that suggest putting large reflective surfaces at the L1 Lagrange point. I've also been thinking of something like capturing a nearby asteroid and turning it into an artificial ring at the equator or dumping lots of small infrared reflecting particles or releasing...

I took this picture on 04/18/2010, and I thought that I see the sun circumference. I just wonder can I calculate the physics and mathematics equations to figure out what is it that I am seeing in this picture. I stood from Earth standpoint, and I took this picture at noon time of the day.

Could you prove to me how one might calculate things like mass, gravity, distance, of the sun, moon and Earth, very quickly, with only some basic knowledge. Such as 365.25 per year, min, avg and max times for the moon to complete a lunar phase 29.26,29.53,29.8). I'm attempting to understand how...

How much longer would the Sun live if it were fully convective, just like a red dwarf star. I mean keep everything else exactly the same, the Sun has the same mass and temperature as it does now, but it goes on to burn every last drop of hydrogen it has in its atmosphere, rather than just the...

When people say that time measured from the Earth is equal to time measured from the Sun minus approx 8 min, are they taking into account Lorentz transformations or simply the fact that light takes approx 8 min from Sun to Earth?

Since the Sun orbits the Solar Systems' Barycenter about once in every 12 Earth years, wouldn't it make sense to say the sun has a "year" - at least in a casual way? After all, although the sun has a lot more mass that the Earth, it orbits the Barycenter no less than the Earth does. We talk...

<Moderator's note: Yellow press link and headline deleted.> Scientists have theorized that a planet (or planets) may have collided with our sun in the solar systems past...

Homework Statement Assuming you know the core mass, and other data about the sun, such as temperatures and pressures. Find the density at the very center of a star. Homework Equations I think this may be involved. P(r) = p(r)/µmH kT(r) The Attempt at a Solution [/B] I don't know where to...

Sun is constantly producing energy from the particles inside it. It is not using the energy from out. So if this is true, as lots of energy is coming to the universe every day, isn't it dangerous as on day energy in the universe will be soo great to burst the universe as energy is entering but...

Homework Statement From near to the center of the solar disc, Fe I line emission from point X shows a spectral line with components 666.823, 666.830 and 666.837 nm, around the rest wavelength of 666.800 nm. The central component is not as bright as those at the longer and shorter wavelengths...

I am exercising on Stellar Physics topics and in particular the questions below: 1) First of all on the rotation profile for the radiative zone: I know that unlike the convective zone, where the rotation varies mainly in latitude (faster at the equator than at the poles), the radiative zone...

If we have 2 atomic clocks on Earth's orbit around the Sun, one on Earth's surface, at one pole, and the other on a spaceship, far from Earth, but traveling with the same speed around the Sun, the clocks would suffer the same kinematic time dilation or not? I'm asking this because the clock on...

I was interested in whether it would be possible to move the Earth away from the Sun by using two ion drives on the Moon. One Ion drive on the far side of the Moon would operate briefly while the Moon was exactly between the Sun and the Earth. The other ion drive on the side facing the...

Hello, In the wikipedia article about solar sails the lightness number is mentioned and the calculation is the characteristic acceleration ac divided by the Sun´s local gravity (distance: 1AU): λ = ac / 5.93 why do they use 5,93 m/s^2 for the sun´s gravity and not 274 m/s^2?