The Cambrian problem

[Astrophile]

In a constant volume, raise the pressure and the temperature
will go up. As the temperature rises, the gas becomes more
active. IOW, the atoms move faster and remain further apart.

How can you raise the pressure of a gas in a constant volume with constant mass? You appear to be confusing cause and effect; the pressure of a gas will increase if the gas is heated, but the gas pressure will not increase independently at constant volume without a rise in temperature.

If an interstellar gas cloud contracts adiabatically, its pressure will rise and so will its temperature. However, interstellar clouds and protostars lose energy by radiation; this energy loss cools them, so their internal pressure decreases, thus allowing the cloud or the protostar to continue its contraction.

 

[Astrophile]

You would have to calculate the pressure and temp required to
form a star, then prove that gravity is strong enough a force to
hold gases together long enough to hit them.

This was done by J.H. Jeans in 1902; 'The Stability of a Spherical Nebula', Philosophical Transactions of the Royal Society A: 199, 1-53. See https:www.en.wikipedia.org/wiki/Jeans_instability.

To go into a little more detail, the dense molecular clouds that collapse to form stars have temperatures of 10-30 Kelvin and number densities of about a billion to ten trillion particles (mostly hydrogen molecules) per cubic metre.

 

[Astrophile]

This is one of my problems with naturalists. NONE of the above can be proven.
The life-cycle of stars is a theory. No one has seen the different stages happen.

The H-R diagrams of star clusters change with the age of the cluster. The main-sequence turn-off moves to lower luminosity as less massive stars exhaust hydrogen in their cores, and the red giant branch (of hydrogen shell burning stars) develops. How do you explain these changes except as a result of stellar evolution?

Nobody has seen star formation. Only lights inside nebulae.

If the 'lights inside nebulae' are not stars, what are they? Astronomers see very specific 'lights inside nebulae'. In particular, there are short-lived very luminous O and early B-type stars. The high luminosities of these stars mean that they exahust their nuclear resources in only a few million years; therefore these stars cannot have moved far from their birthplace. The fact that these luminous OB stars are associated with bright and dark nebulae implies that they are born from interstellar clouds.

The 'lights inside nebulae' also include T Tauri stars. These stars lie on the Hayashi and Henyey tracks in the H-R diagrams; they are not stable, because their cores are not hot enough to generate energy by nuclear reactions. Since these stars are losing energy by radiation, they must contract under their own gravitation.

If the O and early B-type stars and the T Tauri stars are not young, how do you explain the fact that they are invariably associated with dense interstellar clouds?

There is no plausible scientific explanation that would attract gases together in
such mass as to form stars. Every gas law makes it impossible, in fact. {PV=nRT}

As we have already explained, James Jeans calculated the conditions under which a nebula would contract as long ago as 1902.

Have you thought about how they calculate the distance to other stars? Even
if you took measurements at the widest point of earth's revolution around the
sun and used them to triangulate the distance, it would be like triangulating a
point hundreds of miles away, using two points about 1/4 inch apart. Actually,
probably much less.

Yes, I have thought about it, many times; it is a constant preoccupation of mine. If you look at the SIMBAD astronomical database - http://www.simbad.u-strasbg.fr./simbad/ - you will find thousands of stellar parallax measurements. Also, there are distance measurements based on the use of 'standard candles', such as Cepheid variable stars.
By the way, your comparison is not entirely accurate; the parallax of the nearest star (alpha Centauri) corresponds to triangulating a point one mile away from two points ¼" apart. Your comparison is more appropriate to the distance of the Pleiades star cluster (136 parsecs).

 

[AV1611VET]

Do those that have faith in evolutionism realize that when the cambrian fossils are examined it is seen that the major phyla and classes of animals suddenly appear fully developed in the cambrian strata with no ancestral linage leading up to the many different phyla and classes.

It could be that this so-called "Cambrian explosion" is God's way of telling us that life emerged on the earth overnight.

Luke 19:40 And he answered and said unto them, I tell you that, if these should hold their peace, the stones would immediately cry out.

 

[Loudmouth]

Hello Loudmouth.

There is a difference between an everyday assumption that the sun will rise.

That isn't an assumption. We have the physics to explain why the sun comes up every day.

And the assumption or belief, that through the mechanism of observation,
one will unlock the so called secrets of the cosmos. As I said before Loudmouth,
do not put your trust in the observational criteria, you will end up with a paradox.

And yet you use those same things every minute of your day.

 

[Loudmouth]

You would have to calculate the pressure and temp required to
form a star, then prove that gravity is strong enough a force to
hold gases together long enough to hit them.

Are you telling me that you haven't done these calculations?

Don't you think you should do those calculations before telling the entire world of scientists that they are wrong?

 

[Loudmouth]

First, the question was not answerable by yes or no.

Stellar evolution and star formation are theories.
Not very good theories at that.

Why aren't they good theories? Let's see your calculations.

You will also notice that sfs supplied the calculations used to construct the theory.

http://astro.physics.uiowa.edu/~rlm/mathcad/addendum 4 chap 17 stellar evolution 1.htm

The calculations show that stars will form in the typical nebulae where we see star formation. Go figure.

Can you show us where those calculations are wrong?

 

[essentialsaltes]

You would have to calculate the pressure and temp required to
form a star, then prove that gravity is strong enough a force to
hold gases together long enough to hit them.

If we can't make gases clump together under earth's gravity, how
do you think it is possible in space with just gas attracting gas?

Because the mass of stars is much larger than that of the earth. At a mass of about 8% of the mass of the sun, fusion will occur, and you get a star. Less than that, and you get a brown dwarf.

 

[pat34lee]

Because a collapsing gas cloud is much more massive than the Earth. As you consider larger and larger volumes of dust/gas, the volume enclosed goes up by the cube of the radius from the center. The gravitational force felt on the boundary of the region as a result of a given mass drops only as the square of the radius, however. For a cloud with uniform density, therefore, the net gravitational force on particles at the edge of the region increases linearly with the radius. As a result, any sufficiently large region is unstable and will undergo collapse.

That is a bad theory. Long before you get high enough density, the forces
between gas atoms will force it apart. You can never have anything in space
form more dense than a cloud, similar to any cloud on earth.

For his equation to work, the gas must be constrained, as in a balloon.
That will not and cannot happen in space.

 

[pat34lee]

Incorrect. I gave you a hint but you ignored it. You already admitted that a gas under gravitational collapse would get hotter. If an object at a higher temperature than its surroundings it will emit radiation. As it radiates off excessive heat, which is easy to do when the temperature of space is just a few degrees above absolute zero the pressure will drop, the gas will compress and heat up, and compress even more since the gravitational force is even higher. All it takes for a star to compress under gravity is a lot of gas. Any experiment that you are familiar with was done with a pitiful small sample of gas. An immeasurably small percentage of our atmosphere. Even if you had our entire atmosphere to play with that would still be far too small of a mass of gas.

To be able to make your claim you need to show what happens when you get a ball of gas as massive as our Sun. Until then your experiments with small containers of gas are laughably insufficient to prove that stars cannot form on their own.

You keep skipping steps by assuming conditions that are impossible.

You cannot compress gas in space.

There is no way to get a ball of gas, only clouds.

Raise the temperature and the clouds disperse.

 

[pat34lee]

Can you show us where those calculations are wrong?

Cloud densities in space.

The densest nebulae can have densities of 10,000 molecules per cubic centimeter (or sometimes even more).
The air we breathe has a density of approximately 10^19 molecules per cubic centimeter.
http://www.astronomy.ohio-state.edu/~ryden/ast162_3/notes11.html

You have to watch math. It's easy to fudge the numbers.

 

[pat34lee]

Because the mass of stars is much larger than that of the earth. At a mass of about 8% of the mass of the sun, fusion will occur, and you get a star. Less than that, and you get a brown dwarf.

You're starting at the end and trying to work backwards.
Science doesn't work like that.

 

[Dr GS Hurd]

That is a bad theory. Long before you get high enough density, the forces
between gas atoms will force it apart. You can never have anything in space
form more dense than a cloud, similar to any cloud on earth.

For his equation to work, the gas must be constrained, as in a balloon.
That will not and cannot happen in space.

You never took a college course in astrophysics, or even read a competent book.

 

[sfs]

That is a bad theory.

Exactly how many scientific publications do you have in physics again?

Long before you get high enough density, the forces
between gas atoms will force it apart.

You can never have anything in space
form more dense than a cloud, similar to any cloud on earth.

I take it you are unable to point out any actual flaws in the reasoning.

For his equation to work, the gas must be constrained, as in a balloon.

There are no such constraints in those equations.

 

[-57]

Fine show us any aquatic modern species like dolphins, jawed fish and such.

Coelacanth. Would you like a list of living fossils?

 

[Shemjaza]

Coelacanth. Would you like a list of living fossils?

They come from long after the Cambrian, and the modern species are not even the same genus as their ancient relatives. These are also a good example of a jawed fish.

It's not a problem for evolution, it's simply a variant on the asinine "If we come from monkeys, why are there still monkeys.", just in this case: "If tetrapods come from lobe finned fish, why are there still lobe finned fish."

Incidentally, the previous extinction date for the Coelacanth order was the end of the Mesozoic, well after the development of mammals, reptiles and birds.

 

[-57]

Who discovered and published this fact? Hint: it wasn't creationists.

I don't really care who discovered the FACT. The FACT creates quite a problem for evolutionary science.

 

[Shemjaza]

I don't really care who discovered the FACT. The FACT creates quite a problem for evolutionary science.

Except that isn't true. (As has been discussed in this thread already).

The Cambrian animals are the earliest with developed shells and skeletons, but they are still have massively simple body plans compared to later animals. There are less fossils from Precambrian, but there are a few, leaving the evolution of Cambrian life as mysterious, but not inexplicable using normal evolutionary systems that scientists have demonstrated at length.

 

[-57]

They come from long after the Cambrian, and the modern species are not even the same genus as their ancient relatives. These are also a good example of a jawed fish.

It's not a problem for evolution, it's simply a variant on the asinine "If we come from monkeys, why are there still monkeys.", just in this case: "If tetrapods come from lobe finned fish, why are there still lobe finned fish."

Incidentally, the previous extinction date for the Coelacanth order was the end of the Mesozoic, well after the development of mammals, reptiles and birds.

How would you know the Coelacanth wasn't of the same genius? Is it because the plackard in the museum said so?

 

[Shemjaza]

How would you know the Coelacanth wasn't of the same genius? Is it because the plackard in the museum said so?

The biologists and paleontologists compared the fossil skeletons of ancient Coelacanths and compared them to the two modern species of Coelacanth and they were significantly different enough to warrant a change in genus.