The Sun!

  Uboat 20:51 14 Apr 09

Couple of questions for you all please, i am not a genius at our solar system or space & time but have a few questions i would like to put before you all & if you can answer them i will be thankfull

here we see a large photo of our sun click here

can anyone tell me

what makes the sun keep the shape of a almost perfect sphere.

how its energy doesnt die i mean what re-generates the energy back like it has done for hundreds of millions of years

if the core is millions of degrees what stops it from exploding

  Blackhat 21:06 14 Apr 09

click here

Might be a better place to start looking for your answers.

  OTT_Buzzard 21:18 14 Apr 09

The sun ias a fluid - albeit an extremely dense one.

The core IS exploding (actually its undergoing a nuclear fusion process, combining atoms of hydrogen to form helium). It doesn't blow apart because of its own gravity, which is also why its nigh on a sphere, centered around its core.

Nothing is regenerating it. Eventually it will run out of hydrogen, start to try and burn the helium which it will do for a while before it, but that will cause the temperature to drop. As the atoms it truies to burn get heavier and heavier the temperature will drop and the sun will expand out in to a red giant swallowing up half the solar system, earth included.

Nice future!

  john bunyan 21:48 14 Apr 09

Try reading S Hawkins " A Brief History of Time". I'm re reading it and am a bit less puzzled than the first time. Einstein's formula E = MC2 ie Energy = mass x speed of light squared gives a start and as OTT_Buzzard says, the sun is a massive fusion reactor, converting hydrogen into helium, held together by its own gravity.I think this forum is too short to go into the theory of special relativity and quantum theory!

  AL47 21:56 14 Apr 09

pfft we will all be dead by the time the sun explodes [or very unlikely, progressed beyond that!]

1.yep, gravity stops it exploding, because it is so massive [massive as in lots of mass (ie kg)] doesnt as such regenerate its using its fuel up like anything else [be it car etc] its fuel is hydrogen [1 proton] this (under the immense gravity) fuses with another hydrogen to make helium [2 protons] this is the primary fusion process

once it runs out this helium has to fuse with heavier atoms, say carbon [6 protons]

this goes on until a certain point [the bigger the star=more gravity= can fuse heavier and heavier elements] i think iron is the limit [26 protons] but not sure, those are big BIG stars, much bigger than ours

3. shpere because if gravity is centred on a spot, ie the core, and everything is pulled into this[ all the hydrogen helium whatever], and gravity acts in ALL directions EQUALLY then the only real shap it can be is a sphere

hope this is right or there abouts

  gardener 21:59 14 Apr 09

The Sun is a newspaper which enlightens us daily and allows us to continue living in a fantasy world of celebrities and soap operas. It continues to exist because millions of people purchase it every day, thus ensuring that it doesn't collapse under the weight of it's own sordiness.

  gardener 22:03 14 Apr 09

sordidness, sorry.

  Grey Goo 23:05 14 Apr 09

Think the planet still has about 4 billion years to wreck itself before it is purified by the Cosmic event. The Red Giant and reclaimed planets will collapse upon itself and form a White Dwarf

  DieSse 23:07 14 Apr 09

Ah so that's why it's a sphere then - it's clearly full of b***s.

  VNAM75 23:11 14 Apr 09

I've always wondered about the universe. Is the big bang the only credible scientific explanation of how it all started? But what was there before that? It does sound like the theory comes from religion and not science - if there is no explanation of what preceded it.

How is the size of the universe measured? My understanding is that it is forever expanding. But I can't get round what is beyond the point/barrier of expansion. What I mean is, if a line represents the current boundary at which the universe has reached so far, what is beyond that?

  Forum Editor 23:12 14 Apr 09

The sun's surface is a seething mass of explosions, some of them so incredibly violent that they send billions of tons of superheated gas and radiation spewing out into the sun's corona. These solar flares have the power of millions of atomic bombs all exploding at once.

Our sun has been able to keep this spectacular rate of energy production going for the last 4.6 billion years because of its incredible mass - about 333,000 times that of the earth, and around 99.8% of the mass of the entire solar system. There's enough nuclear fuel left in the sun to keep it running for another 5 billion years - plenty to see us out.

What generates the heat of the sun? Nuclear fusion does. Fusion is constantly taking place deep inside the sun, and that fuels the whole process.

As it starts to die the sun will shrink to become a white dwarf. It will still be immensely hot, but it will reduce in size until it's about the same size as the earth. We'll all be gone long before that process starts to happen.

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