36 replies to this topic

[Mat Hunt]

Apologies for starting a new thread but I felt that the things I have to say don't really fit with the others. I apologise in advance as I do theoretical physics and think mathematically rather than intuitively. The first thing that I want to address is Boyle's law, that at constant temperature (and that is the key phrase) the pressure is inversely proportional to the to the specific volume, or that pressure is proportional to the density of the gas. The ideal gas law (sometimes called the perfect gas law) is derivable from theoretical considerations (from the kinetic theory of gases) but can also be derived by using both Boyle's and Charles's laws, both are empirical but can be combined into one law called the ideal gas law. In fact it is stated in Elements of gas dynamics by Liepmann and Roshko, that for many gases at relatively low densities the pressure (p), specific volume (V) and temperature (T) are related by the equation pV=RT, where R is a constant that is dependent upon the gas in question. This can be written in several forms (also seen in Leipmann and Roshko), the temperature and internal energy (which is esserntially the vibrations of the atoms) per unit mass are related to each other (in the ideal gases case, they are linearly dependent upon each other, that is differ by a multplicative constant) . Now it turns out that the ideal gas law is most used in high speed aerodynamics, namely in supersonic flow. The result calculated using the Euler equations for fluid flow and the ideal gas law actually correspond very very well, so that would give some confidance that the use of the ideal gas law isn't a useless equation of state to use for air.

As I have said, the ideal gas law in not a "fudge factor to override Boyle's law", but a generalisation of Boyle's law which contains Boyle's law as a special case when temperature is constant. I have also said that use of the ideal gas law works very well with high-speed aerodynamics, although one could argue that the equations that govern the fluid flow are "wrong" in the other direction, cancelling the error. Now if you think that te ideal gas law isn't good enough to describe the gases which you're referring to, you can if you wish use the Van der Waal's equation as a model for your gas which (if you believe wiklipedia, seems to be valid for a wide varity of gases, even some liquids) has been empirically validated (as has the ideal gas law) to a very high dewgree, I can obtain some papers that clarift this if you like.

So on to star formation (which Boyle's law isn't used for because of the change in temperature) initially hinges on (for a simple initial "toy" model let's say, based upon Newton's second law of motion. I shall take my explanation from the book "Theory of Stellar structure and Evolution" by Dina Prialnik. He derives an equation that describes the theoretical self-gravitation of a ball of gas and put the force of pressure pushing the gas apart and the gravity pulling the gas towards itself. From this simple model one can derive a condition for trhe point at which the force of self-gravitation overcomes the pressure of the gas pushing it apart. All this is based upon equations which have been validated in experiment time and time again, the ideal gas law, Newton's second law of motion and Newtonian gravity, these are the ingredients used in the theory. The criterion derived from this condition is called the Jean's criterion, after sir James Jeans. There will be a point where the pressure will become so large that it matches the force of gravity, this is called hydrostatic equilibrium.

You can of course generalise with model by adding in angular momentum and magnetic fields (in which case you obtain the Bonner-Ebert mass which would be a more accurate representation than the Jean's mass would.

[goldliger]

I believe this is Matthew Hunt, a militant atheist who was previously banned from this forum. Can't be certain but "Mat Hunt" seems a bit more than coincidence, and both are from the UK, same age if I'm not mistaken.

(Just an fyi.)

[Mat Hunt]

Hi can you say what a "militant atheist" is? I am coming at the viewpoint from a scientific point of view. Cheers.

I will add that the name Matthew Hunt" is an extremely common one in the UK, just go on facebook and search for the name.

[Reptoman]

Matt I study reptiles but I also think intuitively--so after that opener above--with respect to stars, are you syaing by this, that the stars evolved? Or are you saying they were created, because I am not sure, but you imply evoutionary model, which most or many creationists would reject. I am a simplton in this area, but using plain logic, I know that the the whole planatary sytem is set up in such a way that the earth is alive because of the placements of the planets even a small demarcation from their positons can cause serious issues for the earth. This does nto seem to be qoincidence in my humble opinion. THe earth obviously is not the center of the universe, also given mathematics the possibility of other planets containing life could be a huge number, but it is interesting that so far we have not found such, we seem to be somewhat unique.

So I imply by what I know of the earths mysteries like DNA, fossil record , carbon 14 of bones, and other such thing that the earth has nothing but footprints in the sand of a creator, and there is not enough time to have implied the possibility of evolution within the pale of earths history. But most of our newest information seem to imply an intelligent designer?

So can you without going through math--give a simple conversation as to your acceptance of evolution as a basis for creation--or you are supporting a creationists view. Your inferences above are so generic in content that ti is not clear what you are saying, if there was a former post, I didn't see it so I am at ground zero with you..... The biblical narrative implies the earth has an age and the age is not the same as what existed before it was formed, so I assume the age of the earth to be cosmologically to be possibly younger. The age of creation itself seems to be implied in the Biblical narrative of a young age, much of science does support this view. The earth was void and without form at one time by the narrative, so from that point on the whole Biblical scenario points to a creator or intelligent designer. I can discuss this in detail as to why that (biblical narrative) is factual and complimentary with known science.

If you are an atheist then you are just as I am a creationist. Atheists reject any idea of a God or intelligent creator, if that is your ilk I would hope that you would eventually come to the knowledge there is no explanation within the pale of DNA information which is outside of nature and not created by nature, I don't know what the tenor or tone of an atheist is? But I am willing to have a small exchange with you, but if its about cosmology, I would have to bale out, I simply put out what seems to be true with the earth, which is my focus and not the whole universe.....

[Mat Hunt]

I wouldn't say that evolutionary model is the correct term to use (speaking strictly as a physicist) but I would say a dynamic (time dependent) model is more accurate. I am saying that under certain conditions that the force of gravity can be greater that the pressure forcing. The condition would be dependent upon the model used for the gas cloud, so one would hope by adding in as much physics as possible we would be able to derive the best approximation for the criterion that would cause a star to form from a gas cloud by using known tested laws (like gravitation and gas equations of state).

"I know that the the whole planatary sytem is set up in such a way that the earth is alive because of the placements of the planets even a small demarcation from their positons can cause serious issues for the earth."
Gravity is an inverse square law which implies (after doing some maths) that the shape of the orbit are elliptical(Newton knew this) and so there will be times when the Earth is close to the sun and times when it is further away, so the demarcation from the orbit wouldn't cause that much of a problem, any small perturbations would essentially oscillate around the unperturbed orbit.

As for Earth-like planets, (exo-planets I believe they're called), astronomers are looking for them in earnest.

I was hoping to talk about star formation and the physics behind the models rather than biological evolution. Biology isn't a specialism of mine, physics is.

[Calypsis4]

Apologies for starting a new thread but I felt that the things I have to say don't really fit with the others. I apologise in advance as I do theoretical physics and think mathematically rather than intuitively. The first thing that I want to address is Boyle's law, that at constant temperature (and that is the key phrase) the pressure is inversely proportional to the to the specific volume, or that pressure is proportional to the density of the gas. The ideal gas law (sometimes called the perfect gas law) is derivable from theoretical considerations (from the kinetic theory of gases) but can also be derived by using both Boyle's and Charles's laws, both are empirical but can be combined into one law called the ideal gas law. In fact it is stated in Elements of gas dynamics by Liepmann and Roshko, that for many gases at relatively low densities the pressure (p), specific volume (V) and temperature (T) are related by the equation pV=RT, where R is a constant that is dependent upon the gas in question. This can be written in several forms (also seen in Leipmann and Roshko), the temperature and internal energy (which is esserntially the vibrations of the atoms) per unit mass are related to each other (in the ideal gases case, they are linearly dependent upon each other, that is differ by a multplicative constant) . Now it turns out that the ideal gas law is most used in high speed aerodynamics, namely in supersonic flow. The result calculated using the Euler equations for fluid flow and the ideal gas law actually correspond very very well, so that would give some confidance that the use of the ideal gas law isn't a useless equation of state to use for air.

As I have said, the ideal gas law in not a "fudge factor to override Boyle's law", but a generalisation of Boyle's law which contains Boyle's law as a special case when temperature is constant. I have also said that use of the ideal gas law works very well with high-speed aerodynamics, although one could argue that the equations that govern the fluid flow are "wrong" in the other direction, cancelling the error. Now if you think that te ideal gas law isn't good enough to describe the gases which you're referring to, you can if you wish use the Van der Waal's equation as a model for your gas which (if you believe wiklipedia, seems to be valid for a wide varity of gases, even some liquids) has been empirically validated (as has the ideal gas law) to a very high dewgree, I can obtain some papers that clarift this if you like.

So on to star formation (which Boyle's law isn't used for because of the change in temperature) initially hinges on (for a simple initial "toy" model let's say, based upon Newton's second law of motion. I shall take my explanation from the book "Theory of Stellar structure and Evolution" by Dina Prialnik. He derives an equation that describes the theoretical self-gravitation of a ball of gas and put the force of pressure pushing the gas apart and the gravity pulling the gas towards itself. From this simple model one can derive a condition for trhe point at which the force of self-gravitation overcomes the pressure of the gas pushing it apart. All this is based upon equations which have been validated in experiment time and time again, the ideal gas law, Newton's second law of motion and Newtonian gravity, these are the ingredients used in the theory. The criterion derived from this condition is called the Jean's criterion, after sir James Jeans. There will be a point where the pressure will become so large that it matches the force of gravity, this is called hydrostatic equilibrium.

You can of course generalise with model by adding in angular momentum and magnetic fields (in which case you obtain the Bonner-Ebert mass which would be a more accurate representation than the Jean's mass would.

So give us the direct observation of a new star from its birth and you win the debate. You can thrown theories and ideas at us every single day but objective truth is not established in the matter until such a direct observation is made. And we are not asking for prototypes: i.e. T Tauri.

Secondly, check out my thread on this subject:
Earliest Spiral Galaxy Ever Seen: A Shocking Discovery


I commented on this article on the Creation vs Evolution thread.

[Mat Hunt]

Calypsis4, we met at carm didn't we? As was probably explained to you before, in astronomy, they make observations. However, laboratory astrophysics is becoming more and more popular and providing more and more information about fusion in stars.

[Calypsis4]

Calypsis4, we met at carm didn't we? As was probably explained to you before, in astronomy, they make observations. However, laboratory astrophysics is becoming more and more popular and providing more and more information about fusion in stars.

What fusion? Give us an observed example from origin to maturity or anything in between.

P.S. I am not asking for theory or guesses. I am asking for direct observation...and you have over 5,000 yrs of written human history to work with for such an observation.

[goldliger]

Hi can you say what a "militant atheist" is? I am coming at the viewpoint from a scientific point of view. Cheers.

I will add that the name Matthew Hunt" is an extremely common one in the UK, just go on facebook and search for the name.

You're funny. You're implying that you're a different Matthew Hunt, and yet here you are on Facebook commenting about this very thread (not to mention, mocking this forum):

http://www.facebook....433321773391040

And what is a militant atheist, you ask? One who makes comments such as this one:

"Take a look here, my eyes spit blood, I was so angry at the willful stupidity there. One guy thinks the idea gas law isn't empirical science... The stupid... It burns..." - Matthew Hunt

[Mat Hunt]

The formation of stars are far longer than the timescale of the human lifespan, so it doesn't make sense that we can actually see one form, we can only observe the formation process at different stages. 5000 years of written human history can't help us when comes to understand star formation from a scientific point of view.

Here is a link to a laboratory astrophysics page for you to see the way they relate the experiments to stars: http://www3.imperial...oryastrophysics

[Mat Hunt]

Goldliger, I do think that the opinions of some creationists here aren't scientific in the slightest. I partly come here to try and put the physics across and see why other people don't accept well known physics.

[Mat Hunt]

Goldliger, nothing to do with atheism, but physics. The comments about Boyle's law really made my jaw drop, that is reason why I started this thread to talk about and try and explain the physics.

Feel free to comment on the science.

[goldliger]

Goldliger, I do think that the opinions of some creationists here aren't scientific in the slightest. I partly come here to try and put the physics across and see why other people don't accept well known physics.

Stellar evolution isn't well known physics. It's unobserved conjecture.

[Calypsis4]

The formation of stars are far longer than the timescale of the human lifespan, so it doesn't make sense that we can actually see one form, we can only observe the formation process at different stages. 5000 years of written human history can't help us when comes to understand star formation from a scientific point of view.

Here is a link to a laboratory astrophysics page for you to see the way they relate the experiments to stars: http://www3.imperial...oryastrophysics

Hmm, multiplied billions of stars out there and not one of them originated in the time frame of human history? Not one was recorded?

O.K. thanks for admitting you have no evidence.

P.S. did you bother to check out my thread as I recommended so you can see how the evolutionist problem is compounded many times over with clear-cut examples of the non-stellar evolution of our universe?

[Mat Hunt]

Stellar evolution isn't well known physics. It's unobserved conjecture.

Actually it is, as I have explained. It uses well known physics to model the self gravitation of a gas cloud and then makes predictions of what stars should look like when they're forming and then we can use telescopes to look for what the models predict.

[Calypsis4]

Goldliger, nothing to do with atheism, but physics. The comments about Boyle's law really made my jaw drop, that is reason why I started this thread to talk about and try and explain the physics.

Feel free to comment on the science.

And my conrontations with you on C.A.R.M. has nothing to do with this subject, so why did you bring it up?

[Calypsis4]

Actually it is, as I have explained. It uses well known physics to model the self gravitation of a gas cloud and then makes predictions of what stars should look like when they're forming and then we can use telescopes to look for what the models predict.

Show us a gas cloud that became a star...by observation. Just one will defeat us on this particular point.

[Mat Hunt]

Hmm, multiplied billions of stars out there and not one of them originated in the time frame of human history? Not one was recorded?

Why did you think they would be out of interest?

O.K. thanks for admitting you have no evidence.

I actually never did that, I pointed out where they were looking for in the lab.

P.S. did you bother to check out my thread as I recommended so you can see how the evolutionist problem is compounded many times over with clear-cut examples of the non-stellar evolution of our universe?

What sort of example do you have? Remember I am talking about the general idea of how stars form.

[Mat Hunt]

And my conrontations with you on C.A.R.M. has nothing to do with this subject, so why did you bring it up?

Just wanted to see if you were the same person there, that's all.

[Mat Hunt]

Show us a gas cloud that became a star...by observation. Just one will defeat us on this particular point.

Are you sure you're asking the right question here? I have told you that the time period for star formation takes many multiple lifetimes and won't be observed by a simgle person. We have to look at different stars at different stages. This is perfectly legitimate physics.