Sun Definition and 1000 Threads

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?

Hi, I'm looking for some help please. I'm struggling to find an equation of the Earth orbiting around the sun. I don't need to include the mass of the sun and the gravity laws, etc. Just the equation to calculate a position in x and y. Can anybody help me please? My idea is to put the orbit...

Homework Statement The focal length of a concave mirror is f=20 cm. It is directed towards the sun and the sun makes an angle= 1° at the pole of the mirror. What is the size of the image of the sun? Homework Equations 1/u +1/v =1/f ...(i) ,magnification= v/u= l2/l1 where l1 =size of the sun,l2...

Hello all! I am trying to make a VISUAL model (in C#) to predict lunar and Earth eclipse periods for a satellite that I have accurate ephemeris for. I want to calculate everything in ECEF reference frame. How would a go about modeling this system to the accuracy I'm interested in? I assume I...

I live in a small town and would like to make some observations today. However i don't have a solar aperture filter, i only have an eyepiece filter of which i do not trust. So is there any household items, materials i could use safely to save me from from ordering on the net and waiting...

Moved into a house with some solar panels facing due south and some facing due west. Our latitude is 33.8 North in California. We are in the Mojave desert with very little cloud cover. The angle of the roof is 22 degrees from horizontal. What is the equation that will accept the azimuth and...

Black bodies are objects that don't reflect radiation. But If I shoot light beams to the sun, it doesn't reflect it , so does that mean the sun is a black body(or at least very close to a theoretical one)?

Blackbody radiation spectra of hot light sources ( stars in this case) should have the full visible light spectrum and still stars less massive than the Sun emit reddish light while stars more massive than the Sun emit blue light. How is the blackbody radiation spectrum altered by the star mass?

Homework Statement Homework Equations The Attempt at a Solution it looks like I got too big numbers for the uncertainty

Hi, there has been much media excitement about the launch of the Parker probe and some rather unhelpful attempts at dumbing down the language to the point where it no longer makes sense, or because science correspondence do not even understand the subject before they try to paraphrase PR...

What are the coordinates for the sun? ?

Homework Statement A satellite of mass m is in a circular orbit of radius R about a star of mass M. The star ejects 1% of its mass by means of a spherically symmetric wind which removes the mass to a large distance. What are the new nearest and furthest distances of the satellite’s orbit around...

Close your eyes and listen to this clip. It may sound like a Tibetan meditation bowl or a giant cosmic didgeridoo, but it's actually the sun! Kind of. A group of very poetic scientists from NASA and the ESA (The European Space Agency) used data from NASA's Solar and Heliospehric Observatory to...

The question “how do we know the composition of the sun” falls shorts everywhere I look. 1. There is the spectral absorption lines. Explanations given how that works, indicate how we know the elements, but fails to tell us how we know about the preponderance of Hydrogen and Helium...

If we have two objects A and B appear on the opposite sides of the equator of a planet like Earth with the same mass as Earth. Object A is a neutron star with the mass of the sun and object B is a iron cube with the mass of one gram. Will A or B hit the Earth at the same time or will one hit...

If it takes anywhere between 5,000 to a couple of hundred thousand years (various internet sources have various values) for photons generated in the sun’s core to reach its surface and radiate out, what is the estimated mass equivalence of all these photons making their way out from the core to...

Homework Statement A new unit of length is chosen such that the speed of light in a vacuum is unity. What is the distance between the sun and the Earth in terms of the new unit, if light takes 8 mins and 20 sec to cover this distance? Homework Equations A new unit of length is chosen such...

I noticed HF radio waves travel farther and easier when the sun is out rather then during the night. Why?

Homework Statement Homework EquationsThe Attempt at a Solution This is an example given in the book . But I am just wondering whether the question itself is correct . How can intensity of light emitted from Sun is given a constant ? Shouldn't 1400 be the power emitted from Sun ? If 1400...

Hi All, I would like to know if the following statement is true or false: The nuclear processes that happen inside the Sun can produce at least one unity of each of the known chemical elements. Best Regards, DaTario

When a cloud of gas reaches a critical density, thermonuclear reaction occurs and a star is born. all other gas is blown away by the staller wind. So how do we get stars so much more massive then the sun?

Homework Statement Homework Equations [/B] delta lambda/lambda = velocity/speed of light radius of the sun= 696 *10^6mThe Attempt at a Solution Hello, the solution states the correct answer for this problem is 5.8*10^-12m. This is exactly 2x my answer but i don't really know what i did...

I had always thought that the Sun was about midway through its regular lifetime (i.e., before it becomes a red giant), but this article seems to say that instead of having another 5 Gy until then, it will be another 10 Gy. https://www.yahoo.com/news/scientists-sun-apos-death-even-164400014.html...

Red dwarf stars are main sequence stars but they have such low mass that they’re much ' cooler' than stars like our Sun. Then Simple question here : Sun is cool or hot??

Hi all, I have some difficulties understanding a formula for calculating the incidence angle for incoming solar radiation on a sloping surface. I found that: angle of incidence calculated as cos(j) = sin((pi/2)-surface slope)*sin(altitude angle) + cos((pi/2)-surface slope)*cos(altitude...

My question to you is this... Can the interior of the Sun be described as an ideal gas? From my knowledge, to describe a body of gas as an ideal gas, the separation between the particles must be much greater than the size of the actual particles. How could one justify whether the Sun fits this?

Greg Bernhardt submitted a new PF Insights post Either the Sun Is Getting Smaller or Gravity Is Getting Weaker Continue reading the Original PF Insights Post.

When the sun's rays break through a cloud there appears a radiating pattern but if one drew a line through these rays they would meet much closer than the distance to the sun. How come?

This question came up at another forum. The delta-v of potential guns is limited to the range 3 km/s to 11 km/s (hydrogen gun). Assume the astronaut is either on the moon or orbiting the moon. I'm wondering if a single impulse followed by gravity assists (and ideal planet alignment) could result...

Struggling a bit in my astronomy class. Trying to understand ..Is there a way to make a 90 degree angle between Earth, Mars, and the Sun? Mars would be the vertex. Is there a simple basic answer? TIA

Is the sun's magnetic field generated by a double dynamo? https://www.ras.org.uk/news-and-press/2680-irregular-heartbeat-of-the-sun-driven-by-double-dynamo Sorry if it was discussed yet but I couldn't find it.

Homework Statement Distance Earth-Sun at perihelion = 1.471×108 km Distance Earth-Sun at aphelion = 1.521×108 km Sun mass = 2.0×1030 kg Earth mass = 5.972×1024 kg G = 6.67×10-11 m3/kg⋅s What is the change in Newton of the attraction force between the Sun and the Earth from the perihelion to the...

The Earth is 1.50 × 1011 m from the sun. The earth’'s mass is 5.98 × 1024 kg, while the mass of the sun is 1.99 × 1030 kg. What is Earth's acceleration toward the sun? I'm really clueless how do this at all? I'm assuming it involves f=ma and GMm/r^2 formulas, but I really don't know. Help please...

How much smaller would the sun be if all it's hydrogen and helium turned to liquid? I can't figure out how to calculate this. But I thought it would be fun to visualize how much smaller in size a frozen sun would be compared to it's gas/plasma state. Anyone?

Homework Statement It's not a piece of homework, I'm doing a project and I've been wondering how I may be able to show it mathematically. I've covered the material before but it was a long long time ago... Homework EquationsThe Attempt at a Solution [/B] A-Thinking about modelling my "ship"...

Homework Statement 14.102 A comet at its closest approach is 125 x 106 km from the center of the sun (between the orbits of the Earth and Venus), where its speed is 45.5 km/s. (a) Show that the comet has an elliptical orbit around the sun. (b) Determine the period of the orbit in years (1 year...

So, I have heard that the deflection of starlight using Newtonian gravity is only half of the deflection predicted by Einstein. NE1 know where I can find an example of the former calculation? thanks

Hello. First post here so hi all. My question(s) is regarding the formation of solar masses by accretion of gases and dust. From what I understand, stars are formed by large clouds of gasses and dust particles pulling together and with enough gravity, (magnetic fields), and time. A fusion...

The discussion here https://www.physicsforums.com/threads/general-relativity-the-sun-revolves-around-the-earth.245334/ concludes that in general relativity there are no privileged reference frames so that, for example, it would be valid to use the Earth as a reference frame and say that...

Homework Statement Homework EquationsThe Attempt at a Solution If P is the power radiated by sun and R is the radius of the planet then power per unit area at a distance d will be P/4πd2 . I am not sure about how to calculate the power received by the planet .Do I need to multiply the above...

Hello, this isn't a homework or anything, I am just trying to understand one thing :) (finals are tomorrow :-0 ) If a person is exposed to heat energy of the sun for 4 hours(5040000 J per hour) and the avg surface area of the person is 1.9 m^2. and specific heat capacity of the body is 3470 J...

Homework Statement (a) What is the escape speed from the sun for an object in the Earth's orbit (of orbital radius R) but far from the Earth? (b) If an object already has a speed equal to the Earth's orbital speed, what additional speed must it be given to escape as in (a)? (c) Suppose an...

Hello, Orbital mechanics is a bit of mystery to me. Let us have a particle with mass m orbiting the Sun (with mass M)in a circular orbit with radius R. The velocity vector V is always tangential to the orbit. Let us also have a weak, constant ("drag") force Fd that is always pointing in the...

I'm confused by these pictures. I understand that the picture on the right has had color "assigned" to it because we can see uv light but the picture on the left is supposed to be taken in the visible spectrum. why is it yellow/orange and not white? isn't the sun white? both of these images...

Homework Statement The distance between the Sun and the Earth varies during the year: it is a minimum in January, and about 3.3% larger at its maximum in July. What is the corresponding change in the Earth's effective temperature? Homework Equations Energy absorbed: $$ E_{abs} = \pi R^2 (1-...

I read in some books that as the sun approaches the end of the fusion process(the complete one) , it will expand and engulf some of the inner planets. But why will it expand?

The reason I made an account is to ask about the effect of gravity from an extra planet hiding behnd the sun. I think that if this was the case we would see much great impacts¿ say like the tides. Would they not be extremely high and low? Nonstop quakes that would be felt across the world? I...

Hi guys, Disclaimer: not a physicist (I wish I was that brainy) Quick question regarding a speculative architecture project I am undertaking; In the completely hypothetical event of a huge, otherworldly solar flare super-charging the Earth's ionosphere beyond anything we have ever recorded...