What Is A Sun?

[A-wal]

Holy **** this is crap, A-wal.  I didn't realize in my previous absentminded attention to this forum how ludicrous your assertions are.  Here, you are, with what I must assume is a straight face, claiming that because we can not easily accomplish nuclear fusion on the surface of the Earth, nuclear fusion in the middle of the Sun is also difficult.  "So far every attempt has required more energy to produce the fusion that the fusion itself is able to release."  This is an excellent description of fusion on the surface of the Earth.  Because the Sun is demonstrably more massive than the Earth, and because fusion becomes easier as gravity increases, your realization that continued fusion on the surface of the Earth has not yet been realized has absolutely no bearing on the core of our sun.

You think gravity makes it easier for nuclear fusion to prevent the collapse of a star? :) I think you need to take a moment to think about just how dumb that statement is.

 

If it's true that nuclear fusion requires more energy to produce than the energy the fusion releases (I'm not claiming it is true, just that getting more energy out of it than is put in has been proven to be even possible) then a greater gravitational force would mean the energy deficit would increase. Yes fusion becomes easier as gravity increases but that doesn't mean that holding a star up becomes easier because gravity is an inward force and that makes it harder to hold the star up. Can't believe I have to explain that, wow!

 

You made a claim, "Except for the fact the all attempts to replicate the nuclear fusion model of the sun for use as an energy source have failed. It's never been shown, even in principle that nuclear fusion is capable of releasing enough sustained energy to not only hold up a star against its own gravity but also have enough left over to release all the radiation that they do."

 

What evidence do you have to support your claim?

 

Edit:  Let's break it down for simpicity's sake.  You made a number of unsupported claims.  1)all attempts to replicate the nuclear fusion model of the sun for use as an energy source have failed. 2)It's never been shown, even in principle that nuclear fusion is capable of releasing enough sustained energy to not only hold up a star against its own gravity but also have enough left over to release all the radiation that they do.

 

I know neither of these claims to be accurate.  You claim that they are.  What is your evidence?

That fact that it's never been done. If you're claiming that it has then you need to provide the link.

 

I’m fairly sure you’re mistaken about this, A-wal. See if you can find a source to back it up.

 

JMJones asks the same thing, less gently. ;)

 

Though models of the complicated details of how the fusion energy in their cores gets to their surfaces, and how stars’ size and mass vary as they age, especially during interesting explode-y and semi-explode-y phases continue to be evolve, the basics of how that energy is produces, and the balance of it vs self-gravity that determines stars’ rough densities has been well-understood since the late 1950s. See the Wikipedia articles Nuclear fusion, Stellar nucleosynthesis, and Convection zone for more.

Well understood in relation to a model that's never been shown to be accurate. You can't use the model as evidence of its own validity, that's extreme circular reasoning. If you work backwards from a model you assume to be right then you the numbers of energy released vs gravity will automatically fit the model because you're using that model to generate them.

 

I think the biggest theoretical puzzle of stellar fusion was the solar neutrino problem, where the number of neutrinos observed emitted by the Sun was almost exactly 1/3rd the amount predicted by the theoretical models. This discrepancy led not to changes in theories of nuclear fusion, but in the nature of neutrinos, specifically support for the theory of neutrino oscillation, where a flavor of a neutrino changes between 3 kinds, so that 2/3rds of the electron neutrinos emitted by solar fusion are on of the other 2 flavors – muon or tau – when they reach detectors on Earth.

How convenient, they are there but undetectable. If you use that kind of reasoning how can any model ever be proven wrong? I was saving that one. :)

 

Seriously though, I think they're setting something up to try to detect them. If they don't find them will the just event another oscillation that can't be detected though?

 

Oh, and I thought it was no more than one tenth of the expected neutrinos, not a third?

 

The trouble with fusion power is not that we can’t artificially produce in a small device more energy than used for a short period – fusion bombs to that quite well – or that long, even power output is impossible in a very large “device” – nature does this very well with stars – but that we can’t make a small device with long, even power output.

A fusion bomb isn't the analogous to a star though, if it was all star would immediately explode. An uncontrolled chain reaction is very different from the stable sustained energy release of a star.

 

Me too. My work for the past few weeks has me up morning and late nights, napping during the day, and other weirdness that confusing my circadian rhythms no end. Right now, I need to try to stay up for a few hours so I can work from 9:00 PM to 4:00 AM tomorrow, then go to a big, social meeting 5 hrs later. How to do this without being weirdly giddy in public is challenging. :)

Good luck.

 

Haha.  It's funny when JMJones asks you to provide evidence for your idiotic claims, A-wal, because JMJones is not "gentle".  I would not need to be concerned about the gentleness of my requests if you were more concerned about the evidence for your claims.

Referring to yourself in the third person is never a sign good sign of mental health. I wonder why you (and some others here) feel the need to take every opportunity to be as patronising as possible to anyone who thinks differently to you? You must be so insecure about your own intellects to feel motivated to go to a science forum not for any real interest (at least that's how it seems) but just to look for opportunities to make yourselves feel clever by attempting to belittle other people. You should be on a counselling forum!

Edited March 30, 2017 by A-wal

[Darky]

Hi,

 

A black hole has an infinite (talking upon facts) mass. The sun's mass can be calculated as 1S ('S' used as a measuring unit - 1S is our sun). This can't be possible as the gravitational pull wouldn't be able to catch light, yet it does. There's nothing discovered of such.

 

Theoretically talking (my favorite way of talking - nothing was done based on facts), this is possible if a sun (not ours) has enough mass to create a gravitational pull strong enough to pull photons.

 

*Gets a theoretical idea*

 

What if the Big Bang was a cause of a black hole? What if our universe in only one of millions? What if everytime the black hole sucks in something, it shoots it out somewhere in deep space causing a big bang? All of these are theories, believe them at your own risk.

 

I believe them though.

[Darky]

You think gravity makes it easier for nuclear fusion to prevent the collapse of a star? :) I think you need to take a moment to think about just how dumb that statement is.

 

If it's true that nuclear fusion requires more energy to produce than the energy the fusion releases (I'm not claiming it is true, just that getting more energy out of it than is put in has been proven to be even possible) then a greater gravitational force would mean the energy deficit would increase. Yes fusion becomes easier as gravity increases but that doesn't mean that holding a star up becomes easier because gravity is an inward force and that makes it harder to hold the star up. Can't believe I have to explain that, wow!

 

 

That fact that it's never been done. If you're claiming that it has then you need to provide the link.

 

 

Well understood in relation to a model that's never been shown to be accurate. You can't use the model as evidence of its own validity, that's extreme circular reasoning. If you work backwards from a model you assume to be right then you the numbers of energy released vs gravity will automatically fit the model because you're using that model to generate them.

 

 

How convenient, they are there but undetectable. If you use that kind of reasoning how can any model ever be proven wrong? I was saving that one. :)

 

Seriously though, I think they're setting something up to try to detect them. If they don't find them will the just event another oscillation that can't be detected though?

 

Oh, and I thought it was no more than one tenth of the expected neutrinos, not a third?

 

 

A fusion bomb isn't the analogous to a star though, if it was all star would immediately explode. An uncontrolled chain reaction is very different from the stable sustained energy release of a star.

 

 

Good luck.

 

 

Referring to yourself in the third person is never a sign good sign of mental health. I wonder why you (and some others here) feel the need to take every opportunity to be as patronising as possible to anyone who thinks differently to you? You must be so insecure about your own intellects to feel motivated to go to a science forum not for any real interest (at least that's how it seems) but just to look for opportunities to make yourselves feel clever by attempting to belittle other people. You should be on a counselling forum!

Hi,

 

I feel like if you can't provide proof, you can create a theory based on it and work on solutions to prove it as a group. If something is not possible, give reasons why it isn't. If it's somewhat possible and somewhat fictional, provide the fictional part and work to make it a reality.

 

Impossible is a relative term; to a human, flying (without the use of planes, rockets, etc.) is impossible but maybe in a later breed of humans, it may as well be possible (theorizing right now).

 

Work together as a community.

[exchemist]

You think gravity makes it easier for nuclear fusion to prevent the collapse of a star? :) I think you need to take a moment to think about just how dumb that statement is.

 

If it's true that nuclear fusion requires more energy to produce than the energy the fusion releases (I'm not claiming it is true, just that getting more energy out of it than is put in has been proven to be even possible) then a greater gravitational force would mean the energy deficit would increase. Yes fusion becomes easier as gravity increases but that doesn't mean that holding a star up becomes easier because gravity is an inward force and that makes it harder to hold the star up. Can't believe I have to explain that, wow!

 

That fact that it's never been done. If you're claiming that it has then you need to provide the link.

 

Well understood in relation to a model that's never been shown to be accurate. You can't use the model as evidence of its own validity, that's extreme circular reasoning. If you work backwards from a model you assume to be right then you the numbers of energy released vs gravity will automatically fit the model because you're using that model to generate them.

 

How convenient, they are there but undetectable. If you use that kind of reasoning how can any model ever be proven wrong? I was saving that one. :)

 

Seriously though, I think they're setting something up to try to detect them. If they don't find them will the just event another oscillation that can't be detected though?

 

Oh, and I thought it was no more than one tenth of the expected neutrinos, not a third?

 

A fusion bomb isn't the analogous to a star though, if it was all star would immediately explode. An uncontrolled chain reaction is very different from the stable sustained energy release of a star.

 

Good luck.

 

Referring to yourself in the third person is never a sign good sign of mental health. I wonder why you (and some others here) feel the need to take every opportunity to be as patronising as possible to anyone who thinks differently to you? You must be so insecure about your own intellects to feel motivated to go to a science forum not for any real interest (at least that's how it seems) but just to look for opportunities to make yourselves feel clever by attempting to belittle other people. You should be on a counselling forum!

Ah. This post is quite revealing. I thought that maybe you had a science background. But it looks as if you may not, after all. Perhaps I need to reconsider how I respond to you. 

 

To take one point in what you say, the energy released by fusion of light atoms to heavier ones is very well understood, quantitatively, and this exceeds the energy needed to start the reaction off. There is no doubt about this whatever, as it is the principle of the hydrogen bomb, the yields of which we can calculate precisely. 

 

The H bomb is exactly the process going on in the sun. It is "exploding" all the time, but due to its gravity and the amount of material available to react, the process goes on in a stable fashion for billions of years, instead of being all over in a fraction of a second, as it is with our puny bombs.

 

The difficulty we have is in creating a way to force small amounts of light elements together slowly, rather than in the uncontrolled form of a bomb. Fusion we can do: it is controlled fusion that is hard.

 

The same applies to many chemical reactions. Have you ever come across something called "activation energy"? In reactions requiring high activation energy, it is hard to get them going, even if the reaction results in net energy release. We use catalysts to lower the activation energy and make the process more controllable.

Edited April 21, 2017 by exchemist

[Darky]

Ah. This post is quite revealing. I thought that maybe you had a science background. But it looks as if you may not, after all. Perhaps I need to reconsider how I respond to you. 

 

To take one point in what you say, the energy released by fusion of light atoms to heavier ones is very well understood, quantitatively, and this exceeds the energy needed to start the reaction off. There is no doubt about this whatever, as it is the principle of the hydrogen bomb, the yields of which we can calculate precisely. 

 

The H bomb is exactly the process going on in the sun. It is "exploding" all the time, but due to its gravity and the amount of material available to react, the process goes on in a stable fashion for billions of years, instead of being all over in a fraction of a second, as it is with our puny bombs.

 

The difficulty we have is in creating a way to force small amounts of light elements together slowly, rather than in the uncontrolled form of a bomb. Fusion we can do: it is controlled fusion that is hard.

 

The same applies to many chemical reactions. Have you ever come across something called "activation energy"? In reactions requiring high activation energy, it is hard to get them going, even if the reaction results in net energy release. We use catalysts to lower the activation energy and make the process more controllable.

Hi,

 

Do you know how a black hole is created or a super nova occurs? It occurs due to the creation of iron. Unlike all the elements created due to fusion before, iron doesn't produce energy. It keeps on growing until the balance between radiation and gravity is destroyed.. and so on (you should know this if you're from a scientific background; I'm not but I like to understand). If you're creating elements such as iron, of course it would use up more and more energy but if you are trying to create atoms such as oxygen/carbon, it wouldn't. It should be able to replenish the energy used. If you continue this process for a long time; the ultimate result would be iron. If too much iron is produced, the balance between gravity and radiation would thus, be destroyed.

 

In the whole passage above, I proved that fusion in more gravity isn't beneficial but instead in less gravity is (the less time till you reach iron). The reason of our puny bombs exploding almost instantaneously is because they give off an extremely small gravity. By that I mean almost negligible gravity. That's why they explode before any element is created and cause radiation.

 

This can be confirmed by a guy working at your nearest nuclear power plant having a basic knowledge of nuclear fusion.

[exchemist]

Hi,

 

Do you know how a black hole is created or a super nova occurs? It occurs due to the creation of iron. Unlike all the elements created due to fusion before, iron doesn't produce energy. It keeps on growing until the balance between radiation and gravity is destroyed.. and so on (you should know this if you're from a scientific background; I'm not but I like to understand). If you're creating elements such as iron, of course it would use up more and more energy but if you are trying to create atoms such as oxygen/carbon, it wouldn't. It should be able to replenish the energy used. If you continue this process for a long time; the ultimate result would be iron. If too much iron is produced, the balance between gravity and radiation would thus, be destroyed.

 

In the whole passage above, I proved that fusion in more gravity isn't beneficial but instead in less gravity is (the less time till you reach iron). The reason of our puny bombs exploding almost instantaneously is because they give off an extremely small gravity. By that I mean almost negligible gravity. That's why they explode before any element is created and cause radiation.

 

This can be confirmed by a guy working at your nearest nuclear power plant having a basic knowledge of nuclear fusion.

I am aware that Fe has the lowest nuclear energy, i.e. that fission of heavier elements leads to Fe and fusion of lighter ones does the same. But I don't see at all where gravity comes into this: it is purely a question of the relative energy levels of the nuclei, surely?

[Darky]

I am aware that Fe has the lowest nuclear energy, i.e. that fission of heavier elements leads to Fe and fusion of lighter ones does the same. But I don't see at all where gravity comes into this: it is purely a question of the relative energy levels of the nuclei, surely?

 

Hi,

 

If it reaches iron, the energy levels won't be replenished. If they're not replenished, the balance between radiation and gravity will be broken causing a supernova - possibly a neutron star (low chances of a black hole, but theoretically, it's possible). A neutron star has more gravity than our sun. Something like that on Earth would mean destruction. Iron must not be reached. Thus having a lower gravity would give you more time as fusion will occur quickly of other elements before you reach iron. Just so you know, Iron isn't having the lowest nuclear energy - it has no energy.

 

Happy to explain.

[A-wal]

Ah. This post is quite revealing. I thought that maybe you had a science background. But it looks as if you may not, after all. Perhaps I need to reconsider how I respond to you. 

 

To take one point in what you say, the energy released by fusion of light atoms to heavier ones is very well understood, quantitatively, and this exceeds the energy needed to start the reaction off. There is no doubt about this whatever, as it is the principle of the hydrogen bomb, the yields of which we can calculate precisely. 

 

The H bomb is exactly the process going on in the sun. It is "exploding" all the time, but due to its gravity and the amount of material available to react, the process goes on in a stable fashion for billions of years, instead of being all over in a fraction of a second, as it is with our puny bombs.

 

The difficulty we have is in creating a way to force small amounts of light elements together slowly, rather than in the uncontrolled form of a bomb. Fusion we can do: it is controlled fusion that is hard.

 

The same applies to many chemical reactions. Have you ever come across something called "activation energy"? In reactions requiring high activation energy, it is hard to get them going, even if the reaction results in net energy release. We use catalysts to lower the activation energy and make the process more controllable.

Yes I'm aware that in the nuclear fusion model of stars there's a sustained nuclear 'explosion'. My point is that in this model, a star uses a sustained nuclear fusion reaction, not a one-off chain reaction. It;s never been shown that you can sustain a nuclear fusion process using less energy than the reaction itself releases. Stars not only have enough energy to hold themselves up but also have enough left over to emit enormous amounts of radiation.

 

That's quite a leap using a process that might not even release enough energy to sustain itself.

Edited April 22, 2017 by A-wal

[Darky]

Yes I'm aware that in the nuclear fusion model of stars there's a sustained nuclear 'explosion'. My point is that in this model, a star uses a sustained nuclear fusion reaction, not a one-off chain reaction. It;s never been shown that you can sustain a nuclear fusion process using less than the reaction itself releases. Stars not only have enough energy to hold themselves up but also have enough left over to emit enormous amounts of radiation.

 

That's quite a leap using a process that might not even release enough energy to sustain itself.

Hi,

 

Very much correct. How do you propose they gain this energy? Fusion. Enough gravity to allow fusion to last for millions of years - allowing it to create energy to hold themselves and emit enormous amounts of radiation. Read my posts above. Such a solution would only be possible if we are to create a strong gravity field in exact correlation to the radiation.

[A-wal]

Ah. This post is quite revealing. I thought that maybe you had a science background. But it looks as if you may not, after all. Perhaps I need to reconsider how I respond to you.

I missed this attempted patronising ad hominem the first time. You know very well that I don't have a scientific background and I'm a little offended by the accusation.

 

How do you propose they gain this energy? Fusion. Enough gravity to allow fusion to last for millions of years - allowing it to create energy to hold themselves and emit enormous amounts of radiation. Read my posts above. Such a solution would only be possible if we are to create a strong gravity field in exact correlation to the radiation.

The gravitational field of a star needs to be overpowered by another force to hold it up against its own weight. I say overpowered rather than matched because there needs to be enough left over to light the star.

[JMJones0424]

Here's an ad hominem A-wal, "You are the offspring of your brother and your mother, so nothing you say should be accepted as true".

 

What is not an ad hominem is the fact that your unsupported claims in this thread are ludicrous.

[Darky]

The gravitational field of a star needs to be overpowered by another force to hold it up against its own weight. I say overpowered rather than matched because there needs to be enough left over to light the star.

Hi,

 

I thought it's pretty obvious that the fusion occurring creates a reaction creating the element/atom and photons. Have you studied the base core of a star?

[exchemist]

Yes I'm aware that in the nuclear fusion model of stars there's a sustained nuclear 'explosion'. My point is that in this model, a star uses a sustained nuclear fusion reaction, not a one-off chain reaction. It;s never been shown that you can sustain a nuclear fusion process using less energy than the reaction itself releases. Stars not only have enough energy to hold themselves up but also have enough left over to emit enormous amounts of radiation.

 

That's quite a leap using a process that might not even release enough energy to sustain itself.

But hang on. If you concede that the fusion process in the sun is the same as that in an H bomb, then it is plain that it releases more energy than it requires to set it off. If it did not, then the "bomb" would just go "phut" and would not go off.  

 

If you think the "chain reaction" in an H bomb is a different process from that in a star, then you will need to explain to me why you think so and how you think it may differ.  

 

Bear in mind that the energy release depends only on the energy of the reactants minus the energy of the products, not on how they get from one to the other. So your different process (if that is what you are suggesting) would need to end with different (i.e. more energetic) products, if the energy release were to be less. 

[exchemist]

I missed this attempted patronising ad hominem the first time. You know very well that I don't have a scientific background and I'm a little offended by the accusation.

 

 

Er, I'm baffled. First I did NOT know you have no science background (though perhaps I should have picked this up earlier, do you think?). You seem to debate with such authority that I thought you knew a fair bit. But I understand better now and can make allowances.

 

Secondly, there was no attempt to be patronising, though now that I know you have no science background I will of course stop assuming that you know certain things already, so I may well come across in future as patronising. 

 

Thirdly, it is not argument "ad hominem", as I was not making an argument at that point, but a discussion of relevant fact concerning you and your intellectual background. Communication on an anonymous forum like this one can lead to many misunderstandings due to assumptions of knowledge or lack of it, since it is only gradually that one gets a feel for what level of knowledge can be assumed in one's interlocutor. Just so you know my own background, I am an Oxford chemist, though my degree was forty years ago. The two pillars of physical chemistry, which is what interested me most, are quantum theory (of atoms and molecules and their properties)  and statistical thermodynamics. So I retain a bit of knowledge about those in particular. (You will find I usually steer clear of discussions about General Relativity, as this does not come up in chemistry. ) 

[DrKrettin]

If you think the "chain reaction" in an H bomb is a different process from that in a star, then you will need to explain to me why you think so and how you think it may differ.  

 

 

We might be talking at cross-purposes here, but the H-bomb uses a fission process which then initiates the fusion process. In that sense, it is a chain reaction process which differs from that in a star. I suspect though that you are referring to the fusion process itself.

[Darky]

Hi all,

 

Let me explain using known facts on what you guys are saying.

 

Hang on. If you concede that the fusion process in the sun is the same as that in an H bomb, then it is plain that it releases more energy than it requires to set it off. If it did not, then the "bomb" would just go "phut" and would not go off.

 

If you think the "chain reaction" in an H bomb is a different process from that in a star, then you will need to explain to me why you think so and how you think it may differ.

 

Bear in mind that the energy release depends only on the energy of the reactants minus the energy of the products, not on how they get from one to the other. So your different process (if that is what you are suggesting) would need to end with different (i.e. more energetic) products, if the energy release were to be less.

Very correct, except some misunderstandings. The process on the atomic bomb is different from the sun as explained here by DrKrettin.

 

We might be talking at cross-purposes here, but the H-bomb uses a fission process which then initiates the fusion process. In that sense, it is a chain reaction process which differs from that in a star. I suspect though that you are referring to the fusion process itself.

Now I'll explain how fusion on earth works and possible ways it may work in the future. There are two ways as of now; the Magnetic Confinement Reactor (MCR) and Inertial Confinement Reactor (ICR).

 

Let me explain how the Magnetic Confinement works now. I'll just go over it so for more detail, check verified sources. The Magnetic Confinement Reactor (MCR) uses a magnetic field to keep the plasma in a donut like shape where it is allowed to fuse. This has been done in the ITE (International Thermo-nuclear Experiment) reactor in France (ITER Source - Proof)

 

Let me explain the second way, Inertial Confinement Reactor. This one uses pulses from super-powered lasers to heat the surface of a pallet of fuel (imploding it), which briefly makes the fuel hot and dense enough to fuse. This has been accomplished in the National Ignition Facility (NIF) in the United States (NIF Facility in the US), using the most powerful laser in the world.

 

Though we can do the fusion, we come back to the point where the energy generated is always less than the energy used to do it. Making the point claimed by A-wal true. You need proof? Do research.

 

It's not confirmed that we'll get there, and we possibly won't, but if we do; a glass of water will be able to produce as much energy to run half of New York (No, I'm not American).

 

So, we can make unlimited energy, with almost no damage to the environment - what's the catch? It's not complete, and even if it does get completed, it'll need more money to run then the the electric bills from people around the world can make. Chances are, it would never be public - thus discussing about it unless we can somehow create a cost-efficient way is purely nonsense (other people have thanked and come up with solutions that work but cost too much).

Edited April 22, 2017 by Darky

[DrKrettin]

Let me explain using known facts on what you guys are saying.

 

 

Very correct, except some misunderstandings. The process on the atomic bomb is different from the sun as explained here by DrKrettin.

 

You don't have to explain known facts to me, I'm a physicist (or was). And you must differentiate between an atomic bomb, which uses fission only, and an H-bomb, or thermonuclear device, which uses the process I described. Very different.