Exploring the Mass & Shape of the Sun

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Discussion Overview

The discussion revolves around the mass and shape of the Sun, exploring questions about its composition, density, gravitational effects, and the implications of its gaseous nature. Participants engage in both conceptual and technical explanations related to astrophysics.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • Some participants question how the Sun can have significant mass given that it is primarily composed of hydrogen gas, suggesting that a large quantity of any substance can lead to substantial mass.
  • Others clarify that the Sun's spherical shape is maintained by gravitational attraction among its components, similar to other celestial bodies.
  • One participant notes that the Sun's average density is about 1.4 grams per cubic centimeter, which is denser than water, while another challenges this by stating it is slightly less dense than water.
  • There is a discussion about the gravitational forces at the Sun's center, with some asserting that gravity is zero at the center, while others argue that pressure, not gravity, is responsible for the conditions necessary for fusion.
  • Participants discuss the Sun's shape, with one asserting it is an oblate spheroid due to its rotation, while another questions the implications of this shape.
  • There is a claim regarding the Sun's mass loss efficiency, with one participant suggesting it loses 99.99% of its mass yearly, while another counters that it loses far less than 0.01% annually.
  • One participant introduces a tangential topic about the Moon's movement towards Earth, which is corrected by another who states it is actually receding.
  • A participant attempts to relate the Sun's mass to a metaphor about the weight of a pack of papers, emphasizing the cumulative effect of many light components contributing to overall mass.

Areas of Agreement / Disagreement

Participants express differing views on the Sun's density, gravitational effects at its center, and the efficiency of its mass loss. There is no consensus on these points, indicating ongoing debate and exploration of the topic.

Contextual Notes

Some claims about the Sun's density and gravitational effects depend on specific definitions and assumptions that are not fully resolved in the discussion.

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How can the sun have much mass if it's just a bunch of gasses? And also what keeps the sun in a circlular shape? I've always wondered.
 
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Actually, its worse than that! How can the sun have much mass if it's just a bunch of hydrogen? (The lightest possible gas.)
Answer: it's one heckuva lot of hydrogen! If you get enough of anything, even the lightest element in the universe, it will have a very large mass!

What keeps it spherical (better than "circular")? The same thing that keeps planets spherical: the gravitational attraction of its parts for each other.
 
The Sun has, on average, density slightly less than that of water (but 90 times greater at its center since its mass, thus gravitation, is so great, thereby maintaining fusion). The Sun has approximately 10 million times the volume of the Earth, and 300,000 its mass.
 
Originally posted by Loren Booda
The Sun has, on average, density slightly less than that of water
Actually, the sun's average density is about 1.4 grams per cubic centimeter, about 40% denser than water.

- Warren
 
Originally posted by Loren Booda
90 times greater at its center since its mass, thus gravitation, is so great, thereby maintaining fusion

Just to clarify (although this may be what you had in mind):

At the center of the sun (or any celestial body), you have the least gravity, since you are pulled the same in all directions; if you could build a spherical room in the center of the sun, it would be a zero-gravity place, much as what happens when you introduce a charge inside a charged spherical shell.

At the center, there is, however, the largest pressure, due to all matter being pulled towards that point.
 
At the center of the Sun, true, you have no gravity, but you do have the pressure, which the gravity acting in the rest of the Sun, brings to the center. It is the pressure, not the gravity itself, which raises the temperature and makes fusion possible.
 
How can the sun have much mass if it's just a bunch of gasses?
A ton of feathers still has a mass of one ton.

Question: Is the sun actually spherical? I think it spins somewhat, which would make it slightly fatter around the equator.
 
It's an oblate spheroid.

- Warren
 
Isn't the sun something like 99.99% efficient per year? As in, each year it would have 99.99% of its mass that it had last year at the same time?
 
  • #10
Originally posted by Decker
Isn't the sun something like 99.99% efficient per year? As in, each year it would have 99.99% of its mass that it had last year at the same time?
It loses far less than 0.01% of its mass yearly.

- Warren
 
  • #11
You can not escape gravity in any way. It's just impossible.

Gravity is everywhere, and as a matter of fact, your body has gravity.
 
  • #12
Thanks for the corrections, folks.
 
  • #13
eventually like 5 billion years later the sun would die out right ?
i guess i don't have to worry about that :wink:

this has nothing to do with the sun but.. the MOON

i heard that its coming towards Earth very very slowly

is it true? if it is true how much is it moving towards the earth?
everyday ?
 
  • #14
bye bye Moon!

It's actually receding ... at ~3 cm/year.

http://scienceworld.wolfram.com/astronomy/Moon.html

However, it'll be back (it's all due to conservation of angular momentum, and neither the Earth nor Moon being a perfectly rigid perfect sphere)
 
  • #15
THE SUN'S MASS ETC..

One has to note that the Sun is a body made of gas mainly hydrogen which then is consumed by the Sun itself to power it's Nuclear reactions. This is then converted to helium. Although hydrogen is light one has to consider the immense size of the Sun which obviously has a huge mass. I don't know if this example is valid but this is liek having a pack of papers, one paper is light but when amounts increase the pack get's heavier. Now about the sun having circular shape. This is like all otehr celestial bodies they have a circular shape because of the effect of the gravitational field.

I am not an advanced PHYSICIST but I hope my post was correct.
 

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